Partial purification and characterization of phytase from Aspergillus foetidus MTCC 11682.

Phytase is a phosphatase enzyme widely used as feed additive to release inorganic phosphorus from plant phytate and enhance its uptake in monogastric animals. Although engineered fungal phytases are used most, a natural enzyme gives opportunity to understand novel properties, if any. In the current study, a novel fungal strain, Aspergillus foetidus MTCC 11682 was immobilized on poly urethane cubes and used for phytase production, purification and molecular characterization. Phytase produced by this method was partially purified by ammonium sulphate precipitation and Sephacryl S-200HR gel filtration to 23.4-fold (compared to crude extract) with recovery of 13% protein. Electrophoresis analysis revealed that phytase has molecular weight of 90.5 kDa on non-reducing and 129.6 kDa on reducing SDS-PAGE. The purified phytase exhibited a wider pH and temperature stability. Analysis of the cloned sequence showed that the gene has 1176 bp that encodes for a peptide of 391 amino acids of the core catalytic region. It was also found that phytase from A. foetidus has a sequence identity of 99% with the phytase gene of other Aspergillus species at nucleotide level and 100% at protein level in A. niger, A. awamori, A. oryzae. In silico analysis of sequence identified the presence of two consecutive and one non-consecutive intra chain disulfide bonds in the phytase. This probably contributed to the differential migration of phytase on reducing and non-reducing SDS-PAGE. There are predicted 11 O-glycosylation sites and 8 N-glycosylation sites, possibly contributed to an enhanced stability of enzyme produced by this organism. This study opened up a new horizon for exploring the novel properties of phytase for other applications.

Response of in ovo administration of zinc on egg hatchability and immune response of commercial broiler chicken.

An experiment was conducted to determine the effect of in ovo administration of different forms of zinc with respect to hatchability and performance of commercial broiler chicken. In trial 1, the fertile eggs on day 18 were divided into six treatment groups: Group I as control without any supplementation of zinc, group II to IV were supplemented with 0.5 mg zinc per egg as zinc sulphate, zinc methionine or nano zinc, respectively, and Group V with nano zinc at 0.25 mg zinc per egg. Sixth group received 0.5 ml citric acid per egg as sham control. The results of the first trial indicated that in ovo administration of nano zinc at both levels and zinc methionine resulted in complete failure of hatchability. A second trial to validate the result of trial 1 consisted of Group I control (no administration). Group II and Group III were supplemented with zinc sulphate and zinc methionine, respectively, at 0.5 mg zinc per egg. Group IV and Group V were supplemented with nano zinc at 0.04 and 0.08 mg per egg. In the second trial, again there was a similar pattern for zinc sulphate and zinc methionine. Administration of Zn by nano form had around 80% hatchability on fertile eggs in comparison with the unadministered control eggs (92%). There was no difference (p > .05) in body weight gain, feed intake and FCR. No difference (p > .05) was observed between treatments for cell-mediated immune response and humoral immune response. Nano Zn-administered group showed a non-significant downregulation of MUC2 gene. It could be concluded that in ovo administration of higher levels of zinc has to be with caution for the developing embryo of commercial broiler chicken.

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.

Value addition of corn husks through enzymatic production of xylooligosaccharides

ABSTRACT Corn husks are the major wastes of corn industries with meagre economic significance. The present study was planned for value addition of corn husk through extraction of xylan, followed by its enzymatic hydrolysis into xylooligosaccharides, a pentose based prebiotic. Compositional analysis of corn husks revealed neutral detergent fibre 68.87%, acid detergent fibre 31.48%, hemicelluloses 37.39%, cellulose 29.07% and crude protein 2.68%. Irrespective of the extraction conditions, sodium hydroxide was found to be more effective in maximizing the yield of xylan from corn husks than potassium hydroxide (84% vs. 66%). Application of xylanase over the xylan of corn husks resulted into production of xylooligosaccharides with different degree of polymerization namely, xylobiose and xylotriose in addition to xylose monomer. On the basis of response surface model analysis, the maximum yield of xylobiose (1.9 mg/ml) was achieved with the enzymatic hydrolysis conditions of pH 5.8, temperature 44°C, enzyme dose 5.7U/ml and hydrolysis time of 17.5h. Therefore, the corn husks could be used as raw material for xylan extraction vis a vis its translation into prebiotic xylooligosaccharides.

Effects of feeding raw or reconstituted high tannin red sorghum on nutrient utilisation and certain welfare parameters of broiler chickens.

