Effects of phytase enzyme supplementation on growth performance, intestinal morphology and metabolism in Nile tilapia (Oreochromis niloticus)

Phytase is crucial in enhancing the bioavailability and release of phosphorus and other nutrients bound to phytic acid, making them more bioavailable for animal absorption. This study was carried out to inspect the effect of supplementing low phosphorus (P) diet with di-calcium phosphate (DCP) and liquid phytase enzyme (LP), which contains 1500 FTU/kg, on growth performance, intestinal morphometry, proximate body chemical composition, blood profile, immunity status, liver mitochondrial enzyme activities, the expression response and economic returns of Nile tilapia (Oreochromis niloticus). Three triplicate groups of fish (initial weight 5.405 ± 0.045 g, N = 90) were fed on three different diets for 90 days. The first was a control diet with zero DCP; the second was a control diet supplemented with 0.71% DCP; the third was a control diet supplemented with 0.03% LP. The groups were designated as CG, DCP and LP, respectively. Results showed that LP induced considerable improvements (p < 0.05) in FBW, body weight gain, weight gain rate, specific growth rate, HIS, viscero-somatic index, spleen-somatic index, feed conversion ratio, blood parameters and the histomorphometry assessment of intestinal villi absorptive capacity, compared with the other groups. Also, whole-body protein and lipid contents pointedly (p < 0.05) increased by LP, compared with the DCP group. A positive response (p < 0.05) to the phytase enzyme was noted in complexes I, III and IV of the mitochondrial liver complex enzyme activity. Likewise, the relative gene expression levels of (GHr-1, IGF-1, FAS and LPL) were notably (p < 0.05) upregulated by phytase enzyme, associated with DCP and control groups. Further, phytase recorded the highest total return and profit percentage. It can be concluded that Nile tilapia benefits from using phytase enzyme 1500 FTU/kg at 0.03% without adding DCP in terms of good performance and profits.

A comparative study on the effect of limestone particle size on performance, ileal digestibility of calcium and phosphorus, and bone characteristics in broilers and pullets

1. The effects of limestone particle size on growth performance, gastrointestinal tract (GIT) traits, ileal morphology, duodenal gene expression of calbindin, apparent ileal digestibility coefficients (AIDC) of calcium (Ca) and phosphorus (P) and tibia characteristics in broilers and pullets were assessed in broilers and pullets. These birds have different growth rates and likely different responses to parameters, such as particle size.2. A total of 240 chicks aged one day, 120 Ross 308 female broilers, and 120 Hy-Line pullets were allocated randomly into four treatments in a 2 × 2 factorial arrangement with two bird types (broilers vs. pullets) and two limestone particle sizes (<0.5 mm versus 1-2 mm) to give six replicates containing 10 chicks in each from 1 to 21 d of age.3. Feed intake and weight gain were greater (P < 0.001) and feed per gain (FCR) was better (P < 0.001) in broilers compared to pullets from 1 to 21 d of age. Greater villus width (P < 0.01), villus height (P < 0.001) and crypt depth (P < 0.01) were seen for broilers compared to pullets.4. Pullets fed coarse Ca particles had higher calbindin gene expression at 21 d of age (P = 0.05). Both AIDC of Ca and P were higher (P < 0.001) in broilers compared to pullets. The AIDC of Ca from 0.463 to 0.516 was increased (P < 0.05) by feeding coarse limestone particles. A significant interaction was found between bird type and limestone particle size (P < 0.01), where pullets fed coarse Ca particles had higher bone P concentration in tibia than broilers.5. Broilers had better ileum absorptive capacity and growth performance compared to pullets. The AIDC of Ca and P was higher in broilers than in pullets. Increased limestone particle size elevated villus height, AIDC of Ca and concentration of P in the tibia.

