Phytase Dose Research Articles

Evaluation of phytase dose effect on performance, bone mineralization, and prececal phosphorus digestibility in broilers fed diets with varying metabolizable energy, digestible amino acids, and available phosphorus concentration

The nutritional composition of diets and the provision of exogenous phytases play important roles in animal performance. Therefore, we evaluated the individual and combined impact of metabolizable energy (ME), digestible lysine (dLys), available phosphorus (avP) and calcium (Ca), and phytase dose (1,000 or 2,000 FTU/kg) on the growth performance, feed efficiency, phosphorus digestibility, and bone ash content of broiler chickens from 10 to 42 d of age. Experimental diets were formulated in a Box-Behnken design to contain various levels of ME (11.9, 12.2, 12.54, or 13.1MJ/kg), dLys (0.91, 0.93, 0.96, or 1.00%) and avP/Ca (0.12/0.47, 0.21/0.58, or 0.33/0.68%). The effect of phytase was expressed in terms of the extra nutrients released. The diets were formulated to have consistent phytate substrate contents (0.28% in average). Body weight gain (BWG) and feed conversion ratio (FCR) were described via polynomial equations (R2=0.88 and 0.52, respectively), with interconnections between variables (ME, dLys, and avP/Ca). No interaction was observed among variables (P > 0.05). Metabolizable energy was the most important factor affecting BWG and FCR (linearly; P < 0.001). Reducing ME content from 13.1 to 11.9 MJ/kg in control diet resulted in a 6.8% decrease in BWG and a 3.1% increase in FCR (P < 0.001). The dLys contents also affected performance linearly (P < 0.001), but to a lesser degree; BWG decreased by 160g when the dLys was reduced by 0.09% units, while the same reduction in dLys increased the FCR by 0.108 points. The inclusion of phytase alleviated the negative effects on feed intake (FI), BWG, and FCR. Phytase improved phosphorus digestibility and bone ash content according to a quadratic relationship. When phytase was added, ME negatively affected FI (r=-0.82,P<0.001), whereas the dLys content was correlated with FCR (r=-0.80,P<0.001). Supplementing phytase allowed the reduction of ME, dLys, and avP-Ca in the diet without affecting performance. The addition of phytase increased of ME, dLys, and avP by 0.20 MJ/kg, 0.04 and 0.18% units for 1,000 FTU/kg and 0.4 MJ/kg, 0.06 and 0.20% units for 2,000 FTU/kg.

Sustainable broiler production with increasing phytase dose and reducing the use of inorganic P to further reduced phosphorus and nitrogen excretion

Sustainable broiler production with increasing phytase dose and reducing the use of inorganic P to further reduced phosphorus and nitrogen excretion

Influence of Dietary Phytase Inclusion Rates on Yolk Inositol Concentration, Hatchability, Chick Quality, and Early Growth Performance

The aim of this study was to determine the influence of dietary phytase in breeder hens on yolk nutrients, hatchability, chick quality, and growth rate of their progeny, and their subsequent performance to 42 d post-hatch when fed diets with the same phytase concentrations. Breeder hens (n = 216) were divided into 3 groups receiving nutrient-adequate diets with reduced calcium (Ca) and phosphorus (P) (by 0.16% and 0.15%, respectively), supplemented with either 500, 1500, or 4500 FTU/kg phytase from 27 to 50 weeks of age. Eggs were collected at 38 weeks of age and incubated. On the day of hatch, the chick quality and hatchability were determined, and 18 chicks/group were euthanized for yolk sac collection and the determination of inositol and glycerol concentrations. The remaining chicks were divided into three groups, receiving different diets with reduced Ca and P (by 0.16% and 0.15%, respectively), supplemented with 0, 500, or 1500 FTU/kg phytase to 42 d post-hatch. Increasing the phytase concentration in the breeder hen diet linearly (p < 0.05) increased the number of early embryo deaths and decreased the number of late deaths and pips. The inositol concentration in the yolk sac at day of hatch increased (quadratic; p < 0.05) as the phytase dose increased in the breeder hen diet. The breeder hen diet (p < 0.05) influenced the body weight (BW), feed intake (FI), and feed conversion ratio (FCR) up to 21 days of age. The supplementation of breeder hen diets with 1500 FTU/kg phytase increased the concentration of sodium (Na), magnesium (Mg), potassium (K), manganese (Mn), and zinc (Zn) in the yolk sac. The inclusion of phytase doses up to 4500 FTU/kg appeared to influence embryo mortality, chick feed intake, and BW gain to 21 days and the FCR throughout the entire production phase.

