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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)
Soaking of a rat diet, high in both plant phytate and
phytase
, progressively degraded the phytate content with time of soaking. This dephytinization in turn enhanced the digestion of feed organic matter in the animals, and it significantly improved the absorption and retention of minerals and trace elements as observed in balance studies. Incorporation of elements into specific tissues was evaluated as a reflection of bioavailability. Some tissues did reflect the preceding absorption of certain elements; other tissues seemed less suitable as indicators of trace element absorption. Dietary calcium addition in many ways contrasted the soaking procedure: inorganic calcium addition to the feed reduced
phosphorus
, magnesium, and trace element bioavailability, and interfered with the internal deposition of the elements. The external dephytinization of the feed did not affect the phosphohydrolase activity of the intestinal mucosa as manifested by alkaline phosphatase activity or
phytase
activity. The mucosal
phytase
and alkaline phosphatase activities were, however, mutually correlated, supporting the view that "phytase" activity is a less substrate-specific action of alkaline phosphatase activity or a fraction of this activity.
...
PMID:Dephytinization of a rat diet. Consequences for mineral and trace element absorption. 750
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.
...
PMID:Phosphorus requirements of laying hens fed on wheat-based diets. 765 2
Phytate is the major storage form of
phosphorus
in seeds and so is a common dietary constituent. Excessive ingestion of undegraded phytates can cause mineral deficiencies in humans. In addition, phytic acid is antineoplastic in animal models of both colon and breast carcinoma. There have been no previous studies quantifying
phytase
activity in the human small intestine although it is present in animals. Small intestinal
phytase
and alkaline phosphatase activity and distribution was measured in vitro in mucosal homogenates from two human small intestinal specimens obtained from transplant donors. Rat intestine was also studied for comparison. Phytase activity was found in human small intestine at low values (30 times less than that in rat tissue and 1000-fold lower than alkaline phosphatase in the same tissue). The activity was greatest in the duodenum and lowest in the ileum. In conclusion, the normal human small intestine has very limited ability to digest undegraded phytates. Although this may have adverse nutritional consequences with respect to metabolic cation imbalances, the presence of undigested phytate in the colon may protect against the development of colonic carcinoma.
...
PMID:Phytase activity in the human and rat small intestine. 795 29
Studies were conducted with corn-soybean meal diets to evaluate the effects of phytate
phosphorus
utilization on zinc absorption and retention in broiler chicks. In the first two experiments, zinc-65 was used to determine zinc absorption. Experiment 1 was a 2 x 2 factorial with 0 or 5 micrograms/kg dihydroxycholecalciferol and 0 or 40 ppm supplemental zinc. In Experiment 2, 5 micrograms/kg 1,25-dihydroxycholecalciferol [1,25-(OH)2D3] or 750 units/kg
phytase
or both were added to a diet containing 35 ppm zinc. The diets in Experiment 3 were similar to Experiment 2 except that 600 units/kg
phytase
was fed. Experiment 4 was similar to Experiment 3 except that dietary
phosphorus
was decreased by .15%. There were no treatment effects on body weight in Experiments 1 and 2. Zinc absorption was higher in zinc-deficient birds in Experiment 1, but there were no other effects on zinc-65 absorption or retention. Body weight was increased by 1,25-(OH)2D3 in Experiments 3 and 4 and by
phytase
in Experiment 4. Phytate
phosphorus
retention was increased by
phytase
and 1,25-(OH)2D3 and was increased additively when both sources were fed. Dietary 1,25-(OH)2D3 increased zinc retention at times during Experiments 3 and 4, but this response was inconsistent. Phytase did not affect zinc retention. Phytase plus 1,25-(OH)2D3 increased zinc retention synergistically in Experiment 3. Bone zinc was increased by 1,25-(OH)2D3 and
phytase
, and there was an additive effect in Experiment 3. Plasma zinc and alkaline phosphatase were not affected. The results suggest that supplemental zinc may be decreased in a corn-soybean meal diet when phytate
phosphorus
utilization is enhanced.
...
