A Polled Future

Monday, July 21, 2014: 2:30 PM
2208 (Kansas City Convention Center)
Morgan Richard , Louisiana State University, Baton Rouge, LA
Cathleen C. Williams , LSU AgCenter, Baton Rouge, LA
Abstract Text:

The horn is an adaptation of the skin, characterized by hardened keratin in the epidermis. Dairy cattle have used their horns as a defense mechanism since the beginning of their existence. However, since dairy cattle no longer need to ward off predators in the wild, the horns do not serve a purpose. Additionally, horns can cause injury to handlers and other cows in the herd. Thus, disbudding or dehorning is necessary in order to lower risk associated with the horns of dairy cattle. Disbudding and dehorning techniques differ; however, they both have disadvantages associated with the procedure relating to cost, health, and animal welfare. The solution presents itself in polled genetics. Animals born without horns carry one or two polled alleles. German researchers found that this genetic marker was associated with certain mutations such as a hairy eyelid.  Since the polled gene is dominant, genetic selection can improve rapidly. An animal with two polled alleles will produce 100% polled offspring. While an animal with only one polled allele will still have 50% of their offspring polled.  Polled genetics are also more cost efficient than dehorning as a farmer can spend an additional $7.50 for polled genetics.  Other advantages of polled genetics include eliminating the risk of infection and reduced labor required. However, limited genetic selection is a major reason dairy farmers are hesitant to embrace polled genetics. Although still a minority, polled dairy cattle are increasing in generic merit and polled bulls are beginning to rank in the top of genetic evaluations.  In conclusion, using polled genetics provided a more cost efficient and less labor-intensive alternative to traditional dehorning methods.

Keywords: dairy cattle, polled genetics