Diferentes níveis de fitase e de densidades energéticas em dietas de frangos de corte sobre desempenho, digestibilidade de nutrientes e integridade óssea de 28 a 35 dias de idade

ABSTRACT The study was carried out with the objective of evaluating the effects of using phytase levels at different energy densities in the diet of broilers, from 28 to 35 days of age. The experimental diets contained increasing levels of apparent metabolizable energy corrected for nitrogen balance and different levels of phytase. Growth performance variables, nutrient digestibility, as well as variables related to bone integrity were examined. Diets containing 500 FTU/kg in combination with 3150kcal.kg-1 of AMEn resulted in better growth performance. Supplementation with 500 and 1000 FTU/kg in the diets provide better coefficients of apparent and ileal digestibility of calcium and phosphorus, but negatively influence the deposition of calcium, phosphorus, dry matter, and ash in the tibia, in addition to adversely affecting the breakage and area of these bones in broilers. Bone length and the levels of magnesium and zinc present in the tibias were not influenced by the energy and phytase levels of the diets. There is no interaction between the different energetic densities and the phytase doses in the variables analyzed in the studied period. Increasing the energy density of diets resulted in improved apparent and ileal digestibility for most nutrients.

Also in Crayfish: How Phytase Inclusion Avoids Phytic Acid Effects on Hepatopancreas Enzymes of Redclaw Cherax quadricarinatus

This work aimed to evaluate the effects of dietary phytic acid on the enzymatic activities of the hepatopancreas of the redclaw crayfish, Cherax quadricarinatus. For this purpose, a completely randomized in vitro trial was conducted with three phytic acid levels (0.56, 1.68, and 2.80%) and three phytase doses (0, 250, and 500 PU/kg DM). Solubilized protein, reducing sugars, and soluble phosphorus showed significant responses to the interaction between phytic acid and phytase p &lt; 0.001 . Only the main effects were detected on the released amino acids, in keeping with the main effects of alkaline protease activity, which are negatively affected by phytic acid p &lt; 0.001 and improved by phytase inclusion p &lt; 0.001 . Differences in released reducing sugars were attributed to a reduction in amylase activity by increased levels of phytic acid and not to cellulase activity, where only a negative trend of phytic acid was found p = 0.068 . Phytic acid depresses calcium availability, which would explain the decrease in amylase activity. A 500 PU/kg DM dose improved amino acid, reduced sugars, and phosphorus release. These in vitro results might have in vivo implications for the digestibility of proteins, minerals, and energy. Further investigations are required to determine the chelated calcium effect on redclaw amylase activity, molting, and survival.

Stabilization and strengthening of chromium(VI)-contaminated soil via magnesium ascorbyl phosphate (MAP) and phytase addition

Cr(VI) contamination of soil threatens the environment and reduces soil strength. Therefore, both Cr(VI) stabilization and soil reinforcement should be considered in site remediation for future construction. This study investigated a biochemical treatment process using magnesium ascorbyl phosphate (MAP) and phytase. MAP was hydrolyzed via phytase catalysis to produce ascorbic acid (AA) and MgHPO4·3H2O precipitation. The AA reduced Cr(VI) into low-toxic Cr(III), which precipitated as Cr(OH)3 and CrPO4. More than 90% of the 500 mg/kg Cr(VI) in soil was reduced by 5% MAP (wt% of soil) and 1% phytase (vol/vol of soil water) doses at the geotechnically optimal soil moisture content of 16.8%. The MgHPO4·3H2O precipitates filled soil pores and enhanced the unconfined compression strength of treated soil by more than two times. This research reports a novel and practical enzymatically induced phosphate precipitation process for the remediation of Cr(VI)-contaminated soil.

Comparison of digestible and available phosphorus release values for a novel phytase determined with fecal phosphorus digestibility and bone mineralization in weaner pigs

The objective of this study was to compare digestible and available P release from phytase through measuring fecal P digestibility and bone mineralization. A total of 336 weaner pigs (7.4 ± 0.9 kg) were used in a randomized complete block design. Three diets were established by including 2.5 (control), 6.0 or 9.5 g/kg monocalcium phosphate (MCP) to establish the standard response curves. The other 4 diets included a novel phytase at 500, 1000, 2000 or 3000 phytase units (FYT)/kg feed to the control. Each diet was fed to 6 pens of 8 pigs each for 21 days. All diets included 3 g/kg TiO2, and fecal samples were collected on d 13–15 of trial. At the end, one pig per pen was sacrificed for the collection of tibias. The results showed that increasing supplementation of MCP linearly (P < 0.001) improved growth performance (body weight gain, feed intake and gain:feed and bone mineralization (percent bone ash and weights of dry bone, bone ash, and bone Ca and P). These parameters responded to the supplementation of phytase both linearly and quadratically (P < 0.01). Supplemental phytase or MCP increased apparent total tract digestibility (ATTD) of Ca and P as well as the amount of ATTD P, but reduced the ATTD Ca-to-ATTD P ratio both linearly and quadratically (P < 0.01). Both MCP and phytase linearly (P < 0.05) increased percent bone ash P. The true total tract digestibility (TTTD) coefficient of P in MCP was estimated to be 0.94 by regressing the ATTD P against the dietary P concentration. The available P release increased from 1.58 to 2.21, 1.77–2.62, 1.17–1.82 and 1.25–1.97 g/kg feed when body weight gain, gain:feed, percent bone ash and bone P weight were used as the response variables, respectively, with increasing phytase dose from 500 to 3000 FYT/kg feed, whereas the digestible P release by phytase calculated from ATTD coefficient of P increased from 1.05 to 1.99 g/kg feed. By multiplying the TTTD coefficient of MCP (0.94), the available P release values based on bone P weight were transformed to their equivalent digestible values of 1.18–1.86 g/kg feed. In conclusion, the available P release from phytase depends on the response variables. Using the TTTD coefficient of P in MCP to convert the available P release values to digestible P values for phytase did not generate comparable results as measured from ATTD coefficient of P.

