INFLUENCE OF ESCAPE PROTEIN SUPPLEMENTATION TO GRAZING EWES SUCKLING TWINS ON MILK-PRODUCTION AND LAMB PERFORMANCE

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. © 1991.