Dietary Phytase Research Articles

Effects of dietary phytase supplementation on growth performance and apparent digestibility coefficients of Pacific White ShrimpLitopenaeus vannamei

A growth trial and a digestibility trial were conducted to evaluate the efficacy of phytase supplemented to practical shrimp feeds. The 5 weeks growth trial evaluated the effects of phytase supplementation in replete phosphorus (P) diets on the performances and compositions of juvenile Pacific white shrimp, Litopenaeus vannamei. No significant differences were observed in final biomass, final mean weight, weight gain, feed conversion ratio (FCR), protein retention and survival across all the treatments. Shrimp reared on the P deficient diet had significantly higher P retention and lower whole body P levels as compared to shrimp fed the other diets. Copper content in the whole shrimp body was significantly increased in the treatment supplemented with 1,000 IU kg−1 feed phytase. The digestibility trial was conducted to study the combined effects of phytase supplementation levels and diet type (plant-based versus fishmeal-based) on apparent digestibility coefficients of Pacific white shrimp, Litopenaeus vannamei. There were no effects of diet type so the data was combined. Phytase incorporation at both 500 and 2,000 IU kg−1 significantly improved protein digestibility, whereas P digestibility was enhanced when 2,000 IU kg−1 phytase was supplemented to the diet. Apparent digestibility coefficients of alanine, arginine, aspartic acid, cysteine, glutamic acid, glycine, histidine, isoleucine, leucine, lysine, methionine, ornithine, phenylalanine, proline, serine, threonine, tyrosine and valine were significantly increased when fed diets contained 500 and 2,000 IU kg−1 phytase supplementation. Results of this work demonstrate that under the conditions of the study growth was not enhanced by phytase supplementation in P replete diets. However, nutrient retention for Cu and digestibility of P, protein and a number of amino acids were enhanced.

Serum biochemistry, body composition and bone mineralization of juvenile <i>Clarias gariepinus</i> fed phytase-supplemented soyabean diets

The effect of microbial phytase on phosphorus utilization by juvenile Clarias gariepinus was tested on two diets consisting of oil-extracted soyabean and full fat soyabean meal. Each of these diets was formulated to replace fish meal at 25%, 50%, 75%, and 100 % as basal controls (P0). Phytase was supplemented in another four groups of the diets at 250 FTU/g (P1), 500 FTU/g (P2), 750 FTU/g (P3) and 1000 FTU/g (P4), respectively. A total of 2132 fish (11.55±0.2g) were stocked in duplicate tanks (26 fish/tank) and fed the phytase diets at 3% body weight for 84 days. Result in trial 1 showed that whole body ash declined with increasing phytase compared to control (Tukey, P>0.05). Phytase supplementation increased serum phosphorus (250 FTU/g and 500 FTU/g). Total protein decreased with phytase (Tukey, P<0.05). Bone minerals declined significantly with phytase at all levels. In trial 2, there was no difference between phytase and control for serum parameters (Tukey, P>0.05). The highest ash and bone minerals were recorded for 250 FTU/g phytase (Tukey, P<0.05). In conclusion, the research showed 250 FTU/g improved phosphorus utilization in full fat soyabean, which may indicate higher phosphorus bioavailability compared to oil-extracted soyabean meal.Keywords: Biochemistry, nutrition, plant protein, mineralization, Clarias gariepinus

238 Impact of super-dosing phytase in diets fed to 40 kg, 60 kg and 80 kg pigs on phytate catabolism

238 Impact of super-dosing phytase in diets fed to 40 kg, 60 kg and 80 kg pigs on phytate catabolism

Dietary Microbial Phytase Improves Growth, Phosphorus Digestibility and Serum Phosphorus, but not Bone Mineralization, in Juvenile Clarias gariepinus Fed Roasted and Oil-pressed Groundnut-Based Diet

Dietary Microbial Phytase Improves Growth, Phosphorus Digestibility and Serum Phosphorus, but not Bone Mineralization, in Juvenile Clarias gariepinus Fed Roasted and Oil-pressed Groundnut-Based Diet

Use of phytases in fish and shrimp feeds: a review

AbstractPhytases have been employed in animal feeds for several years, used primarily for reducing the environmental impact and phosphorus loads of farm effluents. Beneficial effect of dietary phytase has been associated with the limited ability of monogastric animals to utilize dietary plant phytates. To date, numerous studies have shown the positive effect of phytase supplementation on the availability of dietary phosphorus and trace minerals within plant‐based feeds for monogastric farm animals, including farmed fish and shrimp. Individual feed ingredients may also be improved with phytases as an exogenous treatment, also termed pre‐conditioning dephytinization prior to mixing. This review presents data on the potential benefit of phytase application for fish and shrimp species in improving digestibility of phosphorus and other minerals as well as organics nutrient fractions such as protein, amino acids and lipids.

