‘Stayability’ EPD developed

Cattle Market & Farm Reports, Editorials
Feb 21, 2005
by WLJ
A new EPD—Stayability—has been published in the American Simmental Association (ASA) Spring ’05 Sire Summary and will soon be available online.
Calculated by Colorado State University’s Center for the Genetic Evaluation of Livestock, Stayability is defined as the probability that daughters entering the herd will stay in production through 6 years of age.
“Stayability is a compound trait in that several factors may influence it,” said Dr. Wade Shafer, Director of Performance Programs at ASA. “From a Simmental Seedstock Producer’s prospective, traits such as fertility, soundness, productivity and temperament are candidates for influencing Stayability. To the degree that these traits influence commercial producers’ culling decisions, Stayability provides them with an estimate of how long a sire’s daughters will stay in the herd—in accountant terms, ‘the asset’s depreciable life’. Certainly, cows that stay in the herd longer tend to be more profitable; there is simply more time to spread out the substantial cost of getting her into production.”
The age of a bull is one of the major issues with predicting Stayability, as most often bulls will be 10 years or older before having a daughter reach 6 years of age. Consequently, breeds using the trait (Red Angus, Gelbvieh and Limousin) have been relegated to pedigree estimates on bulls younger than 10. To enhance prediction on younger animals, the ASA incorporates information on 3-year-old daughters into its 6-year-old Stayability EPD.
For more information about Stayability or ASA’s Spring 2005 Sire Summary, see www.simmental.org, or call Dr. Wade Shafer at 406/587-4531. — WLJ
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