Fitase em dietas com diferentes concentrações de fitato para frangos de corte

ABSTRACT: This study evaluated the effect of including different doses of phytase in broiler diets with different levels of phytate and reduced levels of calcium (Ca) and available phosphorus (aP), on broilers performance, digestibility (CAID), and bone characteristics. One thousand four hundred and four Cobb®500 broilers were used, distributed in a complete randomized design, and a 2x3 factorial arrangement, with two phytate levels (4.25 kg/ton - MP and 6.0 kg/ton - HP) and three phytase levels (0, 750, and 1500 FTU/kg) totalizing six treatments with nine replicates each. The animals that received phytase in their diet showed higher average feed intake and weight gain, and higher bone weight, % mineral residue, % Ca, and % P, when compared to the treatment without phytase (P &lt; 0.01). Animals that received a diet containing HP with the inclusion of 1500FTU/kg phytase had the best CAID of nutrients (P &lt; 0.0001). Regarding phytate, animals that received the MP diet showed a higher CAID of dry matter, and higher %P in the tibia when compared to animals that received the HP diet. The addition of phytase to diets with reduced Ca and aP levels can improve the CAIDs and bone characteristics in the presence of high phytate levels. However, reducing Ca and aP levels in the diet without adding phytase impairs the performance of broilers and has no effect on their carcass and cuts yield.

Effects of limestone solubility on the efficacy of a novel consensus bacterial 6-phytase variant to improve mineral digestibility, retention, and bone ash in young broilers fed low-calcium diets containing no added inorganic phosphate.

This study evaluated the effect of limestone solubility on the capacity of a novel consensus bacterial 6-phytase variant (PhyG) to improve phosphorus (P) and calcium (Ca) digestibility, retention, and utilization in low-Ca broiler diets containing no added inorganic phosphate (Pi). Male Ross 308 broilers (n = 1,152) were fed one of 16 experimental diets from 11 to 21 d of age in a randomized complete design (12 birds/cage, 6 cages/treatment). Diets comprised three positive controls (PC3, PC2, and PC1) containing 1.8, 1.2, or 0.6 g/kg MCP-P and 7.7, 7.0, or 6.2 g/kg Ca, respectively, and a negative control (NC) containing no added Pi (4.4 g/kg P; 2.8 g/kg phytate-P) and 5.5 g/kg Ca from either low or high solubility limestone (LSL or HSL, respectively, [with 42% and 97% solubility after 5 min at pH 3.0]), supplemented with 0, 250, 500, 1,000, or 2,000 FTU/kg of PhyG. Fecal samples collected on days 18 to 20 and ileal digesta collected on day 21 were analyzed for titanium dioxide, Ca, P, and phytate (IP6, inositol hexakisphosphate). Tibias (day 21) were analyzed for ash content. Data were analyzed by factorial analysis (2 limestone solubilities × 4 MCP-P levels and 2 limestone solubilities × 5 phytase dose levels) and exponential regression. Increasing dose levels of PhyG resulted in an exponential increase (P < 0.01) in the apparent ileal digestibility (AID) of P, ileal digestible P content of the diet, ileal IP6 content, and IP6 disappearance in birds fed either HSL or LSL diets, but AID Ca and ileal digestible Ca were exponentially increased by the phytase only in HSL diets (P < 0.01). Relative to HSL, the LSL increased AID P, ileal digestible P, and IP6 disappearance (P < 0.05) but reduced AID Ca, ileal digestible Ca, and retainable Ca (P < 0.05), resulting in reduced retainable P and tibia ash. Phytase exponentially increased the apparent total tract digestibility of P, retainable P, and tibia ash in HSL and LSL diets, but at or above 500 FTU/kg values were higher in HSL than LSL (interaction P < 0.05). The findings highlight that phytase dose-response effects on mineral digestibility and utilization are different for high- and low-solubility limestones, and it is therefore recommended to use digestible rather than total Ca content during diet formulation to ensure an optimal balance of Ca and P, especially in low-Ca diets. In diets containing HSL, higher phytase dose levels may be needed to compensate for the low digestible P content of the basal diet.

Increasing Doses of Bacterial Phytase (Citrobacter braakii) Improves Performance and Carcass Characteristics of Pigs in Growing and Finishing Phases.

