Livestock Breeding and Genetics Key Terms

Get familiar with livestock breeding and genetics key terms

By Denise Brown

Each type of livestock has its own terminology, but there are some basic terms that anyone with livestock should know. As you learn these terms, you realize that there is a lot of science that goes into making the meat and dairy products that we consume. And as farmers gain more knowledge of breeding techniques and genetics, the quality of our meat improves. Because quantity and quality affect the farmer’s bottom line, animal science is a constantly evolving study.

Birth weight

Farmers study the average birth weight of a particular breed of livestock to determine if it suits their herd. Ideally, the animal's birth weight should give the animal a good head start on life, yet the newborn shouldn't be so large as to cause its mother problems during the birthing process. If the newborn's birth weight is too high, Caesarean delivery might be necessary.
Try: There is a study on the importance of birth weight in cattle from the Journal of Animal Science.

Carcass weight

Carcass weight is the amount of meat available after the animal's slaughter. Carcass weight doesn't include the animal's internal organs, head or hide. Farmers want animals with a good carcass weight.
Try: CattleNetwork offers a detailed yet succinct definition of carcass weight and how this figure is used in the livestock industry.

Estrus, or heat

Estrus, or heat, is the period in a female animal's cycle when her body is ready to mate. In a cow or a pig this cycle occurs roughly every three weeks or until the animal becomes pregnant. The farmer must watch for "standing heat," or when the animal stands still for mating, if he plans to use artificial insemination.
Try: Read more about estrus in cattle from the University of Hawaii.

Artificial insemination

Artificial insemination involves impregnating the female with semen from the male to ensure that she carries the desired male genetics. Artificial insemination is fairly routine in the swine and dairy cattle industry, and is becoming more common among beef cattle producers.
Try: The University of Florida offers detailed information on artificial insemination in dairy cattle. The process is similar to that of other animals as well.

Gestation and gestation period

Gestation, or gestation period, is the term for the length of an animal's pregnancy. The gestation period varies by species. A cow takes 283 days to produce a calf, while a sow has her litter within 116 days.
Try: Farmers often use gestation tables to determine when their cows should deliver calves. Cattle Today has a gestation table, as well as an automatic calculator.

External ultrasound

An external ultrasound, or "preg checker," is a device farmers can use to determine if an animal is pregnant. This is a non-invasive tool used widely in the swine industry.
Try: There is a detailed description of ultrasound techniques in the report published by North Carolina State University.