title: Influence of partial replacement of ground wheat with whole wheat and exogenous enzyme supplementation on growth performance, nutrient digestibility and energy utilization in young broilers.
abstract: This study investigated the influence of pre-pelleting inclusion of whole wheat (WW) and exogenous enzyme supplementation on growth performance, coefficient of apparent ileal nutrient digestibility (CAID) and apparent metabolizable energy (AME) in broilers fed wheat-based pelleted diets. A 2 × 3 factorial arrangement of treatments was used with two methods of wheat inclusion [622 g/kg ground wheat (GW) and 250 g/kg WW replaced GW (wt/wt) pre-pelleting (PWW)] and three enzymes (xylanase, phytase and xylanase plus phytase). A total of 288, one-day-old male broilers (Ross 308) were individually weighed and allocated to 36 cages (8 broilers/cage), and the cages were randomly assigned to the six dietary treatments. Birds fed PWW diets gained more (p < 0.05) weight than those fed GW diets. There was no effect (p > 0.05) of WW inclusion on feed intake (FI). Phytase alone increased (p < 0.05) FI compared to xylanase or the combination. Whole wheat inclusion increased (p < 0.05) the gain-to-feed ratio (G:F). Feeding xylanase plus phytase and phytase-added diets resulted in the greatest and lowest G:F, respectively, with xylanase supplemented diets being intermediate. Birds fed PWW diets had greater (p < 0.05) relative gizzard weights than those fed GW diets. There was no effect (p > 0.05) of WW inclusion on the CAID of nitrogen (N), starch and fat. Combination of xylanase and phytase resulted in greater (p < 0.05) digestibility of N, starch and fat than that of individual additions. Feeding PWW diets resulted in greater (p < 0.05) AME values than GW diets. Combination of xylanase and phytase increased (p < 0.05) the AME compared to the diets with individual additions of xylanase or phytase. The current results suggest that the influence of pre-pelleting WW inclusion and exogenous enzymes on nutrient digestibility and broiler performance is not additive.
authors.affiliation: Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand. M.Abdollahi@massey.ac.nz.
authors.forename: M R
authors.initials: MR
authors.lastname: Abdollahi
authors.affiliation: Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand.
authors.forename: V
authors.initials: V
authors.lastname: Ravindran
authors.affiliation: Danisco Animal Nutrition - DuPont Industrial Biosciences, Marlborough, Wiltshire, UK.
authors.forename: A M
authors.initials: AM
authors.lastname: Amerah
mesh_terms: D010832:6-Phytase / Q000008:administration & dosage / Q000494:pharmacology*; D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002645:Chickens / Q000502:physiology*; D004032:Diet / Q000662:veterinary; D004063:Digestion / Q000502:physiology*; D043364:Endo-1,4-beta Xylanases / Q000008:administration & dosage / Q000494:pharmacology*; D004734:Energy Metabolism / Q000502:physiology*; D005511:Food Handling; D008297:Male; D014908:Triticum / Q000737:chemistry*
chemical_list: D010832:6-Phytase; D043364:Endo-1,4-beta Xylanases
keywords: broiler chickens; digestive tract; performance; phytase; xylanase