• Asian-Australasian Journal of Animal Sciences
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• v.13 no.7
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• pp.957-961
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• 2000

A series of experiments was conducted to evaluate phytin phosphohydrolysis actlVlty in the rumen and to isolate phytase positive rumen bacteria. Endogenous phytase activity of wheat bran was estimated and compared with that of bacterial phytin phosphohydrolysis. Substantial phytase activity was detected in wheat bran during in vitro rumen incubation. Bacterial phytase activity was suggested not to be high. Only two facultative anaerobes, Klebsiella sp. and Corynebacterium sp. were isolated as phytase producing organisms. These belonged to a minor microbial group in the rumen population. Protozoal fraction showed an initial velocity of phytin phosphohydrolysis 7 times higher than the bacterial fraction.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.7
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• pp.985-993
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• 2017

Objective: The objective of this study was to evaluate increasing doses of a novel microbial phytase (Cibenza Phytaverse, Novus International, St. Charles, MO, USA) on standardized total tract digestibility (STTD) of P in canola meal (CM), corn, corn-derived distiller's dried grains with solubles (DDGS), rice bran (RB), sorghum, soybean meal (SBM), sunflower meal (SFM), and wheat. Methods: Two cohorts of 36 pigs each (initial body weight = $78.5{\pm}3.7kg$) were randomly assigned to 2 rooms, each housing 36 pigs, and then allotted to 6 diets with 6 replicates per diet in a randomized complete block design. Test ingredient was the only dietary source of P and diets contained 6 concentrations of phytase (0, 125, 250, 500, 1,000, or 2,000 phytase units [FTU]/kg) with 0.4% of $TiO_2$ as a digestibility marker. Feeding schedule for each ingredient was 5 d acclimation, 5 d fecal collection, and 4 d washout. The STTD of P increased (linear or exponential $p{\leq}0.001$) with the inclusion of phytase for all ingredients. Results: Basal STTD of P was 37.6% for CM, 37.6% for corn, 68.6% for DDGS, 10.3% for RB, 41.2% for sorghum, 36.7% for SBM, 26.2% for SFM, and 55.1% for wheat. The efficiency of this novel phytase to hydrolyze phytate is best described with a broken-line model for corn, an exponential model for CM, RB, SBM, SFM, and wheat, and a linear model for DDGS and sorghum. Based on best-fit model the phytase dose (FTU/kg) needed for highest STTD of P (%), respectively, was 735 for 64.3% in CM, 550 for 69.4% in corn, 160 for 55.5% in SBM, 1,219 for 57.8% in SFM, and 881 for 64.0% in wheat, whereas a maximum response was not obtained for sorghum, DDGS and RB within the evaluated phytase range of 0 to 2,000 FTU/kg. These differences in the phytase concentration needed to maximize the STTD of P clearly indicate that the enzyme does not have the same hydrolysis efficiency among the evaluated ingredients. Conclusion: Variations in enzyme efficacy to release P from phytate in various feedstuffs need to be taken into consideration when determining the matrix value for phytase in a mixed diet, which likely depends on the type and inclusion concentration of ingredients used in mixed diets for pigs. The use of a fixed P matrix value across different diet types for a given phytase concentration is discouraged as it may result in inaccurate diet formulation.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.2
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• pp.203-208
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• 1999

An 8 week feeding trial was conducted with 864 ISA Brown laying hens, 48 weeks old, to determine if microbial phytase $(Natuphos^{(R)})$ supplementation can reduce non-phytate phosphorus (NPP) level in laying diets. The experiment consisted of four dietary treatments: T1, control diet with 0.26% NPP (0.55% total P) wand no supplementary phytase; T2, 0.21% NPP (0.50% total P) diet with 250 U of phytase/kg of diet; T3, 0.16% NPP (0.45% total P) diet with 250 U of phytase/kg of diet; and T4, 0.11% NPP (0.40% total P) diet with 250 U of phytase/kg of diet. T3 showed the highest egg production and egg weight and the lowest feed conversion while T4 gave the lowest egg production and the highest feed conversion and mortality. Daily feed consumption ranged from 130.4 g (T4) to 132.7 g (T2). T1 and T2 were not significantly different in the production parameters. Eggshell strength, egg specific gravity, and eggshell thickness were not significantly different among treatments. However, broken egg ratio was significantly lower in T2 and T4 than in T1. Retentions of Ca, P, Mg, and Cu were greater in phytase supplemented treatments (T2, T3, and T4) than the control (T1), and those in T3 and T4 were greater than in T2. Excretions of P in phytase supplemented treatments (T2, T3, and T4) were significantly (p<0.05) smaller than in T1 but excretions of N were not significantly different among the treatments. Contents of ash in tibiae were not significantly affected by treatments, but contents of Ca, P, Mg, and Zn was increased and that of Cu decreased by phytase supplementation. It is concluded that the NPP concentration in the diet of Brown layers consuming about 130 g/d of feed can be safely lowered from 0.26% (0.55% total P) to 0.16% (0.45% total P). The excretion of P was reduced by the inclusion of 250 U phytase/kg of diet.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.1
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• pp.1-9
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• 2014

