ميحرلا نمحرلا الله مسب
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The genital tract of non-pregnant cows normally lies in the pelvic cavity and consists of the vulva, vagina, cervix, uterus, Fallopian tubes (oviducts), ovaries and their supporting structure. Most of the reproductive structures can be palpated through the rectum. The reproductive tract is supplied by blood from the utero-ovarian arteries of which the middle uterine artery is the largest. The autonomic nerves are supply ovary; uterus and oviducts, while pudic nerve supplies vagina, vulva and clitoris.
The uterus of cow is a muscular organ (V-shaped) consisting of a body, about
4-5 cm long, and two uterine horns (cornua), each 35-40 cm in length and 1-3 cm in diameter. The uterus is suspended by the broad ligament (mesometrium) in a coiled or curled manner. The attachment of the broad ligament is dorsolateral in the region of the illium, so that the uterus is arranged like ram’s horns (convexity dorsal). Its size varies with breed, age, parity, pregnancy and disease.
The cervix is a sphincter-like structure with a thick wall and a narrow lumen. This lumen is tightly closed, except during oestrus and at parturition, and the cervix forms a barrier between the uterus and the outside environment. The length of the cervix varies from 1.5 cm in heifers to 8 cm in multiparous cows of larger breeds.
The mare’s uterus is T-shaped with 2 short uterine horns and a body. The uterine horns extend upward toward the ovaries. The uterine body is palpated via rectum approximately 45-50 cm into the rectum. The uterus will curve up toward the ovaries, thus allowing you to differentiate it from the small colon. There is a cylindrical structure and is about 5-8 cm long.
The female dog (bitch) has a bicornuate (Y- shaped) (or two-horned) uterus which ends as the cervix, a short canal which connects to the vagina. The cervix is muscular with fibrous tissue support. The surface of the uterus in the queen cat is usually smooth and regular (unlike the dog). When pregnant, bulges occur at regular intervals.
Function of uterus:
Endometrium and its fluid play a major role in the reproductive process:
1- Sperm transport from the site of ejaculation to the site of fertilisation in the oviduct.
2- Regulation of the function of the corpus luteum (CL).
3- Initiation of implantation, pregnancy and parturition.
The vagina of cow extends backwards from the cervix and opens into the vulva.
Its length varies with breed and stage of pregnancy. The vaginal epithelial cells near the cervix secrete mucus, especially around the time of oestrous.
Bitches often have a vaginal stricture, which is a remnant of where the vagina and vestibule fused together during embryonic development. This stricture is often asymptomatic and is broken down during mating.
The vestibule extends from vagino-vestibular junction cranially to vulval lips caudally (8-12 cm length in the cow, mare and camel; 2-3 cm in the ewe and goat, and
2 cm in the cat ). It acts as the point of attachment for the entire genital tract to contact upon when expelling the fetus at term. In the bitch, the vestibule makes a steep downward turn exits within the vulva.
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The clitoris is located at the ventral commissure of the labia and it is well developed in the mare.
The ovaries of cow are oval-shaped (almond) structures 1-4 cm long and 1-3 cm in diameter; their size depends on the stage of the reproductive cycle. They are located on the cranial border of the broad ligaments, just lateral to the uterine horns (the size of mature follicle 1-2 cm, CL 3.5 cm). The ovary of a new-born heifer may contain up to 150.000 primordial follicles. However, only a few of these mature and release an ovum.
The ovaries of the female camel (flattened oval with grooves) are located on the cranial border of the broad ligaments, just lateral to the uterine horns. Both ovaries are enclosed within the ovarian bursae (the size of mature follicle 1-2.2 cm, CL 1.2-3.7 cm).
The ovaries of the mare (kidney or bean-shaped) are suspended in the sublumber region (the size of mature follicle up to 9 cm, CL 2-3 cm)..
The ovary of the queen cat is suspended from the dorsal abdominal wall by the mesovarium within which is a plexus of blood vessels and which has an outer covering of smooth muscle.
The predominant tissue of the ovary is the cortex (ovary composed of the medulla and cortex). The ovary is supported by the meso-ovaruim ligament (The ovary is supported dorso-laterally by the broad ligament, and medially by the proper ligament.). The ovary has two major functions: gametogenesis (the production of female gamates) and steriodogenesis (the production of steroid hormones. which play vital roles in the reproductive cycle.
The ovaries are linked to the uterus by the Fallopian tubes which open anteriorly into fimbriae-funnel-shaped structures closed to, but not attached to the ovaries. The parts of the oviduct are the isthmus, ampulla, and, the infundibulum with its fimbriae.
The isthmus is the constricted portion lying next to the uterus. It is continues directly into the uterine horn at the uterotubal junction. In the mare the isthmus opens into the uterine lumen through a small slit on a mound or papilla. In the cow and ewe there is marked flexure at the transition of the isthmus with the elongated curving end of the uterine horn. The latter has a very narrow lumen .
The ampulla widens into a funnel shaped part called the infundibulum. In the queen cat the infundibulum is over the surface of the ovary but does not surround the ovary as in the dog. The opening of the oviduct into the abdominal cavity is called the ostium abdominale, which is surrounded by a fringe of irregular processes called fimbriae, which form the cranial extremity of the tube.
The paired Fallopian tubes are the means by which ova, released from the ovaries at ovulation, reach the uterus. The fimbriae guide unfertilized eggs from the ovary into the Fallopian tubes. The length of oviduct about 25 cm in the cow (30 cm in mare) and is suspended by meso-salpinx ligament (part of broad ligament).
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 The female reproductive system of the chicken is divided into two separate parts: the ovary and the oviduct .
In almost all species of birds, including chickens, only the left ovary and oviduct are functional. Although the embryo as two ovaries and oviducts, only the left pair develops. The right typically regresses during development and is non-functional in the adult bird.
 The ovary is a cluster of developing yolks or ova and is located midway between the neck and the tail of the bird, attached to the back. The ovary is fully formed when pullet chicks hatch, but is very small until they reach sexual maturity.
 Each ovum starts out as a single cell surrounded by a vitelline membrane. As the ovum develops, yolk is added. The color of the yolk comes from fat soluble pigments called xanthophylls contained in the hen’s diet.The ovum, which is enclosed in a sac, ruptures along the suture line or stigma.
 Occasionally the vitelline membrane is damaged and pale spots or blotches develop on the yolk. This is referred to as mottling . Although the appearance of the yolk is changed, there is no affect on the egg’s nutritional value or flavor.
 The female’s reproductive system is sensitive to light exposure, especially the number of hours of light in a day. The release of the next ova typically occurs 30-
75 minutes after the previous egg has been laid. If the egg was laid too late in the day the next ovulation will wait till the next day and the hen will have a day when she doesn’t lay an egg.
 The second major part of the female chicken’s reproductive system is the oviduct . The oviduct is a long convoluted tube (25-27 inches long when fully developed) which is divided into five major sections. They are the infundibulum or funnel, magnum, isthmus, shell gland (uterus), and vagina.
 The first part of the oviduct, the infundibulum or funnel, is 3-4 inches long, and engulfs the ovum released from the ovary. The ovum or yolk remains in the infundibulum for 15-18 minutes. Fertilization, if it is going to occur, takes place in the infundibulum. The infundibulum also serves as a reservoir for spermatozoa so that fertilization can take place.
 The next section of the oviduct is the magnum which is 13 inches long and is the largest section of the oviduct as its name implies. The ovum or yolk remains here
3 hours during which time the thick white or albumen is added.
 The third section of the oviduct is the isthmus which is 4 inches long. The developing egg remains here for 75 minutes. The isthmus is where the inner and outer shell membranes are added.
 The next section of the oviduct is the shell gland or uterus. The shell gland is 4 -
5 inches long, and the ‘egg’ remains here for 20 plus hours. As its name implies, the shell is placed on the egg here. The shell is largely made up of calcium carbonate. The hen mobilizes 47% of her body calcium from her bones to make the egg shell, with the diet providing the remainder of the required calcium.
Pigment deposition is also done in the shell gland.
 The last part of the oviduct is the vagina which is about 4-5 inches long and does not really play a part in egg formation. The vagina is made of muscle which helps
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push the egg out of the hen’s body. The bloom or cuticle is also added to the egg in the vagina prior to oviposition (the laying of the fully formed egg).
 Near the junction of the vagina and the shell gland, there are deep glands known as sperm host glands . They get their name from that fact that they can store sperm for long periods of time (10 days to 2 weeks). When an egg is laid, some of these sperm can be squeezed out of the glands into the oviduct so that they can migrate farther up the oviduct to fertilize an egg. This is one of the really remarkable things about birds; the sperm remain viable at body temperature .
 In chicken hens, ovulation usually occurs in the morning and under normal daylight conditions, almost never after 3:00 PM. The total time to form a new egg is about 25- 26 hours. This includes about 3½ hours to make the albumen, 1½ hours for the shell membranes, and about 20 hours for the shell itself.
 Birds lay eggs in clutches. A clutch consists of one or more eggs laid each day, followed by a rest period of about a day or more. Then another egg or set of eggs is laid.
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The fetal reproductive system consists of two sexually non differentiated gonads, two pairs of ducts , urogenital sinus and vestibular folds.
The system arises primarily from germinal ridges on the dorsal side of abdominal cavity (male or female) (embryonic bisexuality).
Wolffian and Mullerian ducts are both present in the sexually undifferentiated embryo. In the female, the Mullerian ducts develop and the Wolffian ducts atrophy. The opposite is true in male.
The female Mullerian ducts fuse caudally to form a uterus, a cervix and anterior part of a vagina. Urogenital sinus gives rise to the vestibule (lips of vulva).
Reproductive hormones are derived primarily from 4 majors systems:
 Various areas of the hypothalamus.
 Anterior and posterior lobes of the pituitary gland.
 Gonads: testes and ovary including their interstitial tissues and CL.
 Uterus and placenta.
The hormones of reproductive are also classified into two groups, according to their mode of action
1- Primary hormones: regulate the various reproductive processes (ovulation, sexual behavior, fertilisation, implantation, maintenance of gestation, parturition and lactation) (table 1).
2- Metabolic (secondary) hormones: which indirectly influence of reproduction
(general well being, metabolic state and growth of the animal) (table 2).
Source or gland Releasing hormones
Hypothalamus Gonadotropin-releasing hormone (Gn-RH).
Growth-hormonereleasing hormone (GH-
RH).
Thyrotropin-releasing hormone (TRH).
Prolactin-inhibting factor
(PIF).
Corticotropin-releasing hormone (CRH).
Anterior pituitary Follicle-stimulating hormone (FSH).
Luteinizing hormone (LH).
Physiological functions
Stimulates release of FSH and
LH.
Stimulates release of growth hormone.
Stimulates release of thyroid stimulating hormone (TSH) and prolactin.
Inhibits release of prolactin.
Stimulates release of ACTH.
Stimulates follicular growth, spermatogenesis, oestrogen secretion.
Stimulates ovulation, corpus
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Uterus
Posterior pituitary
Placenta
Ovary
Prolactin (PRL).
Oxytocin (also produced in ovary).
Human chorionic gonad- otropin (hCG).
Pregnant mare serum gonadotropin (PMSG).
Oestrogens.
Progestins
(Progesterones)
Relaxin.
Prostaglandins luteum function: stimulates secretion of progesterone.
Promotes lactation, stimulat- es CL function and progesterone secretion in some species, promotes maternal behavior, promotes tissue and bone growth.
Stimulates uterine contract- ion, parturition and sperm and egg transport. Facilitate milk ejection. Possible luteolytic function.
LH activity.
Maintians CL of pregnancy in primates.
FSH activity.
Stimulates formation of accessory corpora lutea in mare.
Promotes sexual behavior; stimulates secondary sex characteristics, growth of reproductive tract, uterine contractions and mammary duct growth.
Controls gonadotropin release, stimulates Ca uptake in bones.
Acts synergistically with oestrogen in promoting oestrus behavior and preparing reproductive tract for implantation.
Maintains pregnancy.
Dilates cervix.
Causes uterine contractions and is luteolytic.
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Source or gland Releasing hormones
Placenta Oestrogen.
Progesterone.
Anterior pituitary Somatotropin hormone
(STH).
Thyroid-stimulating hormone (TSH).
Adrenocorticotropic hormone (ACTH). aedPosterior pituitary
Thyroid
Antiduiretic
(ADH).
Thyroxine. hormone
Parathyroid
Adrenal cortex
Pancreas.
Parathormone.
Aldosterone.
Cortisol & Cortisone.
Insulin
Physiological functions
See ovary (table 1).
See ovary (table1).
Body growth; protein synthesis.
Stimulates thyroid gland.
Thyroxine release and iodine uptake by thyroid.
Stimulates adrenal cortex.
Release of adrenal corticoids.
Water balance.
Body growth; development and maturation; oxidation of feeds.
Calcium and phosphorus metabolism.
Electrolyte metabolism. and water
Carbohydrate, protein, and fat metabolism.
Carbohydrate, protein, and fat metabolism.
The synthesis, storage and release of hypothalamic hormones are regulated by both pituitary and steroid hormones through two feedback mechanisms, a long and short loop. Long feedback involves interaction among gonads, pituitary and hypothalamus. In the short feedback system, the level of pituitary gonadotropin can influence the secretary activity of releasing the gonads. Depending on their concentration in the blood, steroid hormones may exert a stimulatory (positive) or inhibitory (negative) feedback. Positive feedback results when an oestrogen or progesterone stimulates the release of gonadotropin, such as LH. Negative feedback results when large levels of progesterone prevent the releasing of gonadotropin.
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Relates to various phenomena:-
Puberty and sexual maturity, the breeding season, the oestrous cycle, postpartum, sexual activity, and aging. These components are regulated by environmental, genetic, physiological, hormonal, behavioral and psychosocial factors. The level of fertility initiated at the time of puberty is maintained for a few years before it begins to gradually decline due to aging. Secretion of (Gn-RH), LH and FSH always begins during fetal life. In the cow and ewe it starts early, shortly after sex differentiation
(2 months of pregnancy) (sow 1.5 months). This secretion is slightly reduced 2 months before births in cattle, near term in sheep and 1month after birth in pigs (related to maturation of central nervous system).Gonadotropin levels remain low up to the onset of puberty.
Sexual Development (activity):-
 Weaning life.
 Prepubertal life.
 The puberty.
 Sexual maturity.
The Puberty:
Is a period of sexual activity. The age when first oestrous accompanied by spontaneous ovulation occur. The female becomes sexually mature and able to reproduce.
During the prepubertal period the growth of the genital organs is very similar to that of the other organ system, but at puberty their growth rate is accelerated.
The age of puberty in females of domestic species:

Mare: 1-2 years.
 Cow: 7-18 months in foreign breeds and 2-3 years in local breeds.
 Ewe: 6-15 months.

