Dietary Phytase Research Articles

Basal endogenous loss, standardized total tract digestibility of calcium in calcium carbonate, and retention of calcium in gestating sows change during gestation, but microbial phytase reduces basal endogenous loss of calcium1.

The objective was to test the hypothesis that the standardized total tract digestibility (STTD) of Ca and the response to microbial phytase on STTD of Ca and apparent total tract digestibility (ATTD) of P in diets fed to gestating sows are constant throughout gestation. The second objective was to test the hypothesis that retention of Ca and P does not change during gestation. Thirty-six gestating sows (parity = 3.3 ± 1.5; d of gestation = 7 d) were allotted to 4 diets. Two diets containing 0 or 500 units of microbial phytase per kilogram were based on corn, potato protein concentrate, and calcium carbonate. Two Ca-free diets were also formulated without or with microbial phytase to estimate basal endogenous loss of Ca. Daily feed allowance was 1.5 times the maintenance energy requirement. Sows were housed individually in gestation stalls and fed a common gestation diet, but they were moved to metabolism crates from days 7 to 20 (early gestation), days 49 to 62 (midgestation), and again from days 91 to 104 (late gestation). When sows were in metabolism crates, they were fed experimental diets and feces and urine were quantitatively collected for 4 d after 4 d of adaptation. Results indicated that outcomes were not influenced by the interaction between period of gestation and dietary phytase. The basal endogenous loss of Ca was greater (P < 0.05) by sows in early gestation than by sows in mid- or late-gestation, but supplementation of microbial phytase to the Ca-free diet decreased (P < 0.01) the basal endogenous loss of Ca and tended (P = 0.099) to increase ATTD of P. Supplementation of microbial phytase did not affect ATTD of DM, STTD of Ca, Ca retention, ATTD of P, or P retention in sows fed the calcium carbonate-containing diet. The ATTD of DM was not affected by period of gestation, but the ATTD of Ca, the ATTD of P, and the retention of Ca were least (P < 0.05) in midgestation, followed by early and late gestation, respectively, and the STTD of Ca in midgestation was also reduced (P < 0.05) compared with sows in early or late gestation. Phosphorus retention was greater (P < 0.05) in late gestation than in the earlier periods. In conclusion, Ca retention was less negative and ATTD of P tended to increase with supplementation of microbial phytase to the Ca-free diet regardless of gestation period. The basal endogenous loss, STTD of Ca, ATTD of P, and retention of Ca and P in gestating sows change during gestation with the greatest digestibility values observed in late gestation.

Evaluation of high dietary phytase supplementation on performance, bone mineralization, and apparent ileal digestible energy of growing broilers.

The present study was conducted to evaluate four commercially available phytase sources supplemented at regular (R) and super-dose (S) levels on live performance, bone mineralization, and apparent ileal digestible energy. Broiler chickens were allocated in stainless steel battery brooders (six birds per cage and eight pen replicates per treatment). A basal diet formulated to contain 0.2% non-phytate phosphorus (NPP) and 0.7% Ca was subdivided to create 11 dietary treatments: (1) basal diet was kept as the negative control (NC); (2) NC + limestone and monoclacium phosphate to create positive controls 1 and 2 formulated to yield 0.3% and 0.4% NPP; (3) NC + phytase A (250 and 1,500 FTU/kg); (4) NC + phytase B (500 and 1,500 FTU/kg); (5) NC + phytase C (500 and 1,000 FTU/kg); (6) NC + phytase D (1,000 and 2,000 FYT/kg). Performance was evaluated on d 7, 14, and 22. Tibia bone ash, tibia breaking strength, bone mineral content, and bone mineral density were evaluated on d 22. Apparent energy digestibility was evaluated on d 24. At d 7, phytases A and C supplemented at S level improved (P < 0.05) body weight and weight gain when compared to the NC. At d 14 and 22, all phytase sources improved (P < 0.05) body weight, weight gain, and bone mineralization when compared to the chicks under the NC diet. Overall, phytase supplementation at S level improved 17% apparent ileal digestibility at 24 d. Throughout the grow out period, phytase super-dose yield (P < 0.05) better performance, bone characteristics, and energy digestibility than the regular dietary level. In conclusion, all phytase sources were able to compensate the phosphorus deficiency and promote performance and bone mineralization. High levels of phytase showed a higher response when compared to the lower levels of supplementation.

