Animal breeding programs
Next Generation Science / Common Core Standards
Addressed!
 CCSS.ELA-Literacy.RH.9-10.7 Integrate quantitative or technical analysis (e.g., charts,
research data) with qualitative analysis in print or digital text.
 CCSS.ELA-Literacy.RH.11-12.2 Determine the central ideas or information of a primary or
secondary source; provide an accurate summary that makes clear the relationships among
the key details and ideas.
Bell Work!
 Why is it necessary to collect semen from animals?
 Describe “good quality semen”.
 Why is semen extended?
 Explain the process of artificial insemination.
 Why are processes such as artificial insemination and embryo
transfer useful?
 What is estrous synchronization? Is it beneficial?
 Explain rectal palpation.
Terms!
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Artificial Insemination
Embryo Transfer
Estrus
Estrous
Gestation
Microscopic
Macroscopic
Palpate
Rectal Palpation
Semen
Animal Breeding Programs
 The vast majority of range animals are
bred by natural service. In other words
the male mates directly with the female.
 In large confinement operations the use
of artificial insemination eliminates the
need for keeping a large number of
sires (males) on hand.
 This reduces expenses and provides a
safer work environment as many male
animals are aggressive and dangerous
to work around.
Semen Collection!
 The first step in the process of an artificial breeding program is the
collection of quality semen from the male animal.
 The collection of semen allows the producer to evaluate breeding
soundness, to breed animals artificially, to store semen for later use and
increase the number of females to be bred during a mating season.
 A male of any species can breed many more females (dam) increasing
the genetic impact of a quality sire.
 It is very important to evaluate semen prior to storage for future use.
Semen Collection
 When collecting semen from
bulls and stallions there are
risks to handlers working
directly with these animals
because of their size.
 To minimize risks, use proper
restraint and be cautious.
 If using a female in estrus
(heat) she also needs to be
properly restrained especially
when dealing with horses.
Semen Collection Cont.
 Sanitation is especially important when dealing with semen collection.
 Clean all equipment prior to the start of collection.
 Bacteria, antiseptics, debris and disinfectant that come into contact with the
semen will affect its viability.
 Once semen has been collected it must be processed in a very timely manner.
 All equipment and supplies must be ready to complete the process of
evaluation, dilution and storage as rapidly as possible.
 Bull and boar semen may be diluted and stored, whereas stallion semen may
be diluted but is used immediately following collection and evaluation.
Methods of semen collection.
 The method of semen collection used is determined
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by the species of animal to be collected.
Methods may also vary from between species.
The artificial vagina (AV) is the most common
method of “catching” the semen, because it is a
more natural method.
The AV is made from a rigid tube with an inner
liner generally made of latex which is filled with
water at body temperature of the animal to be
collected.
Temperature and pressure of the tube maintain
pressure on the males penis which is very
important in the collection process as it simulates
natural service.
Methods of semen collection cont.
 The electroejaculator is a device that sends
electrical impulses through a probe inserted
in the male’s rectum adjacent to the
accessory sex organs. Stimulation of these
organs results in protrusion and erection of
the penis followed by ejaculation.
 Semen is collected in a tube by one of the
handlers.
 Electroejaculation is generally reserved for
untrained males or males with poor libido.
Semen Collection
 Bulls and rams may be collected with an AV,
electroejaculator, or by massage. Trained bulls at an
AI Stud will mount a cow in or estrus or generally a
dummy.
 Stallions are collected using an AV device. Studs are
trained to mount a dummy in most cases but
occasionally a mare will be used with the penis
diverted into the AV.
 Most boars are collected using an AV device suitable
for their size. In most instances a boar will mount a
dummy for collection.
 Dogs and cats may be collected by manual
stimulation and collected in an AV device.
Semen Evaluation.
 Semen is evaluated macroscopically ( by the naked eye) and
microscopically with a microsope.
 Macroscopic evaluation includes visualization of color, volume and
debri.
 Semen volume will vary from one individual to the next as will the
concentration of sperm cells.
Microscopic Evaluation
 Microscopic observation evaluates the sperm cells motility,
concentration and sperm morphology.
 Generally sperm cells will swim in one direction, there may be a few
abnormal cells. Excessive numbers of abnormal cells will affect
movement within the females reproductive tract.
Semen processing
 After microscopic evaluation is complete the semen will be diluted.
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The dilution process is generally referred to as extending.
The purpose of extending semen is so that a number of females may be
bred from one collection of an outstanding male.
Once the semen has been extended it is ready for storage. With cattle is
frozen in small straws placed in liquid nitrogen and may be kept
indefinitely, swine semen is placed tubes in chilled storage is may be
viable for a week. Stallion semen is generally used immediately.
Semen may be sexed but this process is not commonly used.
If using frozen semen is used it should be thawed quickly for use, often
in a warm water container.
Bull semen storage!
Boar semen!
