Abstract

The intake, apparent absorption, availability and retention of Se, Cu, Zn and Fe were measured in young lambs using nutritional balance and comparative slaughter techniques. Balances were carried out when the lambs were aged 5 to 11 d, 21 to 28 d, 63 to 70 d and 92 to 98 d. During the first and second balance periods the lambs were fed 175 and 300 g dry matter (DM)/d as milk replacer. In balance 3, 210 g DM/d as milk replacer was fed with fresh pasture ad libitum and during balance 4, only fresh pasture was fed ad libitum. The mean liveweight gain was 250 g/d. The fractions of the ingested mineral which were apparently absorbed on the milk replacer diet were Se 0.95, Cu 0.92, Zn 0.62 and Fe 0.50. These progressively decreased to Se 0.45, Cu 0.10, Zn 0.16 and Fe 0.20 for the all pasture diet. From the comparative slaughter study it was found that 44

PJ, L'Huillier, CR Parr, and AM Bryant

Proceedings of the New Zealand Society of Animal Production, Volume 48, , 231-236, 1988