Simple SummaryPhytases of bacterial origin are the exogenous enzymes most widely used in the diets of monogastric animals, acting on the hydrolysis of phytate (myo-inositol 1,2,3,4,5,6-hexakis [dihydrogen] phosphate) to release the phosphate from this complex. However, the efficiency of phytase varies according to the aspects inherent to its own structure and origin, the age and physiological state of the animal, and the dietary composition. Overall, we found that supplementation with phytase between 1500 and 3000 units of phytase (FYT)/kg of feed in diets based on corn and soybean meal with a reduction in inorganic phosphorus (0.13%) and calcium (0.11%) improves the daily weight gain (DWG) and live weight (LW) of animals in the growing phase, which affects performance on finishing phases and slaughter body weight. This input could result in a reduction in the use of phosphorus sources, improving environmental issues with an increase in the main zootechnical parameters.The effects of increasing doses of bacterial phytase (Citrobacter braakii) on performance and carcass characteristics of growing-finishing pigs was evaluated. A total of 120 barrows weighing 25.16 ± 2.80 kg and 68 days old were submitted to five treatments: positive control diet (PC) containing inorganic phosphorus (P) and limestone (Ca); negative control (NC) with reductions in P (by 0.13%) and Ca (by 0.11%); and three NC diets supplemented with 1500 (NC15), 3000 (NC30) and 4500 (NC45) units of phytase (FYT)/kg. The daily weight gain (DWG) in growth phase I (68–91 days) was higher in the PC, NC15 and NC30, compared to the NC (1.06, 1.06, 1.06 vs. 0.95, respectively). The DWG in finishing phase II (141–156 days) was higher in the NC15 (1.20 kg) and NC30 (1.14 kg) than in the NC45 (0.94 kg). The final weights (LW156) in the NC15 (122.95 kg LW) were higher than NC (116.47 kg LW) and NC45 (114.43 kg LW). Over the entire period, a quadratic effect (2012 FYT) was observed for the DWG. The increasing levels of phytase in corn and soybean meal-based diets improved the DWG and carcass traits; however, the addition of more than 3000 FYT/kg of feed should be carefully studied to determine enzyme viability.

Effect of phytase supplementation and drinking water pH for turkey poults

A study was conducted to evaluate the effects of high phytase doses and drinkable water pH on diets for turkey poults on growth performance, nutrient and energy utilization, bone mineralization, and myo-inositol absorption. A total of 420 one-d-old turkey poults were randomly distributed into a 2 × 3 factorial arrangement with 2 water pH levels (5.5 and 8.2) and 3 phytase doses: 0, 1,000, and 2,500 units of phytase (FYT)/kg of diet totaling 6 treatments and 7 replicates of 10 turkeys. Excreta was collected to determine apparent nutrient total tract retention, and ileal digesta was used to determined apparent ileal nutrient digestibility (AID) at 21 d. Phytase linearly improved body weight gain and feed conversion ratio (P < 0.05), whereas water intake was not affected, and water pH did not influence growth performance. Phytase linearly increased AID of crude protein and P, as well as apparent total tract retention of dry matter, crude protein, Ca, and Na (P < 0.05) regardless of water pH. Detected interactions (P < 0.05) showed a linear increase on AID of dry matter and energy utilization at both ileal and total tract levels, which was more pronounced when turkeys drank 5.5 water pH, whereas AID of Ca was only increased by phytase supplementation in combination with alkaline water. Ash, Ca, and P contents in the tibia, as well as plasma concentration of myo-inositol were linearly increased in supplemented chickens, but not affected by water pH. The interactions between phytase and water pH on diet utilization provided conflicting results, but increasing the phytase dose to 2500 FYT increased overall nutrient digestibility, leading to better growth performance, bone mineralization, and greater inositol provision for turkey poults.

Evaluation of High Doses of Phytase in a Low-Phosphorus Diet in Comparison to a Phytate-Free Diet on Performance, Apparent Ileal Digestibility of Nutrients, Bone Mineralization, Intestinal Morphology, and Immune Traits in 21-Day-Old Broiler Chickens.