Artificial Insemination
 Artificial insemination is the placing of semen collected from a male into the
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reproductive tract of the female by a method other than natural service.
The purpose of AI (artificial insemination) is to maximize the value of
outstanding sires. This allows a number of animals to be bred(perhaps
thousands) to an individual sire that would otherwise be unavailable to the
ordinary producer.
AI was first performed by Arab horsemen in the 1300’s, an Italian scientist by the
name of Spalanzinni bred dogs artificially in the 1700’s.
Russian scientists did extensive research before AI became an accepted process in
the US.
In 1949 scientists developed a process where semen may be frozen for future use.
Artificial Insemination Cont.
 AI is used in many classes of domestic livestock.
 Semen collected from Boars, Stallions, Toms and Roosters is
generally used fresh because it does not freeze well. Most
domestic poultry is bred artificially because improved breeding
yields chickens and turkeys with breast muscles that are so large
that natural service is no longer possible.
 Both dairy and beef semen is frozen. Well over 90 % of all dairy
cattle in the US are bred artificially.
Artificial Insemination in Cattle/ Horses.
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A cow in standing heat is chosen for breeding
Straws of semen are retrieved from the liquid nitrogen tank.
Semen is thawed if frozen.
The thawed semen is placed in the insemination device.
The inseminator puts on an arm length plastic insemination glove on
one arm. The gloved hand and arm are inserted into the cows rectum.
The reproductive tract is grasped through the wall of the rectum. In
horses the arm is inserted directly into the mares reproductive tract.
 The insemination device is inserted into the reproductive tract through
the cervix into the uterus where the semen is deposited.
 The tissues in the horses repro. tract are more delicate than those of
cattle and greater care should be taken during the breeding process
Artificial Insemination In Swine.
 A sow or gilt that is in heat is selected of the insemination process.
 The breeding rod is inserted into the repro. tract.
 Upon contact with the cervix the rod should be turned clockwise so that
it will actually thread the cervix of the female.
 When the breeding rod is snugly in place elevate the rod attach the tube
of semen to the breeding rod.
 Slowly/gently squeeze the bottle until all of the semen has entered the
breeding rod.
 Turn the rod counter clockwise until it is free and remove it from the
female.
Estrous synchronization
 Estrous synchronization involves the administration of synthetic hormones to
females to control when they will be in standing heat (estrus).
 The purpose of estrous synchronization is to allow the producer to control
when the female will deliver her offspring.
 Knowing when an animal will deliver will allow the producer to prepare for
delivery and observe animals more closely than normal
Embryo transfer in cattle.
 Embryo transfer in cattle has gained considerable popularity.
 Embryo transfer technology was developed in the 1970’s and 1980’s but
has really become common place in the late 1990’s.
 Historically the first embryo transfer took place in rabbits in the 1890’s,
it was a surgical process which is not applicable today.
 The purpose of embryo transfer is to move the fertile embryo from and
high quality cow bred to an outstanding bull to a “donor” a grade cow
to serve as the surrogate mother.
 It is estimated that a cow may have 150,000 “eggs” within her ovaries,
by natural breeding only a small percentage of these eggs will yield a
calf. As a result of embryo transfer one cow has the potential to yield
hundreds if not thousands of fertile embryos.
Embryo Transfer Cont.
 Steps in the embryo transfer process.
 Step 1 is the selection of a quality donor cow. The calves need to be of
sufficient quality to cover the cost of the process.
 Step 2 - superovulation of the donor cow. Superovulation is the stimulation
via hormone treatment ant the release of multiple eggs in one estrus.
Properly treated cow will yield ten or more viable embryos. Some high
quality cows are treated on a regular 60 interval schedule.
 Step 3 – insemination of the cow. Due to the high number of ova released it is
a good idea to breed the cow more than once. Cows are usually artificially
bred on a 12, 24 and 36 hour schedule.
 Step 4- Flushing the cow. The embryos are collected non-surgically. A
catheter is inserted into the cows uterus where saline solution is used to flood
the entire uterus. As the fluid drains the embryos are removed and collected
in a graduated cylinder.
Embryo Transfer Cont.
 Step 5 – Evaluation of the
embryos. Embryos may be
used immediately or frozen
for future use. Each
individual embryo is
evaluated for:
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Regularity of shape
Variation in cell size
Color and texture of the
cytoplasm (fluid in the cell
wall)
Embryo diameter
The results of embryo transfer.
Pregnancy testing in cattle!
 The most common pregnancy test in cattle is
the “palpation per rectum “ method.
 It is similar to AI in cattle that the operator
will insert a gloved are into the cows rectum
and “palpate” feel through the rectum wall to
touch the reproductive tract to determine
pregnancy.
 In stage one – the operator will be looking for
an enlarged uterus, stage two- feeling for
connective cotyledons, stage three – feeling
for a calf.
Pregnancy Testing Cont.
 Animals other than cattle area pregnancy tested using instrumentation.
Basically a sonogram the same instrumentation used in humans.
The End!