Effects of Keratinase on Performance, Nutrient Utilization, Intestinal Morphology, Intestinal Ecology and Inflammatory Response of Weaned Piglets Fed Diets with Different Levels of Crude Protein (Report‪)‬

INTRODUCTION Soybean meal is one of the most commonly used protein source for pigs (Swick, 2007). Although most of the proteins in soybean meal are easily digested (McDonnell et al., 2010), some are difficult to digest especially for newly weaned piglets. Problematic proteins include glycinin (about 40% of the total soybean globulin proteins), [beta]-conglycinin (about 30%), and other minor proteins (Brandom and Friedman, 2002; Sun et al., 2007). Previous studies have shown that these proteins can damage intestinal morphology and impair immune function in newly-weaned pigs (Qiao et al., 2003; Sun et al., 2007; Yoo et al., 2009). When such dietary factors are combined with the stress of weaning, both nutrient metabolism and the immune function of weaned piglets can be seriously impaired (Kong et al., 2009).