Effect of dietary zinc oxide and phytase on the plasma metabolites and enzyme activities in aged broiler breeder hens

Background: It has been shown that zinc has an effect on physiological responses in animals and birds. On the other hand, dietary phytase in poultry results in increased availability of zinc. OBJECTIVES: This study was conducted to investigate the effects of zinc oxide (ZnO) and Escherichia coli-derived 6-phytase supplemented diets on the plasma metabolites and enzyme activities of broiler breeder hens from 60 to 72 weeks of age. METHODS: A total of 128 breeder hens were randomly assigned to eight dietary treatments, with four replicates of four hens each. Blood concentration of Zn, Ca, P, total protein, cholesterol, triglyceride (TG) and high density lipoprotein (HDL), and plasma activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) were measured. RESULTS: Results showed that supplementary ZnO increased plasma Zn, Ca, P, HDL, and total protein (p<0.01) concentrations, as well as enzyme activities of LDH, ALT and AST (p<0.01). Also, a ZnO-supplemented diet resulted in a decrease in plasma cholesterol and TG (p<0.01) levels. Adding phytase to the diet increased plasma (P) and HDL contents (p<0.01). The interactive effect of phytase × ZnO × period on the plasma levels of Zn, P, total protein, HDL, total cholesterol, and the enzymatic activity of LDH, ALT and ALP was significant. CONCLUSIONS: It is concluded that supplementary ZnO and phytase may improve metabolism and enzymatic activity of aged broiler breeder hens.

Effect of zinc bacitracin and phytase on growth performance, nutrient digestibility, carcass and meat traits of broilers.

A total of 336 one-day-old Hubbard broiler chickens were randomly distributed among 8 groups, each containing six replicates (7 chickens/replicate). From 1 to 40days of age, the groups fed the same starter, grower and finisher diets. The control group was unsupplemented; zinc bacitracin (ZnB) group received the antibiotic at 0.5g/kg; fungal phytase (FP) groups received 250, 500 and 1000U/kg diet of Aspergillus niger phytase (FP_250, FP_500 and FP_1000 groups), respectively; bacterial phyatse (BP) groups received 250, 500 and 1000U/kg diet of Escherichia coli phytase (BP_250EP, BP_500EP and BP_1000EP groups) respectively. Considering the whole experimental period, body weight gain was unaffected by ZnB and different concentrations of bacterial and fungal phytase; however, the feed conversion ratio of the group fed a diet supplemented with 500U of BP was better (p<0.01) than those fed with a diet supplemented with 500U of FP. BP_250 group had a higher (p<0.05) apparent digestibility of ether extract compared to FP_250 group. In conclusion, bacterial phytase at 500U may enhance performance of broiler chickens fed during days 1-40 of age and yield similar growth performance and economic efficiency to those of eB-supplemented groups.

Efficiency of microbial phytases in diets formulated with different calcium:phosphorus ratios supplied to broilers from 35 to 42 days of age

ABSTRACTThe aim of this study was to investigate the efficiency of six microbial phytases (named of A to F) supplemented in diets (1500 FTU/kg) formulated with three different calcium:available phosphorus ratios (3.5:1.0, 5.0:1.0 and 6.5:1.0). Moreover, one positive control diet without phytase that was formulated with a calcium:available phosphorus (Ca:AP) ratio of 6.5:3.0 was also considered. The utilization of dietary nutrients, as well as the bone, plasma and performance parameters of broilers from 35 to 42 days of age was evaluated. Phytase D increased the P and magnesium plasma concentrations. Broilers fed diets containing phytase B showed a lower feed intake and weight gain, while the birds fed diets containing phytase E consumed more feed, gained more weight and excreted less total P. The highest Ca retention and also the best nitrogen utilization were determined when the diet contained phytase D or E. For all phytases evaluated, an increased in the dietary Ca:AP ratio increased the tibia ash content and the Ca balance. Phytase utilization reduced the phytate P excretion, improving its utilization by the broilers. For the rearing period evaluated, it is possible to reduce the AP of the diet to 1.0 g/kg when Ca is maintained at 6.5 g/kg, and the diet is supplemented with 1500 FTU of phytase A, B, C, D or E/kg. This diet allows the maintenance of performance, optimizes the bone mineralization, and it improves the Ca, total P, phytate P and nitrogen utilization in addition to reducing the P excretion.