Doe or nanny goat: 4-8 months.
 Sow: 6-8 months.
 Bitch: 6-20 months.

Queen cat: 7-12 months.
 Female camel: 2-5 years.
1- Nutrition: Animals that are well fed with good growth rates reach puberty before those they are poorly fed with slow growth rates.
2- Season of the year: Seasonal breeder such as the ewe, mare and queen cat.
3- Proximity of the male: Studies in sheep and pigs have shown the at exposure to the male of the species will advanced the timing of the onset of puberty
(ram or boar effect).
4- Climate.
5- Disease: Influence on the growth rate.
6- Stress: Loss of weight influence adrenal gland activity increase secretion of cortisone inhibit pituitary gland.
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The Oestrous Cycle:
The oestrous cycle is a pattern of physiological and behavioral events under hormonal control. The oestrous cycle forms the basis of sexual activity and conception.
The animals are classified according to oestrous cycle to:
1- Seasonal: divided to: i- Seasonal polycyclic animals such as the mare, ewe, doe nanny goat and queen cat. ii- Seasonal monocyclic animals like the bitch.
2- Non-seasonal polycyclic animals such as cow and sow.
Traditionally, the oestrous cycle is divided into a number of phases:
1-Pro-oestrus:
It is characterized by: i- Increase in activity of the reproductive system. ii- There is follicular growth and regression of the CL of the previous cycle (in polycyclic species). iii- The uterus enlarged very slight, the enodmetrium becomes congested and increase secretary activity iv- The vaginal mucosa become hyperaemic. v- The FSH concentration level is increased.
2-Oestrus:
The period of acceptance of the male. The animal usually seeks out the male and ‘stand’ for him to mate her.
The uterine, cervical and vaginal glands secret amounts of mucus, the vaginal epithelium and endometrium become hyperaemic and congested, the cervix is relaxed.
(oestrogen is dominant).
Ovulation occurs during this phase of the cycle (LH level is increase and FSH level is decrease) in all domestic species, with exception of the cow, where it occurs about 12 hours after the end of oestrus.
Signs of oestrus in the mare are include: general receptivity to the stallion, tail raising, frequent urination, winking of the vulva and squatting stance. oestrus in the dog is typified by a bloody vaginal discharge, extreme swelling of the external genitalia and active searching for a mate. The female dog will do anything necessary to satisfy her desire to reproduce including jumping over, digging under or backing up to a fence.
Signs of cat going into heat are usually fairly obvious. She will become more affectionate towards you. She'll often rub her hind quarters against anything available including furniture and you. She will lick her genital area frequently. Her urine will contain more oestrogen and the smell will attract male cats and tell them the cat is in heat. The cat will raise her rear quarters; her front half lowered and will appear to be walking in place. She will yowl loudly and do this often and for several days.
Pro-oestrus and oestrus are frequently referred to collectively as follicular phase of the cycle.
3-Metoestrus:
The phase succeeding oestrus. There is a reduction in amount of secretion from the uterine, cervical and vaginal glands (LH level is increase).Ovulation in the cow occur in this phase.
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4-Dioestrus:
The period of the corpus luteum. The cervix becomes constricted and the secretions of the genital tract are scant and sticky, the vaginal mucosa becomes pale.
The CL is secreting large amount of progesterone (luteal phase).
5- Anoestrus:
Following di-oestrus is anoestrus. This is the quiescent period between heat cycles characterized by no outward physical or behavioral signs of sexuality.
Species Length of oestrous cycle per days
20-23 days
Oestrus duration Ovulation time
Horses
Donkey
Cows
Goats
Sheeps
Pigs
Dogs
Cats
Camels
20-23 days
18-24 days
20-21 days
17 days
19-20 days
3-6 months
17-22 days
15-28 days
4-8 days
2-5 days
12-18 hours
30-40 hours
24-36 hours
53 hours
9-14 days
7-10 days
3-12 days
24-48 hours before oestrus end.
24 hours before oestrus end.
12 hours after oestrus end.
12-36 hours from beginning of mating.
24-30 hours before oestrus end.
38-42 hours from beginning of the oestrus.
1-2 days from beginning of oestrus.
Correlated by occurr- ence of mating.
Correlated by occur- ence of mating.
1- Observation: 3 times daily, 6 morning, 12 afternoon and 6 evening.
2- Videotape (camera) in large herds.
3- Training of farm worker on signs of oestrous.
4- Heat mound detector (KaMaR): release of dye on pressure (unsuitable in wet weather).
5- Chin-ball mating device: a helter fitted with a reservoir of dye that is released by a ball-type mechanism marks a line on the back of the cow.
6- Teasers fitted with marking devices, teasers are: a) Castrated bulls treated with testosterone. b) Steers treated with testosterone. c) Cows with cystic ovaries treated with testosterone or sterile cow.
7- Laboratory Methods:
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
Blood and milk sample to measurement of oestrogen and progesterone concentration by radioimmunoassay (RIA) or (ELISA).

Measurement of mucus viscosity (decreased).

Vaginal pH is decreased.
 Vaginal temperature is increased (about 2 C°).

Vaginal biopsy (increase number of layers, cell becomes squamous and keratinized).

Crystallization of mucus.
8- Dogs trained to detect odors in vaginal mucus, milk or urine
(pheromones) .
9- Rectal palpation to palpate mature Graafian follicle or fossa on ovary surface indicated the ovulation was occurs.
10- Registration of cases (records).
The methods that are available can be divided into:
1- Non-hormonal methods.
2- Hormonal methods.
The onset of cyclical activity in the mare, ewe, goat and cat is dependent upon changes in the hours of daylight.
The mare and queen are stimulated to activity by a lengthening photoperiod, whilst in the ewe and doe (nanny goat) it is the effect of a decreasing photoperiod which is the stimulus.
When the mare receiving 15-16 hours of light each day, reproductive activity will be initiated.
In seasonal breeders is not clear. Improved nutrition can exert a profound affect on ovarian function by increasing the number of follicles which mature and ovulate.
The presence of male animal can exert it is effect upon the cyclical activity of the female.
In sow the weaning of piglets hastens the return of cyclical ovarian activity postpartum (suckling increase prolactin inhibit oestrous cycle).
ACTH stimulate adrenal cortex secret cortisone
inhibit pituitary gland.
A large number of different hormones have been used to manipulate cyclical activity in domestic species.
They can be considered in various groups:
1- Preparations which stimulate the release of anterior pituitary hormones.
2- Preparations which replace or supplement anterior pituitary gonadotropin.
3- Oestrogens.
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4- Progestogens.
5- Prostaglandins.
6- Melatonin.
I. A large number of oestrogens, both naturally occurring and synthetic, have been used to stimulate oestrus.
II. Synthetic (Gn-RH) can be used to stimulate the release of endogenous gonadotropins. It can be used to stimulate the onset of oestrus in the postpartum cow (Receptal 10-
20 µg, Fertagyl 0.5 mg).
a) eCG (PMSG), obtained from the serum of pregnant mares, which has mainly an
‘FSH-like’ effect but with some ‘LH-like’ activity (commercial name is folligon). b) Human chorionic gonadotropin (hCG), obtained from the urine of pregnant women which has mainly an ‘LH-like’ effect but with some ‘FSH-like’ activity
(commercial name is chorulon).
In the anoestrus cow, it is possible to stimulate follicular growth and ovulation by eCG treatment (3000 IU).
The use of hCG alone to induce oestrus is not very successful. Combination of hCG/ eCG have been used to induce oestrus (3-5 days).
The administration of oestrogens, either synthetic or naturally occurring, has been used to induce oestrus in animals that are anoestrus, especially in the bitch.
Source of hormone:

Natural sources (ovary).
 Synthetic sources; from the plants such as phytooestrogen or synthetic such as oestradiol benzoate and diethylstilbosterol.
Progesterone and progestational compounds have been used in most domestic species as method of controlling the oestrous cycle, particularly synchronization within groups of females.
In some racehorses it is desirable to prevent the mare from coming into oestrus at an inopportune time (0.3 mg / kg injection daily, effective in preventing oestrus, with
3-7 days after treatment).
In the cow progesterone can be used to synchronize groups of cows and heifers for artificial insemination.
A. Subcutaneous implant at the same time as an injection of oestradiol valerate.
The implant is removed after 9 days, and following two insemination at 48 -60 hours afterwards, conception rates are 65% (synthetic hormone called
Norgestamet).
B. Progesterone –releasing intravaginal device (PRID):
The (PRID) is a stainless steel coil covered with an inert eslastomer incorporating 1.55g of progesterone, is placed in the vagina, using a special
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speculum. When the coil is removed after 12 days, the cow will come into oestrus in 2-3 days. Some of the coil also contains a small capsule of oestradiol benzoate (10 mg).
C. Progestogen-impregnated intravaginal sponge or tampon:
Progesterone was used initially in the sponges notably Fluorogeston acetate
(FGA) and medroxyprogesterone acetate (MPA).
Intravaginal sponges are used only inside the normal breeding season and removed after 11-13 days (oestrus occur 48-58 hours after removed). When intravaginal sponges are used outside the normal breeding season, it is necessary to use eCG injected (500 IU) either 48 hours before sponge removal
(11 days) and inseminated directly or at the same day of sponge removal and inseminated after 48-58 hours (dose of progesterone is 4045 µg).
Naturally is secreted from the endometrium. All animals are injected with PGF 2α on the same day and observed for oestrus during following 5 days (synchronisation).
The corpus luteum is respond to PGF 2α between 5-17 days. If PGF 2α is injected at 7 th day, the oestrus induced after 4days (cloprostenol, 500g in cow; dinoprost 25-35 mg in cow).
The pineal gland controls reproductive activity in seasonal breeding species by the secretion of melatonin. The hormone is administered as an implant containing 18 mg of melatonin which inserted S/C at the base of the ear. It is critical that rams or bucks should be separated from the ewes or doe goat so that they are out of sight, sound and smell at least 7 days before insertion of the implant. They must remain separated for at least 30 days and not more than 40 days, when rams or bucks should them be reintroduced. Peak mating activity occurs 25-35 days later.
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Fertilisation is penetration of the oocyte ( oocytes: that develops in the ripe follicle at ovulation, containing 1 haploid chromosomes; the fertile life of the oocytes is less than 10 hours for the mare, but up to24 hours for the cow, ewe and goat ) by the spermatozoon and completed by the fusion of the female and male pronuclei with subsequent formation of the zygote. The nucleus of only one sperm is required to fuse with the ovum. Spermatozoa require maturational changes that occur during a 10 to 15 day passage through the epididymis, after which fertilisation is possible. That sperm must reside in the female reproductive tract before becoming capable of attaching to and penetrating the ovum ( ovum: the mature gamete produced by the female ). This final maturation of the spermatozoa in the female reproductive tract called capacitation.
Recently, a specific gene has been isolated from the spermatozoa called phospholipase-zeta (PLC-zeta) which is thought to be responsible for fertilization of the ovum by spermatozoon.
As the ripe follicles is about to rupture, the fimbriated end of the uterine tube is applied to it and, at ovulation, the follicular fluid and egg are discharged. If the female has been mated at the current oestrus, spermatozoa will be waiting in the ampulla of the uterine tube for the arrival of the egg. Following fertilisation, cleavage of zygote begins, as a result of peristaltic contractions and ciliary currents in the uterine tube; it is propelled towards the uterus (at 3-4 days in cattle). When it is reaches the uterus, the zygote consists of 16-32 cells in the form of a morula. With further cell division and cell orientation the morula becomes hallowed out to form a blastocyst ( blastocysts: the last cleavage stage of the embryo before hatching ). From the time of it arrival in the uterus until attachment (implantation), the zygote is propelled aspirated in the uterine lumen, where it is nourished by the uterine milk (by difusion).
Implantation (embryonic attachment) to the uterus occurs at the following times:
12 days, cow; 25 days, sow; 15 days, ewe; and 25-35 days, mare and camel.
The bovine embryo ( Embryo: the conceptus from the time of attachment of blastocyste to the uterus until completed organogenesis; Conceptus:the developing embryo or fetus; Fetus: the conceptus from completed organogenesis until delivery ) elongates slowly as compared with the chorion. The chorionic vesicle, which is at first string-like with a central distended sphere of amnion containing the embryo, is progressively filled by allantoic fluid to form allantochorionic sac.
In the ruminant uterus, where the allantochorion contacts the uterine caruncles, finger-like processes or villi containing capillary tufts grow out from the allantochorion into the crypts of the maternal caruncles, which are also surrounded by capillary plexuses. Thus is formed cotyledon, or placentom, through which nutrient and gaseous exchange between the mother and fetus takes place (120 cotyledons in the cow and 80 in the sheep).
Consist of a primitive yolk sac, amnion, allantios and chorion

Develops from the endoderm, where it replaces the blastocoele. It contains early source of nutrients for the developing embryo.
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
When its content is developed, a portion of it folded into the embryo forming its primitive gut and the rest of it disappears by day 16 in farm animals, except in the horse where it persists to about day 40 post ovulation.

