Dietary Phytase Supplementation Research Articles

Effects of phytase inclusion in diets containing rice protein concentrate (RPC) on the nutrient digestibility, growth and chemical characteristics of rohu (Labeo rohita).

The objective of the current study was to assess the impact of dietary phytase supplementation on Labeo rohita fingerlings and to examine the effects on growth, nutrient digestibility and chemical characteristics of diets containing rice protein concentrate (RPC) as a major protein source. Six experimental diets were made, i.e., a positive control (fishmeal-based diet with no phytase), FM0; a negative control (RPC-based diet with no phytase), RPC0; and four supplemental phytase levels (250, 500, 1000, and 2000 FTU/kg). Fingerlings with an average weight of 9.42 ± 0.02 grams (mean ± SD) were randomly distributed into six experimental groups of three replicates, each containing 25 fish per tank (75 liters of water), provided with experimental diets at a rate equivalent to 5% of their body weight for 90 days, and uneaten feed was collected after 2 hours to determine feed consumption. The feces were collected before feeding to estimate digestibility. Phytase in combination with the RPC-based diet significantly (p < 0.05) enhanced phytate phosphorus in vitro hydrolysis; growth performance; nutrient (crude protein, crude fat, moisture and gross energy) and mineral (P, Ca, Mg, Na, K, Zn, Mn and Cu) digestibility; digestive enzyme (protease, lipase and amylase) activity; and mineral deposition up to 1000 FTU/kg phytase. However, the hepatosomatic and viscerosomatic indices and carcass composition were not influenced (p > 0.05) by phytase supplementation. Increasing phytase supplementation in the RPC-based diets led to a significant (p < 0.05) decrease in the serum biochemical parameters (alkaline phosphatase activity, aspartate aminotransferase, alanine aminotransferase), which resulted in improved liver health. In conclusion, phytase-supplemented RPC-based diets improved the growth, mineral/nutrient digestibility, digestive enzymes, serum biochemistry, and mineral deposition of L. rohita fingerlings up to 1000 FTU/kg. Broken line regression analysis revealed that the optimum phytase concentration in the RPC-based diet for L. rohita was 874.19 FTU/kg.

Supplemental phosphorus can be completely replaced with microbial phytase in White Leghorn layer diets

ABSTRACT 1. A study was conducted to assess the possibility of totally replacing supplemental phosphorus sources in White Leghorn (WL) layer diets (aged 28 to 45 weeks of age) with microbial phytase supplementation. One thousand commercial layers (HyLine White) of 28 weeks of age were housed in California cages fitted in open-sided poultry shed at the rate of 20 layers in each replicate. Ten replicates were randomly allotted to each treatment, and the respective diet was fed from 28 to 45 weeks of age. 2. A control diet (CD) containing the recommended levels of non-phytate phosphorus (3.6 g/kg NPP) and four other test diets (2–5) having sub-optimal levels of NPP (2.4, 2.0, 1.6 and 1.2 g/kg), but with supplemental microbial phytase (600 FTU/kg) were prepared and fed for the trial duration. 3. The layers fed with lower levels of NPP with phytase had the same laying performance as the group fed the CD. Egg production, feed efficiency, egg mass, shell defects, egg density, shell weight, shell thickness, ash content and breaking strength of the tibia and sternum were not affected by feeding the lowest concentration of NPP (1.2 g/kg) plus microbial phytase. 4. Phytase supplementation in diets with sub-optimal levels of NPP (2.4, 2 and 1.6 g/kg) significantly improved the Haugh unit score compared to those fed the CD. 5. It was concluded that supplemental phosphorus can be completely replaced with microbial phytase (600 FTU/kg) in a diet without affecting egg production, shell quality or bone mineral variables in WL layers (28 to 45 weeks).

Bone characteristics, pre-caecal phytate degradation, mineral digestibility and tissue expression were marginally affected by zinc level and source in phytase-supplemented diets in 21-day-old broiler chickens

