Copper sulphate and copper sulphide (CuS) as supplements for growing pigs

Abstract

Seventy-two individually fed, virus pneumonia-free Large White weaners were used in two experiments to compare the effects of dietary supplements of CUSO4 and CuS on the performance of growing pigs from weaning to bacon weight. A supplement of 250 ppm. Cu given as copper sulphate had no significant effect on performance in the first experiment, but in the second it significantly increased growth rate by 12.9%, rate of food consumption by 8.8% and dressing percentage by 1.9%, and decreased carcass length by 2.2%. It also had an adverse effect on the commercial grading of the carcasses. The better performance of the unsupplemented control pigs in the first experiment compared with that in the second experiment is discussed. Small, not significant increases in mean growth rate were apparent in both experiments when 250 ppm Cu was given as copper sulphide. It was concluded that some improvement in growth rate was probably to be expected when this level of Cu was given as the sulphide, but that it was appreciably less than that normally obtained with 250 ppm. Cu given as copper sulphate. A supplement of 62.5 ppm Cu given as sulphide had no effect on the performance of the pigs. It is suggested that the effectiveness of Cu in promoting growth in pigs is related to the amount of soluble Cu in the gut, but whether the site of action is systemic, enteric, or both, remains unknown. Copper sulfate, but not copper sulfide, in the diet significantly increased liver and kidney stores of Cu. Values for total weight and moisture content of various organs and tissues are presented.