Influence of escape protein supplementation to grazing ewes suckling twins on milk production and lamb performance

Abstract

Effects of escape protein supplementation on milk production and lamb growth were determined with 26 mature Finn-Targhee ewes suckling twin lambs. Ewes and their lambs grazed on improved summer pasture. Thirteen ewes received every third day a supplement at a rate of 0.45 kg head −1. Adjusted to a daily intake basis this provided 80 g head −1 of protein of which 40 g was escape protein. The experiment was 84 days in duration and composed of four 21-day periods. Ewes either maintained or improved body condition and gained weight during the experiment with no differences detected ( P > 0.05) between treatment groups. Supplemented ewes had more persistent ( P<0.05) milk production during period 2 than controls. Supplemented ewes produced more ( P < 0.05) milk than those not supplemented (724 vs 586 ml day −1) in period 4. Milk composition percentage was not influenced by protein supplementation. However, supplemented ewes yielded more protein, fat and solids-not-fat ( P < 0.10) during period 4 than controls. Total lamb weight change and gain were not affected ( P > 0.05) by supplementation. Nutrient intake in excess to ewe requirements resulted in positive energy balance which minimized potential benefits of escape protein during the experiment.