The Influence of Calcium Pantothenate, Tryptophan and Methionine Supplementation, and Source of Protein upon Performance of Growing Swine Fed Corn-Meat and Bone Scraps Rations

Abstract

Supplementation of 16.6 and 16.0% crude protein corn-meat and bone scraps rations with 0.04 and 0.08 DL-tryptophan caused a highly significant increase in final weights of pigs fed the experimental rations over 42 or 53 day periods. Neither methionine nor calcium pantothenate supplementation of the basal ration resulted in increased final pig weights, nor was there a significant interaction between either of these nutrients and DL-tryptophan. Final pig weights were unsatisfactory although the rations were formulated to be adequate in other known dietary factors. Although experimental rations as supplemented should have been adequate to promote maximum pig growth, except for excessive calcium, it appears that all essential amino acids determined to be in the ration may not have been available to the pig. Use of separate samples of meat and bone scraps, containing essentially the same amount of crude protein, as protein supplements to corn resulted in large differences in final pig weights. These results suggest differences in availability of amino acids from meat and bone scraps of different sources. Substitution of solvent soybean oil meal and of blood meal for one-half of the supplemental protein supplied by meat and bone scraps caused marked increases in final weight of pigs. A part of this difference in pig performance appeared to be due to the lack of availability of essential amino acids in the meat and bone scraps diets and an increase in the availability of these amino acids from the other supplemental protein sources. The use of rations which appeared to be more nearly adequate in the essential amino acids caused marked improvement in efficiency of feed utilization. The possibility that excessive dietary calcium may have interfered with pig performance was also discussed.