ABSTRACT 1. This study determined the effect of dietary Zn concentration and source in phytase-supplemented diets on bone mineralisation, gastrointestinal phytate breakdown, mRNA-level gene expression (in jejunum, liver and Pectoralis major muscle) and growth performance in broiler chickens. 2. Male Cobb 500 broilers were housed in floor pens (d 0-d 21) to test seven treatments with six replicate pens (12 birds per pen). Diets were arranged in a 2 × 3 + 1-factorial arrangement. The experimental factors were Zn source (Zn-oxide (ZnO) or Zn-glycinate (ZnGly) and Zn supplementation level (10, 30 or 50 mg/kg of diet). A maize-soybean meal-based diet without supplementation and formulated to contain 28 mg Zn/kg (analysed to be 35 mg Zn/kg), served as a control. 3. Zinc source and level did not influence (p > 0.05) bone ash concentration and quantity or mineral concentrations in bone ash. Tibia thickness was greater in the treatment ZnO10 than in the treatments ZnO30 and ZnGly50 (Zn level × Zn source: p = 0.036), but width and breaking strength were not affected. 4. Pre-caecal P digestibility and concentrations of phytate breakdown products in the ileum, except for InsP5, were not affected by Zn source or level. Only the expression of EIF4EBP1 (eukaryotic translation initiation factor 4E-binding protein 1) and FBXO32 (F-box only protein 32) in Pectoralis major muscle was affected by source, where expression was increased in ZnO compared to ZnGly diets (p < 0.05). 5. In conclusion, Zn level and source did not affect gastrointestinal phytate degradation and bone mineralisation in phytase-supplemented diets. The intrinsic Zn concentration appeared to be sufficient for maximum bone Zn deposition under the conditions of the present study but requires validation in longer-term trials.

Impact of Trace Mineral Source and Phytase Supplementation on Prececal Phytate Degradation and Mineral Digestibility, Bone Mineralization, and Tissue Gene Expression in Broiler Chickens.

The objective of this study was to determine how different sources of Zn, Mn, and Cu in the feed without and with phytase affect prececal myo-inositol hexakisphosphate (InsP6) breakdown to myo-inositol (MI), prececal P digestibility, bone mineralization, and expression of mineral transporters in the jejunum of broiler chickens. A total of 896 male broiler chicks (Cobb 500) were distributed to 7 diets with 8 replicate pens (16 birds per floor pen). Experimental diets were fed from day 0 to 28. Diets were without or with phytase supplementation (0 or 750 FTU/kg) and were supplemented with three different trace mineral sources (TMS: sulfates, oxides, or chelates) containing 100mg/kg Zn, 100mg/kg Mn, and 125mg/kg Cu. Prececal InsP6 disappearance and P digestibility were affected by interaction (phytase × TMS: P ≤ 0.010). In diets without phytase supplementation, prececal InsP6 disappearance and P digestibility were greater (P ≤ 0.001) in birds fed chelated minerals than in birds fed sulfates or oxides. However, no differences were observed between TMS in diets with phytase supplementation. Ileal MI concentration was increased by exogenous phytase but differed depending on TMS (phytase × TMS: P ≤ 0.050). Tibia ash concentration as well as Zn and Mn concentration in tibia ash were increased by phytase supplementation (P < 0.010), but the Cu concentration in tibia ash was not (P > 0.050). Gene expression of the assayed mineral transporters in the jejunum was not affected by diet (P > 0.050), except for Zn transporter 5 (phytase × TMS: P = 0.024). In conclusion, the tested TMS had minor effects on endogenous phytate degradation in the digestive tract of broiler chickens. However, in phytase-supplemented diets, the choice of TMS was not relevant to phytate degradation under the conditions of this study.

Dietary Supplementation of Citric Acid and Phytase in Plant-Based Diets Improves Mineral Bioavailability in Common Carp, Cyprinus carpio

Dietary Supplementation of Citric Acid and Phytase in Plant-Based Diets Improves Mineral Bioavailability in Common Carp, Cyprinus carpio

Optimal dietary supplementation of phytase for red drum (Sciaenops ocellatus) based on growth and mineral utilization

A 9-week feeding trial was conducted with juvenile red drum to evaluate the potential benefits of supplementing dietary phytase on growth performance and utilization of phosphorus (P) and various trace minerals. The negative control diet (0.9% of total P and 0.57% of available P) was formulated to have inadequate available P based on the established P requirement of red drum. The positive control diet contained extra monocalcium phosphate (MCP) to provide 0.73% available phosphorus to meet the red drum's minimum P requirement. Another four phytase-supplemented diets were made via adding Quantum Blue phytase (AB Vista, Plantation, Florida) at either 1000, 2000, 4000, or 8000 phytase units (FTU)/kg to the negative control diet. Each diet was fed to quadruplicate groups of 20 juvenile red drum (initial weight of 4.99 ± 0.09 g) in 110-L aquaria operated as a brackish water (7 ppt) recirculating aquaculture system for 9 weeks. The results showed that compared to red drum fed the negative control diet, fish fed the phytase-supplemented diets had significantly (P < 0.05) increased weight gain, feed efficiency, and protein retention. In addition, significantly increased apparent availability of P was observed in red drum fed the diets containing phytase compared to those fed the negative control diet. Red drum given the phytase-supplemented diets also had significantly enhanced utilization of various minerals, except for whole-body retention of Mn and bone deposition of Fe, compared to fish fed the negative control diet. According to the results based on the orthogonal polynomial contrasts, the optimal dietary phytase dosage was found to be 5520 FTU/kg of dry diet. Consequently, the supplementation of dietary phytase significantly improved growth performance of red drum and partly substituted for dietary MCP in diets containing 40% soybean meal and insufficient available P. In addition, dietary phytase supplementation significantly enhanced the utilization of dietary protein and various minerals by red drum.

