What Is Artificial Insemination in Cattle?

Artificial insemination (AI) is a common method of breeding cattle. Semen is collected from a bull, placed into straws, and, if necessary, frozen for storage using liquid nitrogen. When the selected cow comes into heat, a veterinarian or AI technician uses instruments to introduce the semen into the female's reproductive tract and impregnate the cow.

  1. Semen Collection

    • The first step in the AI process is to collect semen from the bull. Semen is typically collected using an artificial vagina or by electro-stimulation. After collection, semen is examined for quality. If the quality is acceptable, the semen is extended with a diluent to make it more suitable for freezing and fertilization. Since the average collection can produce enough semen to inseminate several cows, semen is often frozen using liquid nitrogen and stored in individual straws for later use.

    Detecting Estrus

    • Once semen has been successfully collected, tested for quality and extended, it is ready to be placed in the cow's reproductive tract. For the cow to be successfully impregnated, it must be in heat, or "in estrus," since this is when the female is most fertile. Cows typically come in estrus every 21 days when not pregnant, and heat is detected by watching for "standing heat." This means the cow will stand to be mounted by another animal, usually another cow in the herd. Once estrus is detected, the cow should be inseminated within approximately 12 hours.

    Insemination

    • The actual insemination process takes place once estrus has been detected and fertility is optimal. A veterinarian or AI technician inserts a gloved hand into the cow's rectum and locates the cervix. The other hand then inserts the insemination tube into the vagina. The gloved hand in the cow's rectum is used to guide the insemination tube into the cervix where semen is deposited. Better conception rates are achieved when the semen is inserted deep into the cervix, so precision pays off.

    Advantages

    • The main advantage of artificial insemination is that it increases the pool of available sires a breeder can select from. Superior sires are available to more breeders and a wider population of cows. This also means a sire can be more prolific. Whereas a bull can typically breed 50 to 60 cows per breeding season via natural service, with AI that same bull can impregnate a virtually limitless number of cows each year.

    Disadvantages

    • Although AI has many advantages, it does require specialized knowledge and considerably more time than natural breeding. Cow owners may also incur additional expenses for extra labor.