Fiber-degrading Enzymes Research Articles

Effects of Feeding Diets Based on Wheat Bread or Oat Bran Bread to Broiler Chickens

Abstract Broiler chickens (Ross) of mixed sexes were fed diets based on wheat bread or bread where part of the wheat flour had been replaced by oat bran (oat bran bread). Diets were fed with and without supplementation of a fibre-degrading enzymes preparation in order to study the effects of dietary fibres on animal production, serum cholesterol concentration and carcass composition. The oat bran bread diet gave the lowest growth and poorest feed conversion efficiency of all diets. However, enzyme supplementation significantly improved live weight, cumulative feed intake and feed conversion efficiency. No significant improvements due to enzyme supplementation were observed for the diet based on wheat bread. Enzyme supplementation to the oat bran bread diet also resulted in increases in serum lipid concentrations to levels similar to those of birds fed the wheat bread diets. Carcasses of birds fed unsupplemented oat bran bread generally had lower fat and significantly higher protein contents in comparison with those of birds fed the other diets.

The nutritive value for broiler chickens of pelleting and enzyme supplementation of a diet containing barley, wheat and rye

A diet based on barley (40%), wheat (25%), and rye (7%) was given as a mash diet or as dry or steam pelleted diets to a total of 384 broiler chickens. Diets were given with or without the addition of a fibre-degrading enzyme preparation. Pelleting increased the water solubility (at 38°C) of starch and crude protein. There were, however, no notable effects on the solubility of dietary fibre components following pelleting or enzyme supplementation. Buffer extracts from pelleted diets had a high relative viscosity, while mash diets gave the lowest relative viscosity. Enzyme supplementation diminished the high viscosity obtained for pelleted diets and reduced sticky droppings. Pelleting increased weight gain for chickens receiving the unsupplemented diets by ∼ 30% and for those fed on the enzyme-supplemented diets by ∼ 20%. This improvement, which was similar at both 14 and 20 days of age, was mainly due to a greater feed intake, particularly with the steam pelleting. Enzyme supplementation improved weight gain by 11–24%, and was more effective in the unpelleted diets and at Day 14. This improvement was due to both a higher feed intake and a better feed conversion efficiency. Pelleting tended to increase ileal digestibility of the unsupplemented diet while enzyme supplementation had a similar effect on the unpelleted diet. The latter treatment also increased whole-tract digestibility.