title: True phosphorus digestibility of black-eyed pea and peanut flour without or with phytase supplementation in broiler chickens.
abstract: Two studies were conducted to determine the true P digestibility (TPD) of black-eyed pea (BEP) and peanut flour (PNF) and the TPD response to phytase supplementation using the regression method. Sequential diets containing 115, 230, or 345 g of BEP/kg (experiment 1) and 115, 230, or 345 g of PNF/kg (experiment 2) without or with 1,000 units of phytase/kg were formulated. Chromic oxide was added to the diets at the rate of 5 g/kg as an indigestible marker. At 20 d posthatch in each study, 384 male broiler chickens (Ross 708) were weighed and allotted to the diets with 8 replicates of 8 birds each in a randomized complete block design. The birds had free access to the experimental diets until d 26 posthatch. In both studies, dietary P increase and phytase supplementation improved (P < 0.001) growth performance of the broiler chickens. There were linear increases (P < 0. 001) in ileal and excreta P output but a linear decrease (P < 0.001) in apparent P digestibility with an increase in dietary P levels. Phytase supplementation reduced (P < 0.001) ileal P and excreta P output and increased (P < 0.001) apparent P digestibility and retention. Apparent Ca digestibility was affected (P < 0.01) by P level and phytase addition in BEP and by P level (P < 0.05) in PNF. Apparent Ca retention in BEP increased (P < 0.05) with phytase addition. The TPD in the BEP increased (P < 0.01) from 29 without phytase to 83% with the addition of 1,000 units of phytase/kg. There was an increase (P < 0.01) in TPD of PNF from 67 without phytase to 75% with phytase supplementation. There was a corresponding increase (P < 0.01) in true P retention from 10% without phytase to 61% with phytase in birds on BEP diets and an equivalent increase (P < 0.01) in true P retention from 74% without phytase to 84% with phytase in birds that received the PNF diets.
authors.affiliation: Department of Animal Sciences, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: E A
authors.initials: EA
authors.lastname: Iyayi
authors.forename: F
authors.initials: F
authors.lastname: Fru-Nji
authors.forename: O
authors.initials: O
authors.lastname: Adeola
mesh_terms: D010832:6-Phytase / Q000494:pharmacology*; D000821:Animal Feed / Q000032:analysis*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002645:Chickens / Q000502:physiology*; D004032:Diet / Q000662:veterinary*; D019587:Dietary Supplements; D004063:Digestion / Q000502:physiology; D007887:Fabaceae; D008297:Male; D010758:Phosphorus / Q000378:metabolism*
chemical_list: D010758:Phosphorus; D010832:6-Phytase