Reference Library

Cattle Reproduction in the Space Age
by Rea McQueen

Recent years have given birth to new technologies that use biology to improve cattle reproduction. At this year's Beef Cattle Short Course at Texas A&M University College Station, Texas, Extension livestock specialist Dr. Joe Paschal of Corpus Christi talked about three reproductive technologies that are available to beef cattle producers.

He said breeders could greatly reduce the cost of replacement heifers by using new technology to evaluate fertility in females before they reach sexual maturity. Paschal said it could reduce the expense of replacement heifers, which typically cost ranchers between $500 and $1,200. To evaluate fertility, a prepuberal animal is given an injection of gonadotropin releasing hormone (GnRH). Twenty-four hours later, a blood sample is taken to measure the luteinizing hormone. (LH). "We're reaching out and trying to affect the brain into thinking that it's fertile or mature," he said. "Those animals that have a higher and quicker LH response will be the females who are more fertile."

Another technology will detect the fertility-associated antigen (FAA), which is responsible for improving conception rates of bulls. Paschal said scientists take a sample of the bull's semen and look for fertility associated antigens on the sperm cells. "Bulls that have these hyper-binding proteins are 20% more fertile than bulls that do not have fertility associated antigens," Paschal said. He said FAA tests are reasonably priced and are currently available to breeders.

Finally, Paschal said sexed semen is an area of technology that will be a tremendous benefit to those interested in producing high quality replacement females only or high quality growth bulls only. "Although it is a little bit further out, the concept of sexed semen holds potential," he said. Currently, sexed semen is 80% to 85% accurate, but developers are working on improving accuracy so the technology can be accessed commercially.

For more information, contact Joe Paschal at (5~2) 265-9202 or email at j-paschal@tamu.edu.

Reprinted with permission of Texas Longhorn Trails Magazine and/or TLBAA (Texas Longhorn Breeders Association of America)