The yolk sac of the camel has a limited swelling.
Originate from ectoderm at day 12 post ovulation in the ewe, day 14 in the cow and day 16 in the mare and camel. As pregnancy progresses, the amnion tends to collapse and lies close to the fetus. When the sac is complete it is called the amniochorion and is filled with amniotic fluid.
The amnion which surrounds the embryo directly, it is prevent the embryo from the external concussion, preserve the osmotic pressure of embryo, prevent embryo from adhesions and it is consider antiseptic against bacteria.
The uterine fluids, mouth and nose secretions, and embryo excretion are interred to amniotic cavity.
A highly vascular membrane of the conceptus. It is formed by 24-28 days post ovulation in the cow, mare and camel, but earlier in the ewe. The allantois is origin from the end of digestive tract. It is contains tenacious fluid that may help in fetal slip and fetal expulsion during parturition (lubricant).
As the allantois grows the outer layer fuses with the chorion to form chorioallantois. The chorioallantois become attached to the endometrium to form the placenta.
The outermost fetal part of the placenta, which fuses with the allantios to form the allantochorion The allanto-chorion, which eventually surrounds the allantoamnion, is separated from it by allantoic fluid.
 Connects to the fetus to the placenta. It is directed from the fetus towards the lesser curvature of the uterus.

Consists of two parts; the amniotic and allantioc. The amniotic part runs through the amniotic sac and is composed of jelly (Wharton's jelly) through it run the umbilical vessels. The allantioc part runs through the allantioc sac and consists of a branching vessel.
 The umbilical cord of the equine fetus is strong and average 45-60 cm in length although it may be as long as 90 cm. The umbilical cord of the bovine fetus is 30-
40 cm in length. The camel fetus has an umbilical cord of 45-50 cm in length.
As the embryo (or embryos) grows, the process of nourishment through direct diffusion from the uterus becomes inadequate to maintain its developing life. Therefore, more originated interaction between growing conceptus (conceptuses) and the endometrium develops. It is called palcentation. The type, size and function of the placenta change according to species and even within species during the course of pregnancy.
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Placenta may be classified according to the way the villi are distributed on the fetal Chorion to:
I. Diffuse placenta: Where they are uniformly dispersed as in the mare and camel.
II. Cotyledonary placenta: Where they are grouped into multiple circumscribed areas, as in the ruminants (cow, sheep and goat).
III. Zonary placenta: The villi are disposed in the form of abroad encircling belt
(carnovora).
IV. Discoid placenta: Such as in the women and rabbits.
Division of placental types in which the degree of proximity of the maternal and fetal blood circulation is: a) Epitheliochorial: Seen in the mare and pig, the chorion is everywhere in contact with endometrium, and there is no loss of maternal tissue
(presence of 6 layers). b) syndysmochorial: The Chorion is contact with maternal connective tissue, such as in the ruminants (presence of 5 layers). c) Endotheliochorial: The layers of fetus which contact directly to the maternal capillaries, such as in the carnivores (presence of 4 layers). d) Haemochorial: Only the tissues of the chorionic villi separate the fetal and maternal blood, such as in the man and rodents (presence of fetal layers only). e) Haemoendothelial: Such as in the primates (presence of 2 layers only).
*The placenta acts as a physical barrier separating 2 distinct individuals. It provides an opposition of the fetal and maternal vascular system.
*Failure of the appropriate placental function may result in a retardation, abortion, premature delivery, stillbirth, prolonged gestation or placental retention.
*The placenta has the following functions:
1- Placental exchange:

Respiration: the umbilical arteries carry the unoxygenated blood from the fetus to the placenta and maternal circulation, while the umbilical veins carry the oxygenated blood in the reverse direction.

Nutrition: the placenta permits the transport of sugar, amino-acids, vitamins and minerals to the fetus as substrates for fetal growth. Thus, the placenta substitutes the fetal digestive system.
 Excretory function: the products of metabolism are eliminated through the placenta.
2- Physical barrier (protection): the placenta protects the fetus (fetuses) from physical insult and intrusion of many infections and toxic agents in the maternal blood. The placenta tissues have to permit certain substances to pass from the dam to the fetus, but impede other substances. Iron, copper, amino-acids, free fatty acids, water soluble vitamins, oestrogen and progesterone can easily cross placental barrier. However, other substances such as proteins, fat soluble vitamins and thyroid hormones cannot pass through the placental barrier.
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3- Production of hormones: the placenta is a transient endocrine organ responsible for the production of specific hormones, such as eCG, oestrogen and progesterone.
4- Immunological barrier: since the conceptus differs genetically from the dam, the placenta functions as an immunological barrier to prevent maternal rejection of it.
The maternal immune reaction at the fetal trophoblast is inhibited.
There are two types of fetal fluids produced during pregnancy and expelled during parturition these are:

Originates from fetal urine, secretions from respiratory tract and maternal circulation.
 Its consistency is urine-like in early pregnancy, then changes to clear, colourless, mucoid fluid.
 It contains metabolic constituents, electrolytes, enzymes and hormones.

The amount gradually increases throughout gestation in all farm animals except the sow. It increases from a litre in early pregnancy to 8 litres in late gestation of the cow and to 5 litres of the mare and to 2 litres of the camel. It also increases from 100 ml in early pregnancy to
600 ml in late gestation of the ewe.
 Originates from fetal urine and secretary activity of allantioc membranes.
 Its consistency is urine-like, due to the origin mainly from fetal urine.
 It contains metabolic constituents, electrolytes, enzymes and hormones.

It usually follows the same pattern of increase during pregnancy as the amniotic fluids, but its amount is higher than the amniotic fluid in the cow, ewe and camel. It increases to 15 litres in late gestation of the cow, to 5 litres of the mare, to 8 litres of the camel and to 900 ml of the ewe.
Pregnancy: the period from fertilisation of the ooccyte (or Oocytes) until the expulsion of the fetus (fetuses) with it's their membranes.
Gestation: the period from attachment of the blastocyst to the uterus until the termination of pregnancy. This period of intrauterine development. The duration of gestation is genetically determined, although it can be modified by maternal, fetal, and environmental factors.
The age of dam influence the duration of pregnancy in different species. A twoday extension from the norm occurs in the 8-year-old ewe. Young heifers carry their calves for a slightly shorter period than older heifers.
An inverse relation between the gestation period and litter size in several polytocous species except the pig. Multiple fetuses in monotocous species also have shorter gestation periods. Twin calves are carried 3 to 6 days less than single calves.
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The sex of the fetus may also determine gestation length; male calves and foals are carried 1 to 2 days longer than females.
Breed of embryo determines the length of gestation in cattle. This has been established by transferring the embryos from breeds with shorter gestation length than the donor’s and vice-versa. The hybrids between the horse and (Jack) donkey produce mule foal has longer gestation period like donkey, whereas Jenny donkey covered by stallion carrying hinny foal has shorter gestation period like horse.
Season may influence the duration of gestation. Foals conceived in late summer and autumn have significantly shorter gestation periods than those conceive in early spring.
In the most domestic species, the establishment and maintenance of pregnancy require the luteal phase of oestrous cycle is prolonged by the persistence of a single corpus luteum or a number of corpora lutea (CLs), progesterone concentration remain elevated. This results in the a negative feedback on the hypothalamus and anterior pituitary gland with a resultant inhibition of follicular development, ovulation and a prevention of return to oestrus (in polyoestrus species). In many species, the placenta subsequently replaces (mare and ewe) or supplements (cow and pig) the luteal source of progesterone. The presence of a viable, developing embryo, however, prevents the
CL from regressing and thus, in polyoestrus species, inhibit the return to oestrus
(maternal recognition of pregnancy in cow 16-17 days; ewe, 12-13 days; mare, 14-16 days; sow, 12 days; doe goat, 17 days).
A variety of methods can be used to detect pregnancy. There are four broad categories which are: management, clinical, ulterasonographic and laboratory-based.
After ovulation and the formation of the corpus haemorrhagicum and the CL, plasma progesterone concentration in the peripheral plasma rise to 7-8 ng/ml by 6 days.
They persist in these levels for first 4 weeks of gestation, but there is frequently a transient fall at about 28 days after ovulation to 5 ng/ ml, followed by a later rise.
In the early part of the 2 nd month of pregnancy, the endometrial cups are formed.
These are discrete outgrowths of densely packed tissue within the gravid horn, derived as a result of the invasion of fetal trophoplast ( trophoplast: the outermost layer of the developing blastocyst ) cells into endometrium (give rise endometrial cup cells). The endometrial cups produce eCG or PMSG (reaches a maximum at 60-65 days, decline thereafter and disappears by 150 days of gestation), it provides the stimulus for the formation of accessory CLs and regulates luteal steriodogensis. Because of the presence of the accessory CLs, the progesterone concentrations in the peripheral circulation increase, to reach and maintain a plateau from about 50 to 140 days and then decline. By 180-200 days the concentrations are below 1 ng/ ml and they remain
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so until about 300days of gestation, when they increase rapidly to reach a peak just before foaling and decline rapidly to very low levels immediately after parturition.
Concentrations of fetal oestrogens (oestradiol and oestrone) in peripheral circulation during first 35 days of pregnancy are similar to those of dioestrus. After this time they increase to reach a plateau between 40-60 days (3ng / ml.), the rise due to the increased follicular development (eCG production).
After day 60 it is increase due to placenta or activity of the fetus. Maximum value is observed at about 210 days, the main source being fetal gonads, with a gradual decline towards the time of foaling.
Failure to return to oestrus is a good sign that mare is pregnant.
False positive will occur:

If the mare has a silent heat.
 If the mare becomes anoestrus as a result of lactation or environmental factors.
 If the mare has a prolonged dioestrus yet has not conceived.

If the mare has a prolonged luteal phase associated with embryonic death; this referred to as pseudo pregnancy.
This is best done using a speculum (manual exploration). The vaginal mucosa is pale pink, the mucus is scant and sticky, and the cervix small and tightly closed. False positives can occur in early pregnancy because the vagina is similar to that seen in dioestrus. Errors can be made as a result of prolonged luteal phase and pseudo pregnancy.
For diagnosis of pregnancy by rectal palpation in the mare, the following criteria should be taken in mind:
1) The CL of pregnancy cannot be identified per rectum although it persists for 5-6 months.
2) The FMS and feeling of placentomes are absent, because of the diffuse
Placentation.
Follicles are normally present during the first 3 months of the pregnancy (large size to ovary).
Uterine tone is a marked at 17-21 days of pregnancy, when the uterine cornua can be palpated as resilient tubular organs.
Palpation of the conceptus is first possible at 17-21 days as small soft swelling, at 40 days about the size of a tennis ball. By 60 days, it is becoming oval in shape (13 X
9 cm). At about 100 days, it is often possible to palpate the fetus as it float in the fetal fluid of the uterine body. At the 4 th to 6 th months, thrilling may be start and the fetus may be difficult to locate between the 5 th and 7 th months.
There is no cotyledons and from 7 th month to term of pregnancy the fetal parts are palpates easily.
False positive:

It is confused with pyometra (3 months).

The uterine tone due to incomplete involution.
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B-mode has been used extensively in the mare (imaging mode with 5 MHz transducer). The earliest gestational age that pregnancy has been confirmed in the mare is 9 days. Twin ovulations are very common in mares especially in thoroughbred and draught mares. The birth of live twins is relatively uncommon (0.8-3 %). The reason are:
 Fertilisatrion failure.
 Death of one or both embryos before or after fixation.

