Rumen-protected methionine for lactation, wool and growth in sheep

Abstract

Two experiments were conducted to investigate the value of rumen-protected methionine (RPmet) for lactating ewes and growing lambs. In Expt. 1, 18 lactating Dorset ewes (60.2 kg) with twin lambs and 12 Dorset ewes (59.4 kg) with single lambs were fed a supplement (1.0 kg/day) containing either 0 or 0.2% RPMet and had ad libitum access to chopped alfalfa hay for 42 d commencing 5 d post parturition. Treatment effects were not significant for either ewe or lamb bodyweight gain, ewe milk production, milk protein, or milk fat ( P > 0.05). In Expt. 2, 26 12-wk-old Dorset ewe lambs (16.9 kg) were used to study the effect of RPMet on bodyweight gain and wool growth. Lambs were fed a corn-soybean meal supplement containing either 0, 0.1 or 0.2% RPMet. Lambs had ad libitum access to chopped grass hay. The supplement was offered to appetite for the first 56 d, and at 0.5 kg/d from d 56 to 112. RPMet did not affect bodyweight gain, feed efficiency, wool yield or staple length ( P < 0.05). Results show that RPMet had no affect on bodyweight change, milk production or wool growth in Dorset ewes and growing lambs under the conditions of these experiments.