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PubMed2004

Effect of microbial phytase on ileal digestibility of phytate phosphorus, total phosphorus, and amino acids in a low-phosphorus diet for broilers.

The study aimed to assess the effect of a commercially available microbial phytase added to a corn-soybean meal diet on phytate P and total P in terminal ileal digesta as well as on true ileal amino acid digestibility. Three low-P diets containing 0, 500, or 750 U/kg of microbial phytase were fed to 21-d-old broiler chickens. Titanium dioxide was used as an indigestible marker. Ileal contents were collected from euthanized birds and analyzed, along with the diets, for total P, phytate P, and amino acids. Endogenous P determined at the terminal ileum was 446 +/- 59 mg/kg food dry matter (mean +/- SE). Endogenous ileal amino acids ranged from 219 +/- 33 mg/kg food dry matter for tryptophan to 1,255 +/- 166 mg/kg food dry matter for glutamic acid. Supplementation with microbial phytase resulted in a significantly (P < or = 0.05) greater phytate P disappearance (11% greater disappearance vs. unsupplemented control) from the terminal ileum. Similarly, true ileal total P digestibility was (P < or = 0.05) higher (10 to 12%) when microbial phytase was added. True ileal amino acid digestibility was significantly (P < or = 0.05) greater in the presence of microbial phytase for all the amino acids examined with the exception of methionine, tyrosine, histidine, and tryptophan. The mean increase in true ileal amino acid digestibility was 3.4%. The effect of phytase on true ileal phytate P, total P, and amino acid digestibility was similar for the 2 phytase inclusion levels tested. Microbial phytase improved phytate P and total P digestibility, as well as true ileal amino acid digestibility, for a corn-soybean diet.

6-Phytase↗
PubMed2006

Nitrogen- vs. phosphorus-based dairy manure applications to field crops: nitrate and phosphorus leaching and soil phosphorus accumulation.

Management of animal manures to provide nutrients for crop growth has generally been based on crop N needs. However, because manures have a lower N/P ratio than most harvested crops, N-based manure management often oversupplies the crop-soil system with P, which can be lost into the environment and contribute to eutrophication of water bodies. We examined the effects of N- vs. P-based manure applications on N and P uptake by alfalfa (Medicago sativa L.), corn (Zea mays L.) for silage, and orchardgrass (Dactylis glomerata L.), leaching below the root zone, and accumulation of P in soil. Treatments included N- and P-based manure rates, with no nutrient input controls and inorganically fertilized plots for comparison. Nitrate concentrations in leachate from inorganic fertilizer or manure treatments averaged 14 mg NO(3)-N L(-1), and did not differ by nutrient treatment. Average annual total P losses in leachate did not exceed 1 kg ha(-1). In the top 5 cm of soil in plots receiving the N-based manure treatment, soil test P increased by 47%, from 85 to 125 mg kg(-1). Nitrogen- and P-based manure applications did not differ in ability to supply nutrients for crop growth, or in losses of nitrate and total P in leachate. However, the N-based manure led to significantly greater accumulation of soil test P in the surface 5 cm of soil. Surface soil P accumulation has implications for increased risk of off-field P movement.

Animals↗
PubMed1997

Phytase supplementation of low-phosphorus growing-finishing pig diets improves performance, phosphorus digestibility, and bone mineralization and reduces phosphorus excretion.