Calcium (Ca) and phosphorus (P) are minerals that have important physiological functions in the body. For formulation of diets for pigs, it is necessary to consider an appropriate Ca:P ratio for an adequate absorption and utilization of both minerals. Although both minerals are important, much more research has been conducted on P digestibility than on Ca digestibility. Therefore, this review focuses on aspects that are important for the digestibility of Ca. Only values for apparent total tract digestibility (ATTD) of Ca have been reported in pigs, whereas values for both ATTD and standardized total tract digestibility (STTD) of P in feed ingredients have been reported. To be able to determine STTD values for Ca it is necessary to determine basal endogenous losses of Ca. Although most Ca is absorbed in the small intestine, there are indications that Ca may also be absorbed in the colon under some circumstances, but more research to verify the extent of Ca absorption in different parts of the intestinal tract is needed. Most P in plant ingredients is usually bound to phytate. Therefore, plant ingredients have low digestibility of P due to a lack of phytase secretion by pigs. During the last 2 decades, inclusion of microbial phytase in swine diets has improved P digestibility. However, it has been reported that a high inclusion of Ca reduces the efficacy of microbial phytase. It is possible that formation of insoluble calcium-phytate complexes, or Ca-P complexes, not only may affect the efficacy of phytase, but also the digestibility of P and Ca. Therefore, Ca, P, phytate, and phytase interactions are aspects that need to be considered in Ca digestibility studies.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.9
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• pp.1299-1304
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• 2005

An experiment was conducted to study the production performance of broiler breeder females (25 to 40 weeks of age) fed either reference diet or low non-phytate phosphorus (NPP) diet with or without microbial phytase (500 FYT/kg) supplementation. A weighed (160 g/b/d) quantity of feed from each diet was offered daily to 40 replicates of one bird each housed in California type cage having individual feeders. Each cage was considered as a replicate. A continuous 16-h light per day was provided using incandescent bulbs. Body weight, egg production, egg weight, feed per egg mass, egg specific gravity, egg breaking strength, shell thickness, tibia ash and serum Ca and protein concentrations were not affected by reducing the NPP level from 0.30 to 0.18% in the broiler breeder diet. Supplementation of phytase (500 FYT/kg) enzyme to the diet containing 0.18% NPP had no added advantage on any of the above production parameters. The serum inorganic P was increased significantly (p<0.05) by either enhancing the NPP content from 0.18 to 0.30% or supplementing phytase @500 FYT/kg to the diet containing low P which were found comparable. Retention of Ca and P was positive on all the diets. P retention decreased significantly (p<0.05) with either increase in NPP content or phytase supplementation in the diet. Neither NPP nor phytase supplementation influenced bone mineralization in terms of tibia ash and strength. The hatchability was not influenced by either increasing the NPP content or supplementing the enzyme phytase. Similarly, the P concentration in the egg yolk and day old chick, day old and 14th day body weight and leg score was not altered by increasing the level of NPP or supplementing phytase enzyme. The mortality was within the normal limits in all the three dietary groups. Thus, it can be concluded that 0.18% NPP (288 mg NPP intake/b/d) in the broiler breeder' diet is adequate in sustaining the optimum performance from 25 to 40 wks of age. Enhancing the NPP content or supplementation of phytase (500 FYT/kg diet) to diet containing 0.18% NPP had no added advantage on performance.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.2
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• pp.250-257
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• 2001

An experiment was conducted to determine the effects of phytase supplementation to the diets containing different levels of non-phytate phosphorus (NPP). A $3{\times}2$ factorial arrangement of treatments was employed. There were three dietary NPP levels of control (C) (0.45% for starter diet and 0.35% for grower diet), C-0.1% NPP (0.35% for starter diet and 0.25% for grower diet), and C-0.2% NPP (0.25% for starter diet and 0.15% for grower diet) and two phytase levels (0 and 500 U/kg). Reduced dietary NPP decreased feed intake and weight gain and increased mortality whereas dietary phytase increased feed intake and weight gain and decreased mortality. Supplemental phytase improved availabilities of dry matter, crude fat, ash, P, Zn, Mg, and Cu whereas dietary NPP level did not affect availabilities of nutrients except decreased Zn availability and increased Cu availability in reduced NPP diets. Nutrient retention of N, ash, Ca, P, Mg, and Zn were linearly decreased as dietary NPP levels reduced but dietary phytase increased their retention. Reduced dietary NPP increased ash excretion but decreased P and Cu excretion while dietary phytase decreased N excretion. Weight, length, girth and contents of ash, Ca, P and Mg of tibia linearly decreased as dietary NPP levels reduced. Dietary phytase increased length and ash content of tibia. It is concluded that dietary phytase can reduce P excretion and alleviate adverse affects caused by feeding low dietary NPP. Effects of phytase were greater in the lower NPP diets.

