Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.8 (phytase)
 1,997 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Three experiments were carried out to determine the phosphorus (P) requirements of laying hens aged 34 to 58 weeks (experiment 1), 59 to 70 weeks (experiment 2) and 22 to 50 weeks (experiment 3) given diets containing wheat, sorghum and soyabean meals as the main ingredients. Dietary total P (Pt) varied between 3.2 and 7.3 g/kg (experiment 1), 3.2 and 4.6 g/kg (experiment 2) and 3.0 and 6.6 g/kg (experiment 3). Hens were housed at either 18 degrees or 30 degrees C (experiments 1 and 2) and uncontrolled temperature (experiment 3), and in experiment 2 diets were fed without or with a phytase supplement of 500 units/g. 2. Dietary Pt had no significant effect on production measures in any experiment. Increases in dietary Pt adversely influenced egg shell quality although uterine calcium (Ca), ATPase and carbonic anhydrase activities were unaffected. 3. A 3-d-feeding trial in experiment 1 gave maximum Pt retentions of 228 mg/d at 18 degrees C and 204 mg/d at 30 degrees C. These were obtained with diets containing, respectively, 4.6 and 6.0 g Pt/kg. 4. Plasma inorganic P (Pi) increased consistently with increases in dietary Pt at all temperatures but plasma total Ca, and tibia Ca and P, were unaffected. 5. The inclusion of the phytase supplement in diets containing 3.2 and 4.6 g Pt/kg had an adverse effect on egg production at both temperatures in experiment 2. 6. A dietary Pt concentration of 3.2 g/kg, providing a calculated 1.2 g available P (Pav)/kg, with a dietary phytase activity of less than 200 units/kg, satisfied the P requirements of the hens used in these studies. However, the data from experiment 3 suggest that the Pt requirement of some flocks fed on wheat-based diets may be lower than 3.2 g/kg.
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PMID:Phosphorus requirements of laying hens fed on wheat-based diets. 765 2

A 3-wk feeding trial using 920 day-old turkey poults was conducted to evaluate the addition of seven levels of phytase (Natuphos; 0, 200, 400, 600, 800, 1,000, and 1,200 U/kg of diet) to diets containing three levels of nonphytate P (nP) (.27, .36, and .45%). A positive control diet contained .60% nP. Semi-purified basal diets contained soybean meal as the only protein source. The increase in BW gain from added phytase was greatest for the lowest nP diet (nP by phytase interaction, P < .001). At .27% nP, gains improved (P < .001) to 800 U of phytase/kg of diet and then reached a plateau. At .36 and .45% nP, increases in gains were observed only for 200 U of phytase/kg of diet. The highest phytase addition to.36 and .45% nP diets produced gains equal to those of the positive control diet. Feed intake increases paralleled those of BW gains. Gain:feed was lowest for the .27% nP diets without phytase, but improved (P < .001) to 800 U of phytase/kg of diet and then reached a plateau. The high incidence of leg disorders and high mortality (40%) observed for the poults fed the .27% nP diet without added phytase declined with the addition of 200 to 400 U of phytase/kg of diet. Ash percentage of toes and tibias increased as the levels of nP (P < .001) and phytase (P < .01) increased; the magnitude of the response to phytase decreased as nP in the diet increased, resulting in an nP by phytase interaction (P < .001). Tibial shear force and stress responded in a similar manner to increasing levels of nP and added phytase. Results show that 652 U of microbial phytase is equivalent to 1 g of P from defluorinated phosphate in turkey starter diets using soybean meal as the only source of phytate P. The response per 100 U of phytase decreased as the total amount of phytase added was increased.
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PMID:Response of turkey poults to tiered levels of Natuphos phytase added to soybean meal-based semi-purified diets containing three levels of nonphytate phosphorus. 861 93

A 3-wk feeding trial with 180 sexed day-old broiler chickens was conducted to study the efficacy of microbial phytase (Natuphos 1000) on growth performance, relative retention of P, Ca, Cu, and Zn, and mineral contents of plasma and bone. Treatments involved a normal P level corn-soybean diet, a low-P diet, and a low-P plus phytase (600 phytase units/kg) diet. Phytase supplementation increased (P < or = 0.05) body weight in male and female chickens by 13.2 and 5.8%, respectively, at 21 d. The improvements yielded body weights comparable to those obtained on the normal P diet. Phytase supplementation overcame (P < or = 0.05) the depression of feed intake observed on the low-P diet. Treatments had no effect on feed:gain ratio. Phytase supplementation of the low-P diet increased (P < or = 0.05) the relative retention of total P, Ca, Cu, and Zn by 12.5, 12.2, 19.3, and 62.3 percentage units, respectively, in male chickens. Microbial phytase increased the plasma P by 15.7% and reduced (P < or = 0.05) the Ca concentration by 34.1%, but had no effect on plasma concentrations of Cu or Zn. Phytase supplementation increased the percentage ash in both head and shaft portions of dry, fat-free tibia bone to a level comparable to that of the normal-P diet. Phytase supplementation had no effect on the concentration of any of the minerals measured in whole tibia ash but did increase (P < or = 0.05) the DM percentage of P and Ca min tibia head of male chickens by 0.65 and 1.4 percentage units, respectively. These results show that microbial phytase supplementation of a low-P diet increased growth and relative retention of total P, Ca, Cu, and Zn and improved bone mineralization in broiler chickens.
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PMID:The effects of supplemental microbial phytase on the performance and utilization of dietary calcium, phosphorus, copper, and zinc in broiler chickens fed corn-soybean diets. 873 37