Death of one fetus.
 Abortion of both fetuses.
(i)Milk or blood progesterone: Blood or milk samples collected 16-22 days after service (progesterone concentration is elevated).
(ii) Identification of eCG: Blood sample should be collected preferably between 50 and
90 days after service.
(iii) Blood oestrogens: By 85 days of gestation the concentration should exceed the maximum values obtained in non-pregnant mares.
(iv) Urinary oestrogens: Oestrogens (oestrone and oestradiol) are present in the urine of pregnant mares between 105-300 days of gestation.
(v) Serum early pregnancy factor (EPF): Is an immunosuppressive glycoprotein associated with early pregnancy at 7-10 days after ovulation (rosette inhibition test).
The main source of progesterone for the maintenance of pregnancy in the cow is the CL, the placenta producing only small amounts. The result of ovariectomy and removal of the CL are controversial. Up to about 200 days of gestation removal of the ovary containing the CL, or ablation of the CL either surgically or with the use of PGF 2α usually result in abortion. However after this stage until just before term, pregnancy usually continues.
Progesterone concentrations in peripheral circulation during the first 14 days of gestation are similar to those of di-oestrus. Thereafter the concentration increases slightly during pregnancy until it starts to decline at about 20-30 days prepartum.
Oestrogen concentrations during early and mid-gestation are low, less than 100 pg/ ml.;however toward the end of gestation (after day 250), oestrogen concentrations increase to reach peak value 2-5 days prepartum of 7 ng/ml. oestrone sulphate and 1.2 ng/ ml. oestrone. These rapidly decline from about 8 hours prepartum to low levels immediately postpartum.
Prolactin is low during pregnancy until just before calving, increase from basal concentrations of 50-60 ng/ ml.to peak values of 320 ng/ ml. 20 hours prepartum, until a subsequent decline to basal concentration by 30 hours postpartum.
a. Failure to return to oestrus and persistence of the CL : Failure of regression of the CL at about 21 days, as determined by trans-rectal
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palpation, provides a methods of anticipating that the cow is probably pregnant (it is seldom used as a practical procedure). b. Mammary glands: mammary changes during pregnancy are best observed in primigravida. The teats of the pregnant heifer begin to enlarge about the 4 th month. From the 6 th month the mammary glands become more firm to the touch and their enlargement can be seen.
Hypertrophy is progressive during the terminal month. As parturition approaches, the glands become grossly enlarged and oedematous and teats take on waxy; tumefied appearance. c. Abdominal ballottement: This is often possible as early 7 months of gestation in some small breeds such as the Jersey. The method involves fairly vigorous pummeling of the ventral abdomen and flank with clenched fists. The object is to push the fetus, which is floating in the fetal fluids, away from the body wall and then identify it as it swings back against the abdominal wall.
 Identification of early pregnancy factor (EPF)/ early conception factor
(ECF): EPF is an immunosuppressive glycoprotein associated with pregnancy. Commercially test kits are available which use the ‘dip-stick’
(samples are taken at 7-8 days after insemination).
 Assay of pregnancy-specific protein B: This protein has been identified in the maternal serum of the cows from 24 days of gestation by RIA &
ELISA.
 Progesterone concentration in plasma and milk: Blood samples are taken
21-24 days after previous oestrus, progesterone levels remain elevated.
Milk samples are taken 21-24 days after service, progesterone concentration elevated.
 Oestrone sulphate in milk: The identification of oestrone sulphate in the milk of a cow at 105 days of gestation is very reliable method of pregnancy diagnosis (limited applications because of the lateness are obtained).
Examination may be manual by speculum or visual. During pregnancy the secretion of cervical glands becomes gelatinous and tough, forming a plug for sealing the canal on manual examination, the finger should be pressed gently in the os. The detection of an adhesive, tenacious secretion (the seal can sometimes be seen, light brown in colour, covering the os).
o Landmark structure, always search for this as it leads to the uterus.
o Find it by sweeping the floor of the pelvis from side to side.
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o Caution, location of the cervix should not be used as a primary criterion for pregnancy.
These are the primary structures palpated to determine pregnancy status.
Palpate for:
Size- uterine horns increase in size as gestation advances.
Location- in relation to pelvic rim advances in anterior direction.
o Presence of fluid in the horns.
o Presence of the embryo or fetus.
o Presence of cotyledons.
o Detected by grasping the uterine wall between thumb and forefinger and lifting slightly ; called “ slipping the membrane”. CAUTION, this can terminate pregnancy if too much pressure is used and the chorion is damaged.
o Presence of a corpus luteum (CL) which produces progesterone. o A smooth ovary with no significant structure (follicles, CL) is an indication that the female is probably anoestrus or non-cycling: hence, she is probably not pregnant.
o Found on the right side near the forward edge of the pelvis and the artery is enlarged. o Increased diameter allows for increased blood flow as pregnancy gets older.
 Cervix is in the pelvic canal.

Uterine body and horns are in the pelvic cavity.
 One horn is slightly enlarged and fluid-filled.
 Membrane slip technique used to detect pregnancy. Proceed with caution because damage to membrane can cause the pregnancy to be aborted.
 CL is on the same side as the enlarged horn.
*
 Uterine body and horn begin to fill with fluid.
 One horn is distinctively larger than the other.

Use the membrane slip technique.
 Move your hand completely around the pregnancy.
 CL is on the same side as the enlarged horn.
 Amniotic cavity is about the size of a hen egg.

Cervix moves in anterior position.
 Pregnant horn is at the anterior part of the pelvic brim and may start to fall over the rim.

Fetus is about the size of a small rat.
 Difficult to move hand completely around the pregnant uterus.
 3 rd month known as the ‘early balloon stage’.
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 Cervix is at
the pelvic brim.
 Uterine body is enlarged and fluid-filled and is about the size of a football. It is usually dropped over the pelvic brim.
 Start to feel the cotyledons.

Fetus is the size of a small cat.
 4 th month known as the ‘late balloon stage’ .
 Cervix is almost completely over the pelvic brim.
 Uterine body and horns are not easily palpated.

Fetus is the size of a large cat.
 Cotyledons are larger.
 Cervix is well over the pelvic brim.
 Entire uterus is stretched and fluid-filled and well down into the body cavity.
 Fetus is not palpable.
 There is a nice buzz to the uterine artery.

6 th month known as the sinking stage .

Pregnancy is easy to detect.
 Fetal head at or near the pelvic cavity.
 There is a very strong buzz to the uterine artery.

7 th month known as the floating stage .
 Pregnancy detection is very easy.

Fetal calf is quite often located in the pelvic cavity and its head easy to feel.
Using the ultrasonic fetal pulse detector. It is possible to identify the fetal heart beats from 6-7 weeks using rectal prob. The uterus is imaged trans-rectally, for early pregnancies a 7.5 MHz linear transducer is required, whereas a 3.5 MHz transducer is preferably for late pregnancies.
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Fertilisation rates in domestic animals are generally very high. Under normal circumstance one would expect approximately 90% of ova shed to be fertilized.
However, a high proportion of the ova shed fail to develop to full-term offspring.
In polyestrous species embryonic loss can be suspected when there is an irregular extension of the inter-oestrus period. However, this will be an underestimate of total loss because it will not detect that which is occurring early on, before the maternal recognition of pregnancy and the resultant extension of the life of the CL. Furthermore, in polytocous species like pig, embryos may be lost without termination of pregnancy.
More accurate estimations of embryonic loss can be made by slaughtering at different times during gestation and correlating the number of embryos with the number of corpora lutea. However this method requires the sacrifice of the animal and hence the loss of the pregnancy. More recently, ultrasonic scanning such as Doppler A-mode and real time B-mode techniques.
Loss before fetal maternal recognition and before elongation of the life of the CL, is referred to as early embryonic death (EED). Loss after the CL has been extended is termed late embryonic death (LED). In mares most loss occurs between days 10 and 14 post-service, in dairy heifers occurs after about day 19 post-service. In sheep most losses occur between days 15 and 18 post-service.
Embryonic loss may be due to either genetic or environmental factors or a combination of the two.
Environmental factors include climate, nutrition, stress, ovulation rate, failure of the fetomaternal recognition factors, uterine conditions, hormones, infectious agents, and teratogens.
Genetic factors causing embryonic loss include single-gene defects, polygenic abnormalities and chromosomal anomalies. A few single-gene mutations are lethal and result in the death of the conceptus. If the gene is dominant (Manx gene {M}in the cat), a single copy may be sufficient to cause death. Recessive genes only exert their effect in the homozygous state. Not all genetic defects are lethal. Some abnormal fetuses survive to term, which biologically and economically wasteful.
Chromosomal abnormalities play an important role in infertility in some species.
The chromosome complement can be determined from any dividing cell. The most common cell type used is peripheral blood lymphocytes.
Chromosome abnormalities may be numerical (e.g. aneuploidy or polyploidy) or structural and may occur in the sex chromosome (X or Y) or the non sex chromosomes, which are called autosomes.
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Aneuploidy is when the chromosome number is almost diploid but there are one or two chromosome too many or too few. X chromosome aneuploidy in female (XO-
Turner’s syndrome; and XXX- triple- syndrome) result in infertility. Deviation from the normal number result in oocycte atresia during embryonic development.
Extra X chromosomes in the male (
XXY Klinefelter’s syndrome) result in infertility because extra X interferes with spermatogenesis at puberty. Animals with Klinefelter’s syndrome are phenotypic males but with small tests and are a zoosperm and sterile.
Aneuploidy of the autosomes result in either too many (trisomy) or too few
(monosomy) copies of a particular chromosome and it is associate genes (embryonic death).
This is when are whole multiples of haploid (half the diploid) chromosome number in excess (e.g. triploidy is three times the haploid number).
Problems caused by structural chromosomal abnormalities will depend upon whether genetic material has been lost (deletions) or just rearranged (insertions, inversions and translocations). In the case of deletions, carries of the anomaly may have developmental abnormalities (cause embryonic death). With rearrangements, balanced carrier of the anomaly is phenotypically normal, but problems arise during meiotic prophase (problems at pairing). This often results in non-disjunction and the production of chromosomally unbalanced gametes (leads to trisomies or monosmoies).
The commonest chromosomal abnormality in mares is X chromosome aneuploidy (XO or XXX). Another common anomaly is XY sex reversal, i.e. the animal present as a phenotypic mare but is, in fact, a genetic male. XO mares are usually small for their age and some have poor body conformation. They usually fail to show any signs of oestrus, and the ovaries are small, fibrous and underdeveloped (XXX mares often present with the same clinical history as XO mares).
In some cases the mare may be mixaploid and have normal as well as abnormal cells e.g. (XO/ XX, XX/ XXX, XO/ XX/ XXX or XO/ XY).
The commonest chromosomal abnormality in cattle is a structural anomaly known as a centric fusion translocation. Two chromosomes fuse together near the Centro mere, resulting in a reduction in the chromosome number but little or no loss in genetic material. Heterozygosity for a centric fusion translocation results in a drop in fertility due to non-disjunction at meiosis and the production of chromosomally unbalanced gametes. The resultant unbalanced embryos undergo early embryonic death.
Congenital abnormalities are abnormalities that are present at birth (caused by genetic factors or some other agent). Teratogen is an agent that can induce abnormalities in a developing conceptus. Teratogenic agents may not kill the developing conceptus, but many of the abnormalities they induce are incompatible with life.
Teratogens have their major effect during the embryonic stages. It is only the late-developing systems such as the palate, cerebellum and parts of the cardiovascular
26

and urogental system that are affected. A teratogens may a drug, hormone, chemical, gamma irradiation, trace element, variation of temperature, or an infectious agent
(particularly viruses).
Congenital abnormalities may cause obstetrical problems. For examples:
Which occurs in ruminants and swine, is characterized by hypoplasia or aplasia of the spinal cord which ends in the thoracic region. The regions of the body, including the hind limbs, which are normally supplied by the lumber and sacral nerves, exhibit muscular atrophy, and joint movement does not develop (this position caused dystocia).
It is common in ruminants and swine, has as the main defect acute angulation of the vertebral column such that the tail lies close to the head. The chest and abdominal cavities are incomplete ventrally so that the viscera are exposed.
These are spherical bodies, attached to the fetal membranes of a normal fetus.
They are formed from connective tissue surrounded by skin and may be of a different sex to that of the normal twin.
Which are found in a number of species, will present as absolute fetal oversize
(Siamese’s twin).
It is occur due to defect in function of placenta.
It is common in Friesian.
It is common in Ayrshire.
Insemination too late in the oestrous period leads to ovum aging and embryonic death. Artificial insemination during pregnancy will induce loss. Specific infectious agents causing loss of embryo ( Brucella, rift vally fever).
Cows conceiving too soon after calving have a higher embryonic loss rate (due to poor uterine environment).
Nutritional causes such as selenium, phosphorus and copper deficiencies have all been implicated in embryonic loss.
Stress, e.g. heat stress, has also been shown to result in embryonic loss.
The commonest cause of embryonic loss in mares is twin conceptions (twinning).
Competition for placental space usually results in one fetus growing more slowly than the other. Death of one fetus often results in the loss of the second.
Stress, due to transportation, is cause embryonic losses in the mares.
Lactation and service at the foal heat also result in higher embryonic death rates
(lactational stress). As regards the uterine environment, recurrent endometritis and post-service infection lead to perivascular fibrosis, and this common cause of embryonic and fetal death between 40 and 90 days of gestation.
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Following early embryonic loss the embryonic tissues are usually resorbed, and the animal returns to oestrus if there is no other conceptus in the uterus. If death of the embryo is due to an infection then, even although the embryonic material may be absorbed, a pyometra may follow. In cattle this condition is characterized by persistence of CL, closed cervix and pus accumulation in the uterine body and horns.
If fetal death occurs after ossification of the bone has begun, complete resorption of fetal material cannot take place. Instead fetal mummification occurs.
The commonest form of mummification is papyraceous mummification, where the fetal fluids are resorbed and the fetal membranes become shriveled and dried so that the resemble parchment. The uterus contracts on to the fetus, which becomes twisted and contorted. In polytocous species, if mummification occurs in only some embryos, this does not interfere with the continuation of the pregnancy of the live fetuses.
Mummification is very common in the pig. It is seen in large litters as a consequence of uterine overcrowding and placental insufficiency.
In the dog, fetal mummification is a characteristic of canine herpes virus (CHV) infection.
In the ewe, fetal mummification maybe seen with twins and / or triplets when one of the embryos has died. In the mare mummification is rare and is always associated with twin pregnancies (one of the fetuses usually develops more slowly than the other and is smaller).
In cattle, fetal mummification occurs with an incidence of 0.13-1.8% and haematic mummification is the norm. In this condition the fetal fluids are resorbed but the fetus and membranes are surrounding by a viscous, chocolate-coloured material. It was once thought that the colour was due to caruncular haemorrhage which resulted in fetal death.
Various theories have been but forward as to the causes of the condition:

It has been suggested that there is a genetic cause (Jersey and Guernsey breeds).
 Torsion of the umbilical cord has been suggested as the primary cause of fetal death but this has not been a consistent finding in haematic mummies.

