The aim of the study was to observe the effects of dietary available phosphorus (aP) and calcium (Ca), with regular or super doses of phytase, on phytate hydrolysis and subsequent influences on broiler growth performance and nutrient utilization. In a 2 × 3 factorial design, 384 Ross-308 broilers were allocated to one of 6 dietary treatments with 8 replicates in a randomized complete block design for 21 days. Diets were nutritionally adequate (positive control, PC) or marginally deficient in aP and Ca (negative control, NC), with 0, 500 or 1,500 FTU/kg phytase. Bird and feed weights were recorded on d 0 and 21, excreta were collected on d 19 and 20, and gizzard and ileal contents were collected on d 21. Body weight gain (P < 0.01) increased linearly with phytase in the PC and quadratically in the NC. There was an interactive effect on ileal DM, N, and P utilization, increasing quadratically with phytase supplementation in the NC, but there was no phytase influence in the PC (P < 0.05). Phytase linearly increased copper (P < 0.001) and linearly decreased Ca (P < 0.05) utilization in the ileum. Phytase decreased ileal (IPx, inositol x-phosphate) IP6 and IP5 and increased inositol (quadratic, P < 0.001) but had no effect on IP4 or IP3. The influence of the dietary aP was more apparent on the hydrolysis of phytate and phytate esters after the ileum, with increasing (linear and quadratic, P < 0.05) IP4 and IP3 content in the excreta of birds fed the NC or PC when phytase was added. Phytate hydrolysis improves the growth potential of birds fed NC diets, allowing them to match the growth performance of birds fed PC diets and improve nutrient utilization. These results indicate that dietary Ca and aP concentrations can be reduced when phytase is supplemented. It also may be beneficial to apply the enzyme nutrient matrix to other nutrients in the diet to maintain an optimal balance of nutrients in the digesta.
An experiment was conducted to evaluate phytase supplementation on growth, phytate degradation, and the gene expression of myo-inositol transporters in 21-day old broilers. Ross 308, male broilers (n = 240) were assigned to one of four diets, with 10 pens/diet and six birds/pen from day one to 21. The diets consisted of a negative control (NC) formulated to meet or exceed Ross 308 nutrient requirements, with the exception of calcium (Ca) and available P (avP), which were reduced by 0.16 and 0.15%, respectively. The NC diet was supplemented with 0, 500, 1,500, or 4,500 units/kg of phytase (FTU) to create four experimental diets. On day 21, all birds per pen were euthanized to obtain digesta and tissue samples for phytate degradation and gene expression. Data were analyzed as an analysis of variance using the fit model platform in JMP v 13.0. The model included phytase and significant means were separated using orthogonal linear and quadratic contrasts. Phytase supplementation increased gain (linear, P < 0.05). Phytate (iP6; quadratic, P < 0.05), phytate ester (iP5, iP4, iP3; quadratic, P < 0.05), and inositol (linear, P < 0.05) concentration in the gizzard was influenced by phytase supplementation. Phytate concentration decreased (linear, P < 0.05), iP5 or iP4 concentration increased and then decreased (quadratic, P < 0.05), and inositol concentration increased (quadratic, P < 0.05) in the ileal digesta as phytase supplementation increased in the diet. There was a tendency for the gene expression of the H+-dependent myo-inositol transporter, HMIT, to increase (linear, P < 0.05) in the ileum as phytase dose increased. Gene expression of the sodium-dependent myo-inositol transporter, SMIT2, increased in the jejunum (quadratic, P < 0.05) as phytase dose increased. Intestinal alkaline phosphatase expression increased (linear, P < 0.05) in the ileum as phytase supplementation increased in the diet. The influence of phytase on phytate, phytate esters, and inositol may influence intestinal alkaline phosphatase activity and the gene expression of myo-inositol transporters in the small intestine.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.