Simple SummaryPhytic acid is the main storage form for phosphorus in plants. Although it is the main source of organic phosphorus in broiler diets, its utilization by monogastric animals is limited. In addition, phytic acid displays antinutritional effects, impacting optimal nutrient and energy digestibility. The supplementation of feed with phytases enables broilers to use phytate phosphorus more efficiently. Superdosing of phytase has been reported to have additional beneficial effects on the animal beyond the ones derived from the improved phosphorus utilization. This study tried to elucidate the mechanisms related to the immune response and mucosal morphology contributing to those overall beneficial effects. Although addressing performance was not the primary target of the study, performance improved linearly with increasing levels of phytase. The use of increasing doses of phytase showed linear increases in apparent ileal digestibility of crude protein, crude ash, and phosphorus. Jejunal crypt depth decreased with the addition of phytase to a low-protein diet, as well as the content of CD3-positive intraepithelial lymphocytes, but the results could not demonstrate clear differences between phytase doses in these specific parameters.The supplementation of feed with phytases enables broilers to utilize more efficiently phosphorus (P) from phytic acid (IP6), the main storage form of P in plants. The current study evaluated the addition of 500, 1000, and 3000 FTU of phytase per kg to a phytate-containing diet with low P level (LP) fed to broilers from 1 to 21 days of age and compared it to a hypoallergenic phytate-free diet (HPF). There was a linear improvement in performance parameters with increasing levels of phytase in the LP diet (p < 0.001). Apparent ileal digestibility of crude protein, P, and some amino acids, increased with phytase. Crude ash, P, and the calcium content of tibia bones linearly increased with increasing levels of phytase (p < 0.001). Crypt depth (related to body weight) in the jejunum epithelium linearly decreased with phytase addition (p < 0.001). Cecal crypt depth decreased with phytase supplementation (p = 0.002). Cecum tissue showed lower counts of CD3-positive intraepithelial lymphocytes in broilers receiving the phytase in comparison to LP (p < 0.001), achieving similar counts to HPF-fed broilers. Although results from the current study seem to point out some mechanisms related to the immune response and mucosal morphology contributing to those overall beneficial effects, no clear differences between different phytase doses could be demonstrated in these specific parameters.

Use of fixed calcium to phosphorus ratios in experimental diets may create bias in phytase efficacy responses in swine.

The objective of this study was to investigate the effects of two dietary total Ca/P ratios on available P release by phytase, measured using growth performance and bone mineralization with 528 barrows and gilts according to a randomized complete block design. Three were 11 diets in a factorial of 2 by 4 plus 3, including 3 reference diets consisting of 0.25% (control), 0.70%, or 1.15% monocalcium phosphate (MCP) and 8 diets from combining 4 phytase doses (500, 1,000, 2,000, and 3,000 FYT/kg) with 0.25% MCP and 2 dietary Ca/P ratios (1.05 and 1.20). Each diet was fed to 6 pens of 8 pigs. All diets contained 3 g/kg TiO2, and fecal samples were collected from each pen on d 13–15 of trial. At the end of trial, one pig per pen was sacrificed to collect a tibia and urine in the bladder. The results showed that MCP improved growth performance linearly (P < 0.01), whereas both a linear and quadratic response was observed with the addition of phytase. The MCP increased the percent bone ash and weights of bone ash, Ca, and P linearly (P < 0.01). At both Ca/P ratios, increasing supplementation of phytase increased the percent bone ash and weights of bone ash, Ca, and P both linearly and quadratically (P < 0.05). Both MCP and phytase significantly increased digestibility of Ca and P as well as digestible Ca and P in diets and reduced the digestible Ca/P ratio. The dietary Ca/P ratio of 1.20 resulted in poorer feed utilization efficiency, more digestible Ca, greater percent bone ash, Ca, and P and heavier weights of bone Ca and P than the ratio of 1.05 (P < 0.05). The ratio of 1.20 elicited numerically higher available P release values from phytase, with percent bone ash and bone P weight as the response variables, but significantly lower values with gain:feed. The urinary concentration of Ca increased linearly (P < 0.01) with increasing digestible Ca/P ratios whilst urinary concentration of P decreased quadratically (P < 0.01). In conclusion, fixing the same total Ca/total P ratio in diets supplemented with increasing phytase dosing created an imbalance of digestible Ca and P, which could have an adverse effect on bone mineralization and thus compromise the phytase efficacy relative to mineral P.

The Growth Performance, Nutrient Digestibility, Gut Bacteria and Bone Strength of Broilers Offered Alternative, Sustainable Diets Varying in Nutrient Specification and Phytase Dose.

