Encapsulated Methionine Supplement for Growing-Finishing Lambs

Two growth experiments and one metabolism experiment were conducted to determine the effect of supplementation with encapsulated methionine in lamb fattening rations. Encapsulated methionine (0.45% of ration) had no effect on gains and feed efficiency when a basal corn-alfalfa ration was supplemented with soybean meal. However, when the basal ration was supplemented with corn-urea or corn-blood meal-feather meal, encapsulated methionine increased gains by 11% and feed efficiency by 9% (P<.05). Methionine tended to increase excess carcass fat with the soybean meal supplements and to have the opposite effect on carcass composition with the non-soybean meal supplements. In a second feedlot study, in which the basal ration was supplemented with urea, 0.4% encapsulated methionine increased gains by 12% and feed efficiency by 10%. However, a marked reduction in performance was produced by the 0.6% level, indicating a toxic effect. In a metabolism trial, nitrogen digestibility, nitrogen retention and energy digestibility tended to increase with supplementation of encapsulated methionine.