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1. To label and identify male and female
reproductive anatomy
2. To describe the structures and
functions of male and female
reproductive anatomy
3. To understand the animal reproductive
process, including the estrous cycle,
ovulation, gestation and parturition
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Reproduction is closely
related to the action of
several hormones
called
• Produced by pituitary gland
 follicle stimulating hormone (FSH)
 luteinizing hormone (LH)
• Release is controlled by gonadotropic releasing
hormones or (GnRH) produced by the brain
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• FSH
 stimulates follicle development
 produces estrogen in the ovary
• FSH and LH combined
 prepares the follicle
for ovulation
• LH
 causes ovulation
• Progesterone
 maintains pregnancy
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changes in the hormones secreted by the
ovary and pituitary gland during estrous cycle
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• Are paired, oval shaped organs
• Produce sperm cells
• Produce testosterone (male sex
hormone)
causes development of
secondary sex
characteristics and sex
behavior
produce
testosterone
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• Have seminiferous tubules
coil throughout testes
site of sperm
production and
• Have interstitial cells (Leydig)maturation
lie between seminiferous tubules
• Protects and supports the testes
• Protects sperm
• Regulates temperature
• Lie within the wall of the scrotum
• Raise or lower the testes to
maintain constant testicular
temperature
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Temperature should be 4 – 6°
below body temperature for
normal sperm development
• Is a coiled tube, attached to each
testis
• Is responsible for further
maturation, storage and
transportation of sperm cells
• Transports sperm from the epididymis
to the urethra
Because location of testes vary among livestock
species, location of the epididymis varies
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carries urine from
the bladder
carries sperm and
fluid from
accessory sex
organs
• Provide 95-98% of total ejaculate
• Include:
 seminal vesicles (vesicular glands)
sperm plus the
added accessory
fluids
 secrete fluids providing energy and buffers to
sperm
 prostate gland
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 secretes a thick, milky fluid high in inorganic
ions
 bulbourethral glands (Cowper’s glands)
 secrete fluids before ejaculation to clean
urethra
• Is a passageway for semen and urine
• Deposits semen in the female
reproductive tract
Primarily composed of connective
tissue and depends little on blood for
erections
Supplied with blood
vessels
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• Has a s-shaped curve
• Allows for penis retraction
• Stallions and humans do not have
sigmoid flexure
• Extends the penis upon sexual excitement
• Protects penis from injury and infection
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Both the male and female poultry reproductive systems
vary compared to other domestic animal species
How Male Anatomy Differs
• Testes are located within the abdominal cavity, produce
sperm and seminal fluid
• Papillae emit semen and are considered the copulatory
organs of the rooster
• Cloaca serves as passageway for urinary, digestive and
reproductive tracts
• Androgen is the male sex hormone produced by the
testes
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• Produce eggs
• Produce female hormones
 estrogen
 progesterone
maintains uterine lining during
pregnancy
keeps estrus from occurring
causes mammary system to develop
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stimulates the development
of secondary sex organs
and sexual receptivity
• Follicle
 blister-like mass
on the surface of
an ovary
containing a
developing ovum
(egg)
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follicle
ovum
• Follicle
 functions
hold the growing ovum
produce and store estrogen
 at ovulation, the follicle ruptures,
expels the ovum, enters the
infundibulum and awaits
fertilization in the oviduct
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secreted from follicle
to signal the
remainder of the
reproductive tract to
prepare for ovulation
• Corpus Luteum (CL)
 forms after ovum is
released from the follicle
 function
produce progesterone
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• Transport eggs from ovary to
uterus
• Are site of fertilization
• Pick eggs at ovulation and direct
them into the body of the oviducts
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process of
discharging an ovum
from the mature
follicle of an ovary
• Consists of horns and a body
− uterine horns
− uterine body
• Is site of embryonic growth
• Is site of placental and fetal
development
• Varies in shape among species
A sow has a very long uterus and a mare has a very
short uterus
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• Is receptacle for the penis during
copulation
• Serves as birth canal at
parturition
• Is separated from uterus by the
cervix
major barrier and protection of the uterus and
developing fetus
• Is passageway for expelling liquid
wastes
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• Is external portion of the female
reproductive tract
• Serves to:
 protect internal system from
infection
 initially receive the penis at
copulation
 act as passageway for urine
• Sensory erectile organ
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Both the male and female poultry reproductive systems
vary compared to other domestic animal species
How Female Anatomy Differs
• Mature female poultry have only one functional ovary
and oviduct (left ovary)
• Ova produced in ovary are developed into egg yolks
• Oviduct has five parts
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1.
2.
3.
4.