272 Effects of Increasing Dose of a Novel Hybrid Bacterial 6-Phytase on Apparent Total Tract Nutrient Digestibility, Release of Free Myoinositol, and Retention of Calcium and Phosphorus in Pigs

Abstract The objective of this study was to investigate the effects of increasing dose of a novel hybrid bacterial 6-phytase on apparent total tract digestibility (ATTD) of energy and nutrients, plasma concentrations of free myoinositol, and retention of calcium (Ca) and phosphorus (P). A total of 15 barrows (21.5 ± 1.4 kg BW) were allotted to a triplicate 5 × 5 Latin square design with 5 dietary treatments and 5 periods per each square. Pigs were individually housed in a metabolism crate. Five dietary treatments consisted of 5 levels of phytase-supplemented diets with increasing phytase units (0, 500, 1,000, 1,500, and 2,000 FTU/kg). Diets contained nutrients meeting the requirement except for Ca and P. Degree of deficient Ca and P content in the NC diet were 0.22 and 0.17%, respectively. Each period lasted 10 days consisting of a 5-d adaptation period and 5-d collection period for total collection. Data were analyzed using orthogonal polynomial contrasts using the Proc MIXED and optimal phytase levels were determined using the NLMIXED of SAS. The increasing phytase supplementation linearly increased (P &amp;lt; 0.05) average daily gain (651 to 695 g/d) and tended to linearly increase (P = 0.072) gain to feed ratio (0.53 to 0.56). Increasing phytase supplementation linearly increased (P &amp;lt; 0.01) ATTD of Ca and P and retention of Ca and P and also showed quadratic effects (P &amp;lt; 0.01). Increasing phytase supplementation linearly increased (P &amp;lt; 0.01) myoinositol content in plasma and also showed quadratic effects (P &amp;lt; 0.05). Broken line analyses showed that ATTD of Ca (P &amp;lt; 0.01) and retention of Ca (P &amp;lt; 0.01) were increased until phytase supplementation were increased (79.4 to 92.1% and 77.4 to 91.4%) from 0 to 671 FTU/kg (SE = 67; P &amp;lt; 0.01) and 0 to 668 FTU/kg (SE = 72; P &amp;lt; 0.01), respectively. Broken line analyses showed that ATTD of P (P &amp;lt; 0.01) and retention of P (P &amp;lt; 0.01) were increased (59.0 to 80.1% and 55.7 to 78.2%) until phytase contents were increased from 0 to 783 FTU/kg (SE = 91; P &amp;lt; 0.01) and 0 to 776 FTU/kg (SE = 76; P &amp;lt; 0.01), respectively. The broken line analyses showed that myoinositol contents in plasma (P &amp;lt; 0.01) were increased (13.2 to 23.2 µmol/L) until phytase supplementation were increased from 0 to 624 FTU/kg (SE = 174; P &amp;lt; 0.01). In conclusion, increasing phytase supplementation up to 2,000 FTU/kg feed improved ATTD of Ca and P, retention of Ca and P, complete hydrolysis of phytate, and growth performance of pigs compared with a P-deficient diet. Phytase supplementation at a range of 600 to 800 FTU/kg feeds provided the optimal improvement of Ca, P, and phytate utilization.

48. Increasing the dietary supplementation of a new generation phytase can counteract the detrimental effect of calcium on phosphorus absorption in pigs

48. Increasing the dietary supplementation of a new generation phytase can counteract the detrimental effect of calcium on phosphorus absorption in pigs