The Effect of including a Mixed-Enzyme Product in Broiler Diets on Performance, Metabolizable Energy, Phosphorus and Calcium Retention

The importance of enzymes in the poultry industry is ever increasing because they help to extract as many nutrients as possible from the raw material available and reduce environmental impacts. Therefore, an experiment was conducted to examine the effect of a natural enzyme complex (ASC) on diets low in AME, Ca and P. Male Ross 308 broilers (n = 900) were fed one of four diets: (1) positive control (PC) with no enzyme added (AME 12.55 MJ/kg, AVPhos 4.8 g/kg and AVCal 9.6 g/kg); (2) negative control (NC) with no enzyme added and reduced AME, Ca and P (AME 12.18 MJ/kg, AVPhos 3.3 g/kg, AVCal 8.1 g/kg); (3) negative control plus ASC at 200 g/t; and (4) negative control plus ASC at 400 g/t. Broiler performance, digesta viscosity, tibia mineralization and mineral content were analyzed at d 21. Between d 18 and 20, excreted DM, GE, total nitrogen, Ca, and P were analyzed. ASC at 200 g/t and 400 g/t improved the FCR (p = 0.0014) significantly when compared with that of the NC. There were no significant differences in BW or FI between the treatments. Birds fed ASC at 200 g/t and 400 g/t had significantly improved digesta viscosity (p < 0.0001) compared with that of the PC and NC birds and had significantly higher excreted DM digestibility (p < 0.01) than the NC and the PC birds with 400 g/t ASC. ASC inclusion significantly improved P retention (p < 0.0001) compared to that in the PC. Ca retention was significantly increased by 400 g/t ASC compared to that in the PC and NC (p < 0.001). AME was significantly higher (p < 0.0001) for all treatments compared to that in the NC. There were no significant differences between treatments for any of the bone measurements. This study showed that feeding with ASC can support the performance of broilers when fed a diet formulated to have reduced Ca, P and AME, with the greatest results being seen with a higher level of ASC inclusion.

A study of solely used phytase or in combination with multi-carbohydrase on growth performance along with tibia mineralization, and carcass traits in broilers fed nutrient-deficient diets

The objective of this study aimed to investigate the effectiveness of phytase alone and in combination with multi-carbohydrase in available phosphorus (AP) and energy-deficient diets on growth performance, nutrient digestibility, tibia traits, and carcass quality of broilers. A total of 288 1-d-old Ross 308 broiler chicks were randomly assigned to one of 6 dietary treatments in a completely randomized design, with each treatment having 6 replicates and 8 birds per cage. The treatments were as follows: 1) positive control with adequate nutrition (PC); 2) 0.20% AP-deficient diet without phytase (NC-1); 3) 0.25% AP-deficient diet without phytase (NC-2); 4) NC-1 diet plus 500 FTU/kg phytase (NCP-1); 5) NC-2 diet plus 750 FTU/kg phytase (NCP-2); and 6) NC-2 with 100 kcal/kg ME deficient diet plus 1,000 FTU/kg phytase and multi-carbohydrase: 2,200 U/kg galactomannanase, 30,000 U/kg xylanase, 22,000 U/kg β-glucanase, and 700 U/kg α-galactosidase (NCPM). Broilers in the PC group and those fed enzyme-supplemented diets exhibited greater (P < 0.05) growth performance in terms of body weight, average daily gain, and feed conversion ratio, along with enhanced tibia mineralization through the ash, calcium (Ca), phosphorus (P) composition, and tibia breaking strength compared to NC diets throughout the study. Among the treatments, broilers assigned to the NCPM group showed greater (P < 0.05) levels of energy and P digestibility on days 21 and 35. Concerning carcass characteristics, the leg meat yield was greater (P < 0.05) in broilers fed the NCP-2 diet compared to all other treatments on days 21 and 35. Supplementation of phytase at doses of 500 FTU/kg and 750 FTU/kg effectively recovers AP deficiencies of 0.20% and 0.25%, respectively, in broiler diets without compromising the growth performance of broilers. Additionally, combining multi-carbohydrase and phytase led to AP and energy loss recovery, which improved tibia mineralization and nutrient digestibility through their synergistic interaction.

Effect of Bacterial Phytase on Growth Performance, Nutrient Utilization, and Bone Mineralization in Broilers Fed Pelleted Diets