PMID:Effects of 1,25-dihydroxycholecalciferol and phytase on zinc utilization in broiler chicks. 797 76
1. Three experiments were conducted to evaluate the effects of the dietary addition of fungal
phytase
(derived from Aspergillus niger) on the performance and
phosphorus
utilisation in broiler chickens receiving low
phosphorus
diets without additional inorganic phosphates. 2. Graded amounts of supplemental
phytase
(125, 250, or 500 PU/kg diet) resulted in significant increases in both growth rate and food intake. However, only moderate improvements in food conversion were noted. 3. The enhancement of chick performance was related to an improved utilisation of dietary
phosphorus
, as confirmed by significantly elevated plasma concentrations of inorganic
phosphorus
and increased tibia ash percentages in birds receiving
phytase
-treated diets. The apparent availability of
phosphorus
was markedly improved and its concentration in excreta was reduced (experiment 1, P < 0.05). 4. It was concluded that an inclusion of
phytase
into practical broiler diet will allow the reduction or omission of additional dietary inorganic
phosphorus
.
...
PMID:Effects of supplemental phytase on performance and phosphorus utilisation in broiler chickens fed a low phosphorus diet without addition of inorganic phosphates. 806 10
The effect of the addition of microbial
phytase
to a diet based on field beans (30%), wheat (28%), peas (25%), and barley (14%) was studied in a 2-week experiment with 3 x 8 castrated male, individually housed, hybrid piglets (live weight range 12-16 kg). All diets contained about 4.7 g Ca, 4.2 g P (77% present as phytate
phosphorus
), 1.0 g Mg, 60 mg Zn per kg diet, and 17% crude protein. Group I was fed the basal diet with a native
phytase
-activity of about 260 U per kg diet. In group II, 350 U, in group III, 700 U of microbial
phytase
per kg diet were added. The addition of microbial
phytase
improved the apparent P absorption (% of intake) from 48% (group I) to 66% (group II) and 71% (group III). Comparable positive effects from the
phytase
treatment were obtained for the calcium utilization. The
phytase
supplementation also enhanced plasma zinc concentration significantly. The concentration of inorganic
phosphorus
in plasma, the zinc digestibility, and the magnesium balance were improved in tendency. The utilization of nitrogen remained unchanged.
...
PMID:Dietary effect of phytogenic phytase and an addition of microbial phytase to a diet based on field beans, wheat, peas and barley on the utilization of phosphorus, calcium, magnesium, zinc and protein in piglets. 807 7
Two experiments were conducted to evaluate the effect of dietary
phytase
and increasing levels of available
phosphorus
(P(av)) on the growth performance and
phosphorus
metabolism of broiler chicks. In both experiments, graded levels of P provided by dicalcium phosphate and of
phytase
were added to a low-P corn-soybean meal basal diet. In Experiment 1, diets providing .21, .29, .37, and .44% P(av) without
phytase
; .21% P(av) plus .05, .10, or .30%
phytase
; and .29% P(av) plus .10%
phytase
were each fed to four groups of seven chicks, 3 days of age. In Experiment 2, diets providing P(av) levels of .32, .38, and .44% and
phytase
levels of .5, 1.0, and 1.5% (250, 500, and 750 units/kg) in a factorial arrangement were each fed to four groups of eight chicks, 5 days of age. In Experiment 1, increasing dietary P(av), but not
phytase
, increased feed intake, weight gain, feed conversion, plasma inorganic P, tibia and toe ash, and tibia breaking strength (P < or = .05). Plasma inorganic P responded quadratically to increasing dietary
phytase
. In Experiment 2, feed intake and weight gain were increased by elevating the level of P(av), but not by
phytase
. Toe and tibia ash and plasma inorganic P were increased by dietary
phytase
and increasing levels of P(av) (P < or = .01). Tibia breaking strength was improved (P < or = .05) by dietary
phytase
but not by increasing levels of P(av). The P excretion was elevated (P < or = .01) by increasing levels of P(av) and was decreased by supplemental
phytase
(P < or = .05).(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:The effect of dietary phytase on growth performance and phosphorus utilization of broiler chicks. 826 99
