Influence of Energy-Protein Ratio on Performance and Carcass Characteristics of Swine

Abstract

Seventy-two pigs were used to determine the influence of calorie-protein ratio and fat level in the ration on performance and carcass characteristics. The rations, containing graded levels of from 10 to 18% protein, were formulated so that a similar ratio of amino acids was maintained in all diets. Daily feed consumption was influenced by both calorie-protein ratio and by fat level in the ration. However, gross energy intake was not significantly influenced by either ration treatment. Growth rate, during the first 28 days on test, was significantly influenced by energy-protein ratio. The narrow ratio supported the most rapid rate of gain. This difference was not apparent at the time the pigs reached market weight. Added fat resulted in a significant improvement in both rate of gain and in feed per pound of gain. Energy utilization, however, was not influenced by either calorie-protein ratio or by fat level in the ration. Physical measurements and chemical determination made on the carcasses were not significantly influenced by ration treatments. Factors influencing feed consumption of pigs are discussed.