Simple SummaryPhytase has been routinely included in poultry diets for over 20 years with the benefits to bird growth performance, nutrient digestibility and bone parameters widely documented. However, with the costs of feed increasing, particularly of imported soyabean meal and pressure to reduce the environmental footprint of production, the need for alternative sustainable local protein sources is ever important. This work found that phytase superdosing to rapeseed meal (RSM) and maize dried distiller grains with solubles (DDGS) diets can improve performance, increase digestibility and reduce P excretion by 15% compared to birds offered the diet without exogenous phytase.This study assessed the use of locally sourced sustainable feed ingredients, rapeseed meal (RSM) and maize dried distiller grains with solubles (DDGS) in diets over traditional ingredients on the growth performance, bone strength and nutrient digestibility of broilers. This work also investigated the effects of supplementing exogenous phytase in two doses (500 vs. 1500 FTU/kg). Using male Ross 308 chicks (n = 320) assigned to receive one of four experimental diets: (1) Positive control diet 1 (PC1), a wheat, soya-based diet + 500 FTU/kg phytase. (2) Positive control diet 2, RSM/DDGS diet + 500 FTU/kg phytase (PC2). (3) Negative control (NC) reduced nutrient RSM/DDGS diet, no phytase. (4) The NC diet plus 1500 FTU/kg phytase (NC+). PC1 birds displayed higher feed intake and body weight gain consistently throughout the trial (p < 0.001) as well as increased body weight by 28 d and 42 d (p < 0.001). Whole-body dual emission X-ray absorptiometry (DXA) analysis revealed PC1 birds also had higher bone mineral density (BMD), bone mineral content (BMC), total bone mass, total lean mass and total fat mass than birds offered other treatments (p < 0.01). Diet had no significant effect on bone strength. Phytase superdosing improved the digestibility of dry matter (DM), neutral detergent fibre (NDF), gross energy (GE), calcium (Ca), potassium (K) and magnesium (Mg) compared to birds in other treatment groups. The phytase superdose also improved performance in comparison to birds offered the NC diet. Phytase superdosing increased the IP6 and IP5 degradation and increased the ileal inositol concentration of the birds. N excretion was lower for birds offered the traditional wheat–soya diet and highest for those offered the high-specification RSM/DDGS diet with a commercial dose of phytase. The addition of a phytase superdose to the negative control diet (NC+) reduced P excretion of birds by 15% compared to birds offered NC.

Effects of graded levels of phytase supplementation on growth performance, plasma myo-inositol, tibia mineralization and nutrient digestibility of meat ducks fed phosphorus-deficient diets

Two experiments were conducted to explore the effect of reduction in dietary non-phytate phosphorus (nPP) and supplementation of an exogenous phytase on growth performance, plasma myo-inositol, tibia mineralization and nutrient digestibility of meat ducks. Exp. 1 used 450 one-day-old male Cherry Valley ducks over a 42-d period to evaluate growth performance and plasma myo-inositol. The treatments (6 replicates with 15 ducks per pen) included a positive control diet (PC, 4.0 and 9.0 or 3.5 and 8.0 g/kg of nPP and Ca in starter (d 0–21) and grower (d 21–42) period, respectively), a negative control diet (NC, 1.7 g/kg nPP and 1.9 g/kg Ca less from the PC), and the NC diet plus phytase at 1000, 2000 or 3000 FYT/kg feed. Exp. 2 used 600, seven-day-old, male Cherry Valley ducks in a 14-d trial to evaluate growth performance, tibia mineralization and nutrient digestibility. Dietary treatments (10 replicate cages with 10 ducks per cage) included a PC diet (4.0 and 9.0 g/kg of nPP and Ca, respectively), a NC diet (1.5 and 6.5 g/kg of nPP and Ca, respectively), and the NC diet plus phytase at 500, 1000, 2000 or 3000 FYT/kg feed. In Exp. 1, ducks fed the NC diet had lower (P < 0.05) weight gain (d 0–21 and 0–42), feed intake (d 0–21, 21–42 and 0–42) and body weight at d 21 and 42 compared to those fed the PC diet. There was no effect of diet (P > 0.05) on FCR or plasma myo-inositol. Phytase supplementation linearly increased (P < 0.05) weight gain, feed intake, and body weight; all parameters were equivalent to the PC at 2000 or 3000 FYT/kg. In Exp. 2, ducks fed the NC diet had lower (P < 0.05) weight gain, feed intake, body weight, tibia ash weight and percentage, and P digestibility and higher (P < 0.05) FCR and Ca digestibility compared to those fed the PC diet. Phytase supplementation improved growth measurements (linear and quadratic, P < 0.05), tibia ash weight and percentage (linear, P < 0.05) and P digestibility (linear, P < 0.05). Growth measurements and P digestibility were comparable to the PC level with supplemented phytase ranging from 1000 to 2000 FYT/kg, however, tibia ash weight and percent were below the PC, regardless of the dose of phytase. In conclusion, feeding graded concentrations of phytase improved growth performance, tibia mineralization, and P digestibility in ducks. Phytase supplementation at 2000 FYT/kg could fully restore the gain and P digestibility of ducks fed nPP deficient diets to that of a nutrient adequate PC. However, in extremely nPP deficient diets, tibia ash weight and percentage require a higher supplementation of phytase, which was beyond 3000 FYT/kg.

The Duration of the Trial Influences the Effects of Mineral Deficiency and the Effective Phytase Dose in Broilers' Diets.

