1Effects of Nutritional Environment on Percentage of Mature Weight at which Crossbred Heifers of Varying Proportion of Brahman Breeding Attain Puberty

Crossbred heifers (n=181) produced from mating Bos indicus × Bos taurus cows to Simmental, Senepol, Braford and Simbrah bulls and Angus cows to Brahman bulls were used to determine if restricting postweaning gain for the first 3 mo after weaning followed by rapid gain for the second 3-mo-period (Restricted-Rapid) would affect attainment of puberty as compared to heifers fed for a constant gain (Constant) from weaning to breeding. Both nutritional groups were fed to reach 65 % of there estimated mature weight (EMW) by the start of their yearling breeding season. Percent of estimated mature weight (EMW) at which puberty was reached was not affected by nutritional management (62.7 vs 62.9 % for Constant and Restricted-Rapid fed heifers, respectively), but was affected (P <.0057) by breed of sire (Simmental