EFFECT OF DIETARY NPP LEVEL AND PHYTASE SUPPLEMENTATION ON THE LAYING PERFORMANCE OVER ONE YEAR PERIOD

EFFECT OF DIETARY NPP LEVEL AND PHYTASE SUPPLEMENTATION ON THE LAYING PERFORMANCE OVER ONE YEAR PERIOD

Effects of dietary boron and phytase supplementation on growth performance and mineral profile of broiler chickens fed on diets adequate or deficient in calcium and phosphorus

1. Two experiments were designed to determine the effect of dietary boron (B) in broiler chickens. In Experiment 1, a 2 × 4 factorial arrangement of treatments was used to investigate the effect of dietary calcium (Ca) and available phosphorus (aP) (adequate or deficient) and supplemental B (0, 20, 40, and 60 mg/kg diet). In Experiment 2, B, at 20 mg/kg, and phytase (PHY) (500 FTU/kg diet) were incorporated into a basal diet deficient in Ca and aP, either alone or in combination.2. The parameters that were measured were growth performance indices, serum biochemical activity as well as ash and mineral (i.e. Ca, P, Mg, Fe, Cu and Zn) content of tibia, breast muscle and liver.3. Results indicated that both supplemental B and dietary Ca and aP had marginal effects on performance indices of chickens grown for 42 d.4. There were positive correlations (linear effect) between B concentrations of serum, bone, breast muscle and liver and the amount of B consumed.5. Serum T3 and T4 activities increased linearly with higher B supplementation.6. Increasing supplemental B had significant implications on breast muscle and liver mineral composition. Lowering dietary Ca and aP level increased Cu content in liver and both Fe and Zn retention in breast muscle. Tibia ash content and mineral composition did not respond to dietary modifications with either Ca–aP or B.7. The results also suggested that dietary contents of Ca and aP do not affect the response to B regarding tissue mineral profile. Dietary combination with B and PHY did not create a synergism with regard to growth performance and bioavailability of the minerals.

EFFECTS OF THE COMBINATION OF NON-PHYTATE PHOSPHORUS, PHYTASE AND 25-HYDROXYCHOLECALCIFEROL ON THE PERFORMANCE AND MEAT QUALITY OF BROILER CHICKENS

This experiment was conducted to evaluate the combination effect of low dietary non-phytate phosphorus (NPP) concentrations, phytase (PHY) levels, and 25-hydroxycholecalciferol (25-OH-D3) levels on the growth performance and meat quality of broilers. Two levels of NPP, two levels of PHY, and two levels of 25-OH-D3 resulted in a 2�2�2 factorial arrangements, with eight treatments (TRT). The birds on TRT 1-4 were fed diet 1 (NRC NPP was reduced by 0.1) and the birds on TRT 5-8 were fed with diet 2 (NRC NPP was reduced by 0.2). Each diet was mixed with different levels PHY and 25-OH-D3. Performance and meat quality parameters were measured. Results showed that during entire experiment the most advantageous effects were obtained with TRT 3 (NRC NPP reduced by 0.1 + 600 U/kg phytase + 34.5�g/kg 25-OH-D3) and TRT 4 (NRC NPP reduced by 0.1 + 600 U/kg phytase + 69�g/kg 25-OH-D3). The lowest body weight gain (BWG) and feed intake(FI) were observed with TRT 5 (NRC NPP reduced by 0.2 + 300 U/kg phytase + 34.5�g/kg 25-OH-D3). Lowering NRC NPP by 0.1 to 0.2 significantly reduced weight gain (WG) (p 0.05) and produced small decrease in FI. BWG, FI and feed conversion ratio were not influenced (p>0.05) by different PHY or 25-OH-D3 levels. In addition, the meat color, pH, and shear force were not affected by the different NPP, PHY or 25-OH-D3levels.

Dietary phytase supplementation in rapeseed protein based diets influences growth performance, digestibility and nutrient utilisation in turbot (Psetta maxima L.)