273 Dynamics of Bone Mineralization in Primiparous Sows as a Function of Dietary Phosphorus and Calcium During Lactation

Abstract In a context of maximizing the use of dietary phosphorus (P) in swine production, research should focus on understanding the mechanisms of bone P and calcium (Ca) utilization in sows. A better knowledge of P and Ca quantities that can be mobilized from bones during lactation, which would then be restored during gestation, would allow the development of new feeding strategies including this dynamic process. In turn, it can lead to a substantial decrease in dietary P supply. The role of dietary phytase supplementation also needs to be quantified in such potential strategies. In addition to the bone mineral status of sows, the consequences of these strategies on litter performance need to be documented. The objectives of the experiment were to measure the capacity of the sow to mobilize bone minerals reserves during lactation according to dietary digestible P (P dig) content and phytase addition, to restore them, during the following gestation, and to measure the effects on the growth performance of the offspring. Whole body bone mineral content (BMC) of primiparous Swiss Large White sows (n = 24) from the Agroscope sow herd was measured by dual-energy X-ray absorptiometry (DXA) on days 2, 14, 26, 66, and 106 after parturition. Four lactation diets were formulated to cover all nutritional requirements except for Ca and P dig: control without phytase (100%; 3.0 g P dig, 9.9 g Ca/kg), 75% of P dig without phytase (75%; 2.3 g P dig, 8.3 g Ca/kg), 50% of P dig without phytase (50; 1.5 g P dig, 6.0 g Ca/kg), and 50% of P dig with phytase (50+Phyt; 3.0 g P dig, 7.6 g Ca/kg). The gestation diet was formulated to cover nutritional requirements of Ca and P dig (2.6 g P dig, 8.2 g Ca/kg). Piglets were weighed at 1 and 14 days after parturition and at weaning (day 26), and the average daily gain (ADG) per piglet was calculated. During lactation, BMC of the sow (in g/kg of body weight, BW) tended to be less in treatment 50% than in treatment 100% (-12.8%, linear effect x time quadratic, P = 0.05). During gestation, BMC was similar between treatments. Therefore, sows in treatment 50% were able to recover their bone-mineralization deficit during the next gestation. The BMC (in g and in g/kg BW) was similar between treatments 100% and treatment 50+Phyt throughout the experimental period. Piglet weight at days 1, 14, and 26 and ADG (days 1 to 14, 14 to 26 and 1 to 26) were similar between dietary treatments. These results show the possibility of drastically reducing dietary P during lactation without decreasing litter performance and highlight the ability of primiparous sows to mobilize bone mineral during lactation and restore it during gestation.

Effect of dietary zinc source, zinc concentration, and exogenous phytase on intestinal phytate degradation products, bone mineralization, and zinc status of broiler chickens

This study aimed to determine the effect of Zn source and dietary level on intestinal myo-inositol hexakisphosphate (InsP6) disappearance, intestinal accumulation of lower InsP and myo-inositol (MI), prececal mineral digestibility, bone mineralization, and Zn status of broilers without and with exogenous phytase in the feed. Male Ross 308 broilers were allocated in groups of 10 to 8 treatments with 8 pens each. Experimental diets were fed from d 7 to d 28 and contained 33 mg/kg dry matter plant-intrinsic Zn. Experimental factors were phytase supplementation (0 or 750 FTU/kg) and Zn source (none [0 mg/kg Zn], Zn-sulfate [30 mg/kg Zn], Zn-oxide [30 mg/kg Zn]). Additional treatments with 90 mg/kg Zn as Zn-sulfate or Zn-oxide and phytase were included to test the effect of Zn level. No Zn source or Zn level effects were observed for ADG, feed conversion ratio, prececal P digestibility, intestinal InsP6 disappearance, and bone ash concentration. However, those measurements were increased by exogenous phytase (P<0.001), except the feed conversion ratio, which was decreased (P<0.001). Ileal MI concentrations were affected by phytase×Zn source interaction (P<0.030). Birds receiving exogenous phytase and Zn supplementation had the highest MI concentrations regardless of exogenous Zn source, whereas MI concentrations were intermediate for birds receiving exogenous phytase only. Exogenous phytase and exogenous Zn source increased the Zn concentration in bone and blood of broilers (P<0.001). In conclusion, measures of exogenous phytase efficacy were not affected by phytase×Zn source interaction. Further studies are needed to rule out an effect from Zn sources other than those tested in this study and to investigate the effect of Zn supplementation on endogenous phosphatases. The missing effect of increasing Zn supplementation from 30 to 90mg/kg in phytase-supplemented diets gives reason to reconsider the Zn supplementation level used by the industry.