Relative bioavailability of phosphorus in high-protein sunflower meal for broiler chickens and effects of dietary phytase supplementation on bone traits, growth performance, and apparent ileal digestibility of nutrients

An experiment was conducted to determine the relative bioavailability (RBV) of P in high-protein sunflower meal (HP-SFM) fed to broiler chickens based on bone traits and to determine the effects of dietary phytase supplementation and increasing levels of HP-SFM as a P source on bone traits, growth performance, and apparent ileal digestibility (AID) of DM and nutrients. In total, 240 broiler chicks were randomly allotted to 1 of 10 experimental diets with 6 replicate cages of 4 birds each and fed experimental diets from day 14 to 21 of age. Diets included a corn-soybean meal-based basal diet (0.35% total P; P-deficient diet), or the basal diet supplemented with 0.05, 0.10, or 0.15% P from either monosodium phosphate (MSP) or HP-SFM. Another 3 diets were formulated by supplementing the HP-SFM-containing diets with 500 phytase unit/kg of phytase. The bone mineral content (BMC), bone area (BA), and bone mineral density (BMD) of femur and tibia and tibia ash content increased (linear, P < 0.01) with increasing dietary P content from MSP. A linear increase in femur and tibia BMC, femur BA, and tibia BMD was also observed (P < 0.01) with increasing level of dietary P from HP-SFM. The RBV of P in HP-SFM based on femur and tibia BMC were 41 and 44%, respectively. Dietary phytase supplementation increased (P < 0.01) most of bone traits of the birds except for femur BMD. In addition, birds fed the diets supplemented with dietary phytase had greater (P < 0.05) BW gain, feed efficiency, and AID of P than those fed the diets without dietary phytase. In conclusion, the estimated RBV of P in HP-SFM to P in MSP were 41 and 44% based on femur and tibia BMC, respectively. Also, dietary phytase supplementation increased AID of P, growth performance, and bone traits of the birds fed P-deficient diets containing increasing inclusion level of HP-SFM as a P source.

Effects of High Phytase Supplementation in Lactation Diets on Sow and Litter Performance

A total of 109 sows (Line 241; DNA, Columbus, NE) were used to evaluate the effect of increasing dietary phytase in lactation diets, already adequate in P, on sow and litter performance. On d 107 of gestation, sows were blocked by body weight and parity and allotted to 1 of 3 dietary treatments of increasing phytase concentration (0, 1,000, or 3,000 FYT/kg; Ronozyme HiPhos GT 2700, DSM Nutritional Products, Inc., Parsippany, NJ). The control diet contained no phytase and was formulated to contain 0.50% standardized total tract digestible phosphorus (STTD P; 0.45% available P) and 0.62% STTD calcium (0.90% total Ca). The phytase diets that contained 1,000 or 3,000 FYT/kg were also formulated to 0.50% STTD P and 0.62% STTD Ca including the release of 0.132% STTD P and 0.096% STTD Ca. Diets were balanced for net energy and fed from d 107 of gestation until weaning (d 18 ± 3). All farrowings were monitored, with farrowing duration starting at the time the first pig was born until the first dispersal of placental tissues with no subsequent pigs born. Litters were cross-fostered within treatment until 48 h postfarrowing to equalize litter size. There were no differences among treatments in sow body weight at d 107 of gestation, 24 h after farrowing, or at weaning. Sow average daily feed intake from farrowing to weaning tended to increase (linear, P = 0.093) as phytase increased. There was no evidence for difference in the number of total born pigs, as well as the percentage of stillborns, mummies, and born alive pigs at the completion of farrowing. Similarly, phytase supplementation did not influence (P > 0.05) wean-to-estrus interval or litter size after cross-fostering among dietary treatments. Although not significant (linear, P = 0.226), farrowing duration decreased as added phytase increased with a decrease of 47 min (12%) for 3,000 FYT compared with the control. There were no differences in pig weight at weaning, but as a result of increased survivability (linear, P = 0.002), litter weaning weight and overall litter weight gain increased (quadratic, P < 0.05) up to 1,000 FYT of added phytase with no further benefit observed in sows fed 3,000 FYT. In conclusion, sow feed intake tended to increase linearly with increasing added phytase. Feeding 1,000 FYT/kg maximized overall litter gain and weaning weight; however, a larger-scale study with more sows is needed to determine the addition of phytase in lactation diets to reduce farrowing duration.

Phosphorus Availability in Laying Hens Given Non-phytate Phosphorus Deficient Diets Containing Buckwheat.

