Relationships Among Survival Rates, Predicted Differences for Yield, and Linear Type Traits

Abstract

Sire proofs by BLUP for stayability to 54 and 84 mo were regressed on PD for yields alone and simultaneously with standardized transmitting abilities for 15 primary linear type traits and PD type computed by the Holstein Association of America. Estimates of progeny survival were based on either grade or registered daughters. Traits (after yield) significantly associated with survival to 54 mo in grade cattle were stature, body depth, udder depth, and teats rear view. Regression coefficients for udder depth and teats rear view were positive. In registered cattle most traits were associated with survival to both ages. Udder depth and teats rear view were significantly correlated with survival to 84 mo in grade cattle. Udder depth accounted for as much variation in stayability as yield. Udder depth and teats rear view were the traits most related to survival in both grade and registered cows. Body traits were favorably correlated with survival only in registered cows. Models were explored to determine best predictor models when more than one type trait was included. Highest R2 models were generally a combination of the best single traits. Multiple type traits were significant in some models.