A comparison of two sources of phytase in liquid and dry forms in broilers.
Research with corn-soybean meal diets was conducted to compare phytase sources in commercial broilers. A Ca to nonphytate P (nPP) ratio of 2.5:1 was maintained in all diets. Experiments 1 and 2 were conducted from d 4 to 13 (experiment 1) or d 9 to 23 post-hatching (experiment 2) in batteries. The 10 treatments used in both experiment were: Diets 1 to 4 = 0.20, 0.25, 0.30, or 0.35% nPP; Diets 5 to 7 = diet 1 plus 100, 200, or 300 phytase units/kg of diet from Natuphos (NAT); and Diets 8 to 10 = diet 1 plus 100, 200, or 300 phytase units/ kg of diet from Ronozyme (RON). As nPP levels increased, daily gain (ADG), feed intake (ADFI), gain:feed, and toe and tibia ash percentage were linearly increased (P < 0.06) in experiments 1 and 2. Incremental addition of phytase, regardless of source, linearly increased (P < 0.07) ADG and ADFI in experiment 1. Broilers fed NAT had higher (P < 0.07) toe ash percentage in experiment 1 and 2, and higher (P < 0.02) ADG and ADFI in experiment 2 than those fed RON. In experiment 3, 3,360 broilers were used to test 2 dry phytase products from 0 to 41 d posthatching in a 3-phase feeding program. The treatments were: Diet 1) adequate Ca and nPP; Diet 2) nPP reduced by 0.20%; Diets 3 to 5 = diet 2 plus 300, 500, or 750 phytase units/kg of diet from NAT; and Diets 6 to 8 = Diet 2 plus 300, 500, or 750 phytase units/kg of diet from RON. Broilers fed the adequate Ca and nPP diet had improved ADG and ADFI overall, and tibia ash weight and percentage in all growth phases (P < 0.03) compared with those fed the reduced Ca and nPP diets. Overall, ADG and ADFI were linearly increased (P < 0.05) by incremental phytase addition in experiment 3. Both NAT and RON produce similar growth and bone ash traits in commercial broilers.
Payne
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RL
Department of Animal Sciences, Louisiana State University Agricultural Center, Baton Rouge, Louisiana 70803, USA.
Lavergne
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TK
Southern
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LL
D010832:6-Phytase / Q000008:administration & dosage*; D000821:Animal Feed / Q000032:analysis; D000818:Animals; D001842:Bone and Bones / Q000187:drug effects / Q000502:physiology; D002645:Chickens / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D004032:Diet / Q000662:veterinary*; D004304:Dosage Forms; D004305:Dose-Response Relationship, Drug; D010744:Phosphoric Monoester Hydrolases / Q000008:administration & dosage*; D015430:Weight Gain / Q000187:drug effects
D004304:Dosage Forms; D010744:Phosphoric Monoester Hydrolases; D010832:6-Phytase; C400321:3-phytase