Animal Reproduction
Dreamer
Objectives
A.
B.
C.
D.
E.
Define common terms associated with reproduction
Label reproductive organs and describe their function
Compare estrous cycles and gestation of different species
List stages of development from conception to parturition
Describe signs of parturition and dystocia
F. Describe the purpose and benefits of reproductive technologies
A. Define common terms associated with reproduction
Pregnancy -- carrying a fetus
Fertilization -- the union of the EGG and
SPERM nuclei
Conception - occurrence of fertilization
Ovulation - release of an ovule from the
female.
Gestation - the time from fertilization or
conception of a female until she gives birth
A. Define common terms associated with reproduction
Ovaries - FEMALE reproductive gland in
which eggs are formed and hormones are
produced.
Egg or Ovule- Female Reproductive Cell
Testes - MALE reproductive gland that
produces sperm and testosterone.
Sperm- Male Reproductive Cell
Semen- Fluid that carries sperm
B. Label reproductive organs and describe their function
Female Reproductive Organs
B. Label reproductive organs and describe their function
Function of Female
Reproductive Organs
Vulva -opening of reproductive tract
Vagina - channel for birth and copulation
Cervix - divides vagina and uterus
Uterus - provides nourishment for fetus
Horns of Uterus - where fetus grows
Fallopian Tube - where fertilization occurs
Ovaries - produces eggs and hormones
B. Label reproductive organs and describe their function
Male Reproductive Organs
B. Label reproductive organs and describe their function
Function of Male
Reproductive Organs
Testes - produce sperm and testosterone
Epididymis - collects and stores sperm
Vas deferens - transports sperm
Penis - places sperm in female
 Cowper's Gland
 Prostate Gland
 Seminal Vesicle
produce semen
Scrotum - protects testes & maintains temp.
Sheath - opening of reproductive tract
C. Compare estrous cycles and gestation of different species
Estrous Cycle-Time between periods of
estrus, or “heat”
-often influenced by of hours of light in the day
Species
Estrous
Cycle
Length of
Estrus
(heat)
Ovulation
Cow
21
12-18 hours
10-14 hours after estrus
Mare
22
6-8 days
1-2 days before estrus ends
Doe (goat)
21
30-40 hours
At end of estrus
Doe (rabbit) Constant
Constant
8-10 hours after mating
Sow
20-21
40-72 hours
Mid estrus
Ewe
17
24-36 hours
Late estrus
Dog
-
9 days
1-2 days after estrus begins
Cat
14-21
5 days
24 after mating
C. Compare estrous cycles and gestation of different species
Estrous Cycle
1. Estrus- also known as “heat.” The
period of time when female is
receptive to male and conception
can occur.
-Hormone: Estrogen
4-Proestrus
2. Metestrus- Follows estrus.
Usually when ovulation occurs.
-Hormone: LH (leutenizing hormone)
3. Diestrus- Period of cycle when
system assumes pregnancy.
1-Estrus
-Hormone: Progesterone
4.
Proestrus- If not pregnant,
prepares body for Estrus
-Progesterone drops
3- Diestrus
2-Metestrus
C. Compare estrous cycles and gestation of different species
Gestation
Length of PREGNANCY.
Begins with FERTILIZATION and ends
with PARTURITION (BIRTH).
All animals have different gestation
lengths. Usually the LARGER the animal,
the LONGER the gestation.
C. Compare estrous cycles and gestation of different species
Cattle
Gestation- 283 days or 9 Months
Breeding Season- Dairy: Year round
Beef: Summer-fall
Cycle: Year round, every 21 days
C. Compare estrous cycles and gestation of different species
Sheep & Goats
 Gestation: 145-150 days or 5 months
Breeding Season- Fall (dairy goats year round)
Cycle: Late fall when days get short
“Short day breeders”
C. Compare estrous cycles and gestation of different species
Swine
Gestation- 115 days
OR 3 months, 3 weeks, 3 days
 Breeding Season- year round
 Cycle- Year round every 21 days
C. Compare estrous cycles and gestation of different species
Horses
Gestation- 336 days or 11 months
Breeding Season- Spring
 Cycle- Spring/Summer when days are long
“Long day breeders”
C. Compare estrous cycles and gestation of different species
Rabbits
Gestation- 30 days
Breeding Season- Year round
 Cycle- Constantly, year round
C. Compare estrous cycles and gestation of different species
Chickens
Gestation- 21 days
Breeding Season- Year round or spring
Cycle- Year round, but more productive
when days are long
D. List stages of development from conception
to parturition
3 periods of development from pregnancy
to birth
- Zygote- A cell formed by union of egg
and sperm
- Embryo- Organism in early stages of
development
- Fetus- Unborn animal in late stages of
development
D. List stages of development from conception to parturition
Stages of Development
Fetus
Embryo
Newborn Calf
Zygote
E. Describe signs of parturition and dystocia
Parturition- The act of giving birth
Signs:
-Milk develops in udder
-Abdomen drops
-Nesting
-Restlessness or pacing
-Abdomen muscles contract (watch for young!)
