Revised Estimates of Heritability of Economic Characteristics in Beef Cattle

Abstract

Revised heritability estimates based on the progeny of 64 to 110 Hereford sires are presented. These studies were conducted at the U. S. Range Livestock Experiment Station, Miles City, Montana, in cooperation between the Bureau of Animal Industry and the Montana Agricultural Experiment Station. The following estimates were obtained by the half-sib correlation method: Birth weight 53; weaning weight 28; final feed lot weight at 15 months 86; gain on feed 65; weaning score 28; slaughter steer grade 45; carcass grade 33; and area of eye muscle 68 per cent. Estimates based on sire: offspring regression for final weight at 15 months were 92 percent and for rate of gain in the feed lot were 77 percent. Lower fiducial limits of heritability (P = .01) based on the half-sib correlation method were: birth weight 26; weaning weight 7; final weight 54; gain in the feed lot 37; weaning score 4; slaughter steer grade 19; carcass grade 10; and area of eye muscle 31 percent. These figures indicate the relatively high influence of heredity in determination of growth after weaning. Growth measures were more highly influenced by heredity than were measures of quality and conformation.