Udder Score EPDs
Kansas State University has produced a research run of Expected Progeny Differences (EPDs) for teat size and udder suspension scores in Hereford cattle. Approximately 188,000 udder evaluations on over 78,000 lactating females were used in the evaluation, collected by the American Hereford Association (AHA) since 2000. Contemporary groups were defined as females in the same herd, year and season, and required five or more females per group. Records were adjusted for age of the female.
Prior to 2010, AHA collected a single overall udder score that reflected differences in both teat and udder structure. In 2010, the Beef Improvement Federation recommended collecting separate scores for teat size and udder suspension, and AHA adopted that system. Both systems used a one to nine scoring system, where nine is most desirable (small teats, tight suspension), and one is least desirable. EPDs for teat size and udder suspension are published in this evaluation, but overall udder scores submitted prior to 2010 were included in the evaluation as a correlated trait. Accuracy of udder trait EPDs was calculated according to Beef Improvement Federation procedures. Over 200 Hereford sires have HCR EPDs with accuracy values of 0.55 or higher in the current evaluation.
Like any EPD, udder trait EPDs can be used to identify superior sires for the given trait. Differences in sire EPDs predict the difference expected in the sires’ daughters udder characteristics when managed in the same environment. For example, if Sire A has a teat size EPD of 0.4, and Sire B has a teat size EPD of -0.1, the difference in the values is 0.5, or one-half of a score. If daughters of Sires A and B are raised and managed in the same environment, you would expect half a score smaller teat size in daughters of Sire A, compared to Sire B.
Eric Walker, Morrison, Tenn., is the new AHA president and Sam Shaw, Caldwell, Idaho, is serving as the 2015 AHA vice president. During the Annual Membership Meeting Nov. 1 delegates elected three new Directors — Jim Mickelson, Santa Rosa, Calif.; Kevin Schultz, Haviland, Kan.; and Bob Thompson, Rolla, Mo.
Check out the highlight video from the Annual Meeting, as well as the Annual Meeting powerpoint and the 2014 Annual Report at Hereford.org/AnnualMeeting. All press releases from the event are posted at Hereford.org.
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