Essential Amino Acid Supplementation of Intact Proteins Fed to the Gravid Gilt

Abstract

Semipurified diets formulated to contain 12% protein (N x 6.25) from sesame meal, soluble blood flour or isolated soybean protein were used to evaluate the lysine, isoleucine, and sulfur-bearing amino acid requirements, respectively, of the gravid gilt. These diets contained approximately), 340 kcal. ME per kg. and were fed at the rate of 1.82 kg. per gilt daily. It was shown that 0.42% lysine, 0.37% isoleucine, and 0.28% total sulfur-bearing amino acids adequately met the gilt's need during the period from the 102nd to the 109th day postcoitum. These values are similar to the suggested needs of the finishing pig. The addition of histidine and threonine to the sesame meal diet, in the presence of 0.65% lysine, did not enhance nitrogen utilization. Gilts fed isolated soybean protein responded to methionine, but not to cystine, supplementation. Gilts receiving a 97% corn diet maintained a positive nitrogen retention of 7 gm. daily, compared to 10.5 gm. when lysine and tryptophan were added. Glutamic acid added to the all-corn diet supplemented with lysine, tryptophan, and isoleucine, failed to improve performance. Alteration in serum proteins was apparently more dependent upon the stage of pregnancy than upon adequacy of amino acid intake. The fall in serum gamma globulin prior to parturition paralleled the fall in total serum protein. The relative concentrations of alpha and beta globulin increased as pregnancy progressed, but albumin levels tended to decrease. Copyright © 1965. American Society of Animal Science . Copyright 1965 by American Society of Animal Science