Simple SummaryThe aim of this work was to investigate the effects of reducing the mineral (Ca and P) content and the addition of different doses of a new 3-bacterial phytase in broiler diets in a short- and long-term experiment. Mineral deficiency reduced growth performance only in young animals, and it increased Ca and P digestibility and reduced tibia mineralization, especially in the long-term trial. The effective dose of the new phytase varied with the response criteria and duration of the trial. Phytase increased feed efficiency at 500 FTU/kg, but only in young animals, and increased mineral digestibility and retention at a lower dose (250 FTU/kg) in the short- compared with the long-term (500 FTU/kg) trial. Tibia mineralization increased with only 250 FTU/kg in the long-term trial. Therefore, the age of the animals and duration of the trial are key in determining the effects of mineral levels and phytase addition in broiler feed and should be taken into account for future trials.Two trials varying in duration (short- and long-term) were conducted to evaluate the effects of providing deficient (NC) or sufficient (PC) Ca and P levels, and different doses of a new phytase (250, 500, and 1000 FTU/kg feed), in broiler feed on growth performance, nutrient digestibility and retention, and tibia mineralization. A total of 80 and 490 male chicks (Ross) of 21 and 1 days of age were used in the short- and long-term trials, respectively. In the long-term trial, chicks fed NC diets showed a lower (p < 0.05) average daily gain and feed intake compared to chicks fed PC and a greater (p < 0.05) feed conversion ratio compared to 500 and 1000 FTU/kg feed during the starting period. Regarding the effects on minerals’ and nutrients’ coefficients of retention, animals fed NC showed a significantly higher digestibility for P than those fed the PC diet in the long-term trial. Additionally, feeding 250 to 500 FTU/kg diets increased most of the nutrients’ digestibility in the short-term but only P digestibility in the long-term trial. Tibia mineralization increased linearly with phytase addition (p < 0.05) only in the long-term trial. In conclusion, the effects of dietary mineral and phytase levels on growth performance are more noticeable in young animals. In addition, the duration of the trial is key due to a possible adaptation phenomenon of birds to low P supplementary levels.

Effect of limestone solubility on mineral digestibility and bone ash in nursery pigs fed diets containing graded level of inorganic phosphorus or increasing dose of a novel consensus bacterial 6-phytase variant.

The effect of a novel consensus bacterial 6-phytase variant (PhyG) on total tract digestibility (ATTD) of minerals and bone ash was evaluated in pigs fed diets containing medium- and high-solubility limestone (MSL and HSL, 69.6 and 91.7% solubility, respectively, at 5 min, pH 3.0) in a randomized complete block design. For each limestone, eight diets were formulated: an inorganic phosphate-free negative control (NC) based on wheat, corn, soybean-meal, canola-meal and rice-barn [0.18% standardized total tract digestible (STTD) P and 0.59% Ca]; the NC supplemented with 250, 500, 1,000, or 2,000 FTU/kg of PhyG, and; the NC with added monocalcium phosphate (MCP) and limestone to produce three positive controls (0.33, 0.27, and 0.21% STTD P, and 0.75, 0.70, and 0.64% Ca, respectively; PC1, PC2, PC3). In total, 128 pigs (12.8 ± 1.33 kg, 8 pigs/treatment, housed individually) were adapted for 16 d followed by 4 d of fecal collection. Femurs were collected from euthanized pigs on day 21. Data were analyzed by one-way ANOVA with means separation by Tukey's test, and by factorial analysis (2 x 4: 2 levels of limestone solubility, 4 STTD P levels, and 2 × 5: 2 levels of limestone solubility, 5 PhyG dose levels). Phytase dose-response was analyzed by curve fitting. A consistent negative effect of HSL on ATTD P and Ca was observed in control diets (P < 0.001). Across phytase-supplemented diets, HSL reduced (P < 0.05) ATTD Ca and P (% and g/kg) compared with MSL. Across limestones, increasing phytase dose level increased (P < 0.05) ATTD P exponentially. Limestone solubility had no effect on bone ash, but PhyG linearly increased (P < 0.05) bone ash; 500 FTU/kg or higher maintained bone ash (g/femur) equivalent to PC1. In conclusion, ATTD P and Ca were reduced by a high compared with a medium soluble limestone, but the novel phytase improved ATTD P and Ca independent of limestone solubility.

PSVI-8 Effects of Phosphorus Level and Increasing Phytase Dose on Basal Endogenous Loss of Calcium and Balance of Phosphorus in Pigs Fed Diets Containing Phytate P at Commercial Levels

Abstract The objective was to test the hypothesis that dietary P concentration and level of phytase influences basal endogenous loss of Ca in pigs. Seventy barrows (body weight: 17.66 kg) were housed in metabolism crates and allotted to 7 Ca-free diets containing corn, potato protein concentrate, and full-fat rice bran (0.27% phytate P). A positive control (PC) diet contained P at the requirement for digestible P for 11 to 25 kg pigs. Negative control (NC) diets were formulated by reducing concentration of digestible P by 0.15% and adding a novel consensus bacterial 6-phytase variant at 0, 250, 500, 1,000, 2,000, or 4,000 phytase units/kg diet. Feces and urine samples were collected separately for 4 d after 5 d of adaptation. Dried and ground fecal samples were analyzed for dry matter, Ca, and P and urine was analyzed for P. Data were analyzed using a model that included diet as fixed effect. Positive control and NC were compared using a contrast statement and linear and exponential effects of dietary phytase were tested. Results indicated that apparent total tract digestibility of dry matter was not affected by dietary P or phytase (Table 1). The basal endogenous loss of Ca was not affected by dietary P, but exponentially (P = 0.030) decreased as dietary phytase increased. Phosphorus retention (g/d) was greater (P &amp;lt; 0.001) in pigs fed PC compared with NC without phytase. The standardized total tract digestibility (STTD) of P exponentially (P &amp;lt; 0.001) increased as phytase increased; however, retention of P as % of absorbed P decreased (linear, P = 0.006) as phytase increased because the extra P absorbed as a result of phytase could not be retained due to the lack of Ca. In conclusion, increasing the phytase dose decreased basal endogenous loss of Ca and increased STTD of P.