Hormonal anomaly.
Haematic mummification can occur following fetal death at ages ranging from 3 to 8 months of gestation. Since there is no fetal signal for onset of parturition, the CL is retained and pregnancy will be maintained for an unpredictable time. The condition is often only diagnosed when the cow is examined because of a prolonged gestation period.
Induction of abortion by luteolysis using prostaglandins. The feus normally expelled in 2-4 days. The prognosis for further breeding is good (no damage to the reproductive tract).
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Fetal maceration can occur in any species, but it is described most frequency in cattle. It occurs as a consequence of the failure of an aborting fetus to be expelled, due to uterine inertia. Bacteria enter the uterus through the dilated cervix, and by a combination of putrefaction and autolysis the soft tissues are digested. Under these circumstances a chronic endometritis ensures and there is severe damage to the endometrium. The animal should therefore be sent for slaughter.
Other sequelae to fetal death are abortion and stillbirth. Abortion are often caused by infectious agent (e.g. Brucella abortus, Salmonella, Trichomonas, Toxoplasma, bluetongue and leptospira ). Stillbirth may occur because of developmental anomalies incompatible with life.
Three dropsical conditions of the conceptus may be seen in veterinary obsterices:
Oedema of the placenta, dropsy of the fetal sacs and dropsy of the fetus. They may occur separately or in combination.
This frequently accompanied a placentitis: for example, Brucella abortus infection in cattle. It does not cause dystocia but is frequently associated with abortion or stillbirth.
Both the amniotic and allantoic sacs can contain excessive quantities of fetal fluid (hydramnios or hydrallantois developing on which sac is involved ).
Hydrallantois is much more common than hydramnios, and it is occurs usually during the second half or last third of gestation period in cows and mares. A few cases have been recorded in sheep, associated with either twins or triplets.
A part from the hereditary cases of hydramnios which accompany the Dexter ‘bull dog’ calf, and which may occur as early as the third or fourth month (the cause is not known).
 Distension of the abdomen by excess of fetal fluid (the volume of allantoic fluid varies up to 273 liters at 7 months).
Such large amounts of fluids impose a serious strain on the cow and greatly hamper respiration.
 Reduce appetite.

There is gradual loss of condition, eventually causing recumbency and death.
 Occasionally, the animal becomes relieved by aborting.
 The less severely affected reach term in poor condition and, because of uterine inertia, frequently require help at parturition.
The diagnosis of bovine hydrallantois is based on the easily appreciable fluid distension of the abdomen; with it are associated symptoms, in the last third of pregnancy. Confirmation may be obtained by the rectal palpation of the markedly swollen uterus, and the failure to palpate the fetus either per rectum or externally.

Cases that have become recumbent should be slaughtered.
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
Where the animal is near term a caesarian section is indicated, and it is imperative that the fluid is allowed to escape slowly, so as to prevent the occurrence of hypovolamic shock.
 Using a synthetic corticosteroid (dexamethazone or flumethazone) in conjunction with oxytocin for induce abortion (dose rate: dexamethazone 5-10 mg I/M, flumethazone 20 mg I/M, oxytocin 10 IU I/V).
Cases of hydrallantois which calve / or are delivered by C.S, frequently retain the placenta and, owing to tardy uterine involution, often develop metritis. This may lead to a protracted convalescence and delayed conception.
There are several types of fetal dropsy, and those of obstetric importance are hydrocephalus, ascites and anasarca. The form of the fetus and degree of obstetric hazard are determined by the location and amount of excess of fluid. Dystocia is due to the increased diameter of the fetus.
Hydrocephalus involves a swelling of cranium due to an accumulation of fluid which may be in the ventricular system or between the brain and dura.
It affects all species of animals (most commonly in pigs, puppies and calves).
In the more severe forms of hydrocephalus there is marked thinning of the cranial bones. This facilitates trocarisation and compression of the skull so as to allow vaginal delivery. Where this cannot be done, the dome of the cranium may be sawn off with fetotomy wire or a chain saw. If the fetus is decapitated there is still the difficulty of delivery the head. Caesarian section may be performed (when hydrocephalus is accompanied by ankylosis of the limb joints).
Dropsy of the peritoneum is common accompaniment of infectious disease of the fetus and of developmental defects (Achondroplasia). Aborted fetuses are often dropsical; when the fetus is full-term, ascites may cause dystocia. This can usually be relieved by incising the fetal abdomen with a fetotomy knife.
The affected fetus is usually carried to term, and concern is caused by the lack of progress in second-stage labour. This due to the great increase in fetal volume caused by the excess of fluid in the subcutaneous tissues, particularly of the head and hind limbs. There is frequently an excess of fluid in the peritoneal and pleural cavities with dilatation of the umbilical and inguinal rings as well as hydrocoele.
It is accumulation of gases between the parts of body particularly S/C due to death of fetus and invasion of uterus by bacteria (non-genetic factors), so produced gases.

Death of fetus.
 Opening of the cervix.
 Elevation of temperature.

Non-treated dystocia.
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o The emphysema occurs between 24-48 hours after fetal death.
o Interrupted contraction of uterine and abdominal muscles.
o Vaginal discharges with foul smell and red colors.
o Depression and loss appitite.
o Fetus oversize (via vaginal).
o Creptatation during palpation due to gases (via vaginal).
o Rupture of fetal parts or tissues by hand (via vaginal).
 Partial or complete fetotomy.

Caesarian section is not recommended (peritonitis) .
 Systemic antibiotic.
 Using of oestrogen and oxytocin.

Supportive treatment.
It is pregnancy of more than one conceptus (twins, triplets, and so on) results from either: a) Fertilization of more than one ovum by one father at the same oestrous phase
(fraternal twins), which is the most common form. b) Complete or partial separation of cleavage-stage blastomeres and blastocysts
(identical twins).
Twinning is physiological normal in the ewe and doe and therefore it is desirable.
However, twinning is undesirable in the cow, mare and camel.
Super fecundation is the fertilization of more than one ovum by several fathers at same oestrous phase (conceived contemporaneously). Owing to the number of ova shed and their longevity, as well as to the length of oestrus and the promiscuous mating behaviour of the species, super fecundation is most likely in the bitch. The phenomenon is suspected when mating to two dogs of different breeds is known to have occurred, and the suspicion is heightened when the litter shows marked dual variation in colour pattern, conformation and size.
Super fecundation has been reported when a mare gave birth to twin horse and mule foals, and when a Friesian and Hereford calves.
Super fetation is fertilization of more than one ovum at two successive oestrous phases or is the simultaneous occurrence of more than one stage of developing embryo in the same animal. In this condition the animal already pregnant mates, ovulates and conceives a second fetus or second litter. This means that some females may exhibit signs of oestrus during the pregnancy. It is not uncommon for a cow to be mated when pregnant, but no evidence is available that ovulation occur in a cow carrying a live fetus.
Ovulation does occur in pregnant mares, and in this species super-fetation is theoretically possible.
Superfetation is suspected when fetuses of very different size are born together or when two fetuses, or two litters, are born at widely separated times.
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Reproductive developmental delay patterns have frequently been offered as alternative explanations for the superfetation phenomenon. The most commonly occurring patterns in certain mammals are (1) delayed fertilization, or sperm storage in the female reproductive tract, (2) delayed implantation, which occurs following fertilization, and (3) delayed development, which occurs following fertilization and implantation.
This condition is very common in pigs. Double parturition followed a single mating at which excessively large number of eggs were fertilized and which later distributed themselves normally through both uterine horns. The embryos in the cranial halves of both cornua remained unimplanted in a state of ‘embryonic diapause’ (is the temporary retardation of embryonic development at any stage of embryogenesis)for periods varying from 4-98 days, after which they were reactivated and implanted, thus constituting a spontaneous superfetation in cranial parts of the horns. The embryos which implanted in the caudal parts of the horn underwent a normal gestation and parturition; a second parturition at variable intervals occurred the piglets from the delayed implantation reached maturity.
Prolonged gestation is an increase of gestation period than the normal due to
‘embryonic diapause’. This phenomenon is very common in mares and rarely occurs in cows and others animals. In this condition weights of fetuses are normal (or few increases).
1- hormonal disturbances.
2- malnutrition (vitamin A deficiency).
3- genetic factors like mistakes in genetic structures leads to non-developed some of fetal organs such as a pituitary gland (hypoplasia), so the fetal adrenal gland fail to release the cortisol which is very important hormone in fetal growth and initiation of parturition.

long hair.

Hypertrophy of palate.

Incomplete growth of bones.

Hydrocephalus.

Pituitary hypoplasia.
Most of fetuses are die few days after parturition.
 Induction of abortion by PGF 2α .
 Complete or partial fetotomy (oversize fetus).
*Ectopic pregnancy denotes a pregnancy occurring elsewhere than in the cavity of the uterus ( extra- uterine pregnancy).
*While this condition is well-known
However, the causes in humans, it is rarely diagnosed in animals. and mechanisms leading to an ectopic implantation of the ovum are not always clearly defined in humans or animals.
*Two types of ectopic pregnancy are mainly recognized:
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(1) Tubal pregnancy occurs when an oocyte is fertilized and then remains in the oviduct.
(2) Abdominal pregnancy occurs when the gestation develops in the peritoneal cavity.
The latter may be subdivided oocyte into two subtypes: the primary form, when a fertilized enters the peritoneal cavity and becomes attached to the mesentery or abdominal viscera, and the secondary form, which follows the rupture of an oviduct, or the uterus after the fetus has peritoneal cavity. been implanted, and the fetus is expelled into the
*Several differences exist in ectopic pregnancies species. While abdominal pregnancy between human beings and animal has been described in both human and animal species, tubal ectopic pregnancies would appear to be restricted to primates.
*Ectopic pregnancy is considered catastrophe, since the mother's life is in jeopardy from internal haemorrhage.
Pseudo pregnancy is most common in dogs and cats and accompanied with all signs of pregnancy except presence of fetus. It usually follows early pregnancy failure, however it can occur in non-pregnant animals. This condition result from a prolongation of metoestrus or dioestrus (persistence of CL in sexual quiescence), or sterile mating without fertilization.
It is very rare in the cow. The cow is wrongly diagnosed pregnant if she stops exhibiting the signs of oestrus due to the presence of foreign body (pus or fluid) in the uterus preventing the release of luteolysin.
The condition in the mare results from a prolonged luteal phase following early embryonic death or accumulation of fluids in the uterus.
In the camel, sterile mating usually induces the formation of CL. Therefore, the camel may show the early signs of pregnancy until the regression of the CL.
 Anoestrus.
 Increase in abdominal size.
 Slight development of mammary glands in the term of pregnancy.
 Behavioral change near to parturition like ability to isolation.
Repeat of this phenomenon may leads to pyometra.
1- Administration of oestrogen alone or oestrogen + FSH or Gn-RH.
2- In case of pyometra treated by hysterectomy or ovarohysterectomy.
Female goats sometimes cycle, mate, and display all the attributes of being pregnant, but in fact are not bred. The uterus fills with large amounts of fluid but no fetus or placenta develops. This condition goes by several names . . . . "false pregnancy,"
"cloudburst pregnancy," "pseudopregnancy," and medically speaking, "hydrometra."
 The precise causes of false pregnancy are not completely understood, though several conditions have been found to be involved in its existence. Delaying oestrus (coming into heat) in breeds that cycle seasonally is high on the list of causes.
33


