Supplementation of Degossypolized Cottonseed Meal in Rations for Growing and Fattening Swine

Introduction: Cotton is one of the major sources of income in southern agriculture. Cotton is the highest income crop in Tennessee and is a leading crop in several other southern states. Because of large scale production of cotton in the South, cottonseed meal, a by-product of the industry, has usually been the cheapest and most plentiful of the protein supplements available for livestock feeding in this area. In the past the use of cottonseed meal in livestock rations has been limited mainly to the feeding of ruminants. Swine and poultry show the effects of gossypol toxicity when fed large quantities of ground cottonseed or most of the commercially available cottonseed meals. Recently, improved meals, produced at lower temperatures and with a very low free gossypol content, have been made available. Boatner et al. (1948), Milligand and Bird (1951), Altschul et al. (1954) and others have shown that these new type cottonseed meals can be fed to chicks at relatively high levels with no visible harmful effects. Unpublished data from the University of Tennessee Nutritional Experimental laboratory (obtained in conducting feeding trials for Animal Husbandry 532) indicate that similar results have been obtained with very young albino rats. The quantities which may be used in swine rations have been re-evaluated during the past few years. For example, Stephenson (1952) of Arkansas has demonstrated that cottonseed meal can be used in a swine ration to make up all or a large portion of the protein supplement. Cottonseed meal has been used successfully in complete pre-mixed rations for swine where its exact percentage in the ration can be controlled. In view of the fact that most of the work using these new meals is swine rations was with pre-mixed rations containing cottonseed meal at a fixed level, it was decided to determine the extent to which one of the new meals could be used as part or all of a self-fed supplement to be fed with shelled corn to growing-fattening swine on pasture. Rate of gain, feed consumption, and palatability were problems concerning which additional information was needed to determine whether these meals could be recommended for self-feeding in swine rations