The effects of concurrent increases in supplementation of calcium and phytase on growth performance, balance of Ca and P, and bone mineralization in nursery pigs

Abstract The objective of this study was to investigate the effects of concomitantly increasing supplementation of Ca and phytase on growth performance, balance of Ca and P, and bone mineralization in nursery pigs. There were eight experimental diets. The positive control (PC) one and two were formulated to contain 0.64% and 0.85% total Ca, respectively, whereas the dietary concentrations of other nutrients were identical and adequate. The negative control (NC) was deficient in total Ca (0.48%) and total P (0.41%). Five combinations of incremental levels of Ca and phytase (0.48% and 1,750 phytase units [FYT]/kg, 0.52% and 2,000 FYT/kg, 0.55% and 2,250 FYT/kg, 0.59% and 2,600 FYT/kg, and 0.63% and 3,000 FYT/kg) were added to the NC to establish the remaining five experimental diets. Each diet was fed to six pens of six pigs (three barrows and three gilts per pen). All diets contained 3 g/kg TiO2, and fecal samples were collected from each pen during the trial. In the end, one pig per pen was euthanized to collect the right tibia and urine in bladder. The results showed that the pigs of NC gained less weight, consumed less feed, and utilized feed less efficiently than their counterparts fed the PC and the treatments with phytase (P &amp;lt; 0.01). With increasing supplementation of Ca and phytase, there was a tendency for gain:feed to decrease (P &amp;lt; 0.10). There was a significant reduction in bone dry weight; and in percentages, as well as weights of bone ash, Ca, and P; in pigs of NC compared with pigs of PC1, PC2, or phytase treatments. In comparison to PC2, PC1 and phytase treatments resulted in a higher percentage of bone P and greater weights of bone ash, Ca, and P (P &amp;lt; 0.05). There was no significant effect of concurrent supplementation of Ca and phytase on bone mineralization. The NC had significantly lower apparent total tract digestibility (ATTD) of Ca and P, lower concentrations of digestible Ca and P, but a higher ATTD Ca/ATTD P ratio than PC1, PC2, or the phytase treatments. The averages of ATTD of Ca and P in treatments with phytase were significantly higher than PC1 or PC2 (P &amp;lt; 0.01). With increasing addition of Ca and phytase, the ATTD of P, digestible Ca and P, and the ATTD Ca/ATTD P ratio increased linearly (P &amp;lt; 0.05), which contrasted with a linear reduction in ATTD of Ca (P &amp;lt; 0.05). Meanwhile, there was a linear (P &amp;lt; 0.01) increase in the concentration of urinary Ca. In conclusion, increasing the dietary supplementation of phytase in conjunction with the increasing dietary Ca level increased the dietary ATTD Ca/ATTD P ratio without damaging the absorption of P in the current study. The higher ATTD Ca/ATTD P ratio did not improve the bone mineralization markedly and thus the extra Ca was voided through urine.

Effects of dietary supplementation with microbial phytase on the growth, bone minerals, antioxidant status, innate immunity and disease resistance of African catfish fed on high soybean meal-based diets.

The microbial phytase, derived from Buttiauxella gaviniae, Yersinia mollarettiv and Hafnia spp., is proven to be safe for avian and porcine feeding and promotes their overall growth performance. Here, we have evaluated microbial phytase's effects on the growth, bone mineral content, antioxidant status, immune responses and the resistance of African catfish (Clarias gariepinus) fed with high soybean meal-based diets against Aeromonas hydrophila infection. Five isonitrogenous diets (40% protein) were supplemented with different levels of microbial phytase ranging from 0 as a control to 250, 500, 750 and 1000 FTU/kg diet. African catfish (n = 300; 8.5 ± 0.3 g) were allocated in 15 50-L tanks (in triplicates) and were fed on the prepared tested diets for 12 weeks. After the end of the feeding period of 12 weeks, 10 fish from each replicate was intraperitoneally infected with A. hydrophila (0.5 × 105 CFU/ml) and monitored for 14 days. Dietary phytase levels linearly and quadratically improved the growth performance of African catfish and stimulated feed intake. Bone levels of calcium, phosphorus, magnesium and zinc were also positively modulated in phytase-fed fish, especially at 750-1000 FTU/kg diet. Similarly, counts of red and white blood cells as well as haemoglobin, packed cells volume, platelets, lymphocytes and heterocytes were significantly modulated in all fish fed with phytase-supplemented diets. Higher levels of serum total protein, albumin and globulin were also observed in fish fed with a 750-1000 FTU/kg diet of phytase. Conversely, aspartate and alanine aminotransferase activities were lower in fish fed with a 750-1000 FTU/kg diet of phytase, compared to those fed the control diet. Moreover, antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase), reduced glutathione levels and immune responses (lysozyme, respiratory burst, protease and alkaline phosphatase activities) biomarkers were linearly and quadratically elevated, while malondialdehyde values were linearly and quadratically decreased in fish groups fed with phytase-based diets. After administering A. hydrophila, 60.0% of the fish fed the control diet perished, while no mortalities were observed in fish fed with 750-1000 FTU/kg diets. Taken together, the current study reveals that dietary phytase could improve the growth performance, blood profile, bone mineralization, antioxidant activities, immunity and overall protection of African catfish against A. hydrophila infection. Dietary phytase may be efficiently used in the feeding of African catfish to enhance their overall performance and mitigate health conditions with optimum level of 900 FTU/kg diet.