The influence of a bacterial 6-phytase on growth performance, coefficient of apparent ileal digestibility (CAID) of nutrients, blood parameters, and bone mineralization in broilers was evaluated. A total of 630 one-day-old male broilers were allocated to 7 dietary treatments, including positive control (PC) diet containing dicalcium phosphate, the PC marginally reduced in available P (avP) by 0.1% and calcium (Ca) by 0.2% vs. PC (NC1) or moderately reduced by 0.15 and 0.3% vs. PC (NC2), respectively, and four further diets comprising the NC1 and NC2 supplemented with 500 or 1000 FTU/kg of phytase in starter and finisher phases. A constant Ca to avP ratio was maintained across all diets. The body weight gain (BWG) and feed per unit gain (FCR) of birds fed NC1 and NC2 diets supplemented with phytase (500 and 1000 U/kg) was equivalent to that of birds fed the PC diet at 35 days. Phytase supplementation in the NC1 diet linearly increased the CAID of nitrogen (N) (p < 0.01), phosphorus (P) (p < 0.01), and Ca (p < 0.05). Additionally, phytase reduced (p < 0.01) excreta P concentration by approximately 27%, improved (p < 0.001) toe ash, and tended to increase tibia ash (p = 0.08), comparable with the PC. In conclusion, the addition of bacterial 6-phytase dosed in the range of 500-1000 FTU/kg was effective in replacing 1.5 g/kg avP and 3 g/kg Ca in broilers fed pelleted diets, using bone quality, BWG, and FCR as outcome measures.

Nutritional and Functional Roles of Phytase and Xylanase Enhancing the Intestinal Health and Growth of Nursery Pigs and Broiler Chickens

This review paper discussed the nutritional and functional roles of phytase and xylanase enhancing the intestinal and growth of nursery pigs and broiler chickens. There are different feed enzymes that are currently supplemented to feeds for nursery pigs and broiler chickens. Phytase and xylanase have been extensively studied showing consistent results especially related to enhancement of nutrient digestibility and growth performance of nursery pigs and broiler chickens. Findings from recent studies raise the hypothesis that phytase and xylanase could play functional roles beyond increasing nutrient digestibility, but also enhancing the intestinal health and positively modulating the intestinal microbiota of nursery pigs and broiler chickens. In conclusion, the supplementation of phytase and xylanase for nursery pigs and broiler chickens reaffirmed the benefits related to enhancement of nutrient digestibility and growth performance, whilst also playing functional roles benefiting the intestinal microbiota and reducing the intestinal oxidative damages. As a result, it could contribute to a reduction in the feed costs by allowing the use of a wider range of feedstuffs without compromising the optimal performance of the animals, as well as the environmental concerns associated with a poor hydrolysis of antinutritional factors present in the diets for swine and poultry.

Phytase Supplementation of Four Non-Conventional Ingredients Instead of Corn Enhances Phosphorus Utilization in Yellow-Feathered Broilers

The present study was conducted to evaluate the effects of unconventional feedstuff such as wheat, broken rice, distillers dried grains with soluble (DDGS), and wheat bran, replacing 15% of the corn in the basal diet and the supplementation of bacterial phytase on nutrition digestibility. A total of 500 yellow-feathered broilers with similar body weights of 1.65 ± 0.15 kg were divided into 10 dietary treatments with 5 replicates per treatment (5 male and 5 females per cage). The AME and AIDE were significantly higher when supplied with phytase (p < 0.01) in the DDGS group. The ileal and total tract digestibility of calcium and phosphorus were significantly increased in the phytase-supplied group (p < 0.001). Additionally, the ileal digestibility of CP was increased when phytase was supplemented (p < 0.001). The results infer that the wheat, broken rice, DDGS, and wheat bran had no negative effect when replacing 15% corn. Supplementing 0.02% phytase in their diets can effectively optimize nutrient digestibility in yellow broilers.

Impact of an indigenously produced multi-enzyme complex from Bacillus subtilis KT004404 on growth and blood parameters in broiler chicken

A 42-days experiment was conducted on a day old birds (n = 400) to evaluate the effect of enzyme supplements in feed on the growth, blood parameters, phosphorous content in bones, and nitrogen retention. Different treatments included: control (C) without enzyme supplement, while the other three groups included enzyme mixture T1 and T2 with two commercially available enzyme mix, and T3 with indigenously produced multi-enzyme complex from Bacillus subtilis KT004404. Birds that were fed with indigenously produced multi-enzyme complex showed significant weight gain as compared to other groups. The total feed intake of the birds fed with enzyme supplements was higher than the birds in the control group. The feed conversion ratio was significantly improved (p < 0.05) in treatment groups (T1, T2, T3) as compared to the control. The blood parameters which were analyzed included uric acid, triglycerides, total cholesterol, and serum proteins i.e. globulin and albumin. Birds fed with the enzyme in the group T1, T2 and T3 exhibited higher (p < 0.05) body weight gain. Tibia ash content was significantly higher (p < 0.05) in T1, T2, and T3 as compared to the control. The results of the current study indicate that supplementing poultry feed with the exogenous multi-enzyme produced from Bacillus subtilis KT004404 improved the growth of the birds, feed utilization, and exhibited beneficial effects on the blood parameters, phosphorous and nitrogen retention in broiler chicken.

