Use of Sexed Semen to Alter Gender Ratios and Enhance Marketing Opportunities in Commercial Beef Herds
Efficiency of beef production is important to reducing costs to consumers, maintaining economic sustainability of the family ranch, and the rural economy. Male calves (bulls or steers) produce beef more efficiently than heifers (female cattle). In addition, tractor trailer load lots (approx. 90 animals) of calves of the same sex are worth more than lots of mixed sex calves or partial loads. Smaller family ranches are at a competitive disadvantage to larger ranchers because smaller ranches cannot produce single sex tractor trailer load lots. These ranches make up about 50 percent of the ranches in the US. Sexed semen is a technology currently available to the beef industry to increase the percentage of calves of a desired sex in a beef operation. However, pregnancy rates to sexed semen are 10 to 20 percent less than pregnancy rates with
conventional semen. It is not known if use of sexed semen is economically feasible in a commercial beef operation. In addition, more information is needed on methods to increase pregnancy rates to sexed semen. This project uses a combination of artificial insemination to sexed semen and natural mating of beef cows and heifers to determine the percentage of male calves that can be generated by using sexed semen in a commercial beef operation. In other words, the goal is to shift the sex ratio from 50:50 to 70:30 male to female ratio. Also, this project will help determine if sexed semen technology can assist small ranchers to be more competitive. In addition, the project investigates if a change in the timing of artificial insemination relative to estrus or at a planned time will improve pregnancy rates in cows bred with sexed semen. Information from this project will assist beef
producers in deciding if using sexed semen technology can improve the economic sustainability of their operations. Also, results from these studies will be used by researchers and beef genetic companies to determine areas for technical improvement or changes that will increase pregnancy rates to sexed semen.