Abstract

Ewes and their twin lambs (weighing at least 16 kg) were allocated to three treatments: lambs with dams on ryegrass-white clover (RG-WC) pasture until 15 weeks of age (GRASS) (lambs; n=50), lambs with dams on herb-clover mixes (plantain, chicory, red and white clovers) until 15 weeks of age (HERB) (lambs; n=50), and lambs weaned early (8 weeks old) onto herb-clover mixes and dams on RG-WC pasture (EARLY) (lambs; n=50). Average daily gain, GR soft-tissue depth and muscularity of lambs in EARLY and GRASS were lower than those in the HERB treatment (P<0.05). The muscle to bone ratio of lambs in HERB treatment was higher than those in the EARLY treatment (P<0.05). Lambs can be weaned at 8 weeks of age onto herb-clover mixes to achieve similar carcass characteristics compared to lambs weaned at 15 weeks of age on RG-WC pasture. Lambs weaned early onto herbclover mixes had lower growth rates than the lambs not weaned early on herb-clover mixes. There were no negative effects on lamb carcass characteristics and lean-meat yield (LMY) when lambs were slaughtered at a set weight.

HX, Wong, NM Schreurs, RA Corner-Thomas, WEMLJ Ekanayake, LM Cranston, ST Morris, and PR Kenyon

New Zealand Journal of Animal Science and Production, Volume 78, Lincoln, 189-193, 2018