Ninety-six weanling pigs (initial BW = 9.3 kg, initial age = 37 d) were used in a 4-wk experiment to evaluate the response to three Ca: total (t) P ratios (1.2:1, 1.6:1, or 2.0:1) fed in combination with two P levels (.07 or .16% available that correspond to .36 or .45% tP) and two phytase levels (PY; 700 or 1,050 units/kg of diet). A 3 x 2 x 2 factorial arrangement of treatments was employed using a corn-soybean meal diet. Performance, serum mineral concentrations and alkaline phosphatase (ALP) activity, Ca and P digestibility and excretion, and bone mechanical measurements were examined. Average daily gain (P < .001), average daily feed intake (P < .01), and gain:feed (P < .05) were decreased linearly as the Ca:tP ratio became wider. The digestibility of P and Ca were decreased (P < .001) linearly as the Ca:tP ratio became wider. The digestibility of P (P < .001) and fecal P excretion (P < .01) were increased at the higher level of P. Increasing PY from 700 to 1,050 units (U)/kg of diet increased (P < .05) P digestibility and decreased (P < .01) P excretion but did not improve bone measurements. Shear force, stress and energy, and percentage of ash of both metacarpal and 10th rib linearly decreased (P < .001 to .05) as the Ca:tP ratio became wider, and bone measurements were generally greater for pigs fed the higher P level. Serum Ca concentration increased (P < .01) and the P concentration decreased (P < .001) as the Ca:tP ratio increased, but Mg, Zn, and ALP activity were not influenced by the Ca:tP ratio. Serum Ca and P concentrations were affected by PY supplementation over the 4-wk trial, but serum Mg and Zn concentrations were not affected by dietary treatments. Adverse effects of a wide Ca:tP ratio were greater at the low P diet for all responses. In addition, the activity of supplemental PY in diets seemed to be decreased as the Ca:tP ratio became wider and this negative effect of Ca:tP ratio seemed greater at the low P level, and seemed to parallel the effects of Ca:tP ratio on performance, P digestibility, bone, and serum measurements. Narrowing the dietary Ca:total P ratio from 2.0:1 to 1.2:1 led to an approximate 16% increase in phytase efficacy for improving performance, digestibility, bone measurements, and serum Ca levels.
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PMID:Adverse effects of wide calcium:phosphorus ratios on supplemental phytase efficacy for weanling pigs fed two dietary phosphorus levels. 879 Dec 1

A 3-wk feeding trial with 240 sexed, day-old broiler chickens was conducted to determine the efficacy of microbial phytase at different levels of dietary Ca on performance and utilization of minerals in broiler chickens fed a low-P corn-soybean diet. The experimental design was a 3 x 2 factorial arrangement of treatments; Ca at 0.6, 1.0, and 1.25% and phytase at 0 and 600 phytase U/kg diet. Phytase supplementation, regardless of Ca level, increased (P < or = 0.005) feed intake, (P < or = 0.0001) body weight, and (P < or = 0.025) feed efficiency at 21 d; the optimum levels of body weight, feed intake, and feed efficiency were obtained with low (0.6%) dietary Ca plus phytase. Retentions of P, Ca, and N were increased (P < or = 0.05) by phytase supplementation. Although maximum retentions of P and N were obtained at the 1.0 and 1.25% Ca levels, respectively, they were not significantly different from the values obtained at 0.6% Ca. The increasing level of dietary Ca decreased plasma P ( P < or = 0.05) and Cu (P < or = 0.06). Phytase supplementation had the opposite effect; i.e., increased plasma P (P < or = 0.03) and Cu (P < or = 0.02). The maximum level of plasma P was obtained with phytase at the 1.0% Ca level, but this value was not significantly different from the value obtained with phytase at the 0.6% Ca level. Phytase supplementation increased (P < 0.04) the ash content of both tibia head and shaft but had no effect on mineral contents in the ash. The optimum level of ash content was observed with the 0.06% Ca diet plus phytase. The results show that microbial phytase supplementation to a low P diet improved growth performance and mineral utilization in broiler chickens. Dietary Ca levels had a significant effect on the response to phytase; the optimum growth performance and mineral utilization were achieved at the low (0.6%) level of dietary Ca supplemented with phytase.
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PMID:Efficacy of supplemental microbial phytase at different dietary calcium levels on growth performance and mineral utilization of broiler chickens. 900 Feb 77

1. A 3-week feeding trial with 96 sexed d-old broiler chickens was conducted to examine the effects of microbial phytase supplementation (Natuphos 5000) at 2 dietary energy concentrations on their performance, and the utilisation of nitrogen (N), phosphorus (P), calcium (Ca) and zinc (Zn) and on tibiae ash, Ca, P and Zn concentrations. Four replicate pens (6 birds per pen) of a completely randomised design were used in a 2x2 factorial arrangement of treatments with 2 contents of metabolisable energy (11.72 and 12.55 MJ ME/kg) and 2 additions of phytase (0 and 500 U of microbial phytase/kg). 2. Phytase supplementation significantly improved the utilisation of N, P, Ca and Zn (as a percentage of intake) and increased the concentration of Ca and Zn in the tibiae (P<0.05) because of higher intakes of dry matter, N, P, Ca and Zn. Phytase also significantly reduced the amount of P in the excreta (P<0.05). 3. The AME content of the diet influenced significantly (P<0.05) the excretion of N, P, Ca and Zn and the concentration of P and Ca in tibiae with the birds fed on the high AME diet excreting more minerals and having a smaller percentage of these minerals in their tibiae. However, there were strong interactions between phytase addition and AME in tibia ash and P, with the phytase supplementation producing a higher ash content at the higher AME a and a lower P content at the lower AME.
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PMID:Effects of microbial phytase on growth and mineral utilisation in broilers fed on maize soyabean-based diets. 1047 31