Effects of phytase supplementation of high-plant-protein diets on growth, phosphorus utilization, antioxidant, and digestion in red swamp crayfish (Procambarus clarkii)

Fish meal is increasingly being replaced by plant protein raw materials, meanwhile, it brings phytic acid, which combines with phosphorus to form phytate phosphorus and leads to a low utilization rate of phosphorus in shrimp. To solve this problem, this study investigated the effects of phytase supplementation on growth performance, phosphorus utilization, antioxidants, and digestion in red swamp crayfish (Procambarus clarkii). Crayfish (initial mean weight: 8.69 ± 0.15 g, N = 324) were randomly divided into six groups each with three replicates of 18 individuals each, and hand-fed for 8 weeks with one of six experimental diets (50 and 490 g kg−1 animal and plant protein raw material, respectively): negative control (NC; 11.0 g kg−1 phosphorus), positive control (PC; 15 g kg−1 NaH2PO4 added to NC; 14.7 g kg−1 phosphorus), and phytase supplementation diets (P1–P4: 0.1, 0.2, 0.4, and 0.6 g kg−1 phytase added to NC, respectively). The feeding trial was performed in a micro-flow water culture system. P2 showed a significantly higher weight gain rate (WGR), specific growth rate, protein efficiency ratio, and protein retention efficiency (PRE) but showed the lowest feed conversion ratio (FCR) than other groups. Broken-line regression analyses using WGR, FCR, and PRE as evaluation indices showed that the optimal dietary phytase supplementation level was 0.233, 0.244, and 0.303 g kg−1, respectively. P2 showed the highest crude protein content of whole crayfish and abdominal muscle, and phosphorus deposition rate, which was significantly higher than that in NC and PC. P3 showed the highest calcium and phosphorus contents in whole crayfish and phosphorus content in abdominal muscle, and calcium and inorganic phosphorus content in serum, which were significantly higher than those in NC. P3 showed significantly lowest serum alkaline phosphatase, alanine aminotransferase, aspartate transaminase activities, malondialdehyde content in hepatopancreas, and highest catalase activity, which were significantly lower and higher, respectively, than those in NC and PC. In summary, the addition of 0.2–0.4 g kg−1 phytase significantly improves the growth performance, feed utilization, digestive enzyme activity, and antioxidant of P. clarkii, which has a similar effect to the direct addition of NaH2PO4 at 15 g kg−1 to the feed.

Efficacy of Various Feed Additives on Performance, Nutrient Digestibility, Bone Quality, Blood Constituents, and Phosphorus Absorption and Utilization of Broiler Chickens Fed Low Phosphorus Diet.

