Abstract

An experiment was undertaken to study the effects of calf weaning management on growth rates and susceptibility to gastro-intestinal nematodes. Treatments were: weaned at 6 months (of age) and normal anthelmintic use; weaned at 6 months and no anthelmintics; weaned at 6 months yet grazed with dam until 9 months and no anthelmintics; weaned at 9 months and no anthelmintics. At 9 months of age, calf live weights for the four treatments were: 264, 253, 265 and 308 kg respectively (SED = 2.0). Faecal-egg counts and serum pepsinogen levels were not affected by weaning date. Milk consumption by the later weaned calves was 4.2 kg/day, resulting in herbage intakes being 25% lower than calves in other treatments (P<0.01). When suckling calves to 9 months of age, the cost of this milk production to the cow was 26 kg live weight (SED = 6.3). Later weaning gave a substantial increase in calf live weight (P<0.001), which can be attributed to milk consumption. Faecal-egg counts and serum pepsinogen levels indicated that milk consumption did not have a direct effect on gastro-intestinal nematode burdens.

CJ, Boom, GW Sheath, and A Vlassoff

Proceedings of the New Zealand Society of Animal Production, Volume 63, Queenstown, 61-65, 2003