To date, the effect of buckwheat phytase on laying hens has not yet been investigated. Thus, this study was conducted to compare the production performance, egg quality, and phosphorus (P) balance of laying hens given nonphytate P deficient diets supplemented with non-germinated buckwheat (BU) or germinated buckwheat (GBU). Experimental diets (17.8% CP, 2,988 kcal/kg ME) consisted of two control diets, the positive control (PC), satisfying all nutrient requirements and negative control (NC) containing 0.16% less non-phytate P than that in the PC diet, and six experimental diets (containing 10%, 15%, 20% BU or GBU), prepared by replacing maize with BU or GBU, along with the raw materials of NC diet. Fifty-six laying hens (46 week of age) were allocated to eight dietary groups (seven hens each) and experimental diets were given for a period of six weeks (week one was employed for acclimatization, and the subsequent five weeks for data collection). Deteriorated production performance (hen-day egg production, feed intake, egg weight and egg mass) and eggshell quality (shell breaking strength, shell weight and shell thickness) in laying hens given a non-phytate P deficient NC diet was restored by the addition of at least 15% BU and 10% GBU to the NC diet. Total P retention significantly increased in 20% BU, 15% GBU and 20% GBU groups as excretion decreased considerably in these groups than the NC group. Considering the hen-day egg production as an economically important parameter, we found that a 340 phytase unit (PU)/kg diet of buckwheat phytase was equivalent to 0.10% non-phytate P in laying hens. These results suggested that the addition of buckwheat in non-phytate P deficient diets can alleviate the deficiency and improve P availability in laying hens.

The effect of dietary phytase and various available phosphorus levels on performance and egg quality in Japanese quail

SUMMARY Birds show poor utilization of phytic phosphorus in their diets because of the lack of endogenous enzymes to digest phosphorus and make it bioavailable. Therefore, the objective of this study was to evaluate phytase supplementation in the diets of laying quails. Eighty quails were used in a completely randomized experimental design with five treatments and four replicates of four birds each. The treatments were as follows: 0.35% Pd; 0.20% Pd; 0.20% Pd + 500FTUs of phytase; 0.09% Pd; 0.09% Pd + 500 FTUs of phytase. The birds were housed in metallic batteries during a trial period of 21 days, for evaluation of egg production, egg weight, feed intake and feed conversion. After being collected, the eggs were sent to the nutrition laboratory of the department of zootechnics of the CEO/Udesc, where analyses of albumin, yolk and shell quality were performed. The results were subjected to analysis of variance, and the differences between the averages were compared using the Tukey test at 5% of significance. No differences (P&gt; 0.05) were observed in terms of performance and egg quality parameters. We conclude that the inclusion of phytase in the diet of laying quails can be accomplished without compromising the performance and quality of the eggs. Additionally, 0.09% of 22 disponible phosphorus can be used to grant adequate performance for 21 days.

Effect of different phytases derived from E. coli AppA gene on the performance, bone mineralisation and nutrient digestibility of broiler chicken

AbstractThis study evaluated the effects of three different thermostable phytase variants, based on the AppA gene fromE. coli(AppAT1, AppAT2 and AppAT3) on growth performance, nutrient digestibility and bone mineralisation in broiler chickens at inclusion levels of 250 and 500 FTU/kg. The eight treatment groups included a positive control (PC) which was sufficient in Ca and P, a negative control (NC, the same basal formulation as the PC, but reduced in Ca and P), and NC supplemented with AppAT1 at 250 and 500 FTU/kg (AppAT1-250 and AppAT1-500), AppAT2 at 250 and 500 FTU/kg (AppAT2-250 and AppAT2-500) and with AppAT3 at 250 and 500 FTU/kg (AppAT3-250 and AppAT3-500). Over the entire feeding period, body weight (BW) and average daily gain (ADG) were significantly higher in the PC group, with all phytase supplemented groups being statistically the same, compared to the NC group. Feed conversion (FCR) for the PC-fed birds (1.479) was significantly (P&amp;lt;0.05) better compared to the NC birds (1.582) and those fed the AppAT3-250 diet (1.523). Reduced levels of Ca and P in the NC group led to significantly (P&amp;lt;0.05) lower tibia ash (40.9%) compared to the PC group (47.4%). Birds fed the phytase diets had significantly higher tibia ash compared to the NC birds, with those from the AppAT2-500 and AppAT3-500 groups being statistically the same as the PC group. Diets AppAT1-500, AppAT2-250, AppAT2-500 and AppAT3-500 significantly increased Ca digestibility compared to the NC. Apparent total track digestibility (ATTD) of P was improved for AppAT1-500 and AppAT2-250. The ATTD of Ca and P for all of the phytase supplemented groups reached the same level of the PC and AppAT1-500 group. It was concluded that adding any of the phytases tested, especially when included at 500 FTU/kg to a feed reduced in Ca and P, led to improved performance and bone mineralisation back to the same levels as seen for the Ca and P sufficient diet.