Simple SummarySkeletal disorders and related-welfare complications are an ongoing concern for rapid-growing broiler chickens. Phosphorus is a vital nutrient in the poultry diet, and it is related to bone growth and skeleton rigidity and strength. Poultry utilize approximately 60% of the dietary P, and the residual is excreted and may enter the environment leading to environmental pollution. Consequently, a better understanding of intestinal phosphorus absorption will enable augmenting phosphorus utilization and reducing phosphorus excretion and feed costs in the poultry industry. Therefore, the present trial was designed to assess various supplements on performance, nutrient digestibility, bone physical parameters and mineralization, blood constituents, bone and gut histomorphology, and duodenal phosphorus transporter genes of broiler chickens fed a decreased non-phytate phosphorus. The dietary addition of phytase or probiotic to a low phosphorus diet was beneficial with respect to growth performance and carcass traits. Regarding nutrient digestibility, tibia quality parameters, and gut and bone histomorphology, all three dietary supplements (probiotics, yeast, and fumaric acid) were advantageous, and these improvements were of comparable magnitude to those of the positive control and phytase groups. The up-regulation of duodenal NaP-IIb and PiT-2 genes in the supplemented groups may suggest greater phosphorus availability. It can be concluded that these supplements were beneficial in mitigating the negative effects of phosphorus reduction on the growth performance, health, and bone quality of broilers.The present trial was designed to assess the effect of phytase, multi-strain probiotic, Saccharomyces cerevisiae, and fumaric acid on performance, nutrient digestibility, bone physical parameters and mineralization, blood constituents, bone and gut histomorphology, and duodenal phosphorus transporter genes of broiler chickens fed a decreased non-phytate phosphorus (nPP) diet for 5 weeks. A total of 480 broiler chickens were allotted to six dietary groups and eight replicates each: (1) positive control diet with recommended levels of nPP (PC; 0.48, 0.44, and 0.41% in the three feeding phases); (2) negative control diet with a decreased dietary nPP (NC; 0.28, 0.24, and 0.21% in the three feeding phases); (3) NC + 600 FTU/kg phytase (PHY); (4) NC + 0.05% multi-strain probiotic (PRO); (5) NC + 0.2% Saccharomyces cerevisiae (SC); and (6) NC + 0.2% fumaric acid. Growth performance data were recorded weekly, and blood sampling was performed at days 21 and 35 of age. Bone quality traits, gut and tibia histology, nutrient digestibility, and intestinal gene expression analyses were conducted at the end of the trial (35 days of age). Final body weight and total gain at day 35 of age of the broiler chickens fed with the PHY, PRO, and SC diets were greater (p < 0.01) than in NC, where broilers fed with the PRO and PHY diets had higher values and were similar to that of PC. There was a non-significant variation in the cumulative feed intake among the treatment groups. The PHY and PRO groups had better FCR than the PC group (p < 0.05), and FA and SC had an FCR equivalent to that of PC. The PHY and PRO broilers had greater dressing % than the NC group (p < 0.05) and even better than PC. The PHY, PRO, SC, and FA broilers had higher relative weights of spleen and bursa of Fabricius (p < 0.01) than NC. In comparison to NC, the PHY, PRO, and SC groups improved (p < 0.05) CP, CF, Ca, and P digestibility. Greater tibia breaking strength of the low nPP-supplemented groups was shown to be associated with higher tibia ash, Ca, and P concentrations (p < 0.01) and increased (p < 0.001) tibia cortical area thickness. At days 21 and 35 of age, the dietary supplements to low nPP diets reduced (p < 0.05) serum total cholesterol, triglyceride, triiodothyronine, thyroxine, glucose, and alkaline phosphatase levels, while serum Ca and P concentrations were improved (p < 0.05) compared to NC. All supplements led to enhancement (p < 0.01) in villi height and width and villi absorptive surface area when compared with NC and were even comparable to that of PC. The mRNA expression of NaP-IIb was up-regulated (p < 0.001) in the duodenum of PRO and FA broilers at day 35 of age compared with NC, and their expression levels were similar to that of PC, indicating greater P availability. It is concluded that dietary supplementation of PHY, PRO, SC, and FA to a low nPP diet was advantageous and mitigated the negative impacts of P reduction on the growth performance, health, nutrient digestibility, and bone quality of broilers.

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.

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.

The impact of dietary calcium content on phosphorus absorption and retention in growing pigs is enhanced by dietary microbial phytase supplementation.

Sixty growing male pigs were used to test the hypothesis that high dietary Ca content reduces P absorption to a greater extent in microbial phytase-supplemented diets via reducing inositol phosphate (IP) degradation and enhancing P precipitation. Pigs were equally allotted over diets with three Ca contents 2·0, 5·8 and 9·6 g/kg with or without microbial phytase (0 v. 500 FTU/kg) in a 2 × 3 factorial arrangement. Faeces and urine were collected at the end of the 21-d experimental period. Subsequently, pigs were euthanised and digesta quantitatively collected from different gastrointestinal tract (GIT) segments. Increasing dietary Ca content reduced apparent P digestibility in all GIT segments posterior to the stomach (P < 0·001), with greater effect in phytase-supplemented diets in the distal small intestine (Pinteraction = 0·007) and total tract (Pinteraction = 0·023). Nonetheless, increasing dietary Ca to 5·8 g/kg enhanced P retention, but only in phytase-supplemented diets. Ileal IP6 degradation increased with phytase (P < 0·001) but decreased with increasing dietary Ca content (P = 0·014). Proportion of IP esters in total IP (∑IP) indicated that IP6/∑IP was increased while IP4/∑IP and IP3/∑IP were reduced with increasing dietary Ca content and also with a greater impact in phytase-supplemented diets (Pinteraction = 0·025, 0·018 and 0·009, respectively). In all GIT segments, P solubility was increased with phytase (P < 0·001) and tended to be reduced with dietary Ca content (P < 0·096). Measurements in GIT segments showed that increasing dietary Ca content reduced apparent P digestibility via reducing IP degradation and enhancing P precipitation, with a greater impact in phytase-supplemented diets due to reduced IP degradation.

