Response of Pigs to Graded Levels of Soybean Meal and Added Lysine in Ten Percent Protein Rations

Ten percent protein rations were formulated to supply 12.5, 25, and 50% of the protein from dehulled S.B.M. The remainder of the protein was supplied by corn. These rations were fed with and without 0.4% of added lysine during two consecutive seasons. Six pigs were individually fed each ration during each season. Increasing the proportion of the protein supplied by S.B.M. resulted in significant increases in feed intake and daily gain. Carcass leanness as measured by area of longissimus dorsi muscle was significantly improved by increasing the percent of protein supplied by S.B.M. and by added lysine.