An evaluation of phytase for Channel catfish (Ictalurus punctatus ) fed all plant-protein diet: Growth performance, nutrient utilization and P equivalency value

This study evaluated the effect and phosphorus equivalency value of dietary microbial phytase based on growth performance and nutrient utilization of Channel catfish (Ictalurus punctatus). An all plant‐protein basal diet containing 7.9 g/kg total Phosphorus (P) (Phytate P of 4.5 g/kg) was supplemented with graded levels 0, 300, 500, 1,000, 1,500 and 2,000 U phytase/kg of diet or with 3, 5, 8, 12 g/kg of Ca(H₂PO₄)₂, namely with 0.7, 1.2, 2.0, 3.09 g/kg P as Ca(H₂PO₄)₂. Triplicate groups of Channel catfish (Ictalurus punctatus) juveniles (initial weight, 1.70 ± 0.04 g) were fed the experiment diets for 90 days. The results indicated that dietary phytase supplementation significantly improved growth performance, apparent digestibility coefficient of P and P retention, and decreased feed conversion ratio (FCR), faecal P content and P excretion per gain. Line relation was found between the effects of P and phytase supplementation levels, and the linear response equations of the effects of P and phytase levels were generated and used to calculate the P equivalency values. The average function of P equivalency values (Y, g/kg) of microbial phytase (X, U/kg of diet) was developed: Y = 0.1695 + 0.0021X; R² = 0.996. The results showed that about 0.38 g of P/kg diet was released by per 100 U of phytase over the range of 300–2,000 U of phytase/kg diet for Channel catfish (Ictalurus punctatus) fed all plant‐protein diet.

Engineering Technology of White Shrimp (Litopenaeus vannamei) Intensive System Culture with the Suplementation of Phytase Enzyme in the Diet

This study aims to examine the effect of phytase enzyme in the diet on digestibility of growth of white shrimp (Litopenaeus vannamei) raised in intensive system culture. Research on the suplementation of phytase enzymes in L. vannamei diet is very important to hydrolyze phytic acid in vegetable ingredients as a source of diet protein so as to increase the efficiency of diet utilization to support growth of vaname shrimp. The shrimp used in the research had average weight of 1,19±0,06 g/shrimp. The diet contained 38% of protein and 3200 Kcal DE/kg with various doses of phytase enzyme suplementation, namely: A (0 U/kg diet), B (500 U/kg diet), C (1000 U/kg diet) and D (1500 U/kg diet). Observed parameters were digestibility of phosphore (ADCF), disgetibility of protein (ADCP), efficiency of diet utilitzation (EFU), protein efficiency ratio (PER), diet convesion ratio (FCR) relative growth rate (RGR), and survival rate (SR). The suplementation of phytase enzyme in the diet significantly influenced (P&lt;0.01) on ADCF, ADCP, EFU, PER, FCR, RGR; however, it did not significantly influence on SR of white shrimp. The best treatment result was the suplementation of 1000 U/kg diet phytase enzyme (treatment C). The optimum dose of phytase enzyme in the diet was 867, 920, 923, 915, 1000 and 1000 U/kg of diet respectively for ADCF, ADCP, EFU, PER, FCR, RGR. Based on those result the suplementation of phytase enzyme can increase the growth of white shrimp.

Dietary phytase supplementation during peak egg laying cycle of White Leghorn hens on nutrient utilization and functional gene mRNA expression in duodenum and kidney

ABSTRACTSeventy-five White Leghorn hens during peak egg laying cycle were randomly divided into 5 groups: 1 group with 0.32% NPP (control), 2 groups with 0.24% NPP and laboratory (T1) or commercial (T2) phytase (250 FTU/kg feed), and 2 groups with 0.16% NPP and laboratory produced (T3) or commercial (T4) phytase (500 FTU/kg feed) from 23 to 40 weeks of age. The results indicated T2 group had the lowest (P > 0.05) bone ash, followed by similar ash content in T1, T3 and control groups. Mineral concentration (Ca, P, zinc and manganese) in the bone was not affected (P > 0.05) by variation in dietary phytase and NPP level. In duodenum, NaPiIIb was up-regulated (P < 0.05) in T2 and T3, whereas Calbindin 1 (CALB1) was up-regulated (P < 0.05) only in T3. In kidney, expression of NaPiIIa and CALB1 were down-regulated (P < 0.05) in all groups. The data demonstrated that 250 FTU/kg laboratory phytase supplementation in feed was enough for replacing 50% of inorganic P and 500 FTU/kg commercial phytase capable of replacing 100% of inorganic P. The up-and down-regulation of NaPiIIb, NaPiIIa and CALB1 genes in treatment groups was independent of phytase source and NPP level in feed.

