Relationship between expected progeny differences of Canadian Hereford sires and performance of their progeny in commercial herds

Abstract

Sire expected progeny differences (EPDs) for calf birth, weaning and yearling weight predicted genetic differences between progeny of sires. A 1-kg change in birth weight EPD corresponded to a 1.06 ± 0.14 kg (P < 0.001) change in actual calf birth weight. A 1-kg change in weaning weight EPD or yearling weight EPD corresponded to a 0.45 ± 0.18 kg (P = 0.012) change in 200-d weaning weight or a 0.78 ± 0.15 kg (P < 0.001) change in 365-d yearling weight. Calving ease EPD was not related (0.37 ± 0.27; P = 0.17) to calving ease score. Key words: EPD, calving ease, birth weight, weaning weight, yearling weight