ENZYME SUPPLEMENTATION OF WHEAT-BASED DIETS FOR BROILERS - 1 - EFFECTON GROWTH-PERFORMANCE AND INTESTINAL VISCOSITY

The influence of enzyme supplementation on performance and intestinal viscosity of male broiler chickens fed with diets containing high amou nt of wheat was examined in three experiments. In the first experiment , addition with an enzyme preparation including different cell wall de grading enzymes to diets containing 63 g kg(-1) and 72 g kg(-1) of whe at improved (P<0.05) feed conversion efficiency in the 72 g kg(-1) whe at diet. In addition, intestinal viscosity of chickens fed with the 72 g kg(-1) wheat diet was reduced (P<0.05). Weight gain and feed intake were not influenced by enzyme addition. In Experiments 2 and 3, the i nclusion level of wheat in the diets was more than 80 g kg(-1) and fou r different enzyme preparations were used (two xylanase preparations, two mixed preparations). Overall, a significant effect on performance and intestinal viscosity of chickens was obtained as a result of enzym e supplementation in both experiments. In the first 21 days, improveme nts (P<0.05) in weight gain and feed conversion efficiency were found to be on average 5% and 6% in Experiment 2 and 7% and 8% in Experiment 3, respectively. When weight gain and feed conversion efficiency were examined on a weekly basis it was shown that the significant response of enzyme addition was confined to the first 4 weeks. However, the ef fect of enzyme supplementation was still significant in the whole peri od from 21-42 days. Feed intake was not influenced by enzyme addition. The viscosity of intestinal content in both the jejunum and ileum was in general reduced (P<0.05) with enzyme supplementation, the xylanase preparations proving to be the most efficient. It was concluded that enzyme supplementation of wheat-based diets resulted in improved perfo rmance of broiler chickens, which was related to a concomitant reducti on in intestinal viscosity. However, the response of enzyme supplement ation was most pronounced in diets with a wheat content higher than 80 g kg(-1). (C) 1998 Elsevier Science B.V.