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

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.

A novel consensus bacterial 6-phytase variant added to phytate-rich diets totally replaced inorganic phosphate in broilers

The capacity of a novel bacterial 6-phytase variant (PhyG) to totally replace dietary supplemental inorganic phosphate (Pi) in broilers aged one day old was evaluated using a phased dosing strategy and reduction in dietary phytate. A total of 1,248 one-day-old Ross 308 broilers were assigned to 24 pens (52 birds/pen, 12 pens/diet, six each males and females) in a complete randomised block design with a 2×2 factorial arrangement (two diets, two genders). Diets comprised: (1) a positive control (PC) based on maize, wheat and soybean meal, containing Pi from monocalcium phosphate and 2,000 XU/kg xylanase, and; (2) an inorganic phosphate-free (IPF) diet equivalent to PC but with reduced Ca (-2.0 g/kg) and supplemented with PhyG at 3,000, 2,000 and 1000 FTU/kg from d 0 to 11 (3.4 g/kg phytate-P (PP)), d 11 to 22 (3.3 g/kg PP) and d 22 to 42 (2.8 to 2.9 g/kg PP), respectively. A negative control was not included for animal welfare reasons. Tibias were collected on d 11, 22 and 42 from two birds/pen. Treatment IPF maintained or improved average daily gain (ADG), average daily feed intake and feed conversion ratio (FCR) vs PC during all phases; Body weight was higher in the IPF treatment than the PC at d 42 (+3.97%, P<0.01) and ADG during d 0 to 42 (+4.10%, P<0.01). Overall (d 0 to 42), treatment IPF improved FCR in males (-5 points vs PC, P<0.05) but not females. Tibia ash was equivalent in IPF and PC throughout, with no gender differences. In conclusion, when applied as a phased dosing strategy to diets with graded reduction in PP content, PhyG totally replaced supplemental Pi during all growth phases in males and females.

Effects of phytase and 25-hydroxyvitamin D3 supplementation on growth performance and bone development in weaned piglets in Ca- and P-deficient dietary

BACKGROUND

The beneficial function of phytase and 25-hydroxyvitamin D3 (HyD) on the feed utilization rate has been widely investigated. However, studies concerning its influence on weaned piglets largely lag behind. The aim of this study was to investigate the effects of phytase and HyD supplementation on the growth performance and bone development in weaned piglets under dietary Ca and P deficiency.

RESULTS

The results showed that dietary Ca and P deficiency decreased (P < 0.05) the content of serum P in 6-10 kg piglets, as well as reducing (P < 0.05) the contents of serum Ca and P, average daily gain (ADG), bone mineral density (BMD), breaking force (BF), bone ash and femur Ca in 10-20 kg piglets. Compared with the control group, the feed-to-gain ratio (F/G) of 6-10 kg piglets in the Phy group was decreased (P < 0.05), whereas the ADG, blood Ca and P, BMD, BF, bone ash, P apparent digestibility, Ca and P retention rate of 10-20 kg piglets were increased (P < 0.05). The contents of serum osteocalcin and HyD in 6-10 kg piglets and ADG were higher than in the control group (P < 0.05), as well as the contents of serum Ca and HyD in 10-20 kg piglets in the HyD treatment group. Supplementation with both Phy and HyD decreased the F/D (P < 0.05) and increased the contents of serum Ca, P and HyD in 6-10 kg piglets as well as enhancing the ADG, BMD, BF, bone ash, femur Ca and P, serum Ca and P, HyD, and the apparent digestibility and retention of Ca and P (P < 0.05) in 10-20 kg piglets. Supplementation with Phy and HyD in Ca- and P-deficient dietary decreased bone resorption, and improved tight arrangement of collagen fibers and oblique fibers in weaned piglets.

CONCLUSION

These data indicated that supplementation with both 1500 U kg^-1 Phy and 50 μg kg^-1 HyD could enhance dietary Ca and P utilization and promote bone development in low Ca and P dietary, and supplementation with both Phy and HyD had a significant synergy effect compared to single supplement. © 2021 Society of Chemical Industry.

