Digestibility of nutrients and metabolisability of energy in broiler diets with different ME level and supplemented with exogenous enzyme

Abstract

This experiment was carried out to assess the effects of exogenous enzyme (ROXAZYME®, G2G) supplementation on digestibility of nutrients and metabolisability (ME/GE) in 28-31 days old male Ross 308 broilers. A total of 96 Ross 308 hybrids were allocated randomly to 6 dietary treatments with 4 replicates per treatments, and 4 birds per replicates. In this 3×2 factorial design trial with three different levels of metabolizable energy (13.4, 13.00, 12.6 MJ/kg), with and without exogenous enzyme, the nutrition density was reduced by introducing sunflower meal in different percentages to diet (0, 8 and 16%). The methods used to determine digestibility of nutrients and energy were total and partial collection method and ileal digesta (one percent of Celite was added to the diet for this purpose). Metabolizable energy level had a significant effect (p<0.05) on digestibility of DM, hemicelluloses and ME/GE. By lowering metabolizable energy level, the digestibility decreased. Enzyme supplementation significantly (p<0.05) improved the digestibility of NDF, hemicelluloses and ash determined by partial and total collection method, while statistically significant improvement in digestibility of crude protein was observed only by total collection method. Digestibility determined by ileal digesta showed only significant improvement (p<0.05) in digestibility of hemicelluloses, while the other nutrients had a certain improvement that was not significant. The results suggested that exogenous enzyme, used in this trial, increased digestibility of crude proteins, NDF, hemicelluloses and ash (N€<0.05). However, the effects were most evident in diets with reduced level of metabolizable energy level and were determined by total and partial collection method. It can be concluded that the ME level affected digestibility of nutrients and energy, and that enzymes supplementation had the most profound effect on digestibility of nutrients and energy in diets with reduced ME level. Key words: Exogenous enzymes, digestibility, broilers.