title: The effect of different dietary levels of canola meal on growth performance, nutrient digestibility, and gut morphology of broiler chickens.
abstract: This study evaluated the effects of different levels of canola meal in broiler diets on growth performance, nutrient digestibility, and duodenal morphometry. A total of 320 one-day-old Cobb broilers were used in a 35-d experiment. A completely randomized design with 5 levels of canola meal (0, 10, 20, 30, and 40%) as a substitute for soybean meal was used with 8 replicates of 8 birds each. The basal diets were formulated based on corn and soybean meal to meet nutrient requirements of broiler chickens. The levels of canola meal were evaluated with a polynomial regression at 5% of significance. Weight gain and average BW showed a quadratic response (P = 0.03 and P = 0.04, respectively), decreasing with the addition of 40% canola meal. The apparent nutrient digestibility of DM (P < 0.0001), CP (P < 0.0001), and nitrogen-free extract (P < 0.0001) decreased linearly with increased levels of canola meal. A quadratic effect was observed for villus height (P = 0.003), decreasing up to a 20% inclusion of canola meal in the diet and increasing beyond that level. In conclusion, canola meal can be added up to 16.7% in diets for broilers without affecting the key variables of growth performance. It can be added up to 20% with no negative effect on the CP digestibility, but there was a linear decrease in the digestibility of DM and nitrogen-free extract with increased inclusion of canola meal. Additionally, a quadratic response to canola was observed for villus height with a maximum at 23.6% canola meal.
authors.affiliation: Federal University of Pelotas, Faculty of Agronomy Eliseu Maciel, Department of Animal Science, PO Box 354, 96010-900 Pelotas, RS, Brazil.
authors.forename: E
authors.initials: E
authors.lastname: Gopinger
authors.forename: E G
authors.initials: EG
authors.lastname: Xavier
authors.forename: M C
authors.initials: MC
authors.lastname: Elias
authors.forename: A A S
authors.initials: AA
authors.lastname: Catalan
authors.forename: M L S
authors.initials: ML
authors.lastname: Castro
authors.forename: A P
authors.initials: AP
authors.lastname: Nunes
authors.forename: V F B
authors.initials: VF
authors.lastname: Roll
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena / Q000187:drug effects; D000818:Animals; D001937:Brassica / Q000737:chemistry*; D002645:Chickens / Q000033:anatomy & histology / Q000254:growth & development / Q000502:physiology*; D004032:Diet / Q000662:veterinary; D004063:Digestion; D004305:Dose-Response Relationship, Drug; D004386:Duodenum / Q000166:cytology / Q000187:drug effects*; D007413:Intestinal Mucosa / Q000166:cytology / Q000187:drug effects; D008297:Male; D011897:Random Allocation; D015430:Weight Gain / Q000187:drug effects*
keywords: alternative feedstuff; nutrient digestibility; nutrition; poultry