CHARACTERIZATION OF BEEF-CATTLE BREEDS BY VIRTUE OF THEIR PERFORMANCES IN THE NATIONAL BEEF-CATTLE PERFORMANCE AND PROGENY TESTING SCHEME

Average growth and body weight data, which comprised 745 400 weaning r ecords and 14 990 Phase C growth records of young bulls of 16 breeds w ere obtained from the National Beef Cattle Performance and Progeny Tes ting Scheme and used in this re-analysis to characterize breeds for a variety of important traits. Phenotypically, mature breed size (X) was found to be significantly related to birth weight (Y = 2.85 + 0.066X) , weaning weight (Y = 25.8 + 0.369X) and growth rate(Y = 320 + 2.28X). Nevertheless, some breeds deviate considerably from their predicted v alues. Productive efficiency was, however, unrelated to mature breed s ize and dual-purpose breeds tended to be the most efficient. They were also the breeds showing the highest degree of sexual dimorphism.