Two experiments using 413 crossbred growing-finishing pigs were conducted to assess the use of a commercial microbial phytase (Natuphos) in corn-soybean meal diets to improve phytate P bioavailability and thus reduce inorganic P supplementation and fecal P excretion. In Exp. 1 (n = 189), the following diets were used: 1) .50/.40% total P, respectively, for grower and finisher phases, and no phytase; 2) .40/.35% P and no phytase; 3) diet 2 plus 250 U phytase/kg; and 4) diet 2 plus 500 U phytase/ kg. The total Ca level was .58/.48% for diet 1 and .53/.43% Ca for diets 2, 3, and 4 in the grower and finisher phases, respectively. Feeding the low-P diet without supplemental phytase resulted in an overall 18% reduction in ADG (P < .05), 15% reduction in ADFI (P < .05), and 3% poorer feed efficiency (P < .08). Adding 250 to 500 U phytase/kg to the low-P diet restored ADG, ADFI, and feed conversion to levels not significantly different from and within 96% of that observed for pigs fed the adequate-P diet. The overall apparent digestibility of P was linearly (P < .01) improved with addition of 250 and 500 U phytase/kg to the low-P diet, but Ca and DM digestibilities were not affected by phytase or P level. In Exp. 2 (n = 224) the following diets were used: 1) .38/.33% total P, respectively, for grower and finisher phases, and no phytase; 2) .42/.37% P and no phytase; 3) .46/.41% P and no phytase; 4) diet 1 plus 167 U/kg phytase; 5) diet 1 plus 333 U/kg phytase; and 6) diet 1 plus 500 U/kg phytase. All diets contained .41/.36% Ca for grower and finisher phases, respectively. Pigs fed the low-P control diet grew slower (P < .01) and less efficiently (P < .10) than pigs fed diets with added P or phytase. With increasing levels of supplemental phytase or P there was a linear increase (P < .01) in ADG, digestibility of P, and digested P and a quadratic improvement (P < .05) in feed efficiency. Tenth rib mineralization based on shear force and ash were linearly increased (P < .08 to .001) as phytase or P was added to the low-P diet. There were generally no effects of P or phytase level on carcass quality. Using prediction equations derived from the response traits of ADG and P digestibility in Exp. 1 and ADG, P digestibility, and bone shear force in Exp. 2 to added phytase or P, we estimated that 500 U phytase released an amount of phytate P that was approximately equivalent to .87 to .96 g of P from dicalcium-monocalcium phosphate supplements. Fecal P excretion was estimated to be reduced 21.5%.

6-Phytase↗
PubMed1998

Lowering the dietary calcium to total phosphorus ratio increases phosphorus utilization in low-phosphorus corn-soybean meal diets supplemented with microbial phytase for growing-finishing pigs.

Crossbred growing-finishing pigs (n = 120) were used to investigate the effect of three dietary Ca:total P (tP) ratios (1.5:1, 1.3:1, or 1.0:1) on P utilization in low-P corn-soybean meal diets supplemented with microbial phytase at 500 phytase units/kg. The basal grower (23 to 54 kg BW) diet contained .39% tP including .07% added inorganic P (iP), and the basal finisher (54 to 123 kg BW) diet contained .32% tP without added iP. An adequate-P positive control diet without phytase supplementation contained .60% Ca and .50% tP during the growing phase and .50% Ca and .40% tP during the finishing phase. Lowering the Ca:tP ratio linearly increased ADG during the growing phase (P < .03) and overall (P < .08), gain:feed ratio during the growing phase (P < .001), and P absorption during the finishing phase (P < .04). Lowering the Ca:tP ratio linearly increased BW at slaughter (P < .02), carcass weight (P < .04), bone breaking strength (P < .04), and bone ash weight (P < .06), whereas dressing percentage and backfat depth remained unchanged. In conclusion, pig performance and P utilization were increased by lowering the Ca:tP ratio from 1.5:1 to 1.0:1 in low-P corn-soybean meal diets supplemented with microbial phytase.

6-Phytase↗
PubMed1983

Phosphorus in swine. VI. Utilization of nitrogen, calcium and phosphorus and reproductive performance of gravid gilts fed two dietary phosphorus levels for five parities.

Sixty-two gilts were paired at breeding and assigned randomly to one of the following dietary treatments: (1) low P or (2) high P during gestation and lactation. Two sets of diets (A and B) were formulated; each set to provide a low (10 g) and high (15 g) daily P intake (equal Ca daily intake, 15 g) when fed at 1.82 and 2.27 kg daily, respectively for sets A and B. Females were fed 1.82 kg daily of set A diets during the first 11 wk of gestation, 2.27 kg daily of set B diets for the next 3 wk and 3.34 kg of the appropriate set B diets containing 20% wheat bran until farrowing, at which time the bran was gradually removed from set B diets and the feed level increased to 4 kg daily until weaning. The proportions of defluorinated phosphate and limestone were varied to provide the appropriate level of Ca and P (low and high). At approximately 5 wk before farrowing at each parity, up to 12 females from each group were used in Ca, P and N balance trials that lasted about 2 wk. Dietary P intake did not affect the apparent absorption and retention of N and Ca; 88% of the consumed N was absorbed and one-half of the absorbed was retained, and 37% of the Ca was absorbed and 94% of the absorbed was retained. Females fed the higher P intake, although excreting higher levels of P in the feces and urine, absorbed and retained a larger amount of P; but the low P-fed sows were more efficient in the retention of P when expressed as a percentage of intake or as a percentage of the absorbed P. With the exception of average total litter weight at birth that favored high P-fed sows, live, dead and total pigs at birth, average birth weight and breeding performance were not statistically different between P levels. Except for the first parity, most characteristics favored sows fed the higher P intake. Serum Ca and P levels and hair P concentration were similar between P levels. Hair Ca concentration, however, was higher for the high P-fed sows. Sows fed the higher daily P intake retained more P and there was a trend for better farrowing performance. However, breeding performance, serum Ca and P levels, hair P concentrations and Ca and N balance were similar between dietary P intakes. These results would support current National Research Council-suggested Ca and P levels for sows.

