Heritability estimate for stayability in nelore cows

The objective of the present study was to determine the possibility of using stayability (STAY) of dams as a selection criterion for fertility in the Nelore breed. STAY was defined as whether or not a cow calved in a herd at a specific age or after this age given that she had calved at an earlier age. The specific ages studied were 5 (STAY5), 6 (STAY6) and 7 (STAY7) years. Data on 53271, 46011 and 41517 animals were analyzed for the respective ages. The Method was used to estimate the variance components and a maximum threshold a posteriori model was used to predict the genetic values. The analyses provided h2 estimates of 0.117±0.003, 0.122±0.004 and 0.171±0.005 for STAY5, STAY6 and STAY7, respectively. The ease with which the trait can be recorded and the h2 estimates indicate that the use of this trait as a selection criterion can contribute to increased dam fertility.