Abstract

Ten lambs and 10 kids were offered a low quality meadow hay (7.1 gN/kg/DM) for 12 weeks. Five of each species were then reallocated to lucerne hay (23.8 gN/kg/DM) and the remainder maintained on meadow hay. Feed was offered ad libitum. Digestibility was determined at weeks, 4, 6, 10 and 16. Animals were fed at 2 h intervals prior to slaughter and the retention time of dry matter in the rumen estimated. Body energy changes were estimated by comparative slaughter. In the initial 6 weeks kids and lambs digested meadow hay to a similar extent but whereas it was maintained in kids, digestibility by lambs subsequently declined until week 16. At week 16 values for dry matter digestibility were 0.67 and 0.54 for kids and lambs, respectively. There were no significant differences in the digestibility of lucerne hay between the species nor in the voluntary intake of meadow hay or lucerne hay. Both species consumed more lucerne hay than meadow hay. Kids retained lucerne hay longer than did lambs (18.,7 h and 11.8 h, respectively) but meadow hay had a similar retention time in both species (24.7 h and 27.8 h, respectively). Water intake of lambs was approximately double that of kids. Difficulties in determining maintenance energy requirement from body weight change are discussed.

AH, Kirton, EG Woods, and DM Duganzich

Proceedings of the New Zealand Society of Animal Production, Volume 43, , 111-114, 1983