BRIEF COMMUNICATION: Composition of milk sampled from beef-cross-dairy cows unaccustomed to milking.

摘要

Growth of calves prior to weaning is dependent on energy intake from milk and pasture. Total pasture intake of a cow-calf pair can be estimated based on the growth rate and milk intake of the calf and the live weight and liveweight change of the cow.Estimates of the volume of milk consumed by the calf can be made using the weigh-suckle-weigh technique but estimates of volume alone do not indicate the energy content of the milk.The present experiment is part of a larger project comparing the efficiency of cows of varying live weight and milk production (Hickson et al. 2014). The aim of this experiment was to determine the composition, and implied energy content, of milk consumed by calves reared on Angus (AA), Angus-cross-Holstein Friesian (AF), Angus-cross-Jersey (AJ) and Angus-cross-Kiwicross (AK) cows. It was hypothesised that Angus-cross-dairy breed cows would have greater concentration of fat and protein in their milk than AA cows.