A novel consensus bacterial 6-phytase variant totally replaced supplemental inorganic phosphate from one day of age in both male and female broilers

1. This study tested the capacity of a novel consensus bacterial 6-phytase variant (PhyG) to totally replace dietary supplemental inorganic phosphate (Pi) in broilers from one day of age, using a phased dosing strategy for the phytase and a phased reduction in phytate content of the diet. A 2x2 factorial arrangement including two treatments and two genders was used.2. A total of 1,248, one-day-old Ross 308 broilers were assigned to 24 floor pens (52 birds/pen). Two treatments included: 1) a positive control diet (PC) based on mixed grains and oilseed meals, containing inorganic phosphorus (Pi) from monocalcium phosphate (MCP) and 2,000 XU/kg xylanase, and; 2) an inorganic P free (IPF) diet reformulated without Pi, reduced in Ca (-2.0 g/kg) vs. PC and supplemented with PhyG at 3,000 FTU/kg in starter (d 0 to 11, 3.4 g/kg phytate-P (PP)), 2,000 FTU/kg in grower (d 11 to 22, 3.3 g/kg PP), and 1,000 FTU/kg in finisher 1 (d 22 to d 35, 2.9 g/kg PP) and finisher 2 (d 35 to d 42, 2.8 g/kg PP) phase. Each treatment was assigned to 12 pens, with six pens containing males and six containing females. Tibia samples were collected on d 11, 22 and 42 from two birds per pen.3. The IPF treatment maintained or improved ADG, ADFI and FCR compared to PC in all feed phases. IPF increased BW at 42 days of age by 3.97% (P<0.01) and ADG from d 0 to 42 by 4.10% (P<0.01), and reduced corresponding FCR by 1.5 points (P<0.05), respectively, vs. PC. Males exhibited higher BW, ADG and ADFI than females from 11 d of age onwards (P<0.05). An interaction (P<0.05) between treatment and gender was observed for FCR (d 0 to 22, d 0 to 42) and FCRc (body weight corrected FCR, d 0 to 42), whereby IPF treatment reduced (P<0.05) FCR vs. PC in males but not in females. Tibia ash from birds fed IPF was equivalent to PC at 11, 22 and 42 d of age and did not differ between males and females.4.The data demonstrated that the phytase, when applied in a phased dosing-regimen to broiler diets with a graded reduction in phytate-P content, was effective in totally replacing Pi during all growth phases, as determined by performance and tibia ash from both males and females.

A novel consensus bacterial 6-phytase variant completely replaced inorganic phosphate in broiler diets, maintaining growth performance and bone quality: data from two independent trials

Total replacement of dietary inorganic phosphate (Pi) by a novel consensus bacterial 6-phytase variant (PhyG) in phytate-rich diets (>0.3% phytate-P) was investigated in 2 trials using growth performance and bone quality as outcome measures. Both trials utilized a completely randomized design with 5 dietary treatments across 4 phases: starter (0-10 d), grower (10-21 d), finisher 1 (21-35 d), and finisher 2 (35-42 d). Treatments comprised a nutritionally adequate positive control (PC) diet containing monocalcium phosphate and 4 experimental diets (IPF1, IPF2, IPF3, and IPF4), all containing no added Pi and reduced in Ca by 0.2 to 0.3% units vs. PC. IPF1contained PhyG at 1,000 FTU/kg (all phases); IPF2 contained PhyG at 1,000 FTU/kg (all phases) and was additionally reduced in digestible AA, ME, and sodium (-0.2 to -0.4% points, -74 kcal/kg, -0.04% points, respectively, vs. PC); IPF3 contained PhyG at 3,000 FTU/kg in starter, 2,000 FTU/kg in grower, and 1,000 FTU/kg in finisher phases; and IPF4 contained xylanase (2,000 U/kg) and PhyG (2,000 FTU/kg in starter, 1,500 FTU/kg in grower, and 1,000 FTU/kg in finisher phases) and was additionally reduced in ME (-71 kcal/kg vs. PC). Ross 308 broilers were used (trial 1: n = 1,200 mixed sex; 24 birds per pen × 10 replicates; trial 2: n = 1,300 males; 26 birds × 10 replicates). During all phases in both trials, all IPF treatments maintained or improved BW, ADG, ADFI, FCR and BW-corrected FCRc and bone quality parameters vs. PC. vs. PC, treatment IPF3 increased ADG during starter phase (+10.8%) and reduced overall FCRc (-12 points, P < 0.05) in Trial 1, and increased overall ADG (+4.4%), day 35 and day 42 BW (+3.5%, +4.9%), and reduced overall FCRc (-11 points) in Trial 2 (P < 0.05). IPF4 produced equivalent performance to IPF3 (both trials). These are the first data to demonstrate total replacement of Pi by microbial phytase during an entire growth cycle in broiler diets.