Animals↗
PubMed1996

Phosphorus equivalence of microbial phytase in turkey diets as influenced by calcium to phosphorus ratios and phosphorus levels.

Male day-old turkey poults (n = 768) were fed 0, 300, 600, or 900 U of phytase/kg of a corn-soybean diet in combination with four Ca:total P (tP) ratios of 1.1, 1.4, 1.7, and 2.0:1, and two levels of nonphytate P (nP) of 0.27 and 0.36% in a 21-d trial. Dietary Ca:tP ratios were obtained by varying defluorinated phosphate and limestone at the expense of cornstarch. The calculated dietary percentage of phytate P was 0.266 for all diets. Phytase additions linearly increased (P < 0.05) BW gain, feed intake, gain:feed, toe ash content, and apparent retentions of Ca and P at each Ca:tP ratio and nP level, but the response was influenced by dietary Ca:tP ratios and P levels. The detrimental effect (P < 0.02) of widening the Ca:tP ratio was observed for all measurements at each phytase and P level, and was greatest at lower phytase and P levels. Widening the Ca:tP ratio from 1.4 to 2.0 decreased the phytase efficacy by 7.4 and 4.9%, respectively, for 0.27 and 0.36% nP diets, which was close to the decrease in the phytase activity in vitro by 7.5 and 6.7%, respectively. The largest responses to supplemental phytase were achieved when poults were fed diets with 600 and 900 U of phytase/kg diet, respectively, for 0.36 and 0.27% nP, and for Ca:tP ratios ranging from 1.1 to 1.4:1. Second-order translog equations were generated for the phytase, Ca:tP ratio, and P effect, and nonlinear and linear equations for the phytase and Ca:tP ratio effect. Based on an assessment for the R2 and P values of equations, BW gain, feed intake, toe ash content, and P retention were sensitive measurements of the response to phytase addition. Equivalent equations were developed to determine the P equivalency of supplemental phytase. About 652 and 963 U of phytase were equivalent to 1 g nP, respectively, for 0.27 and 0.36% nP diets in turkey poults from hatch to 21 d of age.

6-Phytase↗
PubMed2005

Soil characteristics and phosphorus level effect on phosphorus loss in runoff.

The loss of phosphorus (P) in runoff from agricultural soils may accelerate eutrophication in lakes and streams as well as degrade surface water quality. Limited soil specific data exist on the relationship between runoff P and soil P. This study investigated the relationship between runoff dissolved reactive phosphorus (DRP) and soil P for three Oklahoma benchmark soils: Richfield (fine, smectitic, mesic Aridic Argiustoll), Dennis (fine, mixed, active, thermic Aquic Argiudoll), and Kirkland (fine, mixed, superactive, thermic Udertic Paleustoll) series. These soils were selected to represent the most important agricultural soils in Oklahoma across three major land resource areas. Surface soil (0-15 cm) was collected from three designated locations, treated with diammonium phosphate (18-46-0) to establish a wide range of water-soluble phosphorus (WSP) (3.15-230 mg kg(-1)) and Mehlich-3 phosphorus (M3P) (27.8-925 mg kg(-1)). Amended soils were allowed to reach a steady state 210 d before simulated rainfall (75 mm h(-1)). Runoff was collected for 30 min from bare soil boxes (1.0 x 0.42 m and 5% slope) and analyzed for DRP and total P. Soil samples collected immediately before rainfall simulation were analyzed for the following: M3P, WSP, ammonium oxalate P saturation index (PSI(ox)), water-soluble phosphorus saturation index (PSI(WSP)), and phosphorus saturation index calculated from M3P and phosphorus sorption maxima (P(sat)). The DRP in runoff was highly related (p < 0.001) to M3P for individual soil series (r2 > 0.92). Highly significant relationships (p < 0.001) were found between runoff DRP and soil WSP for the individual soil series (r2 > 0.88). Highly significant relationships (p < 0.001) existed between DRP and different P saturation indexes. Significant differences (p < 0.05) among the slopes of the regressions for the DRP-M3P, DRP-WSP, DRP-PSI(ox), DRP-PSI(WSP), and DRP-P(sat) relationships indicate that the relationships are soil specific and phosphorus management decisions should consider soil characteristics.

