title: Protein source and dietary structure influence growth performance, gut morphology, and hindgut fermentation characteristics in broilers.
abstract: An experiment with 210 male (Ross 308) 1-d-old broilers was conducted to test the hypothesis that a coarse diet improves performance of broilers fed a poorly digestible protein source. A highly digestible diet based on soybean meal was gradually replaced by a low digestible diet based on rapeseed meal (RSM) in 5 steps (RSM-0%, RSM-25%, RSM-50%, RSM-75%, and RSM-100%). Two diet structures (fine and coarse) were used as an additional factor. These 2 factors and their interactions were tested at different ages in a factorial arrangement with 10 dietary treatments. An increase in indigestible dietary protein negatively affected feed intake (P = 0.003), BW gain (P = 0.008), and feed conversion ratio (P = 0.034). This increase in dietary indigestible protein contents resulted in a decrease (P = 0.001) in total cecal volatile fatty acid concentration from 209.1 to 125.9 mmol/kg of DM digesta in broilers with increasing RSM in diets. Increase in the indigestible protein level, from RSM-0% to RSM-100%, resulted in a decrease (P = 0.042) in villus heights (1,782 vs. 1,574 µm), whereas crypt depths increased (P = 0.021; 237 vs. 274 µm). A coarse diet improved feed intake (P = 0.006), BW gain (P = 0.014), and feed conversion ratio (P = 0.009). Broilers fed coarse diets had approximately 11, 24, and 10% lower relative empty weights of the crop, proventriculus, and jejunum, respectively, whereas a 15% heavier gizzard was found compared with those fed the fine diets. Dietary coarseness resulted in approximately 16% lower gizzard pH, 21% greater villus heights, 27% lower crypt depths, 24% reduced branched-chain fatty acids, and 12% lower biogenic amines in the cecal digesta compared with broilers fed fine diets. In conclusion, feeding coarse particles improved broiler performance irrespective of digestibility of the diet. Hindgut protein fermentation can be reduced by coarse grinding of the diet.
authors.affiliation: Animal Nutrition Group, Department of Animal Sciences, Wageningen University, PO Box 338, NL-6700 AH Wageningen, the Netherlands Shafqat.qaisrani@wur.nl.
authors.forename: S N
authors.initials: SN
authors.lastname: Qaisrani
authors.affiliation: Animal Nutrition Group, Department of Animal Sciences, Wageningen University, PO Box 338, NL-6700 AH Wageningen, the Netherlands.
authors.forename: P C A
authors.initials: PC
authors.lastname: Moquet
authors.affiliation: Wageningen UR Livestock Research, PO Box 65, NL-8200 AB Lelystad, the Netherlands.
authors.forename: M M
authors.initials: MM
authors.lastname: van Krimpen
authors.affiliation: Animal Nutrition Group, Department of Animal Sciences, Wageningen University, PO Box 338, NL-6700 AH Wageningen, the Netherlands.
authors.forename: R P
authors.initials: RP
authors.lastname: Kwakkel
authors.affiliation: Animal Nutrition Group, Department of Animal Sciences, Wageningen University, PO Box 338, NL-6700 AH Wageningen, the Netherlands.
authors.forename: M W A
authors.initials: MW
authors.lastname: Verstegen
authors.affiliation: Animal Nutrition Group, Department of Animal Sciences, Wageningen University, PO Box 338, NL-6700 AH Wageningen, the Netherlands.
authors.forename: W H
authors.initials: WH
authors.lastname: Hendriks
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002645:Chickens / Q000033:anatomy & histology* / Q000254:growth & development* / Q000502:physiology; D004032:Diet / Q000662:veterinary; D004044:Dietary Proteins / Q000008:administration & dosage / Q000494:pharmacology*; D005285:Fermentation; D041981:Gastrointestinal Tract / Q000033:anatomy & histology / Q000187:drug effects* / Q000502:physiology; D008297:Male
chemical_list: D004044:Dietary Proteins
keywords: biogenic amine; broiler; cecal fermentation; intestinal health; particle size