Efficacy and stability of a novel silica supplement for improving bone development in broilers

1. The essentiality of silicon for skeletal development has been established, but the adequacy of bioavailable silicon supply in broiler diets has not been considered for 30 years, despite average daily weight gain of birds increasing by almost a third over that time. Therefore, two studies were undertaken to investigate whether modern strains of broiler chicken benefit from diet supplementation with bioavailable silica. 2. Trial 1 was a 2x2x2 factorial study where six replicate pens of seven chicks were fed one of the eight freshly prepared diets from hatch to 21 days of age, with bodyweight gain and feed intake recorded weekly. Diets combined the following factors: silicon supplement fed at 0 ppm or 1000 ppm, phytase levels of either 0 FTU/kg or 1500 FTU/kg and either 0.6% or 0.7% Ca. Tibia were analysed for bone breaking strength, extent of tibial dyschondroplasia and feet measured for bone ash and pododermatitis score. 3. Trial 2 used a 0.7% Ca with 1500 FTU phytase diet as the control and compared this with the same diet containing either 1000 ppm silicon (MONO-Si) freshly added each week or 1000 ppm silicon added in a single, advance-prepared batch per feeding phase. Each diet was fed to nine pens of seven birds from 0 to 35 d with feed consumption and weight recorded weekly. Two birds per pen were euthanised on d 14, 21 and 35 and tibias collected for measurement of bone breaking strength, ash and mineral content. Serum was collected for Si content. 4. Univariate analysis of means from each trial showed that silica supplementation improved bird weight gain over the starter phase, though there was no effect on feed conversion. 5. Bone strength improved with added silica in both studies, without affecting bone mineral content; indicating that modern strains of broiler may require dietary supplementation with bioavailable silicon.

Interactive effect of 2 dietary calcium and phytase levels on broilers challenged with subclinical necrotic enteritis: part 1-broiler performance, gut lesions and pH, bacterial counts, and apparent ileal digestibility

This study investigated the hypothesis that high dietary calcium (Ca) would stimulate necrotic enteritis (NE) and reduce performance, gut health, and nutrient digestibility, and if increased, phytase would reduce NE. Ross 308 male broilers (n = 768) were randomly distributed to 8 treatments in a factorial arrangement. Factors were NE challenge (no or yes), phytase level (500 or 1,500 FTU/kg using 500 FTU/kg matrix values), and Ca level (0.6 or 1.0% starter, 0.5 or 0.9% grower, 0.4 or 0.8% finisher) with the same level of available P (0.40 S, 0.35 G, and 0.35 F). There were 48 pens, 16 birds per pen and 6 replications. Half of the birds were challenged with Eimeria spp on day 9 and 10⁸ CFU per mL of Clostridium perfringens strain EHE-NE18 on day 14 and 15. Gain was higher in birds fed high phytase on day 14 (P < 0.01), day 21 (P < 0.01), day 28 (P < 0.01), and day 35 (P < 0.01). Birds fed high phytase had greater livability on day 21 (P < 0.01). Ca was more digestible in high-Ca diets on day 16, and an NE × Ca interaction (P < 0.05) showed this effect to be more pronounced in unchallenged than in challenged birds. A challenge × Ca interaction for apparent ileal digestibility (AID) of crude protein (CP) (P < 0.05) indicated lower AID of CP in challenged birds fed high Ca. The challenge decreased AID of Ca (P < 0.01). Ca level had no impact on C. perfringens count, but it decreased Lactobacillus (P < 0.05) and Bifidobacteria (P < 0.05) populations in the ceca. High dietary Ca decreased feed conversion ratio. Overall (42 D), the highest WG was observed in unchallenged birds fed high Ca and high phytase with the lowest WG observed in NE-challenged birds fed low Ca and low phytase. The results suggest that full matrix values for high doses of phytase may be appropriate during NE challenge.