The effect of 25-hydroxyvitamin D3 and phytase inclusion on pig performance, bone parameters and pork quality in finisher pigs.

The objective of this study was to investigate the effects of supplementing both phytase and 25-hydroxyvitamin D3 (25-OH-D₃) on pig performance, nutrient digestibility, carcass characteristics, bone parameters and pork quality in finisher pigs. The experimental design was a 2×2 factorial comprising of four dietary treatments. One hundred and twenty pigs (60 male, 60 female) were blocked according to live weight and sex and allocated to the following dietary treatments: low P (4.81g/kg) diet (basal) (T1); low P diet + phytase (T2); low P diet + 25-OH-D₃ (T3) and low P diet + phytase + 25-OH-D₃ (T4). Pigs supplemented with phytase had a lower average daily feed intake (ADFI) (2.45kg vs. 2.59kg; p<0.05) and lower feed conversion ratio (FCR) (2.74kg/kg vs. 2.85kg/kg; p<0.05) compared to pigs offered the nonphytase diets. Pigs offered phytase diets had a higher (p<0.05) coefficient of apparent total tract digestibility (CATTD) of ash, phosphorous (P) and calcium (Ca) compared with pigs offered the nonphytase supplemented diets. Pigs offered the 25-OH-D3 diets had a higher CATTD of N and ash. Pigs offered the phytase diets had increased (p<0.05) bone DM, ash, Ca, P and density compared to the nonphytase diets. There was a significant interaction (p<0.05) between phytase and 25-OH-D3 on cook loss. Pigs offered 25-OH-D3 had increased cook loss over the basal diet; however, there was no effect on cook loss when phytase and 25-OH-D3 were offered in combination compared to the phytase only diet. Pigs offered 25-OH-D3 exhibited higher (p<0.05) Warner Bratzler shear force values and lower (p<0.05) pork lightness (L*) surface colorimeter values. In conclusion, there was no benefit to offering a combination of phytase and 25-OH-D3 on pig performance, bone parameters or pork quality.

Pond‐raised Hybrid Catfish, ♀ Ictalurus punctatus × ♂ Ictalurus furcatus, Do Not Respond to Microbial Phytase Superdosing

AbstractTwo experiments were conducted in consecutive years to evaluate the responses of hybrid catfish, ♀ Ictalurus punctatus × ♂ Ictalurus furcatus, to “superdosing” of 6‐phytase added to existing commercial catfish feeds. In each experiment, two diets with or without a phytase superdose (2500 and 5000 phytase units/kg, respectively) were compared. In Experiment 1, fingerlings (mean weight: 59 g/fish) were stocked in 17 0.4‐ha earthen ponds at 17,290 fish/ha and were fed once daily to apparent satiation for 198 d. In Experiment 2, fingerlings (mean weight: 47 g/fish) were stocked in 10 0.4‐ha ponds at 24,710 fish/ha and were fed for 128 d. In both experiments, there were no significant differences in total feed fed, gross yield, final fish weight, survival, or Blood packed cell volume between fish fed diets with or without phytase. The diets also had no significant effects on pond water column total phosphorus or chlorophyll a concentrations, but soluble reactive phosphorus concentrations were significantly higher in ponds receiving the phytase diet in Experiment 2. Phytase superdosing of nutritionally complete feeds does not appear to have additional benefits beyond the standard phytase dose on production characteristics or packed cell volume of pond‐raised hybrid catfish and had no beneficial effects on water quality.

High levels of dietary phytase improves broiler performance

The objective of this study was to evaluate the effects of dietary phytase on broilers from 1 to 42 days of age. Five treatments were distributed in a completely randomized design, with eight replicates of 23 birds per experimental unit (per averages). The treatments consisted of a positive control diet (PC), a negative control diet (NC); and the NC diet + 1000, 2000 and 3000 FYT kg−1 phytase. The effects of dietary treatments on performance, bone quality and blood minerals were determined. From 1 to 21 days of age, WG, FI and FCR increased with increasing levels of phytase (P < 0.05), and from 1 to 42 days, body weight peaked with 2000 FTY kg−1 (P < 0.05). The best results for WG, FI and FCRC were obtained using 2051, 1992 and 2101 FTY kg−1, respectively. At 42 days of age, the Seedor Index (SI) and bone-dry matter (DM) were maximized at lower levels of phytase than for WG or FCR. The highest SI and DM values were obtained with 1553 and 1765 FTY kg−1, respectively. At 21 days of age, blood Ca content decreased with increasing phytase levels. Blood P exhibited quadratic behavior, with the maximum recorded at 1680 FYT kg−1 phytase. Tibia Ca increased with increasing phytase at 21 days of age (P < 0.05). Blood P at 42 days of age was lower than at 21 days, but did not vary between treatments. The apparent ileal digestibility coefficients of dry matter, mineral matter, crude protein and crude energy showed quadratic responses, with the highest coefficients obtained for the inclusion of 1164, 1592, 1085 and 1342 FYT kg−1 phytase, respectively. It is concluded that phytase improves broiler performance based on regression analyses. A high dose of 2973 FYT kg−1 had the best weight gain from 1 to 21 days of age. From 21 to 42 days, 2051 FYT kg−1 and 2101 FYT kg−1 showed the best weight gain and feed conversion ratio, respectively. These recommendations did not negatively affect the parameters evaluated.