In this study the performance of juvenile turbot (Psetta maxima L.) fed varying dietary phytase (Natuphos® 5000 G, BASF SE) supplementation levels was determined in a 56day lasting growth trial, followed by a digestibility trial. One control diet (C) based on fish meal and three test diets based on rapeseed protein concentrate (RPC) were produced. RPC based diets contained phytase levels of 0 (P0), 1000 (P1000) and 2000 (P2000) FTUkg−1. Feed intake and growth performance were significantly (p<0.05) improved in fish fed P1000 and P2000 compared to fish fed unsupplemented P0. Furthermore fish fed P2000 showed a significantly improved performance level, comparable to the control group, with regard to FCR, PER and ADC of protein. Also the ADC of ash and phosphorus increased significantly due to phytase supplementation. In contrast, the ADC of other investigated minerals Ca, Mn, Fe, Co, Cu, Zn and Mg were not significantly affected. Moreover, slightly increased retention of nitrogen and significantly increased retention of phosphorus were observed in fish fed P2000 compared to fish fed P0. In conclusion, the supplementation of phytase to plant protein based diets rich in phytic acid increases nutrient digestibility and utilisation, which can positively influence growth performance and nutrient emissions in turbot production. Statement of relevanceTo the best of our knowledge this is the first time that effects of dietary phytase incorporation were studied in turbot nutrition and the results consequently lead to a deeper insight and better understanding of this enzyme.The apparent digestibility coefficient (ADC) of protein and phosphorous increased significantly, which led to an improved growth and may lead to a more efficient utilisation of plant protein sources in turbot nutrition.Retention of nutrients (N & P) was also improved and gives the ability to a more sustainable turbot production via reduced phosphorus supplements/phosphorus contents in feeds and thus potentially decreased nutrient emissions in fish farm effluents.

The sparing effect of phytase in plant-protein-based diets with decreasing supplementation of dietary NaH2PO4for juvenile yellow catfishPelteobagrus fulvidraco

An 8-week feeding trial was conducted to evaluate the sparing effect of dietary phytase on decreasing supplement of dietary sodium dihydrogen phosphate (NaH2PO4) in the diets of juvenile yellow catfish Pelteobagrus fulvidraco. Seven diets were formulated: one reference group that contained only 2% NaH2PO4; one control group that consisted of neither NaH2PO4 nor phytase; and five treatment groups supplemented with 1000 IU kg−1 phytase and 2%, 1.5%, 1%, 0.5%, 0% concentrations of NaH2PO4. Thus, dietary NaH2PO4 was substituted with phytase at ratios of 0%, 25%, 50%, 75% and 100% respectively. Triplicate tanks were each filled with 50 juvenile fish (3.5 ± 0.1 g), which were fed one of the seven experimental diets. Substituting phytase for NaH2PO4 didn't diminish the growth performance, protein, dry matter, lipid and ash deposit and protein retention in the whole body and reduced feed conversion ratio compared to the reference diet. Moreover, phytase substitution at level of 0–50% enhanced P, Mg and Ca deposit. However, weigh gain had a tendendy of decreasing with increasing substituted level. Phytase substituted level exceeding 75% decreased serum P concentration compared to the control group. Apparent digestibility of P peaked when 1000 IU kg−1 phytase substituted 50% NaH2PO4. Phytase also increased apparent digestibility of protein. The improvement of digestibility of protein and P resulted in the decrease in N load by 25% and P load by 31% to environment. Therefore, 50% dietary NaH2PO4 can be substituted by 1000 IU kg−1 feed phytase for juvenile yellow catfish.

Contribution of intestinal- and cereal-derived phytase activity on phytate degradation in young broilers

There is little consensus as to the capability of poultry to utilize dietary phytate without supplemental phytase. Therefore, an experiment was conducted to examine the extent to which endogenous phytase of intestinal and cereal origin contributes to phytate degradation in birds aged 0 to 14 d posthatch. Ross 308 broilers (n = 720) were fed one of 4 experimental diets with differing dietary ingredient combinations and approximate total phytate levels of 10 g/kg, dietary phytase activity analyzed at 460 U/kg, dietary calcium (Ca) levels of 11 g/kg, and nonphytate-phosphorus (P) levels of 4 g/kg. Broiler performance, gizzard, duodenum, jejunum and ileum pH, Ca and P digestibility and solubility, amount of dietary phytate hydrolyzed in the gizzard, jejunum, and ileal digesta phytase activity were analyzed at d 4, 6, 8, 10, 12, and 14 posthatch. Intestinal endogenous phytase activity increased significantly (P < 0.001) between d 4 and 6, resulting in increased phytate hydrolysis in the gizzard (P = 0.003), jejunum (P < 0.001), and ileum (P < 0.001). Phytase activity and phytate hydrolysis continued to increase with age, with a greater phytase activity and associated increase in phytate hydrolysis and mineral utilization between d 10 and 12. Gizzard and jejunum Ca and P solubility and ileal Ca and P digestibility increased significantly (P < 0.001), and gastrointestinal pH decreased significantly (P < 0.001) between d 4 and 6. By d 14, phytase activity recovered in the ileum was approximately 45 U/kg. There were strong correlations between phytase activity measured in the ileum and phytate hydrolyzed in the gizzard (r = 0.905, P < 0.001), jejunum (r = 0.901, P = 0.023), and ileum (r = 0.938, P = 0.042). This study shows intestinal- and dietary-derived endogenous phytase activity is responsible for phytate-P hydrolysis in broilers.

