Technical Keynote Session 3

Evaluating Reproductive Success

By Meghan Richey

“A successful female is one who calves every year,” said Michael MacNeil, U.S. Department of Agriculture (USDA) Agricultural Research Service (ARS), “and we’re analyzing data looking for those genetic lines that are capable of sustained reproductive success.”

MacNeil spoke about the stayability project May 2 at the 2009 Beef Improvement Federation (BIF) symposium in Sacramento, Calif.

The Fort Keogh Livestock and Range Research Laboratory in Miles City, Mont., is analyzing the data from the American Hereford Association, which requires whole-herd reporting. Contemporary groups were formed by yearling weight plus age at first calving, which initially yielded 47,643 data entries. The data was then edited down to 32,460 entries after dropping females who first calved before 600 days of age, those who first calved after 3 years of age, those who were transferred before their first calving, sires with less than three daughters and contemporary groups that contained just one animal.

The females that were left were then eligible to earn “success points” based on each successful calving if the calving interval was 425 days or less (one year plus three heat cycles). If a female failed to calve within the allotted time each year she became ineligible to earn points in successive years. So far females in the study have been eligible to earn a maximum of six success points, and only 831 have done so.

The study also collects and tracks pedigree information on the successful females to identify those genetic lines that have greater stayability. There are still 16,541 records under analysis, representing 2,149 sires.

The study is ongoing.

Editor’s Note: This summary was written under contract or by staff of Angus Productions Inc. (API). To request reprint rights contact Shauna Rose Hermel, editor, at 816-383-5270. PowerPoints are posted with permission of the presenter and may not be reproduced in whole or in part without the express permission of the presenter.

The 41st BIF Research Symposium and Annual Meeting was hosted by the California Beef Cattle Improvement Association and the California Cattlemen's Association. For more information, visit www.bifconference.com or www.calcattlemen.org/bif2009.html.