Effect of suckler cow genotype on milk yield and pre-weaning calf performance

Milk yield and pre-weaning calf performance of spring-calving Charolais (C) and Beef × Holstein-Friesian (BF) cows was compared over 3 experiments. Cows were individually offered a restricted allowance of grass silage pre partum in Experiments 1 and 2 and ad libitum silage in Experiment 3. In all three experiments cows received silage to appetite for the first 34 (s.d. 16.2) days of lactation. In Experiments 1 and 2, cows and calves were grazed together during the subsequent grazing seasons. The daily milk yield of C cows was significantly lower from parturition until turnout to pasture (1.8 to 2.5 kg/day lower) and subsequently at pasture (4.5 and 3.1 kg/day lower in Experiments 1 and 2, respectively) than that of BF cows. Calves from C cows consumed more (P < 0.01) concentrate creep feed during the indoor period than calves from BF cows. Compared to calves from BF cows, pre-weaning daily live-weight gain was lower for calves from C cows in Experiments 1 (P < 0.05) and 2 (P = 0.06). The pre-weaning growth response per 1 kg increase in milk yield was greater for calves from C cows than those from BF cows. In conclusion, compared to BF cows the milk yield of C cows was lower resulting in increased calf concentrate intake indoors and lower pre-weaning calf daily live-weight gains.