Infectious diseases such as Toxoplasmosis and Border disease may induce hydrometra in does, and certain plant materials which contain phytoestrogens may be causing.
 A more common cause of hydrometra is the artificial induction of does into heat by producers who use gonadotrophin-releasing hormones to chemically bring them into season.
Until real-time ultrasound technology became available, diagnosis was virtually impossible. At 40 days or more of gestation, the producer and/or his veterinarian can view the uterus via ultrasound to determine if it is liquid-filled or if fetuses are present.
When a doe spontaneously aborts a pseudo pregnancy early in gestation, the material coming from her body may be visually indistinguishable from early-stage fetal abortion.
If the doe has not spontaneously aborted an ultrasound-diagnosed false pregnancy and the producer decides that the uterus must be emptied so that she can be immediately re-bred, injections of prostaglandin may be used under close veterinary supervision.
The vet may decide to follow up with oxytocin injections, depending upon the results obtained from the prostaglandin treatment. Once the "cloudburst" of fluid has left the doe's body, she can usually be re-bred within two months.
Whatever the actual causes, it appears that external circumstances oftentimes induced by the producer are the reason that hydrometra occurs in female goats. For those of you old enough to remember the butter commercial, "It's not nice to fool Mother Nature."
Administration of PGF 2α (dose 2.5 mg ) will be followed by expulsion of the fluid and oestrus occur approximately 4 days.
Mucometra, a condition where mucus of variable consistency and amounts collects in the uterus, has been described in cattle. It is associated with conditions such as imperforated hymen, segmental aplasia of the vagina, cervix and uterus or secondary to longstanding cystic ovarian disease with cystic endometrial hyperplasia.
Mucometra in goats associated with persistent corpus luteum.The uterine horns are symmetrically distended (each horn is 10 cm in diameter) and there is a well developed corpus luteum
(CL) on the ovary (diameter 1.8cm). The uterus is filled with about one litre of watery fluid admixed with mucoid debris.
In all domestic species there will be occasions when it will be desirable to either prevent pregnancy occurring or terminate it prematurely. Such occasions may follow an unintended mating (misalliance), where pregnancy and parturition may present a severe risk to dam’s health, or where the owners of the animal do not want the pregnancy to continue.
Termination of pregnancy in the mare associated with twin. The treatment of choice is PGF 2α administered after the CL has become responsive to the hormone 4 days after ovulation and before the formation of the endometrial cup (about 35 day).
Therefore, it is preferable to treat approximately 10-15 days after mating. Alternatively, intrauterine infusion of 250-500 ml. normal saline during the same period will also be effective (flushing out of the conceptus).
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Pregnancy can be terminate from 4-5 to100 days after ovulation with PGF 2α .
After 150 days, the placenta is major source of progesterone for the maintenance of pregnancy, until about 270 days of gestation; PGF 2α alone is not effective. During this period, either long-acting corticosteroids alone, or in combination with PGF 2α are required.
Large doses of oestradiol benzoate can terminate pregnancy up to about 150 days by stimulating endogenous PGF 2α release.
Pregnancy can be terminate at any stage with PGF 2α in doe goat. In the ewe
PGF 2α is effective in terminating pregnancy after day 4 and before day 12. After 45-55 days, the CL is no longer the main source of progesterone for the maintenance of pregnancy, and at this stage corticosteroids will be necessary to terminate pregnancy.
Pregnancy can be prevented in the bitch by the strategic use of oestrogens during the first 5 days after mating.
They exert their effect by interfering with the transport of the zygotes from uterine tube to the uterine horns, probably by causing oedema of the endosalpinx and thus a temporary tubal occlusion (oestradiol benzoate 0.01mg / kg intramuscular, diethylstilboestrol 1mg / kg orally).
Most commonly, carbergoline (prolactin inhibitor) is administered orally daily (5
µg / kg), whilst cloprostenol (5 µg / kg ) is given parenterally on alternate days. Abortion
/ resorption usually follow 10 days after treatment.
Oestradiol cypoinate by I/M injection at dose rate of 125250 µg within 40 hours of mating has been shown to be effective in preventing pregnancy.
Termination of pregnancy may induce surgically by ligation of oviduct and ovarohysterectomy (most common in bitch and queen).
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Parturition or labour is defined as the physiologic process by which the pregnant uterus delivers the fetus and placenta from the maternal organism.
Parturition is triggered by the fetus and is completed by a complex interaction of endocrine, neural, and mechanical factors. Parturition occurs as result of activation of the fetal hypothalamus-pituitary-adrenal axis (HPA). There is still uncertainty about the mechanisms responsible for the activation of the fetal hypothalamus. A number of theories have been proposed. There are:
1- Maturation of the fetal hypothalamus which might result in the development of critical synapses in the para ventricular nucleus, allowing in an increase in fetal neuroendocrine function .
2- Ability of the hypothalamus to respond to the effect of placental hormones.
3- Fetal stressors such as hypoxia, hypercapnia, changes in blood pressure and glucose.
A significant increase in the fetal plasma concentration of cortisol occurs during the final stages of gestation in sheep, which is due to placental production of PGF 2α , which in turn activates the (HPA). A similar rise in fetal cortisol secretion triggers parturition in goats, cattle, and pigs. The mechanisms that follow the release of cortisol differ among species depending on the source of progesterone maintaining the pregnancy. The rise in fetal cortisol stimulates the placenta to convert progesterone to oestrogen by activating the placental enzyme 17α-hydroxylase; this hydroxylates progesterone via androstendione to oestrogen.
The consequences of the rise in oestrogen in the peripheral circulation are threefold: firstly , oestrogens have a direct effect upon the myometrium, increasing it is responsiveness to oxytocin; secondly , they produce softening of the cervix; thirdly , they act upon the cotyledon-caruncle complex to stimulate the production and release of
PGF 2α . Further stimulation of synthesis and release of the PGF 2α from the myometrium can also be induced by action of oxytocin and mechanical stimulation of vagina.
Prostaglandins (PGF 2α ; PGI
2
) they cause smooth muscle contraction, luteolysis, and softening of cervical collagen. The effect of theses contraction is to force the fetal lamb towards the cervix and vagina where it well stimulate sensory receptors and initi ate Ferguson’s reflex, with release of large amounts of oxytocin from the posterior pituitary. Oxytocin stimulate further myometrial contractions. Both these hormones
(PGF 2α and oxytocin), together with uterine contraction and consequent expulsion of the fetus.
 The fetal endocrine changes that occur in late pregnancy not only initiate parturition but also stimulate a variety of maturational changes which enable the newborn animal to survive.
 Fetal cortisol stimulates lung maturation and enhances the pancreatic response to glucose by insulin secretion.
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
The maintenance of newborn body temperature after the abrupt transition from the neutral thermal environment is influenced by fat and glycogen accumulation.
The thermogenic contribution of fat and glycogen is under the effect of triiodothyronine (T
3
). Maturation of the thyroid gland is influenced by fetal cortisol released at the time of parturition.
 Adequate storage of glycogen in the liver is vital as an immediate source of energy for the newborn. This is influenced by fetal cortisol.
The indications for the premature induction of foaling are few, the main one being to ensure that it occurs in the presence of skilled assistance; then if dystocia occurs it is possible quickly to correct the difficultly so as to ensure survival of the foal and reduce the danger to the mare. When, because of disease or illness in the mare, it may be advantageous for foaling to be induced. A number of different hormone preparations have been used:
 I/M injection of oxytocin either with or without priming with stilboestrol dipropionate (oxytocin dose of 120 IU to mares between 360 and 600 kg live weight). Foaling occurred 15-60 minutes later.
 Dexamethazone has been used successfully to induce foaling in Ponies. A dose rate of 100 mg every day for 4 days result in foaling 6-7 days after start of treatment (the regimen was started at 321 days of gestation).
 PGF 2α and it is analogue fluprostenol have also been used to induce foaling
(dose rate 1.5-2.5 mg every 12 hours of PGF 2α ).
 Fluprostenol will induce foaling when given as a single dose of 250 µg to ponies and 1000 µg to thoroughbred mares.
The indications for the induction of calving are as follow:
1. Advancing the time of calving to coincide with the availability of suitable pasture for milk production (this used in New Zealand and parts of Ireland).
2. Ensuring that cows calve at a predetermined time when skilled assistance is available so that prompt attention can be given.
3. Reducing the birth weight of the calf by shortening the length of gestation to avoid dystocia due to feto-maternal disproportion (dam is immature with small pelvis).
4. In diseased or injured cows where the termination of pregnancy will alleviate the condition, or where a live calf can be obtained before slaughter, premature induction may be used (hydrallantois).
A number of different hormones have been used successfully to induce calving so that a live calf is born. Since induction before 270 days will usually result in the birth of small, weakly calf with poor of prospects of survival it is important that the date of service or insemination is accurately known.
ACTH has been used to induce calving, it is effect by stimulating endogenous corticosteroid production, it is best replaced by the direct administration of corticosteroids. Corticosteroids are also immunosuppressive and thus should not be given without broad-spectrum antibiotic if infection is present.
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PGE
1
, PGE
2
, and PGF 2α and analogues: have been used from about 275 days of gestation with a laten of 2-3 days. Good results have been obtained by using a combination of corticosteroid and prostaglandin (calving occurs after 72 hours). In summary, for early induction (250-275 days) a long-acting corticosteroid is administered followed by a short acting corticosteroid or PGF 2α after 8 days if calving has not occurred; the laten period is about 48 hours. After 275 days a medium acting corticosteroid, with either a short-acting corticosteroid or PGF 2α after 8 days if cow has failed to calve, is used. After 282 days, PGF 2α or short or medium-acting corticosteroids are effective on their own.
 The birth weight of the calf is lower than it would have been at term, and thus the subsequent growth rate is reduced.
 High incidence of retained fetal membranes.
 Milk yield is initially affected, with a delay in reaching peak lactation.
 Subsequent fertility is fairly normal although the calving to conception interval and the number of services per conception intervals are slightly increased in those cows that retain their fetal membranes.
 Reduction in the quality and quantity of cholesteral immunoglobulin.
Parturition can be induced in the ewe by mean of ACTH, corticosteroid and oestrogens. The indication for induction is limited since dystocia due to fetomaternal disproportion. Parturition has been successfully induced in doe goat with ACTH, corticosteroid, PGF 2α and analogues and oestrogens.
The signs of approaching parturition may vary from species to species and from animal to animal within the species, but generally follow the same dramatic events.
Cow and buffalo:
*2-4 weeks prior to calving, the cow and buffalo show the following signs: a) Relaxation of the sacroisciatic ligament causing grooving on each side of the base of the tail. b) Obvious abdominal distension. c) Hypertrophy of the udder. d) Oedematous vulva. e) The external cervical os is dilated 1-2 fingers, but the cervical canal is completely closed.
*1-2 days prior to calving, the cow and buffalo show the following signs:
 Body temperature drops 0.5 to 1.0 0 C.
 Segregation from the herd.

Reduced appetite.
 Increased frequency of urination.
 Signs of colic and discomfort, such as grinding of teeth, lip smacking, biting other animals and objects, standing and laying down, shaking the head, looking to the flank, and raising the tail up and down.
 Udder and teats distended with colostrums.
 Whitish vaginal discharges from the liquefied cervical seal.
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Mare :
The mare is very sensitive to human disturbance and prefers solitude and quiet at foaling. Therefore, the mare can delay the signs of approaching foaling until the night hours.
*2-4 weeks prior to foaling, the mare shows the following signs:
- Obvious abdominal distension.
- Hypertrophy of the udder.
- Oedematous vulva.
- Relaxation of the sacroisciatic ligament, but with no clear grooving on each side of the base of the tail due to the heavy muscle.
-The external cervical os is dilated 2-3 fingers, but the cervical canal is completely closed.
*1-2 days prior to foaling, the mare shows the following signs:
 Segregation from the herd.

Reduced appetite.
 Increased frequency of urination and large amount of sweating.
 Signs of colic and discomfort, such as grinding of teeth, lip smacking, biting other animals and objects, standing and laying down, shaking the head, looking to the flank, and raising the tail up and down.
 Udder and teats distended with colostrums with teats waxing.
Ewe and goat:
One week prior to lambing and kidding, the ewe and goat show the following signs:
 Relaxation of the sacroisciatic ligament causing grooving on each side of the base of the tail.

Obvious abdominal distension.
 Hypertrophy of the udder.
 Oedematous vulva.

The external cervical os is dilated 1-2 fingers, but the cervical canal is completely closed.
*1-2 days prior to lambing and kidding, the ewe and goat show the following signs:
 Body temperature drops 0.5 to 1.0 0 C.
 Segregation from the herd.
 Reduced appetite.
 Increased frequency of urination.
 Signs of colic and discomfort, such as grinding of teeth, lip smacking, biting other animals and objects, standing and laying down, shaking the head, looking to the flank, and rising the tail up and down.
 Udder and teats distended with colostrums.
 Whitish vaginal discharges from the liquefied cervical seal.
Nest building is a feature of impending parturition in polytocous species such as the pig.
 Fetal maturation.
 The fetus is alive.

Preparation for birth.
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
Responsiveness of fetus to uterine contractions.
Successful parturition depends on two mechanical processes: the ability of the uterus to contract and the capacity of the cervix to dilate sufficiently.
The expulsive forces consist of the contractions of the myometrium (90%) and the abdominal musculature (10%).
The birth canal must allow the passage of the correctly disposed fetus.
Traditionally the process of parturition has been divided into three separate stages:
Beginning of uterine contractions until cervix is fully dilated and continuous with vagina. The changes that occur during this phase of parturition are not visible externally.
A number of important changes occur.
Firstly, the structure of the cervix changes so that it can dilate; secondly, there is the onset of myometrial contractions; and finally, the fetus assumes the disposition for expulsion, which involves rotation about it is longitudinal axis and extension of the extremities.
In the sheep and goat during late gestation, in some cases as early 2 months before parturition, uterine contractions occur once every 30-60 minutes; they are of low amplitude but of 5-10 minutes duration. This pattern continues until at least the last 4 days prepartum when the frequency and amplitude increase. It is only in the last 12 hours the coordinated contraction occur at regular frequency (30 per hour), of short duration (1 minute) and substantial amplitude (20-25 mm Hg).
In the cow. The frequency also increases from 12 to 24 per hours in the last 2 hours and 48 per hour just before expulsion.
First stage duration in the cow is 2-6 hours, in the mare 1-4 hours, in the ewe 2-6 hours and in the pig, queen and bitch 2-12 hours.
In the monotocous species this refers to the expulsion of the fetus; however, in polytocous species the fetal membranes are sometimes voided together with fetuses and hence this stage cannot be separated from the third stage.
The sign of onset of 2 nd stage is the appearance of abdominal contractions. It should be remembered that these abdominal contractions which cause straining are not related directly to the release of oxytocin and should not be confused with Ferguson’s reflex. The coordination between the two is due to fact that the myometrial contractions force the fetus into the pelvic inlet, which activates the pelvic reflex and stimulates straining. The straining forces the fetus against the cervix and anterior vagina, thus initiating Ferguson’s reflex,, so that the oxytocin which released causes further contractions of the myometrium.
The allantochorionic sac ruptures, as a consequence of its backward movement being restricted by its placental attachments, and gush of urine-like fluid escapes from vulva. The distended amnion together with parts of the fetus, is forced into pelvic inlet, these stimulating the pelvic reflex, which induces powerful contractions of the abdominal muscle.
40

