Effects of total collection method and dietary enzyme supplementation on the energy utilisation and metabolisable energy values of diets fed to broiler chickens

초록

This experiment was conducted to determine the effects of dietary enzyme supplementation on the energy utilisation and metabolisable energy values of diets fed to broiler chickens using 2 different total collection methods. The experiment was performed using a completely randomised design with a 2 x 2 factorial arrangement of two total collection methods (marker to marker method or precision-fed method) and two dietary treatments (with or without 1 g/kg dietary multi-enzyme supplementation). A total of 48 35-day-old Ross 308 broiler chickens were randomly allotted to one of two total collection methods, and within each method, birds were randomly assigned to one of two dietary treatments with 6 replicates of two birds (one male and one female) per replicate. Additional 12 birds were used to estimate endogenous losses of gross energy (GE) and nitrogen (N). No significant interactions were identified for any measurement, and therefore, the main effects were analysed. Results indicated that birds assigned to the marker to marker method had greater (P<0.01) total tract apparent retention of DM and GE than those assigned to the precision-fed method. The AME and AME(N) values of diets measured by the marker to marker method were greater (P<0.01) than those measured by the precision-fed method. When the endogenous losses of GE and N were corrected, however, the average AME(N) value (12.6 MJ/kg) of diets measured by the marker to marker method was comparable to the average TMEN value (12.8 MJ/kg) of diets measured by the precision-fed method. The AME(N) values of diets measured by both 2 methods were increased (P<0.01) by dietary enzyme supplementation. Likewise, dietary enzyme supplementation increased (P<0.05) TMEN values of diets in the precision-fed method. In conclusion, the energy utilisation of diets fed to broiler chickens and the efficacy of dietary enzyme can be reasonably determined by both total collection methods if the endogenous losses of GE and N are corrected in the precision-fed method.

키워드