5.
funnel: receives yolks from ovary and stores sperm cells
magnum: secretes thick white of egg
isthmus: adds two shell membranes
uterus: adds thin white and outer shell
vent: opening where egg is laid
• Reoccurs and repeats itself as long as the female is
not pregnant
• Is controlled by hormones preparing the
reproductive tract for ovulation and pregnancy
• Includes two phases
1. follicular phase
2. luteal phase
short phase;
period from
regression of the
CL to ovulation
long phase; period from
ovulation to CL regression
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• Is categorized by frequency of occurrence
throughout the year
 seasonally polyestrus— cycles occur only during
certain times of the year
cycle when day length increases
cycle when day length decreases
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• Is categorized by frequency of occurrence
throughout the year
 monoestrus— one cycle per year; estrus periods
last for several days
Example: dogs
 polyestrus— uniform, regularly occurring estrous
cycles throughout the year
Example: cattle and swine
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• Proestrus
 begins after CL regression and ends at the onset of
estrus, period of follicle growth
• Estrus
 period of sexual receptivity; sometimes referred to as
“heat”
• Metestrus
 early postovulatory period; CL begins to develop
• Diestrus
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 begins approximately four days after ovulation and
ends with the regression of the CL
• Before ovulation
release of egg cell
from ovary;
occurs near the end
of estrus period
 egg cell is contained in follicle
• During ovulation
 follicle breaks, releases the egg into the oviduct
 if sperm is present, egg may become fertilized
• After ovulation
 CL forms on ovary and releases progesterone
If egg is not fertilized, CL does not grow, allowing another follicle to
grow and another estrus period to occur
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• Functions of progesterone
 prepares uterus for implantation of the embryo
 stops other eggs from forming
 maintains pregnant condition
 develops mammary glands which produce milk to
feed young after they are born
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time in which female
is pregnant
• Fetus develops in uterus and is surrounded by a
watery membrane
• Blood vessels in umbilical cord supply nutrients,
oxygen and carry off waste products
• Placenta is connected to the fetus by the umbilical
cord and lies along wall of uterus
• Food, oxygen and wastes are exchanged between
mother and fetus through the placenta
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process of giving
birth
• Near the end of the gestation period, the CL
decreases its production of progesterone
• Increased estrogen levels, cause uterine muscles to
contract, beginning the birthing process
• Sequential set of events:
1. cervix widens (dilates)
2. pelvic region relaxes
3. uterus begins contractions
4. fetus passes through the cervix, pelvic region and finally
the vagina
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COW
Estrus
10 – 26 hrs. (18 hr avg.)
Estrous Cycle 18 – 24 days (21 day avg.)
Ovulation
4 – 16 hrs. post estrus
Gestation
283 days
EWE
SOW
Estrus
Estrus
20 – 42 hrs. (30 hr avg.)
Estrous Cycle 15 – 18 days (17 day avg.)
Ovulation
12– 18 hrs. estrus onset
Gestation
150 days
1 – 4 days (2 day avg.)
Estrous Cycle 16 – 25 days (21 day avg.)
Ovulation
31 Gestation
16 – 48 hrs. estrus onset
114 days (3 months, 3 weeks, 3 days)
GOAT
Estrus
2 – 3 days (2.5 day avg.)
Estrous Cycle 15 – 24 days (21 day avg.)
Ovulation
Near end of estrus
Gestation
151 days
POULTRY
MARE
Estrus
Estrus
Estrous Cycle 15 – 18 days (17 day avg.)
Ovulation
12– 18 hrs. estrus onset
Gestation
150 days
4 – 9 days (5 day avg.)
Estrous Cycle 15 – 24 days (21 day avg.)
Ovulation
32 Gestation
1 – 2 days before end of estrus
336 days
20 – 42 hrs. (30 hr avg.)
1. Which part of the male reproductive anatomy
is responsible for further maturation, storage
and transportation of sperm cells?
2. What female hormone prepares the uterus to
maintain implantation of the embryo?
3. What term is used for the process of giving
birth?
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4. Which specie discussed has the longest
gestation length?
5. Gonadotropins are produced by which
gland?
6. What male hormone is responsible for the
development of secondary sex
characteristics?
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7. Name two functions of the scrotum?
8. Accessory glands provide what percent of the
total ejaculate?
9. Which part of the female reproductive tract is
the site of fertilization?
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10. Which part of the female anatomy serves as
the birth canal at parturition?
11. Name the two phases of the estrous cycle?
12. Animals cycling when day length increases
are considered to be what type of breeders?
36
Pond, Kevin R., and Wilson G. Pond. Introduction to Animal Science. John
Wiley & Sons, Inc., 2000.
Reece, William O., Physiology of Domestic Animals. College of Veterinary
Medicine, Iowa State University. Williams & Wilkins, 1997.
Sam Prien, Ph.D.
Texas Tech University
Health Sciences Center
Production Coordinator
Clayton Franklin
Executive Producer
G.W. Davis
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Production Manager
Geoff Scott
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