Artificial Insemination, Estrous Synchronization, and Embryo Transfer

Producers seek new ways to improve reproductive efficiency

Artificial insemination (AI) – semen deposited in the female reproductive tract by artificial means (not a male of the species by natural mating) First accomplished in the dog in 1780 Permits extensive use of outstanding sires to maximize genetic improvement

Semen can be stored for years after a bull is dead

Artificial Insemination

Methods of collection Artificial vagina

Penis is directed into the artificial vagina by the person collecting the semen

Electro-ejaculation Used frequently in bulls and rams

Semen Collection

Semen Evaluation

After collection, the semen sample is evaluated for

It is often diluted with an extender

Increases the number of straws from a single collection

Semen Storage Semen can be used fresh or stored in liquid nitrogen

Stored semen is stored in a liquid nitrogen tank

Detecting Estrus

For AI to be successful, estrus must be detected

Methods

Chin ball marker (cattle)

Brisket marking harness (sheep, goats)

Chalk tail-head (cattle)

KMAR patches (cattle)

“teaser bull” (cattle)

Animals checked several times daily

Estrous Synchronization

Controlling or manipulating the estrous cycle so that a group of females express estrus a approximately the same time

Useful in

AI

Embryo Transfer

Many systems exist to achieve synchronization, all have advantages and disadvantages

Embryo in early stage of development is transferred from its biological mother’s (donor) reproductive tract to another female’s reproductive tract

Superovulation Treating a female with hormones to cause the release of a large number of eggs

Embryo Transfer