These studies were conducted to determine if supplementation of a corn-soybean meal diet with 1,25-dihydroxycholecalciferol [1,25-(OH)2D3] would increase the utilization of natural phytate
phosphorus
by broiler chickens. Two experiments were conducted to evaluate the effect of dietary 1,25-(OH)2D3 in the presence and absence of supplemental
phytase
and at several dietary levels of inorganic
phosphorus
supplementation. The criteria measured in these studies were weight gain, gain:feed ratio, bone ash, rickets due to
phosphorus
deficiency, plasma calcium and
phosphorus
and retention of calcium,
phosphorus
and phytate
phosphorus
. In the first experiment, the types and amounts of fecal inositol phosphates were determined by HPLC, and the total fecal phytate was determined by the classic FeCl3 precipitation technique. In the first experiment, the addition of 1,25-(OH)2D3 to the diet in the presence of dietary
phytase
resulted in greater 9-d weight and bone ash and lower incidence of rickets; the retention of total fecal phytate and phytate
phosphorus
was greater than in controls. The second experiment was a complete 2 x 2 x 2 factorial design [
phosphorus
levels x
phytase
x 1,25-(OH)2D3]. The addition of 1,25-(OH)2D3 alone to the diet resulted in greater 9-d weight and bone ash, lower incidence of rickets, and greater retention of total calcium and
phosphorus
and phytate
phosphorus
. The highest retention of phytate
phosphorus
(79.4%) was obtained when both
phytase
and 1,25-(OH)2D3 were present in the diet. The possible mode of action and importance of these results in many areas of nutrition and environmental science are discussed.
...
PMID:Dietary 1,25-dihydroxycholecalciferol supplementation increases natural phytate phosphorus utilization in chickens. 838 10
Two experiments were conducted to determine the effects of supplemental microbial
phytase
on utilization of dietary zinc by weanling pigs. Experiment 1 was a 2 x 3 factorial arrangement of treatments with 24 pigs for 4 wk. Two levels of
phytase
activity (0 and 1350 units/g) and three levels of zinc (0, 30 and 60 mg/kg as ZnSO4.7H2O) were added to a corn-soybean meal basal diet. Weekly measures included growth performance, plasma alkaline phosphatase activity and plasma mineral concentrations. In Experiment 2, mineral balances were determined in 12 pigs fed the basal diet or the diet with added zinc (30 mg/kg) or
phytase
(1350 units/g). The results indicated that either supplemental
phytase
or supplemental zinc increased plasma alkaline phosphatase activity and plasma zinc concentrations, but these increases were not additive. Supplemental
phytase
decreased plasma alkaline phosphatase activity in pigs supplemented with zinc. Supplemental
phytase
also significantly enhanced weight gain, feed intake, gain:feed ratio, plasma concentrations of inorganic
phosphorus
, and retention of
phosphorus
and calcium. Neither supplemental
phytase
nor zinc affected zinc retention. Supplementing corn-soybean meal diets with microbial
phytase
at 1350 units/g feed improves bioavailability of zinc as well as of phytate
phosphorus
to weanling pigs.
...
PMID:Supplemental microbial phytase improves bioavailability of dietary zinc to weanling pigs. 838
Microbial
phytase
was added at concentrations of 0, 500, and 1,000
phytase
units per gram (PU/g) to a diet that derived the majority of its
phosphorus
content from organic sources. In addition, a positive control diet was prepared by adding calcium phosphate to increase the total dietary
phosphorus
by 1.7 g/kg. Each diet was available ad libitum for 3 wk to nine individually penned pigs approximately 5 wk old and with an initial weight of 10.2 kg. Digestibility of
phosphorus
was estimated, using chromic oxide as an indicator, from fecal samples obtained during the 3rd wk of the trial. Blood serum and metatarsal bones were obtained at slaughter. The addition of the microbial enzyme resulted in increased rate and efficiency of gain, increased digestibility of dietary
phosphorus
, increased serum
phosphorus
, decreased serum alkaline phosphatase, and increased metatarsal ash and weight of metatarsal
phosphorus
. The response to dietary microbial
phytase
was similar to that resulting from feeding a diet containing 1.7 g/kg of additional
phosphorus
from calcium phosphate.
...
PMID:Addition of microbial phytase to diets of young pigs. 839 74
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