• Korean Journal of Poultry Science
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• v.34 no.3
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• pp.207-215
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• 2007

This work was carried out to assess the effect of microbial phytase (MP) on the performance, retention and excretion of phosphorus, and nutrients availability in broiler chicks. Two hundred and sixteen one day old Ross strains broiler chicks were used to investigate on performance for 5 weeks (earlier $(0{\sim}2wk)$, finisher $(3{\sim}5wk)$) and were divided 3 treatments, three cages per treatment and 12 birds per cage. Treatments are P0 (basal diet), P1 (microbial phytase 300 FTU/kg), and P2 (microbial phytase 600 FTU/kg). After 5 weeks, three diets containing 0, 300, 600 FTU/kg of microbial phytase were fed to 5-wk-old broilers to assess the digestibility. Twenty seven broilers were divided into 3 treatments (9 birds per treatment) to investigate on the absorption and retention of phosphorus and nutrient digestibility. Body weight gain and feed efficiency were highly significant at P1 and P2 treatments compared to those of P0 (P<0.05), however, feed intake was no significant difference among all treatments (P>0.05). The excretion of phosphorus decreased in P1 and P2 compared to P0 (P<0.05). The digestibility of nutrients and amino acid was high in P1 and P2 treatments compared to P0 (P<0.05). Ileal digestibility was lower about $1{\sim}2%$ than feces digestibility (P>0.05). Finally, microbial phytase influenced on the performance, the retention and excretion of phosphorus and ileal and feces digestibility in broilers.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.8
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• pp.1158-1164
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• 2003

In two feeding experiments male and mixed-sex broiler chicks were offered diets based on sorghum and a wheatsorghum blend with two tiers of nutrient specifications, without and with microbial phytase (600 and 800 FTU/kg), from 7-25 and 1-42 days post-hatch, respectively. The nutrient specifications for protein, amino acids, energy density and phosphorus (P) of standard diets were reduced to formulate the modified diets on a least-cost basis. Calculated differences in nutrient specifications between standard and modified diets ranged from 14.3 to 17.1 g/kg crude protein, 0.24 to 0.40 MJ/kg apparent metabolisable energy (AME) and 1.06 to 1.20 g/kg available P. In both experiments, reduced nutrient specifications had a negative impact on growth rates and feed efficiency and phytase supplementation had a positive influence on growth performance and protein efficiency ratios (PER). Phytase addition to the less expensive, modified diets either partially or entirely compensated for reduced growth performance and, consequently, feed costs per kg of live weight gain were reduced. In Experiment 1, phytase increased (p<0.001) nitrogen-corrected AME (AMEn) from 15.39 to 15.89 MJ/kg dry matter. For nitrogen (N) retention there was an interaction (p<0.05) between diet type and phytase as the effects of phytase on N retention were more pronounced in the modified diets, with an increase from 0.512 to 0.561. These results demonstrate the positive effects of phytase on protein and energy utilisation, in addition to its established liberation of phytate-bound P and illustrate the feasibility of assigning nutrient replacement values to the feed enzyme for consideration in least-cost ration formulations. Further work is, however, required to define the most appropriate reductions in nutrient specifications in association with phytase supplementation.

• Journal of Microbiology and Biotechnology
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• v.24 no.1
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• pp.113-118
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• 2014

Environmental microorganisms are emerging as an important source of new enzymes for wide-scale industrial application. In this study, novel phytase genes were identified from a soil microbial community. For this, a function-based screening approach was utilized for the identification of phytase activity in a metagenomic library derived from an agricultural soil. Two novel phytases were identified. Interestingly, one of these phytases is an unusual histidine acid phosphatase family phytase, as the conserved motif of the active site of PhyX possesses an additional amino acid residue. The second phytase belongs to a new type, which is encoded by multiple open reading frames (ORFs) and is different to all phytases known to date, which are encoded by a single ORF.

• Journal of Microbiology and Biotechnology
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• v.24 no.2
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• pp.177-187
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• 2014

Microbial phytases are enzymes with biotechnological interest for the feed industry. In this article, the effect of spray-drying conditions on the stability and activity of extracellular phytase produced by R. microsporus var. microsporus biofilm is described. The phytase was spray-dried in the presence of starch, corn meal (> $150{\mu}m$), soy bean meal (SB), corn meal (< $150{\mu}m$) (CM), and maltodextrin as drying adjuvants. The residual enzyme activity after drying ranged from 10.7% to 60.4%, with SB and CM standing out as stabilizing agents. Water concentration and residual enzyme activity were determined in obtained powders as a function of the drying condition. When exposed to different pH values, the SB and CM products were stable, with residual activity above 50% in the pH range from 4.5 to 8.5 for 60 min. The use of CM as drying adjuvant promoted the best retention of enzymatic activity compared with SB. Spray drying of the R. microsporus var. microsporus phytase using different drying adjuvants showed interesting results, being quite feasible with regards their biotechnological applications, especially for poultry diets.