Determination of Net Energy and Energy Loss through Volatile Fatty Acids in Broiler Chickens

Abstract

The apparent metabolisable energy assay is the default system of energy estimation in the poultry industry. However, the system is not capable of accounting for the utilisation of ME within the birds. The system is limited because it does not account for losses of chemical energy in the solid, liquid and gaseous excreta or as heat. Such energy losses may become significant if the composition of the diet changes substantially. This was the basis for the current study. Two experiments were conducted to examine (1) whether the amount of energy lost via heat increment and as volatile fatty acids in the excreta is influenced by the types of cereal grain, for example, maize and barley, and (2) whether (a) consumption of diets with elevated levels of soluble NSPs would increase energy loss as heat increment and volatile fatty acids in the excreta, and (b) enzymatic supplementation would enhance depolymerisation of the NSPs 'in vivo', and thus alleviate these losses.