E. Describe signs of parturition and dystocia
Stages of Parturition
Stage 1 - Preparatory Stage
(Labor)
Stage 2 – Delivery of Fetus
Stage 3 - Expulsion of the
placenta
Stage 4 - Period of Rest
Video
E. Describe signs of parturition and dystocia
Dystocia- Difficulty giving birth
Causes:
-Presentation
-Oversized fetus
-Multiple births
-Exhaustion, uterine contractions stop
Solutions: Call vet or assist yourself
-Cesarean Section (c-section)
-Assist manually
E. Describe signs of parturition and dystocia
Presentation
(position the fetus is coming out)
Normal
Breech
Head Back
Upside down &
Backward
Leg Back
F. Describe the purpose and benefits of
reproductive technologies
Reproductive Technology
Any method of reproduction that is
different from natural methods
F. Describe the purpose and benefits of reproductive technologies
1-Artificial Insemination
placing sperm into the female
reproductive tract by means
other than natural mating
F. Describe the purpose and benefits of reproductive technologies
Steps of Artificial
Insemination
1- Collect & Store Semen
-Collect Semen
-Extend sample and place in straws
-Store in liquid nitrogen
F. Describe the purpose and benefits of reproductive technologies
Steps of Artificial
Insemination
2- Inject semen into female reproductive
tract at the right stage of estrus
F. Describe the purpose and benefits of reproductive technologies
Advantages of A.I.
Wider selection and use of outstanding
sires
Example - one bull if used for natural
reproduction could have 30-40 calves per
year for 8-9 years = 240 - 360 calves; one
bull used to A.I. Could produce over 100,000
calves.
F. Describe the purpose and benefits of reproductive technologies
Advantages of A.I.
Rapid Genetic and herd improvement
Can overcome physical barriers to
mating
example - behavior or injuries
Danger of the bull is eliminated
Elimination of cost of purchasing and
keeping a bull
F. Describe the purpose and benefits of reproductive technologies
Disadvantages of A.I.
Skilled technicians are required
Closer supervision of female is
required
F. Describe the purpose and benefits of reproductive technologies
Synchronized Ovulation
the process of causing a herd of cows or
heifers to come into estrus and ovulate at
or near the same time
Methods:
-Prostoglandin F2a -- hormone which can be
used to synchronize estrus
Examples: Brand Names -- Lutalyse, Esrumate, Bovilene,
Synchro-Mate B
F. Describe the purpose and benefits of reproductive technologies
Embryo Transfer
The transfer of FERTILIZED egg(s) from
a DONOR female to one or more
RECIPIENT females
F. Describe the purpose and benefits of reproductive technologies
“Scamper”
•First Million Dollar Cowgirl, 1990
•Most Professional Rodeo
•11 Consecutive Barrel Racing Championships
•First WPRA Member listed in Guinness Book
of World Records, 1987&92
•WPRA Record Most NFR Qualifications, 19
(consecutive)
•All won on her beloved horse, “Scamper”
Few people involved in the horse industry haven't heard the legendary story of Gill's Bay Boy, affectionately known
as "Scamper," and his jockey and partner Charmayne James who together set the world of pro rodeo on fire beginning
in 1984. Scamper came to Charmayne as an untrained young prospect with a renegade reputation and was best known
in those days for bucking off ranch cowboys. At the tender age of 14 Charmayne did the inconceivable. She trained
and cared for Scamper and in the process revealed the limitless potential concealed beneath his common exterior.
With dedication and careful attention to conditioning Charmayne produced an equine legend whose historical
achievements will not soon if ever be duplicated. The young horsewoman was herself a prodigy honing her training
skills to take Scamper from the anonymity of the feedlot to the spotlight of the rodeo arena. The two inevitably raced
to unforgettable performances in arenas from Houston to Las Vegas and most everywhere in between along the way.
Scamper and Charmayne's list of accolades together are endless and include Scamper's induction into the PRCA Hall
of Fame, as well as Charmayne's place in the National Cowgirl Hall of Fame, National Cowboy Hall of Fame, and
Texas Cowboy Hall of Fame, among others.
F. Describe the purpose and benefits of reproductive technologies
Cloning
The production of an exact GENETIC
COPY of an organism
Is Cloning a NEW technology??
F. Describe the purpose and benefits of reproductive technologies
Cloning
www.breedtoclayton.com
F. Describe the purpose and benefits of reproductive technologies
Mule: Cloned at USU
F. Describe the purpose and benefits of reproductive technologies
Sheep: Cloned in 1996 “Dolly”
F. Describe the purpose and benefits of reproductive technologies
Clone a Ding Dong
Carefully hold the ding dong
and remove the filling with
the straw
Suck the nucleus (cream)
out of the donor cell and
insert it into the egg cell
(ding dong)
Don’t break it open.
Damaged cells won’t survive!
F. Describe the purpose and benefits of reproductive technologies
Clone a Ding Dong
Ding Dong= Donor Cell
Ding Dong filling=
Cup= cell of animal you
want cloned
Colored Cream= Nucleus of
animal to be cloned (genetic
info)
Straw=Pipette
F. Describe the purpose and benefits of reproductive technologies
Clone a Ding Dong
What does the ding dong
represent?
What does the cup represent?
Why do we have to take the
nucleus out of the ding dong
first?
What will the ding dong grow up
to be? ( a cup or a ding dong? )
why?
Bell Quiz
What is the difference between “estrous”
and “estrus?”
How long is the gestation of a sheep or
goat?
How does daylight effect the estrous cycle
of some animals?
What is unique about a rabbit’s
reproductive system that allows them to
reproduce quickly?
Bell Quiz
What is the definition of dystocia?
What does the word, parturition mean?
Name 3 signs that could indicate that an
animal will give birth soon.
What purpose does the placenta serve in
the growth and development of a fetus?
What is a zygote?
Bell Quiz
What reproductive technology is used to
enhance the # of offspring a superior
SIRE can have
What reproductive technology is used to
enhance the # of offspring a superior
DAM can have
What are 2 benefits of Artificial
insemination?
What are 2 disadvantages of Artificial
Insemination?
A
B
C
D
E
Label the following organs:
A
B
D
E
C
F