1. A feeding trial was conducted on 360 1-d-old chicks from 0 to 6 weeks of age to assess the effect of processed high tannin red sorghum in the diet of broiler chickens on nutrient utilisation and certain welfare parameters. 2. Each of 9 dietary treatments was allotted to 4 groups (replicates) of chicks in a completely randomised design. The treatments were a maize-soy based standard broiler diet (control, RS(0)) and eight test diets formulated by incorporating either raw red sorghum (RS(25), RS(50), RS(75), RS(100)) or reconstituted red sorghum (RS(25)(R), RS(50)(R), RS(75)(R), RS(100)(R)) replacing 25, 50, 75 or 100% of maize from the control diet. 3. The tannin content was reduced from 23 to 16 g/kg in reconstituted red sorghum. 4. Utilisations of nitrogen, calcium and phosphorus retention were similar in all the dietary groups. 5. The cell-mediated immune response measured as footpad index (FPI) value of birds given raw red sorghum was significantly higher than in control and reconstituted red sorghum groups. Similarly, comparatively better humoral response measured as HA titre value was observed in raw red sorghum based groups than in reconstituted ones. 6. Plasma albumin, globulin, protein, glucose, calcium, phosphorus, SGOT, SGPT and uric acid levels did not differ significantly due to dietary treatments. 7. Mild histopathological changes were observed in liver and kidney tissues of birds given raw red sorghum. 8. From the present study, it is concluded that (1) the reconstitution of high tannin red sorghum resulted in about 30% reduction in its tannin concentration; (2) the feeding of reconstituted sorghum based diets to broiler chickens did not exert any appreciable influence on nutrient utilisation, blood biochemicals and enzymes and gross pathological changes; and (3) the birds fed on raw red sorghum exhibited higher immuno-responsiveness in comparison to their reconstituted counterparts.

Effects of supplemental vitamin E in diet of Japanese quail on male reproduction, fertility and hatchability.

1. Two experiments were conducted to examine the effect of feeding higher supplemental vitamin E (VE) concentrations on male reproductive variables, fertility and hatchability of quails. 2. In experiment 1, sixty 5-week-old male quails, reared in individual cages, were fed male breeder diets supplemented with 0, 75, 150, 225 or 300 IU alpha-tocopherol acetate/kg. At 10 weeks, observations on cloacal gland size, foam production, testes weight and blood samples for testosterone estimation were taken. 3. In experiment 2, 50 male and 50 female cage-reared quails (5 weeks old) were fed male breeder and layer rations, respectively, supplemented with 0, 75, 150, 225 or 300 IU/kg. At 13 weeks, 9 different mating pairs (5 pairs/group) were formed. Group 1 contained one control male and one control female in each of 5 pens. In groups 2 to 5, control males were paired with females on supplements of 75, 150, 225 or 300 IU/kg. In groups 6 to 9, control females were paired with males on supplements of 75, 150, 225 and 300 IU/kg. During subsequent adaptation and egg collection periods, each of 10 d, control layer ration was fed to all groups. All the eggs laid during the 10-d egg collection period were incubated artificially to estimate fertility and hatchability. The trial was repeated at 15 weeks. 4. Adult male quails receiving moderate supplemental VE (75 and 150 IU/kg) had a higher cloacal gland index, quantity of foam secretion, testicular weight and plasma testosterone than quails fed on either VE-deficient or more highly supplemented diets (225 and 300 IU alpha-tocopherol acetate/kg). 5. It was concluded that a supplement of 75 IU VE/kg in maize/soybean diet could provide the best reproductive performance of male breeder quails. Cloacal gland index, quantity of foam secretion, testicular weight and plasma testosterone can serve as indirect indicators of testicular activity and fertilising ability in quails. Supplemental VE did not affect the fertility and hatchability of male and female Japanese quails.

Comparative apparent metabolisable energy values of high, medium and low tannin varieties of sorghum in cockerel, guinea fowl and quail.

1. Nitrogen-corrected apparent metabolisable energy values (AMEN) of three varieties of sorghum (white-low tannin, brown-medium tannin and red-high tannin) were measured in three species of poultry (cockerel, guinea fowl and Japanese quail) by a practical diet replacement (total collection) method. 2. Each variety of sorghum was tested at two concentrations (200 and 400 g/kg of reference diet) in 6 replications with one cockerel or guinea fowl or two quails per replication. The duration of the trial included a 10 d preliminary feeding period (on conventional grower diet) followed by a 12 d adaptation period (on reference and test diets) and a 3 d balance period (with recording of feed intake and excreta output). 3. The calculated AMEN values of different sorghum varieties were: white--12.9, 12.8 and 12.7; brown--12.7, 12.3 and 12.6; and red--11.4, 11.1 and 11.6 MJ/kg for cockerels, guinea fowls and quails, respectively. The mean AMEN value of red sorghum (11.3 MJ/kg) was significantly lower than those of brown (12.5 MJ/kg) or white sorghum (12.8 MJ/kg). A negative correlation was observed between tannin concentration and AMEN. 4. There was no significant difference in the AMEN values of white, brown and red sorghum varieties to the different poultry species. AMEN values of sorghum for the cockerel could, therefore, be used in practical feed formulation for guinea fowl and quail.