Influence of meat and bone meal, phytase, and antibiotics on broiler chickens challenged with subclinical necrotic enteritis: 1. growth performance, intestinal pH, apparent ileal digestibility, cecal microbiota, and tibial mineralization

This study investigated the influence of meat and bone meal (MBM), phytase, and antibiotics (AB) on the performance, intestinal pH, ileal digestibility, cecal microbiota, and tibial mineralization in Ross 308 broilers challenged with necrotic enteritis (NE). A total of 672-day-old male Ross 308 chicks were allocated to 8 treatments with 6 replicate pens, with 14 birds each. The study employed a 2 × 2 × 2 factorial arrangement of treatments: MBM (no or yes), AB (no or yes, zinc bacitracin + salinomycin), and phytase level (500 or 1,500 FTU/kg; both using 500 matrix recommendations). Diets were based on wheat–soybean meal–canola meal. All birds were challenged with Eimeria spp on day 9 and Clostridium perfringens (C. perfringens) strain EHE-NE18 on day 14 and day 15. On day 21 (postchallenge), birds fed MBM had reduced weight gain (WG; P < 0.05) relative to without MBM. A 2-way phytase × AB interaction for WG on day 14 (P < 0.001) and day 21 (P < 0.001) and feed conversion ratio on day 21 (P < 0.001) and day 42 (P < 0.01) indicated positive effects of high phytase on bird performance in the presence of AB. On day 42, a 3-way MBM × phytase × AB interaction (P < 0.01) was observed for WG, showing high phytase increased WG with AB, relative to the birds without AB in the presence of MBM. A 2-way MBM × phytase interaction (P < 0.01) was observed for apparent ileal digestibility of Ca and P on day 16, whereby there was a notable reduction in Ca and P digestibility in birds fed MBM-free diets and a low phytase level, but with the high phytase level, Ca and P digestibility was not influenced by MBM. In conclusion, in NE challenged birds, high phytase has a beneficial effect on leg health and mineral utilization to the extent that it can replace MBM and has beneficial effects on bird performance in the presence of AB.

Effects of Adding Phytase from Aspergillus niger to a Low Phosphorus Diet on Growth Performance, Tibia Characteristics, Phosphorus Excretion, and Meat Quality of Broilers 35 days after hatching

This study was designed to determine the effect of phytase extracted from Aspergillus niger (Natuphos^® E) on growth performance, bone mineralization, phosphorous excretion, and meat quality parameters in broilers fed available phosphorous (aP)-deficient diet. In total, 810 one-day-old Indian River broilers were randomly allotted into one of three dietary treatments, with six replicates per treatment. The three dietary treatments were 1) control group (CON: basal diet with sufficient aP), 2) low phytase (LPY: available phosphorus-deficient diet supplemented with 0.01% phytase), and 3) high phytase (HPY: available phosphorus-deficient diet supplemented with 0.02% phytase). Average daily gain and, feed intake, and feed conversion ratio were measured for 35 days. Excreta were collected from each pen on day 35. One broiler from each cage was euthanized to collect visceral organs and tibia samples. Broiler chickens fed LPY and HPY showed improved (P<0.05) growth performance compared to broilers fed CON on day 35. The tibia length of HPY-fed broilers was more than those of broilers fed other diets on day 35 (P<0.05). However, tibia calcium and phosphorous contents in LPY-fed broilers was higher (P<0.05) than in CON and HPY-fed broilers. Tibia length and calcium and phosphorous content showed a positive correlation (P<0.05) with the weight gain of broilers on day 35. Phosphorous level in the excreta of LPY- and HPY-fed broilers was lesser than those of CON broilers on day 35 (P<0.05). Furthermore, HPY-fed broilers showed lower (P<0.05) phosphorous content in the excreta than LPY-fed broilers. LPY- and HPY-fed broilers showed higher (P<0.05) liver weight than the CON broilers. In conclusion, broilers fed aP-deficient diet supplemented with phytase from Aspergillus excreted less phosphorus, which enhanced growth performance and tibia development from time of hatching to day 35 post-hatching.

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

This 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&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&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.

Current and Future Applications of Phytases in Poultry Industry: A Critical Review

Phytases are enzymes that initiate the removal of phosphate from phytate. This enzyme has been widely utilized in animal feeding especially in the poultry industry to enhance phosphorus intake and minimize environmental pollution. Phytases are widely distributed in microbial, plants and animals. Supplementations of phytase into the diets of poultry have great impact to the improvement of poultry immune systems and increase bird weight. In addition to that, phytase are able to improve both quantity and quality of eggs, egg mass and egg shell quality. This review covers the classifications and distribution of phytases in different biofactoris. In addition, it shed more light on the recent trends of application and beneficial impact in poultry farming.