PROTEIN AND COPPER SUPPLEMENTATION OF CORN-SOYBEAN MEAL DIETS FOR YOUNG PIGS
Four trials, involving a total of 426 Yorkshire pigs weaned at approximately 25 days of age, were conducted to measure the effect of including fish meal, dried skimmilk and copper, and of varying the protein level, in diets based on corn and soybean meal, on pig performance. The inclusion of 5% fish meal, 5% dried skimmilk or a combination of the two did not consistently alter pig performance when compared with a corn-soybean meal basal diet of a similar protein content. Levels of protein above 21.9% (dry matter basis) in the starter period did not alter pig performance. In the two trials in which 0.05% copper sulfate was added to the diets, it increased rate of gain. Seventeen pigs out of a total of 144 pigs in one trial died. Various of the following lesions were observed in the dead pigs: hepatosis dietetica, mulberry heart disease, exudative diathesis and ulcers. There was an apparent inverse relationship between the incidence of death and the protein or selenium content of the diet.