INTERACTION BETWEEN DIETARY MINERAL AND PHYTASE ON BIOLOGICAL PERFORMANCES OF JAPANESE FLOUNDER, Paralichthys olivaceus. PART II. MINERAL DIGESTIBILITY AND VERTEBRAL MINERAL CONTENT

Interactive effects between dietary inorganic phosphorus (IP) and phytase (P) on mineral digestibility and vertebral mineral content were investigated in a 30 days feeding trial followed by three weeks digestibility trial with Japanese flounder, Paralichthys olivaceus. Eight experimental diets were formulated based on two levels of dietary Ca at 0% and 0.2% combined with either 0% or 0.25% of dietary IP and either with 0 and 2,000 fytase unit (FTU)/kg of phytase in diet, respectively. Result indicated that digestibility of total phosphorus significantly increased by three dietary compounds where the highest was observed in fish fed diet contained 0.25% IP and 2,000 FTU phytase/kg and dietary Ca also included in diet. Significant interaction was only detected between dietary IP and P on this parameter. Supplementation of IP and Ca not phytase significantly improved Ca digestibility. Ca digestibility was very poor when dietary IP and Ca were not supplemented in diet even with when phytase supplemented in diet. There was significant interaction between dietary IP and Ca on Ca digestibility. Vertebral total phosphorus, Ca, and Mg content as well as Ca:P ratio were significantly enhanced by dietary IP and phytase. Dietary Ca has significant effect only on vertebral total phosphorus. Interaction between dietary IP and Ca was significantly found on vertebral Ca content and Ca:P ratio. No significant second-order interaction was observed among the three dietary mineral on overall parameters. Based on total phosphorus and Ca digestibility as well vertebral phosphorus content found in this study, dietary IP, Ca, and phytase at rate of 0.25%, 0.2%, and 2,000 FTU phytase/kg diet, respectively are needed to supplement in diet for a better mineral absorption and bone mineralization.

Effect of super dosing of phytase on growth performance, ileal digestibility and bone characteristics in broilers fed corn-soya-based diets.

A feeding trial was designed to assess the effect of super dosing of phytase in corn-soya-based diets of broiler chicken. One hundred and sixty-eight day-old broilers were selected and randomly allocated to four dietary treatment groups, with 6 replicates having 7 chicks per treatment group. Two-phased diets were used. The starter and finisher diet was fed from 0 to 3 weeks and 4 to 5 weeks of age respectively. The dietary treatments were consisted of normal phosphorus (NP) group without any phytase enzyme (4.5 g/kg available/non-phytin phosphorus (P) during starter and 4.0 g/kg during finisher phase), three low-phosphorus (LP) groups (3.2 g/kg available/non-phytin P during starter and 2.8 g/kg during finisher phase) supplemented with phytase at 500, 2500, 5000 FTU/kg diet, respectively, to full fill their phosphorus requirements. The results showed that super doses of phytase (at 2500 FTU and 5000 FTU/kg) on low-phosphorus diet improved feed intake, body weight gain, ileal digestibility (serine, aspartic acid, calcium, phosphorus), blood P levels and bone minerals such as calcium (Ca), P, magnesium (Mg) and zinc (Zn) content. It could be concluded that super doses of phytase in low-phosphorus diet were beneficial than the normal standard dose (at 500 FTU/kg) of phytase in diet of broiler chicken.

Effect of zinc and phytase supplementation on performance, serum biochemical profiles and carcass quality of crossbred (Hampshire × Assam local) pigs

Twenty-four castrated weaned (42 days, 11.39 kg) pigs were used in a 2 × 2 factorial experiment to determine the influence of dietary zinc (0 upto 100 ppm/kg) and phytase (0 or 200 FTU phytase units/kg) supplementation on the performance, serum biochemical profiles and carcass quality. Growth rate and feed efficiency were significantly higher (P < 0.05) for pigs supplemented with phytase and zinc. Total serum protein, glucose, cholesterol, Ca, P and Zn concentrations were significantly higher (P < 0.05) in phytase supplemented group, whereas serum alkaline phosphatase estimates were lower (P < 0.05). No significant differences in carcass characteristics and proximate composition of meat were observed which indicated no adverse effect of zinc and enzyme supplementation. These results indicated that the growth-promoting effect of phytase may be due to increased zinc and other serum mineral concentrations and zinc dependent blood biochemical functions.