As the intermittent straining continues, the amnion transverses the vagina and appears at the vulva as the ‘water-bag’.
Respiration of fetus, often accompanied by a cry, and then begins. The stimulus to breathing is apparently the impact of air at the nostrils.
When the mother gives birth in lateral recumbency the offspring is often born with an intact umbilical cord, and some minutes may elapse before the cord is ruptured by movement of the young animal or mother. It is important to allow this to happen naturally, for artificial and premature rupture, or ligation of the cord may deprive the newborn of a large volume of blood which would normally pass to it from the placenta.
The second stage of labour is complete when all fetuses have been delivered. It lasts from an average of 12-30 minutes in the mare to an average of 0.5-3 hours in the cow.
In the ewe and goat, average duration of 2 nd stage is 0.5-2 hours, while in the bitch, cat and pig it is 6 hours.
In the mare, cow and ewe the fetus is usually delivered anterior presentation, dorsal position and extended posture, although a small proportion of normal deliveries may occur in posterior presentation, dorsal position and extended posture.
In the polytocous bitch and sow up to 40-45% of fetuses may be normally delivered in posterior presentation.
After birth of the young, regular abdominal contractions cease. Myometrial contractions persist; in the general, they decrease in amplitude but become more frequent and less regular. These contractions important for dehiscence and expulsion of the fetal membranes. The fetal villi have shrunk, owing mainly to the sudden loss of turgidity related to the escape of blood from the fetal side of the placenta when the umbilical cord ruptured.
In the polytocous species, the dehiscence and expulsion of the fetal membranes are interspersed with fetal birth; but only the expulsion of the last afterbirth stimulates the 3 rd stage of monotocous. The 3 rd stage lasts from an average of 1-3 hours in the mare to 6-12 hours in the cow (2-3 hours in the ewe and goat). With the exception of the mare, domestic animals normally eat the afterbirth. With exception of the sow, the females of the other domestic species indulge in intensive licking of the newborn offspring. Within an hour of birth it is normal for the young of the all species to be suckling, and it is known that stimulus of suckling causes release of oxytocin, which promote the ‘letdown’ of milk as well as an augmentation of myometrial contractions.
As soon as a cow shows complete relaxation of the posterior border of the sacrosciatic ligament she should be put in a clean, well-bedded box and kept under frequent observation. If after 12 hours of restlessness there is no straining, a veterinary examination should be made to exclude primary inertia, failure of cervix to dilate and uterine torsion.
1 st stage usually lasts about 6 hours. Another feature of the cow is that occasional straining may occur during the first stage. Food is only ‘picked’; rumination is irregular; there may be ‘lowing’ or kicking at the belly. The line of demarcation between the 1 st and 2 nd stages is not clear-cut, as in the mare. The 2 nd stage is less intense but longer duration than in the mare. During the passage of the head through the vulva,
41

however, the cow generally goes down and remains recumbent until calf is born (sternal recumbency). The 2 nd stage is longer in heifers than cows. In twin births, intensive straining for the birth of the 2 nd calf begin 10 minutes after delivery of the 1 st calf.
Placental separation occurs more slowly in the cow than in the mare. The umbilical cord is shorter in the calf than in the foal, and its rupture generally occurs as it falls from vagina. Expulsion of the fetal membranes usually takes place about 6 hours later; occasionally it may be delayed to 12 hours, but when 24 hours elapse and the membranes are still in the uterus it is probable that the cause is pathological retention.
The mare seems as likely to foal by day as during the night. The best indication that the 1 st stage has begun is the onset of pathy sweating behind the elbow and about the flanks. It commences about 4 hours before the birth of the foal and increases as the stage progresses. The tail is frequency raised or held to one side. As the end of stage approaches the mare becomes very restless. This indicated by crouching, straddling of the hindlimbs, going down on the knee or sternum and rising again, glancing at the flank.
In the 2 nd stage, very soon after straining begins, the mare goes down. The umbilical cord is intact when the foal is born. It subsequently ruptures, 5-8 cm beneath the belly, as the result of movement by either the mare or the foal. In the majority of mares the membranes are expelled quickly after the birth of the foal, generally within 3 hours.
Bitch:
The imminence of parturition has been indicated by the animal preparing her bed. There is nothing characteristic about the 1 st stage, but is generally noticed that the bitch is restless, indifferent to food and inclined to pant. The onset of the 2 nd stage is indicated by straining (the animal remains in her bed in sternal recumbency).
The umbilical cord is intact at the birth of the puppy, but it is quickly torn by the mother, who bites it away. As a rule the bitch rests for a time after the birth of her first puppy (the stage most irregular). Expulsion of fetal membranes is also irregular.
A feature of parturition in the bitch is that much of the uterine discharge is dark green in colour. This is due to the breakdown of the marginal haematoma and to the escape of blood pigment, biliverdin or uteroverdin.
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The Puerperium (post-partum) is that period after the completion of parturition, including the 3 rd stage of labour, when the genital system is returning to its normal nonpregnant stage. Also it is defined as the interval between parturition and the occurrence of the first oestrous at which conception can occur (open period). The genital system does not completely return to the original pregravid state since, particularly after the first gestation, certain changes are not completely reversible.
There are four main areas of activity:
I. The tubular genital tract, especially the uterus, is shrinking and atrophying due to tissue loss, thus reversing the hypertrophy that occur in response to the stimulus of pregnancy (involution).
II. The structure of the endometrium and deeper layers of the uterine wall is restored (restoration of the endometrium).
III. There is a resumption of ovarian function in polyoestrous species and a return to cyclical activity (ovarian rebound).
IV. Bacterial contamination of the uterine lumen is elimination.
The reduction in the size of the genital tract is called involution, the greatest change occurring during the first few days after calving (oxytocin is an increase after the end of parturition, in which peak values occur 3 days post-partum and do not return to basal levels until 15 days post-partum). Uterine contractions continue for several days, although decreasing in regularity, frequency, amplitude and duration. The whole of the uterus is usually palpable per rectum by 8 and 10 days post-partum in primipara and pluripara, respectively.
There is some dispute about when uterine involution is complete. In six studies reported in dairy cattle the time taken for complete involution ranged from 26 to 52 days.
The cervix constricts rapidly post-partum; within 10-12 hours of a normal calving it becomes almost impossible to insert a hand through it into the uterus, and by 96 hours it will admit just two fingers. The cervix also undergoes atrophy and shrinkage due to the elimination of fluid and the reduction in collagen and smooth muscle.
In human gynaecology the post-partum vaginal discharge is referred to as lochia.
The presence of such a discharge in cows is normal, although sometimes individuals will mistake it for an abnormal discharge due to uterine infection and request treatment.
The lochial discharge is usually yellowish brown or reddish brown. The greatest flow of lochia occurs during the first 2-3 days; by 8 days it is reduced, and by 14-18 days post-partum it has virtually disappeared. At about 9 days it is frequently bloodstained, whilst before it ceases it become lighter in colour and almost ‘lymph-like’.
Normal lochial discharge does not have an unpleasant odour.
The lochial are derived from the remains of fetal fluids, blood from the ruptured umbilical vessels and shreds of fetal membranes, but mainly from the sloughed
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surfaces of the uterine caruncles. The slough occurs following degenerative changes and necrosis of the superficial layers.
The endometrial crypts frequently contain remnants of the chorionic villi which were detached from the rest of the allantochorion at the time of placental separation. By
10 days post-partum, most of the necrotic caruncular tissue has sloughed and undergone some degree of liquefaction and by 15 days post-partum sloughing is complete, leaving only stubs of blood vessels protruding from the exposed stratum compactum. This eventually becomes smooth by 19 days, owing to disappearance of the vessels.
Regeneration of the epithelium of the endometrium occurs immediately after parturition in those areas which were not seriously damaged and is complete in the intercarncular areas by 8 days. Complete re-epithelialisation of the caruncle, which is largely derived from centripetal growth of cell from the surrounding uterine glands, is complete from 25 days onwards, although the stage at which complete healing occurs is variable.
Anovulatory follicular waves occur periodically during pregnancy with the emergence of follicles. However, because of the prolonged period of inhibition during pregnancy, due to the continuous
–ve feedback effect of progesterone secreted by the
CL and placenta, the pituitary is refractory post-partum, as demonstrated by a lack of response to the administration of Gn-RH. As a result of the absence or low output of gonadotropins the ovary is relatively quiescent and the cow is in anoestrus phase, which may be prolonged in suckler and high-yielding cow. However, during this postpartum phase the ovaries frequently contain numerous large anovulatory follicles which become atretic.
In the immediate postpartum period both oestradiol and progesterone are low.
The anterior pituitary is capable of releasing FSH during the first few days post-partum, so that with sporadic release of endogenous Gn-RH there is a gradual and sustained rise in plasma FSH. After about 7-10 days, this is sufficient to result in the emergence of the first follicular wave. The ability of the pituitary to release LH is much slower, for although the early release of Gn-RH cause some rise in LH, it quickly returns to basal levels. If standard doses of Gn-RH are given at 10 and 16 days post-partum in milked cows, then LH rises. Further evidence of the refractory state of the hypothalamus and pituitary gland has been demonstrated by the failure of a 1 mg dose of oestradiol benzoate to elicit a surge of LH at 0-5 days post-partum; a response was obtained by
10 days which was increased by 25 days. A dominant follicle may emerge from the first follicular wave, but ovulation will occur only if the dominant follicle produces enough oestradiol to stimulate adequate LH secretion in the form of one pulse per hour; if this occurs, then there is a first ovulation at 21 days in dairy cattle and 31 days in beef cattle. The majority of ovulations post-partum occurs in the ovary contro-lateral to the previously gravid horn. The availability of the milk progesterone assay has enabled the onset of cyclical activity to be determined by the presence of elevated progesterone concentrations.
Usually oestrous observed for the first time at about 35 days post-partum in dairy cows (dairy cow are bred after 50 days post-partum). The conception rate is lower at
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first post-partum oestrous than at subsequent oestrous period (the calving to conception interval 85 days).
The adrenal cortex plays an important role in influencing the return to oestrus post-partum. ACTH and corticosteroids administration suppress the secretion of LH.
Stimulation of the teat and milk removal cause arises in glucocorticoids. Suckling which is known to delay the return of cyclical ovarian activity.
At calving, and immediately post-partum, the vulva is relaxed and the cervix is dilated thus allowing bacteria to gain entry into the vagina, and thereafter the uterus.
Awide rang of bacteria may be isolated from the uterine lumen ( E.coli, Staphylococcus,
Streptococcus ). In all studies there is a decrease with time in the percentage of uteri from which bacteria are isolated.
Blood, cell debris and sloughed caruncular tissue provide an ideal medium for bacterial growth. The main mechanism involved in the elimination of bacteria is phagocytosis by migrating leucocytes; however, persistence of uterine contractions, sloughing of caruncular tissue and uterine secretions all assist in the physical expulsion of the bacteria. Early return to cyclical activity is probably important since the oestrogen dominated uterus is more resistant to infection (early return may be disadvantages, if bacteria are not eliminated at first oestrous then cow enter the first luteal phase
{progesterone is dominant}).
1) Age, most observers have found that involution is more rapid in primipara than pluripara.
2) Season of year. If there is any influence, involution is probably most rapid in spring and summer.
3) Suckling and milking. It may be a breed influence on the effect of the time to return of cyclical ovarian activity.
4) Climate. Heat stress can accelerate and inhibit the speed of involution.
5) Periparturient abnormalities. Dystocia, retained placenta, hypocalcaemia, ketosis, twin calves and metritis delay involution.
6) Delayed return to cyclical ovarian activity. This inhibits involution.
Retained fetal membranes and metritis inhibit healing (regeneration), whilst ovarian rebound to cyclical activity may have an influence.
 Periparturient abnormalities delay ovarian rebound.
 Milk yield. There is much contradictory evidence on the influence of current milk yield.
 Nutrition. In both beef suckler and dairy cows inadequate feeding (energy), during the dry period and after calving inhibit ovarian rebound.

