Abstract

A multi-year grazing study was undertaken on three commercial properties in the southern South Island to compare the performance of lambs grazing high-sugar ryegrass/white clover (HSG) with lambs grazing a standard ryegrass/white clover pasture (SRG). Cultivars were established in late spring 2012; approximately 400 lambs in each treatment group per property grazed the swards in autumn 2013 and summer/autumn 2014 at a density of 30 to 35 lambs per hectare. Lambs were weighed regularly throughout the season; those that reached the desired weight were sent for slaughter. Across both years and properties, lambs grazing the HSG pasture grew 31 grams per day faster (17%) on average than those grazing SRG (P<0.001). These lambs were an average of 0.4 kg heavier in terms of carcase weight at slaughter (P<0.001) yielding 0.2 kg more meat per carcase based on VIAScan yield. These results suggest that lambs grazing HSG outperform those grazing SRG.

LE, Proctor, HJB Craig, NJ McLean, PF Fennessy, JI Kerslake, MJ Behrent, JCL Chuah, and AW Campbell

Proceedings of the New Zealand Society of Animal Production, Volume 75, Dunedin, 235-238, 2015