Abstract

Artificial rearing is routinely used in large-scale dairy sheep farms. One approach is to offer milk replacer (MR) and meal ad libi-tum to lambs. Our aim was to evaluate growth performance of female lambs in the first 12 weeks of rearing with (M) and without (NM) grain-based meal access (n=30/group) during four feeding periods. In period 1 (wk 0-3) lambs were offered MR and meal ad libitum, and in period 2 (wk 4-5) were transitioned outdoors onto pasture with continued access to MR and meal. Lambs were weaned off MR in period 3 (wk 6-10), and meal in period 4 (wk 10-12). The NM lambs received identical management but meal was excluded. A treatment-by-time interaction was found whereby NM lambs had lower average daily gain (ADG) (P<0.05) in periods 1 (376±6 vs. 414±8 g/day) and 3 (146±7 vs. 241±7 g/day), no difference in period 2 (P>0.05), and higher ADG in period 4 (157±18 vs. -55±18 g/day, P<0.05) than M lambs. There was no difference (P>0.05) in live weight by week 12, and all lambs survived. These results indicate when lambs fed MR ad libitum are offered unrestricted access to good-quality pasture before weaning, meal may not be required to achieve a similar live weight at 12 weeks.

AC, Jensen, MA Khan, FW Knol, SW Peterson, PCH Morel, C McKenzie, DR Stevens, and SA McCoard

Proceedings of the New Zealand Society of Animal Production, Volume 77, Rotorua, 13-17, 2017