Agriculture↗
PubMed2006

Estimation of intracellular phosphorus content of phosphorus-accumulating organisms at different P:COD feeding ratios.

The intracellular phosphorus content of phosphorus-accumulating organisms (PAO) was determined based on a stoichiometric equation and phosphorus balance for an enhanced biological phosphorus removal system fed with different P:COD ratios. The data indicated that a higher P:COD feeding ratio could significantly promote the growth of PAO. As the P:COD feeding ratio increased from 0.02:1 to 0.04:1 and 0.16:1, the phosphorus in the sludge increased considerably from 0.053 to 0.084 and 0.205 mg P (mg VSS(aerobic))(-1), respectively, indicating a dynamic condition in the microbial population. From the calculations, the mass fractions of the PAO, glycogen-accumulating organisms, and ordinary heterotrophs changed from 0.10-0.15, 0.83-0.88, and 0.02 at 0.02:1 to 0.19-0.28, 0.70-0.79, and 0.02 at 0.04:1 and to 0.478-0.71, 0.26-0.50, 0.03 at 0.16:1 P:COD feeding ratios, respectively. Despite the variation in microbial diversity, the calculated phosphorus contents of the PAO at all P:COD feeding ratios were consistent between 0.241 and 0.378 mg P (mg VSS(PAO))(-1). The initial specific phosphorus release and uptake rates were 84.7-167.9 mg P (g VSS(PAO))(-1)h(-1) and 52.8-90.0 mgP (g VSS(total))(-1)h(-1), respectively.

Aerobiosis↗
PubMed2003

Sediment characteristics, phosphorus types and phosphorus release rates between river and lake sediments.

The Han river is 469.7 km long with 26219-km2 area watershed, and is the primary drinking water source for the 20 million people that live in Seoul, Kangwon-Do and Kyunggi-Do, Korea. Phosphorus release from sediments impacts water quality, and is endangering the beneficial use of the river. This research measures phosphorus release and predicts future releases from bottom sediments of two tributary areas (Chungpyung Lake (CPL) and Jamsil submerged dam (JSD) area in the Han river). Sediment samples were taken over a 4-year period from four points in the Jamsil dam area and from 92 points in CPL. The sediments were analyzed for total phosphorus, the form of the phosphorus and release rates under different conditions to the water column. Sediment phosphorus distribution from CPL was 3-5% adsorbed-P (Ads-P), 15-20% non-apatite-P (NAI-P), 25-30% apatite-P (A-P) and 45-57% residual-P (R-P). In the JSD area, the phosphorus distribution ranges were 1-3% Ads-P, 22-39% NAI-P, 26-40% A-P and 30-39% R-P. Laboratory experiments showed that phosphorus release rates from 60 to 80 mg/m2 week in JSD area and ranged from 25 to 40 mg/m2 week in CPL sediments.

Aerobiosis↗
PubMedDate not supplied

[The phosphorus supply of pigs in the body weight category of 11-38 kg. 1. The effect of the phosphorus supply on the performance, nutrient digestibility, protein and fat content in soft tissue and skeleton and protein and fat deposits].