Effects of extrusion and microbial phytase on the apparent and standardized total tract digestibility of phosphorus in hemp hulls fed to growing pigs.

An experiment was carried out to determine the apparent total tract digestibility (ATTD) and the standardized total tract digestibility (STTD) of P and the effects of extrusion and microbial phytase on ATTD and STTD of P in hemp hulls (HH). Thirty-six pigs (30.3 ± 2.7 kg) were randomly allotted to 1 of 6 experimental diets in a complete randomized design with 6 replicates per diet. A corn-soybean meal (SBM)-based basal diet was formulated. Two additional diets were formulated by replacing 40% of corn and SBM (on a 100% of total diet basis) with HH or extruded HH (EHH). The test ingredients, corn, and SBM were the only sources of P in the diets. Three additional diets were also prepared by supplementing 500 unit/kg of microbial phytase to the initial 3 diets (the corn-SBM basal diet and diets containing test ingredients). Pigs were fed experimental diets at 3 times the maintenance energy requirement (197 kcal ME/kg BW0.60). Results indicated that fecal P concentration and daily P output were reduced (P < 0.05) from pigs fed diets with dietary phytase compared with pigs fed diets without dietary phytase. The ATTD and STTD of P in experimental diets were not different. However, the ATTD and STTD of P in experimental diets supplemented with dietary phytase were increased (P < 0.05) compared with the diets without phytase. The ATTD and STTD of P in HH were 18.8% and 22.0%, respectively, whereas respective values for EHH were 22.5% and 26.3%. Extrusion had no effects on ATTD and STTD of P in HH. However, the ATTD and STTD of P in HH and EHH increased (P < 0.05) when dietary phytase was added to the diets. The concentration of Ca in feces and daily Ca output were reduced (P < 0.05) as a result of phytase supplementation. Addition of dietary phytase increased (P < 0.05) the ATTD of Ca in all experimental diets. In conclusion, the ATTD and STTD of P in HH fed to growing pigs were 18.8% and 22.0%, respectively. Respective values for EHH were 22.5% and 26.3%. Extrusion did not affect the ATTD and STTD of P in HH. However, the addition of microbial phytase to experimental diets increased the ATTD and STTD of P in diets and test ingredients and decreased fecal P output from pigs fed experimental diets. There was no interaction between extrusion and dietary phytase supplementation.

Combined effect of dietary protein and phytase levels on growth performance, feed utilization, and nutrients digestibility of African catfish, Clarias gariepinus (B.), reared in earthen ponds

ABSTRACTThe present study was based on a 2 × 4 factorial design with two levels of dietary protein (33% or 37% CP) and four phytase levels (0.0, 750, 1,000, and 1,250 FTU/kg diet). African catfish, Clarias gariepinus (B.) (10.7 ± 0.4 g), were distributed into earthen ponds (100 m2 surface area per each) at a density of 4.5 fish per m2. Fish were fed on the experimental diets up to satiation twice a day for 3 months. Another experiment with the same treatments was conducted in 45-L tanks for 2 months to evaluate nutrient retention and digestibility. The growth and production of African catfish fed phytase-enriched diets were higher than those fed the control diet. The highest fish performance and production was observed with fish fed 37% CP enriched with a 1,200 FTU/kg diet of phytase. Feed intake was significantly affected by supplemental phytase alone, where it increased significantly as dietary phytase increased at both protein levels, resulting in similar FCR values (1.31–1.46). Additionally, the maximum values of protein efficiency ratio, protein retention, and phosphorus retention were obtained at 33% CP with phytase levels of 750–1,000 FTU/kg diet. It is also noticed that organic matter, protein, and phosphorus were more digestible in fish fed a 37% CP diet with high phytase levels. These results suggest that the optimum performance and production of African catfish were observed at a 37.0% CP diet enriched with a phytase level of 1,200 FTU/kg diet.

