Cooperative Regional Studies with Growing Swine: Effects of Vitamin E and Levels of Supplementary Copper during the Growing-finishing Period on Gain, Feed Conversion and Tissue Copper Storage in Swine

Two cooperative experiments were conducted by the North Central Regional Committee on Swine Nutrition. Ten stations participated and utilized 125 pens (802 pigs) in experiment l to evaluate the effect of high dietary copper levels and vitamin E on performance, hemoglobin level and liver copper stores of pigs. In experiment 2, 142 pens (934 pigs) were used to evaluate the effect of different levels of copper and copper withdrawal after 8 weeks on rate and efficiency of gains and liver copper stores. Analysis of variance based upon performance for the entire feeding period of pigs by pens demonstrated that 250 ppm of copper or 22 IU of vitamin E per kilogram of diet did not significantly affect rate or efficiency of gain. However, differences among stations in response to copper were noted by a significant station x copper interaction. The level of 250 ppm of copper resulted in reduced hemoglobin and increased copper stores in the liver. Daily gains were increased during the initial 8-week period by feeding dietary levels of