Sexed Semen Uses and Opportunities
STILLWATER, Okla. (Oct. 9, 2014) — “Sexed semen is a technology whose time has come in the beef industry; however, producers need to understand the risks and limitations,” said John Hall, superintendent of the Nancy M. Cummings Center at the University of Idaho. He spoke to more than 210 attendees of the 2014 Applied Reproductive Strategies in Beef Cattle (ARSBC) symposium hosted in Stillwater, Okla., Oct. 8-9.
Gender-sorted semen is here to stay, said John Hall, adding that fertility will improve as sorting damage decreases, synchronization protocols are more adapted and bull selection for gender-selected semen is more established.
Gender-selected semen is gaining popularity and use in the beef industry, with more bulls with gender-selected semen becoming available through bull studs. Pregnancy rates with gender-selected semen, on average, are about 15%-20% lower than those bred by conventional semen. However, there are some factors affecting pregnancy rates, including the timing of insemination and the bull’s effect on sorting semen.
Breeding with gender-selected semen after detected estrus has showed the best results in several studies, he shared, though fixed-time artificial insemination (FTAI) is feasible.
Hall reported that there is a 20%-35% reduction in transferable embryos when using gender-selected semen. However, even though fewer embryos are obtained with gender-sorted semen compared to conventional semen, the embryos are 90% of the desired gender. Therefore, fewer recipients are needed and fewer animals of the undesired gender are produced.
Another option is called reverse sorting. This sorts previously frozen semen by gender, which can allow production of gender-selected semen from bulls no longer producing semen. He said it is generally used for in vitro fertilization (IVF).
The most exciting use for gender-selected semen, Hall said, is to produce maternal lines to be mated to terminal lines, a practice which is limited in beef cattle compared to other meat animals. Producing maternal lines by means of replacement heifers would be quicker and use fewer resources with use of gender-selected semen. This could also produce higher-quality females without producing subpar steers in the process.
Gender ratios could also shift with use of gender-selected semen given the desires of the operation. Seedstock applications include using Y-sorted semen for bull production, and X-sorted semen for replacement-heifer production or enhancing female lines.
Commercial operations can use it to create a marketing advantage by producing more steers for a uniform trailer load and to meet specific customer needs. He shared data that showed three loads of similar-quality cattle, two all-steer loads and a mixed load. The heifers were discounted in the mixed load, and the steers were also discounted for being in a mixed load. The all-steer loads earned $5,180 and $6,746 more than the mixed load.
In this case study, Hall noted that the mixed-load cattleman already used AI, and the additional cost of using gender-selected semen would add $2,000-$3,000, which would still be accounted for in additional profits.
He concluded that sexed semen is here to stay, and fertility will improve as sorting damage decreases, synchronization protocols are more adopted and bull selection for gender-selected semen is more established. Applications continue to improve.
Hall spoke during Thursday’s ARSBC session focused on advanced reproductive technologies. Visit the Newsroom at www.appliedreprostrategies.com to view his PowerPoint, read the proceedings or listen to his presentation.
Comprehensive coverage of the symposium is available online at www.appliedreprostrategies.com. Compiled by the Angus Journal editorial team, the site is made possible through sponsorship by the Beef Reproduction Task Force.
Editor's Note: This article was written under contract or by staff of the Angus Journal. To request reprint permission and guidelines, contact Shauna Rose Hermel, editor, at 816-383-5270.