Effect of Diet Complexity on the Performance of Newly Weaned Pigs Fed Pharmacological Levels of Zinc Oxide

Zinc (Zn) is an essential trace mineral for swine. The requirement for Zn has been suggested to be in the range of 50 to 100 mg/kg for pigs at various stages of growth. The bioavilability of zinc oxide (ZnO) as a source of Zn is lower than other Zn sources such as zinc sulfate (ZnSO4), zinc carbonate (ZnCO3) and Znmethionine in weanling pigs. Recent studies have shown that adding pharmacological levels (2000-4000 mg/kg) of Zn as ZnO to corn-soybean meal based diets improved started pig performance and was effective in controlling E. coli scours for weanling pigs. Very high levels of Zn can be toxic. Studies have demonstrated that Zn toxicosis is not found or is much less severe when ZnO is supplemented in corn-soybean meal dies for weanling pigs than ZnCO3 is the source of pharmacological levels of Zn. The response for weaned pigs to the addition of pharacological levels of ZnO to simple diets containing corn, soybean meal, and dried-whey has not been compared to the addition of the same levels of Zn to complex diets containing these same ingredients plus animal protein supplements. The objective of this study was to determine whether diet composition affected the growth promoting properties of ZnO in weaned pig diets