The influence of phosphorus supply on performance and nutrient composition of the empty body was studied in two individual feeding experiments with two and three groups resp. (7 or 8 animals per group). The phosphorus content of the unsupplemented diet was in the experiments I and II 2.97 and 2.41 g/kg, the supplemented phosphorus (as monocalcium phosphate) amounted of 2.5 and 2.33 g/kg diet respectively. The phosphorus supplementation increased live weight gain in both experiments by 84 and 45% and improved feed conversion by 35 and 23% respectively. Phosphorus deficiency did not influence the digestibility of nutrients. The fat content of soft tissue and skeleton of the phosphorus deficient animals was increased. They deposited 0.7 kg more fat (in both experiments) and 1.5 or 0.7 kg less protein in experiment I and II respectively. The utilisation of energy for deposition was not influenced by the different phosphorus supply.

Adipose Tissue↗
PubMed1999

A bioassay to determine the effect of phytase on phytate phosphorus hydrolysis and total phosphorus retention of feed ingredients as determined with broilers and laying hens.

In order to accurately formulate diets for broilers and laying hens to meet phosphorus requirements without overfeeding, precise knowledge of an individual feed ingredient's contribution to the retainable phosphorus is needed. Seven feed ingredients, included as the sole source of phosphorus, were tested with and without the addition of 600 phytase units (FTU) phytase/kg diet, in a 5-d bioassay with 10 22-d-old male broilers. Without addition of phytase, the amounts of phytate phosphorus hydrolyzed in corn, soybean meal, wheat, wheat midds, barley, defatted rice bran, and canola were 30.8, 34.9, 30.7, 29.1, 32.2, 33.2, and 36.7%, respectively. The addition of phytase increased (P < or = 0.05) each value to 59.0, 72.4, 46.8, 52.2, 71.3, 48.0, and 55.8%, respectively. The addition of phytase increased total phosphorus retention from 34.8, 27.0, 16.0, 31.9, 40.3, 15.5, and 39.4% to 40.9, 58.0, 33.8, 43.4, 55.5, 26.5, and 45.7%, respectively. A similar bioassay was conducted with laying hens fed corn, soybean meal, and defatted rice bran. Without phytase addition, phytate phosphorus hydrolyzed in soybean meal, corn, and rice bran was determined to be 25.7, 23.0, and 36.1%, respectively, and was increased (P < or = 0.05) to 62.4, 52.0, and 50.9%, respectively, with the addition of 300 FTU phytase/kg feed. Total phosphorus retention of soybean meal, corn, and rice bran increased from 36.8, 28.6, and 35.9% to 53.4, 44.7, and 43.0%, respectively, with the addition of phytase.

6-Phytase↗
PubMed1983

Impaired phosphorus conservation and 1,25 dihydroxyvitamin D generation during phosphorus deprivation in familial hypophosphatemic rickets.

The pathogenesis of familial hypophosphatemic rickets (FHR) is incompletely understood. We therefore examined the effects of acute dietary phosphorus deprivation to see whether renal phosphate conservation and increased 1,25 dihydroxyvitamin D [1,25(OH)2D] plasma levels, which normally follow restriction of phosphorus intake, could be induced in patients with FHR. Six healthy male volunteers (age 26 +/- 3 yr) and seven male patients with FHR (age 24 +/- 3 yr) were placed on a low phosphorus diet supplemented with aluminum hydroxide and studied over a 4-d period. The patients with FHR excreted more than five times as much phosphorus per day at the conclusion of the study than did the controls (176 +/- 61 mg/24 h vs. 33 +/- 11 mg/h). In the normal subjects, maximum tubular reabsorptive capacity for phosphorus/glomerular filtration rate (TmP/GFR) rose progressively during phosphorus deprivation, and the rise from base line was more than two times greater than that seen in patients with FHR. Immunoreactive parathyroid hormone levels and nephrogenous cyclic AMP were initially normal in both groups and no change was seen in either group with phosphorus deprivation. In the normal subjects, 1,25(OH)2D levels rose progressively over the 96 h of the study (49 +/- 3 to 63 +/- 6 pg/ml, P less than 0.05), while mean circulating 1,25(OH)2D in the patients with FHR did not change (34 +/- 3 to 29 +/- 3 pg/ml). The changes in individual plasma 1,25(OH)2D levels correlated strongly with the change in individual nephrogenous cyclic AMP measurements in the patients with FHR (r = +0.93), while no such correlation was observed in the normal subjects. These data demonstrate a defective renal response to phosphorus deprivation in patients with FHR including a qualitatively abnormal response in 1,25(OH)2D generation.

Absorption↗