Effect of enzyme supplementation on the metabolisable energy content of solvent-extracted rapeseed and sunflower seed meals for chicken, guinea fowl and quail.

(1) The nitrogen-corrected apparent metabolisable energy (AME(N)) content of solvent-extracted rapeseed and sunflower seed (un-decorticated) meals in relation to species (chicken, guinea fowl and quail) and dietary addition of feed enzymes (0 or 0.5 g/kg diet) was evaluated by a diet replacement method in a 3 x 2 factorial design. (2) The metabolism trial was conducted at two substitution levels (200 and 400 g/kg diet) of each meal with or without supplementation of commercial enzyme preparation in 6 individuals or 6 groups of cockerels, guinea fowls and quails. (3) The experimental diets were fed for a period of 12 d followed by a 3-d collection period during which total feed consumed and droppings output were quantitatively recorded. (4) The AME(N) values of rapeseed meal for cockerels, guinea fowls and quails were 8.4, 8.7 and 8.8 MJ/kg, respectively, while the corresponding values for sunflower seed meal were 6.1, 6.1 and 6.2 MJ/kg dry matter, without enzyme supplementation. (5) The AME(N) value of rapeseed meal did not improve with enzyme supplementation. However, AME(N) values of sunflower seed meal significantly increased with enzyme supplementation, from 6.1 to 6.5 MJ/kg dry matter. (6) Since AME(N) values of rapeseed meal and sunflower seed meal were similar in chicken, guinea fowl and quail, values reported for chicken could, therefore, be used for guinea fowl and Japanese quail.

Comparison of broiler chicken performance when fed diets containing meals of Bollgard II hybrid cotton containing Cry-X gene (Cry1Ac and Cry2ab gene), parental line or commercial cotton.

(1) Total and free gossypol contents were 6.2 and 0.8, 5.4 and 0.5, and 6.1 and 0.7 g/kg in meals processed (solvent extracted) from Bollgard (BG) II, non-BG II or commercial cottonseeds, respectively. (2) Broiler chicks were given one of 7 dietary treatments (iso-nitrogenous, 220 and 195 g crude protein/ kg diet at 0 to 21 and 21 to 42 d, respectively, at a metabolisable energy concentration of 12.15 MJ/kg). The treatments were: D1 (control, soybean meal [SBM] based), D2 and D3 (commercial CSM at 100 g/kg of diet with and without additional iron), D4 and D5 (BG II CSM with and without additional iron), and D6 and D7 (non-BG II parental CSM with or without additional iron). (3) Body weight gain, feed intake, feed conversion efficiency, nutrient utilisation, certain blood constituents and carcase traits were not significantly affected by dietary treatments. (4) Weights of bursa and thymus were significantly higher in groups given diets containing BG II or non-BG diets containing added iron. (5) The results suggest that low free gossypol content cottonseed meals, for example, BG II, non-BG II and commercial solvent-extracted CSM could be included at 100 g/kg in broiler diets, safely replacing soybean meal without additional iron.

Neem (Azadirachta indica) kernel meal in the diet of White Leghorn layers.

1. Neem kernel meal (NKM) was incorporated into a standard layer diet at 0, 100, 150 and 200 g/kg, replacing parts of the soyabean meal and deoiled rice bran. Each diet was offered to 18 White Leghorn layers (25 weeks, 50% egg production) in individual cages for a period of 12 weeks. 2. Results indicated significantly lower food intakes (P < 0.01), rates of egg production and egg weights in birds fed on the diets with NKM at 150 and 200 g/kg. Fertility and hatchability were also adversely affected by the higher inclusion rates of NKM. 3. Except for lower egg shell weight and shell thickness (P < 0.05) in hens fed NKM at 150 and 200 g/kg, the internal egg quality characteristics were comparable in all groups. 4. Feeding NKM beyond 100 g/kg to laying hens significantly (P < 0.01) reduced the content of haemoglobin, erythrocyte count, packed cell volume, serum calcium and uric acid concentrations. However, the leucocyte count, plasma glucose concentration and serum glutamate oxaloacetate transaminase activity were unaltered. Serum glutamate pyruvate transaminase activity was significantly (P < 0.05) reduced in birds fed NKM at 200 g/kg. 5. Thus NKM at 100 g/kg in a layer diet would appear to be safe and cost-effective.