Effects of lamb live weight, sex and forage type (grass or plantain-clover mix) on lamb growth during summer

摘要

Two studies were carried out, over consecutive summers, to examine the effect of lamb sex and initial live weight on liveweight gain when grazing a grass-based sward (undeveloped hill country pasture) or a plantain-clover mix (plantain, red clover andwhite clover sown on cultivatable hill country). There were no interactions (P>0.05) between the sex of the lamb, initial live weight or forage type on lamb liveweight gain. In year 1, ewe lambs grew at a slower rate than wethers (169 vs 181 g/day; P<0.01), but there was no difference between the two sexes in year 2 (P>0.05). In both years lambs with a lighter initial liveweight profile were also lighter (P<0.00T) at the end of the study, but there was no difference (P>0.05) in the liveweight gains ofthe light and heavy lambs. In both years lambs grazing the plantain-clover mix grew 47-141 g/day faster than did lambs grazing the grass-based sward (P<0.001). This indicates that the plantain-clover mix can be utilised for a range of lamb classes, withsimilar positive results.