Biological efficiency of meat and wool production of seven sheep genotypes.
The efficiency of lamb production in 132 purebred Merino (M) and Merino crossbred ewes (with Finn [Finnish Landrace] (FLM), Border Leicester (BLM), Bleu du Maine (BMM), Texel (TM), Cheviot (CM) and Merino Landsheep [Merinolandschaf] (MLM)) was evaluated. The mean annual feed intake of BLM and BMM ewes and lambs (866 and 926 kg, respectively) was significantly higher than that of FLM, TM and MLM ewes and lambs (774, 751 and 785 kg, respectively); Merino ewes and lambs had a significantly lower feed intake (673 kg). The efficiency of lamb production (kg lamb produced/kg feed intake by lamb and ewe) was highest for FLM (0.066), followed by TM (0.048), M (0.042), MLM (0.040), BLM (0.032), CM (0.032) and BMM ewes (0.031). The efficiency of lamb production for ewes rearing single lambs was not significantly different between genotypes when ewe live weight was included as a covariate. The efficiency of wool production of Merino ewes (5.09 kg) was significantly higher than that of FLM and TM ewes (4.02 and 3.87 kg, respectively).