Effect of Ratio of Protein from Corn and Soybean Meal in Diets of Varying Total Protein on Performance, Carcass Desirability and Diet Digestibility in Swine

Abstract
Four trials, involving a total of 144 pigs, were conducted to determine the effects of varying the ratio of amino acids from corn and soybean meal, and the dietary protein level on performance, carcass quality and diet digestibility. The diets contained a 60:40, 50:50 or 40:60 ratio of amino acids from corn and soybean meal. The pigs were self fed from an initial weight of 20.9 kg. to approximately 95 kilograms. The results of this study indicate that satisfactory growth can be obtained from weanling (21 kg.) pigs fed a 11.3% protein corn-soybean meal diet when at least 50% of the amino acids is supplied by soybean meal. At least 12.8% protein with 50% or more supplied by soybean meal was required for maximum feed efficiency, and carcass leanness was improved up to 14.3% dietary protein. A further increase in dietary protein level did not result in a further increase in lean cuts. The level of amino acids required appears to be different for maximum growth, feed efficiency and muscle development. Copyright © 1967. American Society of Animal Science . Copyright 1967 by American Society of Animal Science