Animal Reproduction
The process by which offspring
are reproduced.
The Basics
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Insemination- The placing of sperm in the
reproductive tract.
Natural Insemination- A male depositing
semen into the vagina of the female.
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Copulation
The Basics
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Artificial Insemination- (AI) A technician
collecting semen and placing it in the female.
Why?
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Better animals
Use high quality bulls without bringing them to
your farm.
Control calving times much easier.
Oklahoma State AI Instructional Video 1
AI - Cattle and Horse Rancher
The Basics
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Breeding- Promoting animal reproduction so
the desired offspring result.
Reproductive Efficiency- The timely
replacement of a species. The difference
between success and failure in animal
production. The probability of success.
Cycles
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Estrous Cycle- The time between periods of estrus.
Animals will continually cycle unless they are
pregnant. There are four periods of the estrous
cycle.
Anestrous- The absence of cycling.
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Some animals are seasonal breeders.
This is often related to the number of daylight hours in a
day.
 Sheep
 Cats
 Dogs
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Goats
Horses
Estrous Cycle: Part 1
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Estrus- Also known as heat, is the period
when the female is receptive to the male and
will stand for mating.
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The length of estrus varies by species.
Estrus is triggered by the hormone estrogen.
Symptoms of estrus:
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Restlessness
Mucus discharge
Swollen vulva
Standing to be ridden by other animals
Estrus
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Heat cycle
Begins at puberty
Each species is different
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Cow- 21 days (polyestrus)
Horse- 21 days
Dog- every 6-8 months (monestrus)
Cat- 15-21 days
Sheep- 17 days
Goats- 21 days
Pigs- 21 days
Determining Standing Heat
Estrous Cycle: Part 1
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Ovulation- When a mature ovum is released
by the ovary.
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Takes place during estrus for most species.
The number of eggs ovulated varies between
species.
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The cat ovulates after mating.
Estrous Cycle: Part 2
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Metestrus- Ovulation occurs during
metestrus in cattle & goats.
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Once the egg is released, the Lutenizing
Hormone (LH) causes the corpus luteum (CL)
to develop from follicular tissue that remains
after release of the ova (egg).
Estrous Cycle: Part 3
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Diestrus- The period in the cycle in which the
system assumes pregnancy.
A fully functional corpus luteum (yellow body)
releases high levels of progesterone.
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Progesterone: Hormone that maintains
pregnancy.
Estrous Cycle: Part 4
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Proestrus- Begins with the regression of the
corpus luteum and a drop in progesterone.
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Late in this period, changes in behavior may
occur.
Reproductive
Development
Throughout the Life of an Animal
Puberty
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The time at which animals reach a level of
sexual development that makes them
capable of reproduction.
In Females, the first estrus with ovulation.
In Males, the first ejaculate with fertile sperm.
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Neither are sexually mature at puberty.
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Females are to small to bear young.
Males is not capable or fertile enough to breed
regularly.
Fertilization & Gestation
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Fertilization is the union of a sperm & egg.
This forms a ______?
Gestation is the period of pregnancy.
Begins with conception and lasts until
parturition (or birth).
Parturition
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The process of giving birth.
Hormone levels change to start this process.
Behavior changes can indicate the animal is
nearing parturition.
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Nesting
Restlessness
Attempt to separate from the herd
Parturition
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Begins by dilation of the cervix and entry of
the fetus into the cervix. This is the longest
stage, raging from 1-12 hours.
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The second stage completes the birth
through a series of strong contractions.
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The last stage is expulsion of the afterbirth
(placenta) from the uterus. This usually
occurs shortly after giving birth.
Lactation
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The production of milk.
Hormones that trigger the onset of lactation
also play an important role in parturition.
Incubation (only egg layers)
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Development of a new animal in a fertile egg of
poultry, fish or another egg laying species.
Occurs outside the body. 4 Key Steps:
1. Temperature of 99-103F.
2. Humidity should be about 60% during the first
18 days and 70% the last 3 days.
3. Air Exchange to maintain a 21% oxygen level.
4. Eggs should be rotated 2-5 times daily for the
first 18 days.