Breed. There is a longer delay in beef compared with dairy cows.
 Parity. Ovarian rebound is delay in primipara compared with pluripara.
 Season of the year. By experimentally subjecting heifer to continuous darkness, which inhibit the ovarian rebound.
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
Climate. Cows in tropical climates show a delay compared with those in temperate zones.
 Suckling intensity and milking frequency. The intensity of suckling and greater the frequency of milking, as well as calf presence, the longer the period of a cyclicity.
i. Magnitude of bacterial contamination. A massive bacterial flora may overwhelm natural defense mechanisms. ii. Nature of bacterial flora. Many obligate Gram-negative anaerobic, such as
Fusobacterium necrophorum , exhibit synergy with Gram-positive aerobic contaminants. iii. Delayed uterine involution. iv. Retained placenta. v. Calving trauma to the uterus. vi. Return of cyclical ovarian activity.
The Puerperium is shorter in the mare than in the cow, with rapid involution and good conception rates at the first post-partum oestrus.
Lochia discharge is relatively slight in most mares and usually ceases by 24-48 hours after foaling. The uterine horns shrink rapidly, reaching their pregravid size by day
32.
The cervix remains slightly dilated until after the first oestrus. Ovarian rebound is rapid, the foal heat occurring 5-12 days post-partum. Evidence of follicular activity can be determined as early as the second day. Although conception rates at this first oestrus are lower than at other times, a large number of mares are fertile. The endometrium was fully restored by 13-25 days post-partum.
As in the cow bacterial contamination of uterus from the environment is a frequent occurrence, the species most frequently isolated being B-haemolytic streptococci and coliforms.
These organisms are usually eliminated at the foal heat; if not, although they may increase during the subsequent dioestrus, they usually disappear at second post-partum oestrus.
Retained fetal membranes delays involution, whilst exercise is said to hasten it.
The Puerperium in both these species is very similar to that in the cow. The main difference is that, since they are both seasonal breeders.
Parturition is followed by a period of anoestrus. Involution is complete by 20-25 days (about 28 days in suckling ewes).
The restoration of endometrium is complete by 28 days. The quantity of lochia voided is variable. In temperate climates ewes normally become anoestrus after lambing there are numerous reports of ovarian activity occurring within a few days to 2 weeks post-partum. Follicular growth is common but ovulation is unusual and when it does occur it is usually associated with a silent heat.
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Since the bitch is monocyclic, parturition is followed by anoestrus, the onset of the next heat being unpredictable.
The rate of involution is similar to that of other species and the uterine horns are restored to their pregravid size
by 4 weeks. The lochial discharge immediately postpartum is very noticeable because of it is green colour due to the presence of uteroverdin.
After pregnancy and normal parturition, the time taken for regeneration of the endometrium is about 2 weeks longer and the whole process of regeneration has ended by 12 weeks.
The sudden change at birth from the constant, controlled, cosseted environment of the uterus to the variable and frequently stressful free-living environment demands great adaptability from the newborn.
At birth, and for a variable period of time afterwards, a number of important events must occur, and it is responsibility of the person involved in supervising or assisting at the parturition to assist newborn so that the likelihood of survival is enhanced.
If parturition occurs normally then spontaneous respiratory movements will occur within 60 seconds of expulsion.
There are a number of the factors that are responsible for the initiation spontaneous respiration. During the birth process, PO
2
and blood pH are falling and
PCO
2
is rising due to the start of placental separation and occlusion of the umbilicus, thus restricting gaseous exchange. These changes have been shown in the lamb to stimulate chemo-receptors in carotid sinus. Tactile and thermal stimuli are also important, for it has been shown that if the face of the fetal lamb is cooled there is stimulation of respiratory movement, whilst the licking and nuzzling of the dam probably provides some stimulus.
The first respiratory movement is usually a deep. Forceful inspiration which necessary to force air into the lungs.
Once birth is complete, it is important first to ensure that the upper respiratory tract is cleared of fluid, mucus and attached fetal membranes. This can be done with aid of fingers or, preferably with elevation of the rear of the calf, particularly by suspension from the hindlimbs, result in the escape of copious quantities of fluid. Brisk rubbing of the chest with straw or towels frequently provides the necessary tactile stimulus respiration, whilst a protable oxygen cylinder and resuscitator are useful pieces of equipment to have available.
In most cases, if resuscitation does not result in spontaneous respiration in 2 or 3 minutes it is unlikely that the newborn will survive.
The fetus at the time of a normal birth will usually have a mild metabolic and respiratory acidosis; in the case of the former, this is corrected within a few hours, whereas the latter may last up to 48 hours. Dystocia is likely to cause a severe respiratory and metabolic acidosis. Severe acidosis will have an adverse effect on both respiratory and cardiac function, and in the case of the calf will reduce vigour, the suck
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reflex resulting in reduced colostrums intake and impaired passive immunity. One of the simplest methods of assessing the degree of acidosis is to determine the time to the calf assuming sternal recumbency. Following a normal calving this was 4.0+/- 2.2 minutes, whereas following traction it was 9.0 +/- 3.3 minutes; a time greater than the 15 minutes was found to have a high predictive value for death of the calf. The presence of good muscle tone and a pedal reflex are indicators of a well-oxygenated calf with fairly normal acid-base status. The presence of scleral and conjunctival hemorrhage is indicative of hypoxia and acidosis and carries a poor prognosis.
A calf requiring resuscitation is likely to be suffering from both a metabolic (low plasma bicarbonate concentration) and respiratory (high PCO
2
) acidosis. The PCO
2
will be reducing with improved alveolar gas exchange and tissue perfusion; however, the metabolic acidosis may be treated with Na HCO
3.
The origin of the metabolic acidosis is due to primarily to the production of lactic acid by tissues.
Manipulative obstetrical procedures, particularly traction, can result in injury to the newborn.
In the period immediately following birth, the newborn has to adjust to an environment whose temperature may fluctuate widely and which is also usually below that of the uterus.
Following birth, the body temperature of the newborn falls quickly from that of the dam before it eventually recovers; the degree of decline and speed of recovery vary from species to species and with the environmental temperature. In the foal and calf, the fall is transient; in the lamb recovery occurs within a few hours, whilst in the kitten and puppy the period before the temperature recovers to approximately that of birth is
7-9 days.
In the newborn, thermoregulation controlled in two ways. Firstly, the metabolic rate is increased to three times the fetal rate soon after birth. The increased rate is dependent upon adequate substrate, and since glycogen and adipose tissue reserves are low in the newborn it is very important that immediate and adequate food is available. However, the metabolic rate can increase only to a certain level, known as summit metabolism; if this is insufficient to maintain body temperature then hypothermia occurs. The second method of thermoregulation is to reduce heat loss. The body surface is wet and thus heat is lost due to evaporation.
Thermoregulation in the newborn can be improved in a number of ways: o Ensure that there is adequate food intake. o Arrange for birth to occur in at least a thermally neutral environment. (the newborn puppy should be placed in an environmental temperature of 30-33 C for the first 24 hours). o Reduce heat loss by ensuring that the coat is adequately and quickly dried.
Provided that birth occurs in a clean environment with adequate hygiene it should not be necessary to handle the umbilicus. However, if there is outbreak of ‘navel ill’ it may be necessary to introduce some prophylactic measures. The navel should be carefully cleanest with an antiseptic solution, dried and treated with antibiotic spray or dressing.
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When there is a high neonatal mortality rate in the absence of dystocia, the possibility of deficiencies should be investigated (selenium and iodine), as well as the possibility of the presence of infectious agents (stillbirth and weakly offspring).
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Family Camelidae
Genus Camelus (dromedarius & Bactrianus)
Lama (galama, pacos, guanaco & vicugna)
The dromedary, or Arabian camel, (one-humped) ( Camelus dromedarius) which gets its name from the Greek word meaning runnin.
It is economically important in northern
Africa, particularly Sudan and Somalia, as well as in the Arabian States.
The two- humped (Bactrian) camel (Camelus Bactrianus) is bred manly in Russia and
Central Asia (it's named after the area of Bactriana in Central Asia).
Female camels reach puberty at 3 years of age, but are not usually mated until there are 4-5 years old. Male camels are sexually active at 3 years of age, but are not usually used at stud until they are 5-6 years old.
When sexually mature, in most countries male camel show an annual rut associated with a decline in day length and, roughly, from November to July, after which they are sexually quiescent.
During the rut, the temperament changes towards an aggressive, less tractable nature, including a predisposition to fight others males and an inclination to bite other animals, as well as human beings. Rutting males, when urinating they stand with hind legs spread a part and spray the urine around their hindquarters by vigorous movements of the tail. A prominent feature of rutting behavior is frothing at the mouth and loud vocal gurgling, accompanied by the protrusion of the markedly oedematous and mobile soft palate. An additional characteristic is a profuse secretion of fetid fluid from the poll glands.
The uterus is bicornuate, with a well-developed uterine body, from which the two horns diverge and taper cranially to give a combined uterine shape intermediate between that of the letters Y and T. The left horn (length 8-12 cm) is longer than the right (length 6-8 cm), even in the fetus. The oviducts of the camelidae, as in other mammalian species, play an important role in the storage of semen (sperm reservoir), fertilization and early embryo development.
In camels the ovaries are suspended by the mesovarium at the level of the sixth or between the 6th and 7th lumbar vertebra. The position of the ovary is subject to great variations depending on the physiological state - especially if the animal is pregnant, when it becomes more ventral and is pulled forward with advancing stages of pregnancy. The size and shape of the ovaries vary with their content of follicles and corpora lutea. Follicular activity is dominated by 4 types of follicles: small growing follicles, mature pre-ovulatory follicles, regressing follicles, and large anovulatory follicles. The corpus luteum forms after ovulation, which occurs 24 - 48 hour after mating.
Regression of the corpus luteum occurs between the 10th and 12th day following a sterile mating or just before parturition in the pregnant camel. The anoestrous ovary is roughly oval and thin.
The left and right ovaries function equally and ovulate alternately. Because ovulation is induced by coitus the length of oestrus depends on whether and when mating occurs. In the absence of a male, oestrus may last about 2 weeks. Twin
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ovulation occurs in 14% of mating. The signs of oestrous are restlessness, vulval swelling, bleating and mucous vaginal discharge. The female camel urinates and moves its tail up and down when hearing the gurgling voice of the rutting male.
The gestation period being 370-400 days. Despite the equal function of right and left ovaries, 99% of pregnancies are in the left horn (and uterine body). Embryonic migration from right horn to left is frequent and always seems to occur when the right ovary ovulates and left ovary does not. The camel placenta is diffuse, like mares.
Ablation of the CLbearing ovary or administration of PGF2α or its analogue causes abortion or premature parturition at all stages of pregnancy, thus it would seem likely that the placenta either fails to secrete progesterone at all, or it does so in amounts insufficient to maintain pregnancy without help from the ovaries.
The allantoic fluid volume is about 8 liters at a fetal body length of 101-107 cm.
Trans-rectal palpation: The technique of palpation of the genital organs is the same as for the cow, but the female camel needs to be restrained in sitting position. In connection with early diagnosis, it is important to remember 4 features of camel reproduction:
 Large corpora lutea are only present in pregnancy.
 99% of pregnancies are in the left horn.

The empty (or early pregnant) right horn is congenitally shorter than the left.
 The amount of fetal fluid at all stages of camel pregnancy is less than in the cow.
The presence of a palpable corpus luteum in one or both ovaries is very strong indication of pregnancy.
Tow weeks post mating and on, the early pregnant camel exhibits a characteristic feature of steady rising with curling of the tail, called tashwee l (Tail
"cocking"). If the male is exposed to her, she performs this feature and usually the male does not force her sitting. Some non-pregnant camels may show this feature if male is strange or they do not fancy.
At the 40 days a slight swelling at the base of the left uterine horn becomes detectable and the ovaries are easily felt with a large CL.
At the end of the 3 rd month the pregnant left horn is clearly larger and softer and in front of the non-pregnant right horn.
At the 4 th__ 5 th month the uterus is just in front of the pelvic brim but most of it is palpable. The right ovary is easily detected, but the left ovary is hardly detected.
During 5 th __ 6 th month the uterus falls within the abdominal cavity but, the dorsal surfaces it can be palpated. The right ovary can be reached.
From the 6 th __ 8 th month individual parts of the fetus, namely head and legs, can be identified. Thrilling of the left middle uterine artery is weak.
At 9 th __ 11 th the fetus can be balloted and the right ovary cannot be palpated.
Thrilling of the left middle uterine artery is strong. In the 11 th the vulva is slightly swollen and hypertrophy of the udder is first noticed.
In the 13 th month relaxation of the pelvic ligaments is pronounced. The fetus can be balloted from both flanks.
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Diagnosis by trans-rectal B-mode real time ultrasound scanning can be made consistently at 17-18 days after mating. The embryos are first visible at about 20 days and the heartbeat becomes discernible between days 22 - 25.
 The measurement of progesterone concentration in peripheral blood can be invaluable in the early detection of pregnancy. If a blood sample is taken between days 12 - 15 and the value is still high (i.e. > 1.0 ng/ml) this would indicate that the camel is possibly pregnant. If the value has dropped to < 1.0 ng/ml then the camel is definitely not pregnant.

Serum oestradiol-
17β concentrations show a first definite increase around day
20 - 25 after ovulation and continue to rise until concentrations of around 100 pg/ml are reached between days 60 – 70. This increase in rate of secretion of oestrogen could be ovarian or placental in origin. In dromedaries the oestrogen sulphate concentrations show two definite peaks of about 10 ng/ml in early gestation. The first peak occurs around day 26 and the second around day 70.
*2-4 weeks prior to calving, the camel shows the following signs:
1) Relaxation of the sacroisciatic ligament causing grooving on each side of the base of the tail.
2) Obvious abdominal distension.
3) Hypertrophy of the udder.
4) Oedematous vulva.
5) The external cervical os is dilated 1-2 fingers, but the cervical canal is completely closed.
*1-2 days prior to calving, the camel shows the following signs:
 Body temperature drops 0.5 to 1.0 0 C.
 Segregation from the herd.

Reduced appetite.
 Increased frequency of urination.
 Signs of colic and discomfort, such as grinding of teeth, lip smacking, biting other animals and objects, standing and laying down, shaking the head, looking to the flank, and raising the tail up and down.
 Udder and teats distended with colostrums.
 Whitish vaginal discharges from the liquefied cervical seal.
Most camel parturient in winter and spring. First stage of labour, which lasts about 2-
7 hours. Normally, the duration of the second stage of labour is about half an hour.
The fetal membranes may be completely expelled soon after the fetus, more commonly, within 1 hour.
At the end of parturition, the vulva is very oedematous and remains that way for about 2 to 3 weeks. In the dromedary the size of the vulva returns to prepartum size about 16 to 42 days after parturtion. Uterine involution is rapid in the female camelidae due to the diffuse nature of the placentation in this species, which does not cause a great loss of uterine tissue. This process is completed in 94% of the cases between 30 -
50 days.
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