Effect of high doses of Natuphos E 5,000 G phytase on growth performance of nursery pigs.

A total of 360 pigs (DNA 200 × 400, initially 5.9 ± 0.1 kg) were used in a 42 d trial to determine the effect of high doses of a recently available phytase source (Natuphos E 5000 G, BASF Corporation, Florham Park, NJ) on nursery pig growth and bone ash. Pigs were randomly allotted to pens at weaning by BW and pens were allotted to one of eight corn-soybean meal-based dietary treatments in a randomized complete block design. There were five pigs per pen and nine pens per treatment. Diets were fed in three phases (d 0 to 7, 7 to 21, and 21 to 42) with formulated total calcium:phosphorus (Ca:P) of 1.07, 1.05, and 0.93, respectively. Treatments included a negative control (NC) with 0.40, 0.30, or 0.25% aP from monocalcium P for Phases 1, 2, and 3 respectively; and NC with either 500, 1,000, 2,000, 3,000, or 4,000 FTU/kg phytase. The last two treatments were a positive control (PC) with 0.55, 0.45, or 0.40% aP from monocalcium P for Phases 1, 2, and 3, respectively, or PC with 2,000 FTU/kg phytase. The NC diet with 500 FTU/kg and PC without added phytase were formulated to be equivalent in available Ca and P. On d 42, one pig per pen was euthanized and the right fibula was removed for bone ash analysis. From d 0 to 42, pigs fed increasing phytase in the NC tended to have increased (quadratic, P = 0.064) ADG and (linear, P = 0.082) ending BW and had improved (quadratic, P = 0.008) G:F. Adding 2,000 FTU/kg phytase to the PC did not influence ADG or ADFI, but tended to improve (P = 0.060) G:F compared with the PC. In addition, percentage bone ash increased as phytase increased in the NC (linear, P < 0.001) or when 2,000 FTU/kg was added to the PC diets (P < 0.001). Pigs fed the PC had increased (P = 0.007) ADFI and tended to have greater (P = 0.099) percentage bone ash than pigs fed NC+500 FTU/kg phytase, but the pigs fed NC+500 FTU/kg phytase had improved (P = 0.032) G:F compared to pigs fed the PC. In summary, increasing concentrations of dietary phytase in a P-deficient diet improved growth and bone ash measurements, and was optimized at 1,000 FTU/kg. There were varied improvements when 2,000 FTU/kg phytase was added in P adequate diets.

The effect of phytase, xylanase and their combination on growth performance and nutrient utilization in Nile tilapia

Increasing the inclusion rate of plant ingredients will increase the content of non-starch polysaccharides (NSP) and phytate in the fish feed. Both NSP and phytate are undesired in fish feed due to their anti-nutritional properties. The main objective of the present study was to assess the impact of exogenous enzyme supplementation on growth, body composition, digestibility and the energy, nitrogen and phosphorus balances in Nile tilapia. Four experimental diets were tested in a 2×2 factorial arrangement of treatments. The first factor was phytase supplementation at a dose of either 0 or 1000 FTU/kg and the second factor was xylanase supplementation at a dose of 0 or 4000U/kg. This resulted in a control diet (CON-CON) without enzymes, phytase diet (PHY-CON), xylanase diet (CON-XYL) and a diet with both xylanase and phytase (PHY-XYL). In total 24 tanks (6 replicates/treatment) were used with 30 (mean initial body weight 42g) fish each. Fish were restrictively (80% of expected satiation) fed the experimental diets for 38days. Growth was significantly affected by the interaction between phytase and xylanase supplementation (P<0.05), showing a synergism between both enzymes. Growth at the CON-CON and CON-XYL diets were similar, whereas fish fed the PHY-CON had an improved growth. The effect of phytase supplementation on growth was further enhanced when xyalanse was supplemented (PHY-XYL diet). Phytase significantly improved the digestibility of dry matter, crude protein, carbohydrates, energy, ash, phosphorus and calcium (P<0.001). Xylanase enhanced the digestibility of dry matter, crude protein, carbohydrates and energy significantly (P<0.05). In contrast to growth, there was no significant synergetic effect of the combination of phytase and xylanase on the digestibility (P>0.05). The significant synergetic effect of the combination of phytase and xylanase on growth was not reflected on the digestibility (P>0.05). The nitrogen balance showed that the synergism on growth was predominantly due the significant synergistic effect of phytase and xylanase on the protein retention (P=0.005). Both xylanase and phytase showed to be an effective tool to improve the nutrient availability and growth in Nile tilapia. Fish fed the diet supplemented with both phytase and xylanase had a significantly higher growth than all other treatments.

