Effect of cultivar and enzyme supplementation on nutrient availability and performance of broilers fed Maritime Canadian wheat

Abstract

The feeding value of wheat is affected by the content of soluble non-starch polysaccharides (NSP), which varies among cultivars and the environment in which they are grown. Dietary enzymes can reduce the negative effects of NSP and improve the apparent metabolizable energy (AME) content of the wheat. This study examined differences in feeding value of four wheat cultivars grown in 2 crop years in the Maritime provinces of Canada and the need for enzymes. In a growth trial, diets containing one of the Maritime wheats or corn were fed with or without commercial enzymes containing, for wheat-based diets a mixture of xylanase and protease, and for corn-based diets a mixture of xylanase, protease, and amylase. In a broiler chick bioassay, diets containing 80% wheat were fed with or without a commercial enzyme with xylanase and protease activities. Enzymes significantly lowered body weight gain of birds fed Walton wheat in the second year, and improved the grower feed conversion ratio of birds fed Norboro wheat. Enzyme supplementation significantly improved apparent metabolizable energy and digestibility of crude protein. The AME content did not appear to be a direct indicator of performance. There were significant differences in AME content among the wheat samples. Enzymes generally did not improve performance in this study, possibly due to the relatively low in vitro viscosity values of these samples. Maritime wheats were equal or compared favourably with the sample of wheat from Western Canada and to locally obtained corn. Key words: Wheat, broiler performance, apparent metabolizable energy, enzyme