PSIV-16 Phytase Expressed from Schizosaccharomyces Pombe Ameliorates Footpad Lesions in Cage-Reared Broiler Chicks

Abstract Footpad lesion is a problem that plagued the poultry industry, because it occurs in birds that are either reared in the cage or on the floor. Reports from previous studies about amelioration of footpad lesions by feeding phytase to floor-reared broiler chicks via reduction in litter moisture content is inconclusive. Therefore, phytase supplementation may have other potential mechanisms to improve the footpad lesions. The cage-reared broiler chicks were used in this study because they are divided with litter. A total of 234 1-d-old broiler chicks were randomly assigned to 3 groups based on the initial body weight (42.22 ± 0.18 g) with 6 replicate cages and 13 birds (mixed sex) per cage. The experimental period was 45 d. Dietary treatments were based on a corn-soybean meal-basal diet and supplemented with 500 and 750 FTU/kg S. pombe-expressed phytase. The unit of phytase (FTU) was defined as the amount of enzyme that catalyzes the release of one micromole phosphate from phytate per minute at 37°C and pH 5.5. Orthogonal contrasts were used to examine the linear and quadratic effects in response to increasing the dietary supplementation of phytase. We found that dietary supplementation of S. pombe-expressed phytase increased (P &amp;lt; 0.05) the apparent ileal calcium and phosphorus digestibility and toe ash in a dose-dependent manner, whereas decreased (P &amp;gt; 0.05) the footpad lesions score. From this, we considered that footpad lesions ameliorated by phytase supplementation were related to the improvement of calcium and phosphorus digestibility and toe ash.

Effects of added phytase on growth performance, carcass traits, and tibia ash of broiler chickens fed diets with reduced amino acid, crude protein, and phosphorus concentration

This experiment was conducted to investigate the effect of phytase supplementation in diets reduced in amino acids ( AA ), crude protein ( CP ), and phosphorus ( P ) on growth performance, carcass traits, and tibia ash of broiler chickens. A total of 2,240 unsexed Ross 308 broiler chickens were used in 56 floor pens with 40 birds each and fed one of eight dietary treatments in seven replicates until 35 d of age. A positive control ( PC ) diet and diets with dietary AA/CP level reduced by 2, 4, and 6% were used with and without supplementation with 1,500 FTU phytase/kg. Starter, grower, and finisher diets were fed from d 1 to 10, d 10 to 25, and d 25 to 35, respectively. For the total period, no significant interaction effects between AA/CP level and phytase supplementation were detected for any measured traits. The ADG, ADFI, carcass weight, breast weight, and tibia ash weight were lower and FCR was higher compared to the PC diets when the AA/CP level was reduced by more than 2%. Phytase supplementation increased ADG, ADFI, final BW, and tibia ash weight. Tibia ash measurements showed that birds were adequately supplied with digestible phosphorus in all treatments, although dietary phosphorus and calcium were reduced in the phytase-supplemented diets. This enabled the feeding of broiler chickens without mineral phosphate supplements in grower and finisher diets. The results showed that supplementation with 1,500 FTU phytase/kg diminished the growth-decreasing effect of lower dietary AA/CP at all reduction steps.

Effect of Dietary Phytase Supplementation on Growth Performance, Organ Weight and Tibia Ash of Broilers

This study was conducted to investigate the effects of dietary inclusion of phytase on the growth performance, organ weight, and tibia ash of broilers. A total of 1008 one-day-old Ross 308 broiler chicks (mixed gender) with body weight 42 ± 0.90 g (mean ± SD) were used in a trial for 32 d. Chicks were assigned to one of the two treatment diets. Each treatment consisted of 28 replicate cages, with 18 birds per cage. The dietary treatments were as follows: CON, basal diet; TRT1, basal diet + phytase 1,500 Fan Terminal Unit (FTU)/kg diet. Dietary inclusion of 1,500 FTU/kg phytase supplementation in broilers showed only slight improvements in daily feed intake (<i>P</i>=0.086) and feed conversion ratio (<i>P</i>=0.065) on day 9 compared with that in the control group. However, organ weights of the breast muscle, liver, spleen, kidney, and bursa of Fabricius were not affected by the dietary treatments. In addition, the dietary inclusion of 1,500 FTU/kg phytase supplementation in the broiler diet had no effect on tibia ash. The addition of 1,500 FTU/kg phytase in the basal diet of broilers did not have any adverse effect on growth performance, organ weight, and tibia ash, suggesting that phytase supplementation in broiler diets will exhibit comparable effects as that of corn-soybean meal-based diet.