Productive and reproductive performance of Romney Marsh and Merino Branco sheep in the Azores under different feeding regimens

Rosa, H J D ,Ventura, P F M ,T Sousa, J, Moreira, D, Borba, A E S e Rego, O A

The objective of this study was to compare the productive and reproductive performances of Romney Marsh (RM) and Merino Branco (MB) ewes in the Azores. In a preliminary trial, fertility, prolificacy and fecundity of 25 RM and 27 MB ewes, mortality rate of lambs born and growth rate of lambs (14 RM and 20 MB) from birth to weaning at 24 kg live weight were determined. In a second trial following weaning, the same group of lambs were raised on pasture and supplemented either with concentrate or maize silage until slaughter (101 days later), and growth rate, carcass and meat characteristics were evaluated. Reproductive indices (fertility: 96% versus 93%; prolificacy: 117% versus 140%; fecundity: 112% versus 130%) and mortality rates (18% versus 17%) for RM and MB, respectively, were not significantly different. Pre-weaning gain was higher (P<0.05)>.

(In Small ruminant research )