Distillers' By-Products in Swine Rations

Studies were made with 18 litters of fall-farrowed creep-fed pigs. A basal ration of ground yellow corn, wheat flour middlings, soybean meal, tankage fish meal, minerals and fortified cod-liver oil was compared with the basal ration plus six per cent of dried corn distillers' solubles and with the basal ration plus 12 per cent of corn distillers' dried grains with solubles. Up to weaning no significant differences were noted.When rations containing the same ingredients were fed to pigs after weaning, the pigs failed to thrive normally, thus confirming the observations of other investigators that drylot rations commonly fed are nutritionally inadequate in factors other than protein, minerals, and vitamins A and D. The basal ration appeared to be adequate in quantity and quality of protein and in minerals. With 0.5 per cent of fortified cod-liver oil in the basal, vitamins A and D were not lacking. Assay values for riboflavin, niacin, and pantothenic acid indicated that the basal ration supplied more than the minimum requirements for pigs weighing 100 pounds or less. Available evidence would not lead one to suspect a deficiency of vitamins B1(Hughes, 1940a) and B6(Hughes and Squibb, 1942) in the basal ration. If the basal ration was not deficient in riboflavin, niacin, and pantothenic acid, as indicated by present knowledge, the possibility then exists that other factors known or unknown required by the pig may exist and were supplied by the distillers' by-products.The addition of either six per cent of dried corn distillers' solubles or 12 per cent of corn distillers' dried grains with solubles contributed to the nutritive qualities of the basal rations. Both of these feeds are sources of the water-soluble vitamins.Dried corn distillers' solubles were superior to corn distillers' dried grains with solubles as a supplement to the basal ration.The pigs which were fed the fortified rations up to weaning and then changed to the basal, manifested a so-called residual effect. Since the vitamin A and D content of the rations was about the same, at least a part of this effect must be attributed to the ability of pigs to store certain water-soluble factors for future use.The high death losses were probably due in part to persistent scouring in all lots throughout a major portion of the test period. Post-mortem examinations indicated involvement of the alimentary tract, but the data do not justify any conclusive statement in regard to the association of nutritional status and death losses.