The effect of dietary phytase on broiler performance and digestive, bone, and blood biochemistry characteristics

The dietary inclusion of phytase increases nutrient and energy bioavailability for broilers. The effect of phytase increases nutrients and energy bioavailability for either the objective of this experiment was to evaluate the influence of nutrient and energy reduction in diets supplemented with phytase on the performance, gastrointestinal pH, organ and bone composition, and blood biochemistry of broilers between eight and 21 days of age. In the study, 1.120 male Cobb 500(r) broilers, with 161±1g average weight, were used. At eight days of age, birds were distributed according to a completely randomized experimental design with seven treatments in a 3x2+1 factorial arrangement with eight replicates of 20 broiler each. Treatments corresponded to reduction of calcium (Ca) and phosphorus (P), amino acids and energy, or reduction of Ca, P, amino acids and energy; supplementation or not of phytase; and a positive control treatment. Broiler fed the diet with reduced Ca and P levels and phytase supplementation presented the best performance of all groups. The diet with reduced amino acid and energy levels and phytase addition reduced gizzard and proventriculus pH. Dietary Ca and P reduction increased relative liver and heart weights, as well as albumin blood levels. The bones of broilers fed phytase-supplemented diets presented higher ash content.

Phosphorus digestibility response of growing pigs to phytase supplementation of triticale distillers' dried grains with solubles.

An experiment was conducted in growing pigs to determine the true total-tract digestibility (TTTD) of P in triticale distillers' dried grains with solubles (DDGS) with or without phytase using the regression method. Six diets were formulated in a 3 × 2 factorial arrangement, including 3 levels of triticale DDGS (300, 400, or 500 g/kg) and phytase (0 or 500 phytase units [FTU]/kg of diet). A total of 48 barrows (initial BW 22.2 ± 1.3 kg) were assigned to the 6 diets in a randomized complete block design. There was a 5-d adjustment period followed by a 5-d total collection of feces. The results show that P intake, fecal P output, and digested P increased linearly ( < 0.01) with increasing level of DDGS in diets. There was a main effect ( < 0.001) of phytase on apparent total-tract digestibility (ATTD) of P. In diets without added phytase, the ATTD of P in triticale DDGS was 65.0, 67.7, and 63.2% for the diets with 300, 400, and 500 g/kg triticale DDGS, respectively; the corresponding values for diets with added phytase were 77.3, 76.3, and 75.7%. By regressing daily digested P against daily P intake, the TTTD of P was estimated at 75.4% for triticale DDGS or 81.1% with added phytase, respectively. In conclusion, the TTTD of P in triticale DDGS without supplemental phytase was 75.4%, and it was 81.1% in the presence of phytase at 500 FTU/kg of the diet, but the difference was not statistically significant. For triticale DDGS, the supplementation of 500 FTU/kg phytase in diet could increase the ATTD of P ( < 0.001) but not the TTTD of P.

Efficacy of citric acid and microbial phytase on the tibial characteristics, tibial and serum mineral concentrations in broiler chicken

One hundred and ninety two, day-old broiler chicks (Vencobb) were divided into four identical groups, four replicates with 12 birds in each replicate in each group. The birds were fed either standard broiler ration, with 0.5% available P (T1), with 0.3% available P (LP) and 3.0% citric acid (T2), LP supplemented with 700 U of Phytase/kg (T3) and LP with 1.5% citric acid and 350U of phytase/kg (T4). All the rations were formulated as per BIS specifications except the level of available P. Effect on tibial characteristics, serum and tibial mineral contents were evaluated. Tibia length and weight was significantly high (P 0.05) in T2, T3 and T4 compared to T1. No significant difference could be noticed in tibial and serum Ca, P, Mg, Zn and Mn except for a significantly higher (P<0.05) tibial Mg in T1 and serum Zn in T3 at sixth week. From this study, it could be concluded that the available P level in the feed could be reduced by 40 per cent by inclusion of dietary citric acid or phytase alone or the combination of both, with better utilization of minerals in broiler chicken.