123 Superdosing Phytase Fed During Transition Phase in Sows Increased Piglet Weight Gain

Abstract Farrowing and lactation periods require a high demand for nutrients. Superdose (≥1500 FTU/kg) of phytase may increase the nutritive value of diets and improve litter performance. The objective of this study was to determine whether the superdosing of phytase (Quantum Blue; AB Vista) in the peripartum diet affects sow and piglet productivity and serum biomarkers (urea, cortisol, and calcium). A total of 54 sows, Topigs TN70 (27 control group, 27 superdosing group) were blocked by parity and randomly assigned to the treatments. The control lactation diet was a mixed-cereal and soybean meal-based, formulated to meet sow’s requirement with 500 FTU/kg phytase inclusion. The superdosing diet, was supplemented with a further 2,000 FTU/kg phytase to give a total of 2,500 FTU/kg. Peripartum treatment diets were provided from 10 d before farrowing until 10 d after, after which a common standard lactation was fed. Piglets were weaned at 26 d of age. Data were analyzed with ANOVA evaluating the effects of phytase dose and parity using the fit model platform in JMP15.1. Significant treatment means were separated using Student’s t-tests, with significance accepted at P ≤ 0.05. Birth weights of piglets were significantly affected by parity, with piglets born from parity 1 or 4+ sows being around 180g lighter in weight (P &amp;lt; 0.01) than piglets born from parity 2 or 3. The superdosing treatment increased piglet weight at weaning by 490g/weaned piglet (P &amp;lt; 0.01). Cortisol levels were greater (3.7 vs. 1.3 µg/dl, P &amp;lt; 0.01) at farrowing compared with 10d post-farrowing. Urea concentrations were 37% higher in the superdosing treatment at farrowing compared with control (P = 0.02). It can be concluded that the use of phytase at superdosing levels can be used in peripartum diets to improve piglet weight gain during lactation which is linked with greater utilization of nutrients that has been associated with greater phytate breakdown.

Effect of phytase supplementation on plasma and organ myo-inositol content and erythrocyte inositol phosphates as pertaining to breast meat quality issues in chickens

‘Woody breast’ (WB) and ‘white striping’ in broiler meat is a global problem. With unknown etiology, WB negatively impacts bird health, welfare and is a significant economic burden to the poultry industry. New evidence has shown that WB is associated with dysregulation in systemic and breast muscle-oxygen homeostasis, resulting in hypoxia and anaemia. However, it has been observed that phytase (Quantum Blue (QB) a modified, E. coli-derived 6-phytase) super dosing can reverse dysregulation of muscle-oxygen homeostasis and reduces WB severity by ~5%. The objective of this study was to assess whether levels of Ins(1,3,4,5,6)P 5, the main allosteric regulator of haemoglobin, are influenced by changes in plasma myo-inositol arising from super dosing with phytase. To enable this, methods suitable for measurement of myo-inositol in tissues and inositol phosphates in blood were developed. Data were collected from independent trials, including male Ross 308 broilers fed low and adequate calcium/available phosphate (Ca/AvP) diets supplemented with QB at 1,500 phytase units (FTU)/kg, which simultaneously decreased gizzard InsP 6 (P&lt;0.001) and increased gizzard myo-inositol (P&lt;0.001). Similarly, male Cobb 500 broiler chicks fed a negative control (NC) diet deficient in AvP, Ca and sodium or diet supplemented with the QB phytase at 500, 1000 or 2,000 FTU/kg increased plasma (P&lt;0.001) and liver (P=0.007) myo-inositol of 18d-old birds at 2,000 FTU/kg. Finally, QB supplementation of Cobb 500 breeder flock diet at 1,250 FTU/kg increased blood myo-inositol (P&lt;0.001) and erythrocyte Ins(1,3,4,5,6)P 5 (P=0.011) of their 1d-old hatchlings. These data confirmed the ability of phytase to modulate inositol phosphate pathways by provision of metabolic precursors of important signalling molecules. The ameliorations of WB afforded by super doses of phytase may include modulation of hypoxia pathways that also involve inositol signalling molecules. Elevations of erythrocyte Ins(1,3,4,5,6)P 5 by phytase supplementation may enhance systemic oxygen carrying capacity, an important factor in the amelioration of WB and WS myopathy.