The Effect of Dietary Phytase Supplementation on Digestibility and Growth of Asian Seabass Lates calcarifer

The purpose of this research is to evaluate Asian sea bass digestibility and growth fed with phytase dietary supplementation on soybean based fish diet. The initial weight of fish was 4.99±0.2 g with stocking density of 20 fishes per tanks reared in 80 L tank of sea water for 6 weeks. Completely Randomized Design of 50% soybean meal with phytase supplementation of 0; 500; 1,000; and 1,500 FTU kg-1 and three replication was used in this trial. Chromium oxide (Cr2O3) was used as digestibility indicator. Multivariate anova and One way anova (SPSS); linear regression (Microsoft Excel) and polynomial orthogonal (Microsoft Excel and Maple) was used to analyze the data. The results of Multivariate anova showed that phytase supplementation affect total digestibility (KCT) and relative growth rate (RGR) of asian seabass significantly (P&lt;0.01) with phytase dose 1,000 FTU. One way anova also indicated that phytase 1,000 FTU significantly affect all parameters. Apparent digestibility coefficient (ADC) phosphorus had a very significant and dominant effect to total digestibility with R2 = 0.9669 than ADC protein and ADC fat (linear regression). KCT significantly affects efficiency of dietary protein (EPP) 30.57% and protein efficiency ratio (PER) 0.67%. EPP and PER significantly effect RGR 1.56% day-1, simultaneously. The optimal dose of phytase supplementation is 1,220 FTU.

Efficacy of dietary phytase supplementation on laying performance and expression of osteopontin and calbindin genes in eggshell gland.

This study was conducted to evaluate the effects of different levels of dietary phytase supplementation in the layer feed on egg production performance, egg shell quality and expression of osteopontin (OPN) and calbindin (CALB1) genes. Seventy-five White Leghorn layers at 23 weeks of age were randomly divided into 5 groups consisting of a control diet with 0.33% non-phytate phosphorus (NPP) and 4 low phosphorus (P) diets: 2 diets (T1 and T2) with 0.24% NPP + 250 FTU/kg laboratory produced phytase or commercial phytase and another 2 diets (T3 and T4) with 0.16% NPP + 500 FTU/kg laboratory produced phytase or commercial phytase with complete replacement of inorganic P. The results indicated that there were no significant differences (P > 0.05) in egg production performance and quality of egg during the first 2 months of trial. However, in next 2 months, a significant drop in egg production and feed intake was observed in birds fed diets with low P and 500 FTU/kg supplementation of laboratory produced phytase. Osteopontin gene was up-regulated whereas the CALB1 gene was down regulated in all phytase treatment groups irrespective of the source of phytase. The current data demonstrated that 250 FTU/kg supplementation of laboratory produced phytase with 50% less NPP supplementation and 500 FTU/kg supplementation of commercial phytase even without NPP in diet can maintain the egg production. The up-regulation of OPN and down regulation of CALB1 in egg shell gland in the entire phytase treated group birds irrespective of the source of enzymes is indicative of the changes in P bio-availability at this site.

Effect of dietary phytase supplementation on greenhouse gas emissions from soil after swine manure application

Effects of supplementing swine diets with phytase on manure composition and greenhouse gas (GHG) emissions from soil after manure application were investigated. The experiment was laid out in a completely randomised 3 × 2 × 2 factorial design, with three manure treatments (no manure, manure from unsupplemented diet and manure from phytase supplemented), two soils (Carman and Gunton sandy loam soils from Southern Manitoba, Canada) and two moisture levels (low and high moisture with 0.50 and 0.80 water-filled pore space, respectively). Gas emissions were greater (P < 0.05) from high than from low moisture soils. Manure addition increased CO2 and N2O emissions. When applied to high moisture soils, CO2 emission was increased and that of N2O decreased when phytase manure was applied compared with non-phytase manure. Methane emission was not affected by manure addition or by type of manure applied. Inorganic N remaining in soil at the end of the experiment was greater with phytase than with non-phytase manure application. Plant extractable P concentrations in soil were reduced with phytase manure, probably due to lower total P added with the manure. For a successful dietary strategy to reduce GHG from manure, a good understanding of the soil properties that influence emissions becomes necessary. Supplementation of swine diets with phytase contributes to reduce disposal of P and N in manure, but has a limited effect on GHG emissions from manure amended soils. Emission of N2O may be reduced using manure from piglets fed phytase supplemented diets to fertilise high moisture soils.