Abstract

Sixteen kids, 16 lambs and 16 calves approximately 4 months of age were allocated at random in balanced groups of 4 per species at a common allowance to 4 herbage masses (1800, 3000, 3900 and 5000 kgDM/ha) on a ryegrass white clover sward. A further calf, lamb and kid and a mature goat and ewe, fitted with oesophageal fistulas, grazed continuously with their own species at each herbage mass during the 8 day trial. These fistulated animals were randomly relocated to herbage masses every 2 days so that individuals sampled each herbage mass. On similar swards the diet of the lamb contained a greater proportion of clover (+0.23) and a smaller proportion of grass (-0.19) and dead material (-0.03) than the calf. The diet of the kid was intermediate between that of the lamb and the calf. The extent of dietary overlap suggests the species are in a major way competitive rather than complementary when grazing intensively managed swards. While older goats consumed a diet similar in composition to the young goat, older sheep consumed more dead material than lambs, although the proportions concerned were small. There was no difference in the in vitro digestibility of the diet selected by young goats, lambs and calves even though there were differences in botanical composition of the diet selected among the species. The in vitro digestibility of the diet selected was not affected by age of animal.

J, Hodgson

Proceedings of the New Zealand Society of Animal Production, Volume 44, , 99-104, 1984