Feed Utilization for Calf Production in the First Lactation by 2-Year-old F1 Crossbred Beef Cows1

Abstract

Twenty-eight Simmental × Angus (SA), 27 Charolais × Angus (CA), 23 Hereford × Angus (HA) and 21 Jersey × Angus (JA) cows that calved as 2-year-olds were fed individually at one of two levels of energy intake (normal [N] and normal + 10% [N + 10]) during late pregnancy and first lactation. Their Red Poll-sired calves received a high energy creep feed through weaning at 6.6 months of age. Cows on the N + 10 level of energy intake were heavier, produced more milk and had heavier calves at weaning. Calves from dams in the two groups had similar conversions of energy consumed in milk and creep feed to preweaning weight gain. However, digestible energy (DE) consumed by the dams or by the dams and calves per kilogram of calf weaned was greater for dams on the N + 10 level than for those on the N level. Daily DE intakes during lactation averaged 23.9 Meal for SA and CA cows, 21.8 Meal for HA cows and 22.5 Meal for JA cows. Daily production of energy in milk was greater for JA than for CA or HA cows (5.3 vs 4.2 and 4.4 Meal) but not significantly greater than that for SA (4.8 Meal) cows. Calves from CA and HA cows consumed 24% more (P<.05) DE as creep feed per kilogram of gain than did calves from SA or JA cows to compensate for lower milk production of their dams. Consumption of DE per kilogram of calf weaned averaged 20.6 Meal for dams and 24.1 Meal for dams and calves, with no significant differences among breed types of dams. Copyright © 1980. American Society of Animal Science . Copyright 1980 by American Society of Animal Science