Inositol and gradient phytase supplementation in broiler diets during a 6-week production period: 2. Effects on phytate degradation and inositol liberation in gizzard and ileal digesta contents

Abstract

An experiment was conducted to evaluate effects of dietary phytase and inositol supplementation on phytate degradation in gizzard and ileal digesta contents of broilers from 1 to 43 d of age. One thousand nine hundred and twenty Yield Plus × Ross 708 male chicks were placed in 64 floor pens (30 birds/pen). Each pen received 1 of 8 dietary treatments from 1 to 43 d of age. Treatment 1 was formulated to contain 0.165 and 0.150% lower calcium and phosphorus, respectively, than treatment 7. Treatments 2 to 6 were formulated by adding phytase at 500, 1,500, 4,500, 13,500, and 40,500 phytase units ( FTU )/kg, respectively, to treatment 1. Treatment 8 was established by adding inositol to treatment 7 based on the maximum inositol liberation in treatment 6. At 15, 29, and 43 d of age, gizzard contents, ileal digesta, and blood were collected for analysis of inositol and inositol phosphate ( IP ) 2, 3, 4, 5, and 6 concentrations. Increasing phytase from 0 to 40,500 FTU/kg resulted in log-quadratic reductions ( P < 0.01) of inositol pentaphosphate and inositol hexakisphosphate concentrations in the gizzard and ileal digesta contents of broilers at 15, 29, and 43 d of age. The increase in phytase doses in treatments 1 to 6 reduced IP3 and IP4 concentrations in a log-quadratic manner ( P < 0.05) at each collection period in gizzard contents but only at 43 d of age in the ileal digesta of broilers ( P < 0.01). Log-quadratic increases ( P < 0.05) of inositol concentrations were observed in gizzard and ileal digesta contents when increasing phytase activity from 0 to 40,500 FTU/kg at each collection period, which translated to a log-quadratic increase ( P < 0.01) in plasma inositol concentration of broilers at 15, 29, and 43 d of age. Phytase supplementation up to 40,500 FTU/kg may benefit broilers by reducing phytate concentrations in the gizzard and ileal digesta contents. Moreover, inositol release in the ileal digesta may translate to increased plasma inositol concentration.

Rapeseed meal processing and dietary enzymes modulate excreta inositol phosphate profile, nutrient availability, and production performance of broiler chickens

“…The stepwise manner of dephosphorylation of IP6 ( Greiner et al, 2000 ) will lead to a release of different InsP (and isomers). As expected ( Pirgozliev et al, 2019a ; Olukosi et al 2020 ; Kriseldi et al 2021 ), feeding phytase reduced the excreta concentration of IP6-5. However, the degree of dephosphorylation for IP5 differed between treatments, as it was lower for MT compared to BD and ST, 46 vs. 83%, respectively.…”

Mucosal phosphatase activity, phytate degradation, and mineral digestibility in 6-week-old turkeys and broilers at different dietary levels of phosphorus and phytase and comparison with 3-week-old animals

“…Thus, different endogenous InsP 6 degradation in broilers and turkeys is likely to exist, but this has not yet been proven. Another factor that may influence endogenous InsP 6 degradation is the age or age-dependent physiological development of animals ( Morgan et al., 2015 ; Olukosi et al., 2020 ; Kriseldi et al., 2021 ).…”

Phytase dose-dependent response of kidney inositol phosphate levels in poultry

“…We are not aware of any studies of tissue response of inositol phosphates to circulatory inositol or phosphate, other than in blood [20]. Nonetheless, increases in circulatory inositol with dietary phytase are widely reported in poultry [9,16,17,[23][24][25][26][27].…”

“…For feed and digesta, freeze dried and milled samples are typically extracted using sodium fluoride and EDTA solution, pH 10 [11, 21] and InsP 3-6 analysed by high performance liquid chromatography (HPLC) with post column complexation with ferric ion and detection by UV at 290 nm. Commonly, inositol is measured by HPLC-pulsed amperometry [9,11,[22][23][24] by GC [25,26] or by enzymatic assay [16,17,27]. For tissue samples, however, the methods of extraction and analyses are markedly different.…”