Genetic Testing for Cattle

Genetic or DNA testing on cattle is performed by collecting hair bulbs, blood or semen samples, then sending these samples to a laboratory for analysis. The samples are analyzed to determine various qualitative and quantitative genetic traits of the animal. Results of these tests can be used as one of the tools in selecting breeding stock that has the potential to deliver calves with desired characteristics.

  1. Qualitative Genetic Traits

    • Qualitative genetic traits in the foreground: her black color and being polled.

      There are two general types of genetic characteristics to consider when breeding cattle. A qualitative trait describes a characteristic that is readily visible. Examples of a qualitative trait are hair color and polled versus having horns. A polled animal is born without the ability to grow horns which is considered a desirable trait by many cattlemen.

    Quantitative Genetic Traits

    • A cut of meat with a large amount of marbling will be tasty and tender.

      Quantitative genetic traits, along with environment and management, primarily affect carcass quality. These traits include marbling, tenderness, weight and amount of fat. Marbling is the network of fat that runs through choice sections of meat and should not be confused with fat often found around the perimeter of a cut of meat. Desired carcass characteristics are a large amount of marbling and very little fat. Marbling makes meat tasty and tender.

    Preparation for Sampling

    • The numbered ear tag identifies this cow as L4.

      Several commercial laboratories offer genetic testing for cattle, including MMI, Igenity and Bovigen. Upon request, these companies will supply sample collection kits, information forms, and sampling and shipping instructions. If more than one cow or bull is to be tested, it is very important to have some means to identify and describe each animal. Some of the ways to identify animals are by ear tag numbers, branded numbers or ear tattoos.

    Hair Sampling

    • This cow has a black switch at the end of her tail.

      The most common sample collected for DNA testing is hair roots because they are gathered quickly and easily. To collect this sample, a pencil-thickness tuft of hair is pulled from the tail switch which is the long hair on the end of a cow's tail. Hair bulbs or roots are under the skin and easily come out of the tail when pulled correctly. The bulb on each hair contains a significant amount of DNA.

    Sampling Calves and Bulls

    • Semen is the best DNA sample from a bull.

      For calves under 8 months of age, blood samples are required because their hair follicles are not thick enough to provide good-quality DNA. Blood samples are collected with needles and syringes or with pin-prick devices. The best sample for accurate DNA analysis from a bull is semen.

    Economics

    • Presently, there is very little unbiased economic information available to beef cattle producers that tells them whether genetic testing can positively impact ranch profits. Some purebred producers are using genetic testing results as part of their marketing information at annual sales; but they are supplementing it with production data from dams and sires of animals being sold.