Effect of different dietary levels of low-glucosinolate rapeseed (canola) meal and non-starch polysaccharide-degrading enzymes on growth performance and gut physiology of growing turkeys

Zdunczyk, Z., Jankowski, J., Juskiewicz, J., Mikulski, D. and Slominski, B. A. 2013. Effect of different dietary levels of low-glucosinolate rapeseed (canola) meal and non-starch polysaccharide-degrading enzymes on growth performance and gut physiology of growing turkeys. Can. J. Anim. Sci. 93: 353-362. One-day-old male turkey poults were randomly assigned to eight dietary treatments and were fed diets containing 0, 60, 120, or 180 g kg⁻¹ of low-glucosinolate rapeseed meal (RSM) from 1 to 56 d of age without or with a commercial non-starch polysaccharide-degrading enzyme product containing pectinase, cellulase, xylanase, glucanase, mannanase and galactanase activities. There were no significant differences (P>0.05) in body weight and feed conversion ratio between the Control soybean meal-based diet and the diets containing RSM. Overall, the inclusion of up to 180 g kg⁻¹ of RSM did not affect the growth performance of turkeys. When compared with the Control treatment, the diet with the lowest RSM content increased the pH of the small intestinal contents and the amounts of cecal digesta. The moderate level of RSM also increased the pH of the small intestinal contents although no increase in the cecal digesta contents was noted. In comparison with other treatments, the highest RSM content increased the content of the small intestinal digesta considerably and decreased the pH of the small intestinal contents to that of the Control treatment. All three dietary levels of RSM significantly reduced the activity of bacterial β-glucuronidase in the ceca. Enzyme supplementation tended to reduce ileal viscosity (P=0.079), decreased ammonia concentration, increased the glycolytic activities of the intestinal microflora enzymes a-glucosidase, a-galactosidase, and β-galactosidase, decreased the activity of β-glucuronidase and increased the growth rate of turkeys.