Prediction of Age and Weight at Puberty in Beef Heifers

Publisher Website
Google Scholar
Abstract
Data obtained over 4 years on puberty in 353 Hereford, Angus and Shorthorn heifers and their reciprocal crosses were analyzed by the least squares procedure for the effects of year of birth and breed of sire and dam on age (Age-P) and weight (Wt-P) at puberty, and for the regression of Age-P and Wt-P on birth date (B), actual weaning weight (W) and post-weaning average daily gain (A). Generalized predictive equations were obtained for Age-P and Wt-P. Predictive equations specific for each breed group for Age-P and Wt-P were also fitted. The predictive accuracies of four equations (two generalized and two for Angus heifers) were tested with two sets (Years I and II) of puberty data of unrelated Angus heifers. Age-P values predicted by equations 1 and 2 in Year I were similar but lower (P<.01) than observed values. The same was true of equations 8 and 9 for Wt-P in Year I. In Year II, Age-P predicted by equations 1 and 2 and Wt-P by equations 8 and 9 were not significantly different (P>.05) from observed values. Under situations where independent variables B, W, and A are normally distributed, these equations may be useful for predicting Age-P and Wt-P in Angus heifers. Copyright © 1974. American Society of Animal Science. Copyright 1974 by American Society of Animal Science.

This publication has 0 references indexed in Scilit: