Higher concentrations of folic acid reduced the dietary requirements of supplemental methionine for commercial broilers

OBJECTIVE

An experiment was conducted to study the effect of supplementing DL methionine (DL Met) at graded concentrations on performance, carcass variables, immune responses and antioxidant variables in broiler chicken fed folic acid (FA) fortified (4 mg/kg) lowmethionine diet.

METHODS

A basal diet (BD) without supplemental DL Met, but with higher level (4 mg/kg) of FA and a control diet (CD) with the recommended concentration of methionine (Met) were prepared. The BD was supplemented with DL Met at graded concentrations (0%, 10%, 20%, 30%, 40%, and 50% supplemental DL Met of CD). Each diet was fed ad libitum to 10 replicates of 5 broiler male chicks in each from 1 to 42 d of age.

RESULTS

Body weight gain (BWG) reduced, and feed conversion ratio (FCR) increased in broilers fed low-Met BD. At 30% and 20% inclusion of DL met, the BWG and FCR, respectively were similar to those fed the CD. Similarly, supplementation of 10% DL Met to the BD significantly increased ready to cook meat yield and breast meat weight, which were similar to those of the CD fed broilers. Lipid peroxidation reduced, the activity of antioxidant enzymes (GSHPx and GSHRx) in serum increased and lymphocyte proliferation increased with increased supplemental DL Met level in the BD. The concentrations of total protein and albumin in serum increased with DL Met supplementation to the BD.

CONCLUSION

Based on the data, it can be concluded that supplemental Met can be reduced to less than 50% in broiler chicken diets (4.40, 3.94, and 3.39 g/kg, respectively in pre-starter, starter and finisher phases) containing 4 mg/kg FA.

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

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).

Feed emulsifier improves the performance and nutrient digestibility in broiler chicken fed diets without antibiotic growth promoter

1. A study was conducted to assess the impact of supplementing-graded concentrations of emulsifier on the production performance, gut microbial count, and digestibility of nitrogen and energy in broiler chicken fed diets without AGP.2. Male broiler chicks (n = 1500; Vencobb-430), aged one-day-old, were randomly allocated into six dietary groups each with 10 replicates of 25 birds each. A maize-soybean and meat and bone meal-based basal diet without antibiotic (AGP) growth promoter served as negative control (NC). The basal diet was supplemented with BMD (AGP, bacitracin methylene disalicylate-BMD 100 g/T), which served as the positive control (PC). Emulsifier was added to the NC diets at either 250 g/ton in all phases (250-All), 250 g in starter and grower phases, and 500 g in the finisher phase (250:250:500), 250 g in starter and 500 g in both grower and finisher phases (250:500:500) and 500 g in all phases (500 g-All).3. Two broilers per replicate were slaughtered to record carcase traits and gut microbial count on day 43. There was significant improvement in body weight gain (BWG) and reduced FCR in broilers fed 250:250:500 and 250:500:500 g emulsifiers compared to other treatment groups. Carcase traits and faecal microbial count did not differ among treatments. The inclusion of BMD significantly improved nitrogen (N) digestibility compared to the NC group. The digestibility of emulsifier-supplemented groups was similar to those fed by the BMD group except for the 500-All group, which was an intermediary between NC and other emulsifier-fed groups.4. It was concluded that supplementation with emulsifier (250:250:500 or 250:500:500) without antibiotic growth promoter significantly improved FCR and body weight gain similar to broilers receiving antibiotic growth promoter, which was associated with increased ileal digestibility of N and energy.

Feed withdrawal influences egg production, egg quality and anti-oxidant variables in White Leghorn layers reared during the tropical summer season

1. An experiment was conducted with White Leghorn layers (Babcock BV 300) to optimise the feed withdrawal schedule for egg-laying chicken (67 to 80 weeks) reared in open side poultry house during the tropical summer season.2. Four feeding schedules (1. ad libitum access to the layer feed, 2. feed withdrawal from 9 AM-5 PM, 3. 11 AM-5 PM, and 4. 1 PM-5 PM followed by free access to the layer feed) were examined. Each feeding schedule was offered to 12 replicates consisting of 12 layers housed in four adjacent cages (45.7 × 35.6 × 43.2 cm).3. Fasting the layer from 1-5 pm reduced egg production compared to layers fasting from 9 or 11 am. The FI/egg or unit egg mass was highest in layers fasted from 1-5 pm. In the 9 am-5 pm fasted group, the cloacal temperature (CT) increased significantly at 11 am and gradually reduced at 3 pm. In the 1-5 pm fasted group, the CT remained higher at 3 pm and 5 pm.4. The cell-mediated immune response in layers fasted from 9 am or 11 am was higher than those fed ad libitum or 1-5 pm fasted group. Lipid peroxidation was higher in layers 1-5 pm fasted group and significantly lower LP was found in groups that fasted from 9 am or 11 am. In general, the activities of serum antioxidant enzymes (glutathione peroxidase, glutathione reductase, superoxide dismutase) were higher in layers that fasted from 9 am or 11 am compared to those that had ad libitum feed or fasted from 1-5 pm.5. It was concluded that the feed withdrawal should be initiated during the forenoon (9 AM/11 am-5 pm) for optimum production and to reduce oxidative stress in egg-laying chicken reared during summer in the tropical region.

Effect of dietary supplementation of organic and inorganic Se on performance and antioxidant response in commercial broiler chickens

1. The study was carried out to determine the effects of supplementing organic (OG) or inorganic (IOG) Se to record the performance, immune and anti-oxidant response in broiler chickens.2. One-day-old Vencobb-400 (50.1 ± 0.84 g; n = 280) male broiler chicks were allocated randomly into seven treatments to give eight replicates containing five chicks each and housed in deep littered floor pens (76 cm × 91 cm) for a period of 42 d.3. The control diet (CD) was formulated without any Se supplementation (diet I), CD plus 0.15, 0.30 or 0.45 mg/kg OG Se (diets II, III and IV, respectively) and CD plus 0.15, 0.30 or 0.45 mg/kg IOG Se (diets V, VI and VII, respectively).4. Feed intake (FI), body weight gain (BWG), immune variables and mRNA expression profile of hepatic selenoproteins (SepW, GSHPx1, TrxR and GSHPx3) genes were determined. The BWG, FI and feed conversion ratio did not differ among various dietary treatments.5. The lipid peroxidation and activity of RBC catalase were lower (P < 0.05) in groups fed diets supplemented OG Se compared to those fed IOG Se and CD. The activity of GSH Px was higher among the groups fed diet supplemented OG Se compared to those groups fed OG Se and CD. However, supplementing diets with OG or IOG Se did not affect humoral or cell mediated immune responses.6. The expression levels of SepW were higher (P < 0.01) among the groups supplemented with OG Se. Expression levels of GSH-Px1, TrxR and GSHPx3 were higher (P < 0.01) among the groups supplemented with OG Se compared to those groups fed IOG Se or CD.7. Supplementing OG Se improved the activities of anti-oxidant enzymes and hepatic expression of selenoproteins genes in the present study. However, supplementing OG or IOG Se did not affect growth performance and immune variables in broiler chickens.

Effect of dietary supplementation of zinc proteinate on performance, egg quality, blood biochemical parameters, and egg zinc content in White Leghorn layers

A study was conducted to investigate the effects of zinc proteinate (Zn-P) on laying performance, egg quality, antioxidant indices, and egg zinc content in laying hens from 38 to 49 weeks of age. A total of 150 White Leghorn layers were randomly assigned to five treatments, each with six replicates with five birds per replication. Dietary treatments included a corn-soybean meal-based basal diet with no zinc addition and basal diet supplemented with Zn-P at 40, 80, 120, or 160 mg/kg of feed for 12 weeks. The analyzed zinc concentrations of the five diets were 29.5, 70.8, 110.2, 147.5, and 187.5 mg Zn/kg, respectively. Dietary Zn-P supplementation had no effect on feed intake and egg production. However, raising the zinc level improved egg weight (P < 0.01) and egg mass (P < 0.05) and lowered the feed conversion ratio (P < 0.05) during the later (46-49 weeks) period. The Zn-P supplementation also significantly (P < 0.05) increased Haugh units, egg shell strength, and shell thickness and had no influence on other egg quality parameters. Increasing zinc levels in the diet resulted in increase in egg zinc contents and serum zinc level. The serum triglyceride and LDL-cholesterol levels significantly decreased (P < 0.05) in Zn-P-supplemented groups. Supplementation of Zn-P significantly (P < 0.05) increased serum Cu-Zn-SOD activity and reduced MDA concentration. It could be concluded that dietary supplementation of higher levels of Zn-P, more than 80 mg/kg diet, significantly improved the egg zinc content, some egg quality traits, antioxidant activity, and serum zinc levels.

Genome assisted probiotic characterization and application of Bacillus velezensis ZBG17 as an alternative to antibiotic growth promoters in broiler chickens

The present study describes genome annotation and phenotypic characterization of Bacillus velezensis ZBG17 and evaluation of its performance as antibiotic growth promoter substitute in broiler chickens. ZBG17 comprises 3.89 Mbp genome with GC content of 46.5%. ZBG17 could tolerate simulated gastrointestinal juices prevalent in the animal gut. Some adhesion-associated genomic features of ZBG17 supported the experimentally determined cell surface hydrophobicity and cell aggregation results. ZBG17 encoded multiple secondary metabolite gene clusters correlating with its broad-spectrum antibacterial activity. Interestingly, ZBG17 completely inhibited Salmonella enterica and Escherichia coli within 6 h and 8 h in liquid co-culture assay, respectively. ZBG17 genome analysis did not reveal any genetic determinant associated with reported safety hazards for use as a poultry direct-fed microbial. Dietary supplementation of ZBG17 significantly improved feed utilization efficiency and humoral immune response in broiler chickens, suggesting its prospective application as a direct-fed microbial in broiler chickens.

Interaction effects of sunflower oil and aflatoxin at graded levels in diet on performance, serum and tissue biochemical profile, organ weights and immuneresponse in broiler chicken

The dietary supplementation of fat has great potential in countering the toxic effects of aflatoxin (AF) in chickens, but the issue was less researched upon. An experiment was conducted to evaluate the response of broiler chickens to graded levels of AF B1 (0, 150 and 300 ppb) and sunflower oil (SFO) (0, 1.5 and 3.0%) in the diet in a 3 × 3 factorial manner to understand their interaction effects. A total of 360 broiler chickens divided into 9 equal groups were fed the diets during 0 to 35 days of age, and their response was evaluated in terms of performance, serum biochemical profile, organ weights, liver fat content and bone mineralization. Sunflower oil at 1.5% in diet countered (P ≤ 0.01) the adverse effects of 150 ppb AF on body weight, whereas at 300 ppb AF, such a response was seen at the higher level (3%) of SFO. Aflatoxin decreased (P ≤ 0.01) feed intake by 4 and 11% at 150 and 300 ppb concentration, respectively at 35 days of age, which was increased (P ≤ 0.01) with each incremental level of SFO supplementation (by 3.0 and 8.8%, respectively at 1.5 and 3%, respectively). Serum protein concentration increased (P ≤ 0.01) by SFO supplementation only at the higher concentration (300 ppb) of AF (by 42.4%), whereas total cholesterol and triglyceride concentration, and immune response to SRBC inoculation increased (P ≤ 0.01) with SFO at either level of AF (by 16.8, 18.7 and 75.6% at 1.5% SFO and 33.1, 36.9 and 94.2% at 3.0% SFO, respectively at 35 days of age). Weights of the liver, giblets, kidneys and pancreas increased (P ≤ 0.01) by 23.2, 14.7, 34.2 and 16.9%, respectively, and thymus weight decreased (P ≤ 0.04) by 25.4% with 300 ppb AF, and SFO at 3% in diet countered the effect on weight of the liver and giblets. Fat deposition in the liver increased (P ≤ 0.01) as the concentration of AF increased in diet (by 9.4 and 17.3%, respectively at 150 and 300 ppb AF), which was significantly (P ≤ 0.05) countered by SFO at 3% in diet. Tibia bone Ca content increased by 2.4% (P ≤ 0.01) with SFO supplementation in AF-fed chickens. It is concluded that dietary SFO supplementation countered the adverse effects of AF in broiler chicks in a dose-dependent manner, and higher level of oil (3% in diet) was required at the higher concentration of AF (300 ppb) in diet.

Evaluation of feeding value of combination of alternate protein sources in White Leghorn layers

1. A study was conducted to evaluate the effects of including graded levels of an alternate protein mixture (APM) containing cottonseed meal, distillery dried grain with solubles and mustard seed meal in a fixed ratio as a substitute for soybean meal in layer diets (hens aged 27 to 46 weeks). The trial studied the possibility of higher inclusion levels of APM with increased dietary concentrations of crude protein (CP) or critical amino acids (CAA). 2. Maize-soybean meal diet was used as the control diet. In experiment 1, APM was included at 0, 120, 160 and 200 g/kg diet (145 g/kg CP). In experiment 2, the control and three test diets (200 g/kg APM) with three levels of CP (145, 155 and 165 g/kg) were used. In experiment 3, a control and four test diets (200 g/kg APM) with four concentrations of CAA (100%, 105%, 110% and 115% relative to the control) were used. In all experiments, each diet was fed ad libitum to nine replicates of 88 birds each, housed in colony cages. 3. In experiment 1, egg production (EP) and feed intake (FI) were not affected by feeding up to 160 g/kg APM, but, at 200 g/kg, EP was significantly reduced. Feed conversion ratio (FCR) for the hens fed the highest level of APM was similar to the control. Egg weight (EW) and egg mass (EM) in the 160 and 200 g/kg AMS groups were lower than the control group. 4. Increase in dietary CP from 145 to 155 g/kg improved EP and reduced FCR to levels similar to the control group. EM in hens fed 165 g/kg APM was similar to the control in experiment 2. 5. Increasing concentrations of CAA progressively improved EP and reduced FCR in experiment 3. The EP at CAA 110% and FCR at CAA 105% were similar to the control group. 6. Based on the results, it was concluded that the APM can be included up to 160 g/kg diet without affecting layer performance, as long as the diet supplied the recommended levels of protein and amino acids. By increasing either protein from 145 to 155 g/kg or CAA concentrations by 10%, the dietary levels of the APM could be increased to 200 g/kg without affecting the layer performance.

Increasing dietary phytate has a significant anti-nutrient effect on apparent ileal amino acid digestibility and digestible amino acid intake requiring increasing doses of phytase as evidenced by prediction equations in broilers

Cobb 400, male broilers (n = 4,752) were housed in 12 pens/diet and 33 birds/pen. There were 3 levels of phytate P (0.24, 0.345, or 0.45%) and 4 phytase doses (0, 500, 1,000 or 2,000 phytase units (FTU)/kg) to evaluate the influence of phytate and phytase dose on apparent ileal digestibility (AID) and digestible nutrient intake. Diets were formulated with reduced Ca (0.22%), available P (0.20%), energy (80 to 120 kcal/kg) and amino acids (1 to 5%). On day 21, digesta was collected from 8 birds/pen. Prediction equations determined the linear or non-linear influence of phytate P, log phytase dose, and the interaction. The AID of amino acids, Ca or P and digestible amino acid or Ca intake were influenced by linear or non-linear phytate P × log phytase dose (P < 0.0001). Increasing the dietary phytate P from 0.24 to 0.345 or 0.45% was predicted to reduce the AID of amino acids in a non-linear manner by an average of 6 to 7 percentage points, respectively. This corresponded to a non-linear decrease in digestible amino acid intake of an average of 80 to 90 mg/D. The negative effect of increasing dietary phytate P from 0.24 to 0.45% on AID was greatest for cysteine (-14 percentage points), aspartic acid or glycine (-9 percentage points) and lowest for methionine, tryptophan, serine, or glutamic acid (-5 percentage points). The predicted digestible intake of lysine (-120 mg/D), aspartic acid (-180 mg/D), or glutamic acid (-290 mg/D) were reduced in birds fed diets containing 0.345% vs. 0.24% phytate P. Phytase supplementation was predicted to increase the AID of amino acids, Ca, or P in a non-linear-log or log-linear manner at all levels of phytate P, with the greatest response at higher doses of phytase in diets containing 0.345 or 0.45% phytate P. The effect of phytase on digestible nutrient intake was less clear. Prediction equations can be useful to determine the influence of phytase and phytate P on AID and digestible nutrient intake in broilers.

Dietary phytate has a greater anti-nutrient effect on feed conversion ratio compared to body weight gain and greater doses of phytase are required to alleviate this effect as evidenced by prediction equations on growth performance, bone ash and phytate degradation in broilers

Cobb 400, male broilers (n=4,752) were fed one of 12 diets, with 12 pens/diet and 33 birds/pen. Treatments consisted of 3 levels of phytate P (0.24, 0.345, or 0.45%) and 4 doses of phytase (0, 500, 1,000, or 2,000 phytase units (FTU)/kg). Diets were formulated with reduced Ca (0.22%), available P (0.20%), energy (80 to 120 kcal/kg), and amino acids (1 to 5%) when compared with breed requirements. Prediction equations suggested feeding dietary phytate P > 0.275, 0.295, or 0.319% reduced feed intake (FI) and body weight gain (BWG) and increased feed conversion ratio, respectively, from day 0 to 21. Supplementing phytase at 561, 1,285, or >2,000 FTU/kg resulted in the maximum FI, BWG, or feed efficiency, respectively. From day 0 to 42, maximum BWG or feed efficiency were achieved at phytate P concentrations <0.281 or 0.25%, respectively. Supplementing phytase at 449 or 2,000 FTU/kg maximized BWG or feed efficiency, respectively. Tibia ash weight, percent or Ca concentration were maximized at phytate P concentrations <0.24, 0.296, or 0.24%, respectively and phytase supplementation at 822 or >2,000 FTU/kg maximized tibia ash weight or percent respectively. In the absence of phytase, phytate (IP6) concentration in the gizzard was greatest in birds fed 0.45% phytate P and phytase supplementation between 1,132 to 1,285 FTU/kg resulted in the lowest IP6 concentration in the gizzard. There was no effect of dietary phytate P on the concentration of phytate esters (IP5 or IP4) in the gizzard, which were minimized at 1,208 FTU/kg of phytase. In the absence of phytase, the concentration of phytate ester (IP3) or inositol in the gizzard was greatest in birds fed 0.345% phytate P and phytase supplementation at ∼500 FTU/kg minimized IP3, whereas 2,000 FTU/kg maximized inositol, except in birds fed 0.45% phytate P, which was maximized at 202 FTU/kg of phytase. Prediction equations can be useful to determine the influence of phytase and phytate P on broiler performance, phytate degradation and bone ash.

Feeding status of free-range scavenging chickens in different agro-climatic regions of India

1. The aim of this study was to determine the nutritional status of backyard chickens reared under 4 different agro-climatic conditions (tropical, humid subtropical, cool-temperate and semi-arid) of India during different seasons of the year and to compare their nutritional status with those reared under confined feeding system (CFS). In each season, 15 adult and 15 grower chickens were slaughtered for collecting content of crop and gizzard to assess the nutritional status from different agro-climatic conditions.2. The dry matter content of crop and gizzard was higher (P < 0.01) in chickens reared under backyard conditions compared to those reared under CFS.3. Higher (P < 0.01) crop and gizzard contents were recorded during winter compared to the rainy season. The proportion of grains in the crop during summer and winter season was higher compared to rainy season. Further, there were more insects present in the crop during the rainy season and winter compared to summer.4. The proportion of insects was higher in chickens reared in humid, subtropical and cool temperate regions compared to semi-arid conditions. The consumption of grasses was higher in cool-temperate regions as compared to those reared under other areas.5. Crude protein (CP), Ca, P and gross energy (GE) content of the crop were higher in chickens reared under CFS compared to those reared in backyard systems and CP in the crop contents was lower in backyard chickens reared in humid subtropical and semi-arid regions compared to other areas. Similarly, lower (P < 0.01) Ca levels were seen in crop and gizzard contents from birds reared in semi-arid Rajasthan, and P and GE were lower in tropical wet and dry Telangana (TWT) compared to the chickens reared in the backyard conditions in other regions.6. Based on the results, the nutrient intake for birds utilising the scavenging feed resource base (SFRB) in the TWT region was below the requirements of backyard chickens from the other regions selected in the present study. GE and CP were critically deficient in the SFRB of the TWT region. Therefore, evolving location-specific supplementary diets using locally available feed resources to meet nutrient requirement of backyard chickens is required for optimising production potential.

Effect of supplementing moringa (Moringa oleifera) leaf meal and pomegranate (Punica granatum) peel meal on performance, carcass attributes, immune and antioxidant responses in broiler chickens

An experiment was conducted to study the benefits of dietary supplementation of moringa (Moringa oleifera) leaf meal (MLM) and pomegranate (Punica granatum) peel meal (PPM) on the performance, carcass attributes, immune and antioxidant responses in commercial broiler chickens during 1–42 days of age. In total, 450 Cobb-400 broiler male chicks raised in wire-floor stainless-steel battery brooder pens in an open-side poultry house were divided into five experimental groups with 18 replicates of five chicks each and fed a standard control diet (CD) and the test diets supplemented with MLM (500 and 1000 mg/kg) or PPM (250 and 500 mg/kg), each at two different concentrations. Bodyweight gain, feed conversion efficiency and carcass attributes were not affected (P &gt; 0.05). The cell-mediated immune response to phytohaemagglutinin phosphate was not influenced (P &gt; 0.05), but the antibody titre against Newcastle disease (ND) vaccine was significantly (P &lt; 0.05) improved by supplementation of MLM or PPM in broiler diet at 42 days of age. However, at 21 days of age, the ND titre was similar in broilers fed CD and 500 mg/kg PPM fed group. Activities of glutathione reductase and super oxide dismutase in liver were not influenced (P &gt; 0.05), while lipid peroxidation (LP) reduced significantly (P &lt; 0.05) with the herbal additives. The LP in the PPM group was significantly (P &lt; 0.05) lower than that in groups fed MLM. The activity of glutathione peroxidase (GSHPx) was significantly (P &lt; 0.05) improved in the PPM group. Activities of antioxidant enzymes (super oxide dismutase, glutathione reductase, GSHPx) in spleen were not influenced (P &gt; 0.05). The degree of LP in the 500 mg/kg PPM group was significantly (P &lt; 0.05) lower than that in groups fed the CD. It is concluded that supplementation of MLM (500 and 1000 mg/kg) or PPM (250 and 500 mg/kg) in diets improved humoral immune response (against ND vaccine) at 42 days of age and reduced LP in liver in commercial broilers, without showing any negative effects on performance and carcass attributes. Supplementation of PPM (250 and 500 mg/kg) significantly improved the activity of GSHPx in the liver of broiler chickens.

Effect of supplementing graded concentrations of non-phytate phosphorus on performance, egg quality and bone mineral variables in White Leghorn layers

1. An experiment was conducted to determine optimal non-phytate phosphorus (NPP) concentrations for White Leghorn (WL) layers (22-72 weeks) fed diet containing 38 g Ca/kg. 2. Eight diets with graded concentrations (1.5-3.25 g/kg in increments of 0.25 g) of NPP were prepared. Each diet was fed to eight pen replicates containing 88 birds in each. Performance data was evaluated in three different phases (phase I-22-37 weeks, phase II-38-53 weeks and phase III-54-72 weeks). Optimum levels of NPP were determined by fitting a quadratic polynomial (QP) regression model. 3. Egg production (EP) was not affected (P = 0.059) by the concentration of NPP and interaction between NPP and diet phase was non-significant, indicating that the lowest concentration (1.5 g/kg diet) of NPP used in the study was adequate across the three phases. However, EP was influenced by phase (P < 0.001). 4. Optimum concentration of NPP for feed intake (FI) was estimated to be 1.5, 1.71 and 2.40 g/kg diet during phases I, II and III, respectively. FI per egg mass (EM) or feed efficiency (FE) responded quadratically with NPP and also differed significantly between phases. Optimum concentration of NPP for FE during phases I, II and III was 1.5, 2.56 and 2.32 g/kg diet, respectively. 5. Egg weight (EW), EM, shell weight and thickness were not affected by NPP concentration although all of these variables (except shell weight) were influenced by phases. 6. Breaking strength of tibia and Ca contents in tibia ash were not affected by the concentration of NPP, but bone ash and P contents in tibia ash were influenced (P < 0.001) by NPP. Predicted optimal concentrations of NPP for responses for tibia ash at 44 or 72 weeks, tibia ash P at 44 weeks and tibia ash P at 72 weeks were 1.55, 2.63 and 1.5 g/kg diet, respectively. 7. Based on the results, it was concluded that WL layers required 1.5 g, 2.63 g and 2.4 g, respectively/kg diet during phase I, II and III with the calculated daily intake of 137.3, 278.3 and 262 mg NPP/b/d.

High doses of phytase on growth performance and apparent ileal amino acid digestibility of broilers fed diets with graded concentrations of digestible sulfur amino acids

Two experiments of the same design were conducted to determine the influence of phytase on performance and apparent ileal digestibility (AID) of amino acids in broilers fed graded concentrations of digestible sulfur amino acids (dgM+C). Cobb 400 male broilers were allocated to 1 of 10 diets consisting of 5 basal diets formulated at 75, 82, 89, 96, or 103% of the Cobb 400 dgM+C requirements for each feeding phase. Phytase was included in each basal diet at 0 or 2,000 FTU/kg. In experiment 1, 33 birds/pen from hatch to day 42 were fed a 2-phase feeding program with 10 replicate pens/diet. In experiment 2, there were 26 birds/pen from hatch to day 21 and 8 replicate pens/diet. Data were analyzed as a 5 × 2 factorial and means separated using orthogonal contrasts. In experiment 1, overall (hatch to day 42) feed intake (FI) decreased (linear, P < 0.05), body weight gain (BWG) increased (quadratic, P < 0.05), and feed conversion ratio (FCR) was improved (quadratic, P < 0.05) as dgM+C increased to ≥96% in the diet. Phytase increased (P < 0.05) BWG and improved (P < 0.05) FCR, regardless of the percent dgM+C in the diet. In experiment 2, overall (hatch to day 21) BWG increased (quadratic, P < 0.05), and FCR was improved (quadratic, P < 0.05) as dgM+C increased to ≥96% in the diet. Phytase increased FI (P < 0.05) and BWG (P < 0.05) and improved FCR (P < 0.05), regardless of the percent dgM+C in the diet. In the absence of phytase, the AID of all amino acids was greatest (quadratic, P < 0.05) in birds fed between 89 and 96% dgM+C. However, in the presence of phytase the AID of all amino acids was greatest (quadratic, P < 0.05) in birds fed 82% dgM+C and greater at all levels of dgM+C than birds fed diets without phytase (dgM+C × phytase, P < 0.05). In conclusion, phytase improved AID of all amino acids and improved growth performance regardless of the level of dgM+C in the diet.

Effect of dietary inclusion of graded levels of toasted guar meal on performance, nutrient digestibility, carcass traits, and serum parameters in commercial broiler chickens

An experiment was conducted in a completely randomized design to explore the replacement value of toasted guar meal (TGM) for soybean meal (SBM) in commercial broiler diets. Hypothesis was tested by including graded levels (0, 6, 9, 12, 15, and 18% of diet) of TGM to replace maize-SBM on growth performance, apparent nutrient digestibility, carcass traits, and serum parameters. A total of six iso-nitrogenous and iso-caloric diets were prepared, and each diet was fed ad libitum to 12 replicates of five chicks each from 1 to 42 days of age. Results showed that inclusion of TGM up to 12% in broiler diets did not affect the body weight gain, feed efficiency, and energy digestibility. Feed intake, dry matter, nitrogen digestibility, and relative weights of ready-to-cook yields, breast muscle, abdominal fat, liver, and pancreas were not affected (P > 0.05) by incorporating TGM even up to 18% in broiler diets. Concentration of glucose, total protein, and triglyceride in serum was also not affected (P > 0.05), while serum total cholesterol concentration was found to be higher (P < 0.05) in broilers fed diets containing TGM as compared to those fed on 0% TGM diet. From the results, it was evident that TGM may be incorporated up to 12% in commercial broiler diets for better growth performance, nutrient digestibility, and carcass traits.

Effect of dietary inclusion of toasted guar (Cyamopsis tetragonoloba) meal as a source of protein on performance of White Leghorn layers

Two experiments were conducted to study the effect of including toasted (120°C/35 min) guar meal (GM, Cyamopsis tetragonoloba) in the diet on performance and egg shell quality of White Leghorn (WL) layers. Totals of 2376 and 2816 layer chickens (Babcock, BV 300) were randomly distributed into 27 and 32 replicates with 88 birds each in Experiments 1 and 2, respectively. Three diets in Experiment 1 (0, 50 and 100 g GM) and 4 diets in Experiment 2 (0, 50, 100 and 150 g GM/kg) were prepared having similar concentrations of energy and protein. Each diet was fed ad libitum to 9 and 8 replicates, respectively, in Experiments 1 (from 53 to 68 weeks) and 2 (35 to 46 weeks of age). Compared to soya bean meal (SBM) GM contained similar concentrations of protein, but was deficient in all essential amino acids except arginine, which was 70% higher than in SBM. Total non-starch polysaccharide (NSP) content in GM (166 g/kg) was lower than that of SBM (179 g/kg). Amongst different NSP fractions, GM contained higher levels of arabans, xylans, mannans and glucans compared to SBM. The galactomannan gum content in GM was 46 g/kg. Egg production (EP), body weight (BW), food intake (FI), food efficiency (FE) and egg quality (shell weight, shell per cent, shell thickness, Haugh unit score, egg density and egg breaking strength) parameters were not affected by incorporating GM up to 100 g/kg diet in Experiment 1. However, egg weight (EW) and egg mass (EM) were reduced significantly in groups fed on 100 g/kg diet. In Experiment 2, EP and FE were not affected by incorporating GM up to 100 g/kg, but were reduced at 150 g/kg diet. FI, EW, BW and egg quality parameters were not affected by incorporating toasted GM up to 150 g/kg diet. Based on the results of both experiments, it is concluded that toasted GM can be included in WL layer diets up to 100 g/kg without affecting EP, FE, EW, EM, Haugh unit score, BW and egg shell quality parameters.

Effect of Supplementing Organic Forms of Zinc, Selenium and Chromium on Performance, Anti-Oxidant and Immune Responses in Broiler Chicken Reared in Tropical Summer

Two experiments were conducted to study the effect of supplementing organic forms of zinc (Zn), selenium (Se) and chromium (Cr) on performance, anti-oxidant activities and immune responses in broiler chickens from 1 to 21 days of age, which were reared in cyclic heat-stressed condition under tropical summer in open-sided poultry house. A total of 200 (experiment I) and 450-day-old (experiment II) broiler male chicks (Cobb 400) were randomly distributed in stainless steel battery brooders (610 mm × 762 mm × 475 mm) at the rate of five birds per pen. A maize-soybean meal-based control diet (CD) containing recommended (Vencobb 400, Broiler Management Guide) concentrations of inorganic trace minerals and other nutrients was prepared. The CD was supplemented individually with organic form of selenium (Se, 0.30 mg/kg), chromium (Cr, 2 mg/kg) and zinc (Zn, 40 mg/kg) in experiment I. In experiment II, two concentrations of each Zn (20 and 40 mg/kg), Se (0.15 and 0.30 mg/kg) and Cr (1 and 2 mg/kg) were supplemented to the basal diet in 2 × 2 × 2 factorial design. A group without supplementing inorganic trace minerals was maintained as control group in both experiments. Each diet was allotted randomly to ten replicates in both experiments and fed ad libitum from 1 to 21 days of age. At 19th day of age, blood samples were collected for estimation of anti-oxidant and immune responses. Supplementation of Se, Cr and Zn increased (P < 0.05) body mass gain (BMG) and feed intake compared to those fed the CD in experiment I. The feed efficiency (FE) in Cr-fed group was higher (P < 0.05) compared to the CD-fed group. Se or Cr supplementation reduced lipid peroxidation (LP) compared to broilers fed the CD. In experiment II, BMG was not affected (P > 0.05) by the interaction between levels of Zn, Se and Cr in broiler diet. The FE improved (P < 0.05) with supplementation of the trace minerals tested at both concentrations except in group fed 40 mg Zn, 0.5 mg Se and 1 mg Cr/kg. Reduction in lipid peroxidation (LP, P < 0.05) and increased (P < 0.05) activity of superoxide dismutase were observed in broiler fed organic Zn, Se and Cr compared to the CD-fed group. The dietary concentrations of Zn, Se and Cr did not influence (P > 0.05) the immune responses (Newcastle disease titre and cell-mediated immune response to phytohaemagglutinin-P) in both the experiments. Based on the results, it is concluded that supplementation of organic form of Se, Cr and Zn (0.30, 2 and 40 mg/kg, respectively) either alone or in combination significantly improved performance and anti-oxidant responses (reduced LP and increased superoxide dismutase) in commercial broiler chicks (21 days of age) reared in cyclic heat stress conditions in open-sided poultry house during summer.

Effect of Embryonic Thermal Exposure on Heat Shock Proteins (HSPs) Gene Expression and Serum T3 Concentration in Two Broiler Populations

The present experiment was conducted to evaluate the Hsp-70, 27 and Ubiquitin mRNA expressions and serum T3 concentration in synthetic colored broiler female lines, Punjab Broiler-2 (PB-2), and Naked neck (NN) broiler chicken whose eggs were exposed to 2°C increased incubation temperature for 3 hours each on the 16th, 17 th, and 18th day of incubation. Another set of eggs were incubated at normal conditions that were utilized as the control. A total of 432 chicks, 216 from each breed (PB-2; NN) and treatment (Heat exposed: HE; normal: N), were randomly distributed and reared at high ambient temperatures (32°C-45°C) during the summer season in battery brooders. Birds were sacrificed at 0 and the 28th day post hatch and different tissues (heart, liver, muscle, spleen, and bursa) were collected to study Hsps and ubiquitin mRNA expression. There was no difference between the breeds and age of slaughter in Hsp-70 mRNA expression. The Hsp(70, 27, and ubiquitin) mRNA expression was significantly (P≤0.001) lower in HE birds than that of N birds in PB-2 chickens. Nonsignificant variation was observed in NN chicken. The Hsp-70 mRNA expression was highest in bursa and lowest in muscle and liver. Serum T3 concentration was similar in both HE and N birds. The study concludes that exposure to increased temperature during incubation results in reduced expressions of Hsp mRNA in almost all tissues indicating better thermotolerance of the HE birds.

Effect of dietary ellagic acid supplementation on semen quality parameters in chickens

Ellagic acid (EA), a polyphenoloic constituent in fruits and nuts, has been shown to have antioxidant and antiapoptotic properties. The aim of this study was to investigate the effect of dietary EA supplementation on semen quality parameters in chickens. Forty roosters (Dahlem Red breed), 28 weeks of age, were randomly assigned to four groups and fed diets containing EA at 0, 25, 50, or 75 mg/kg for 8 weeks. Semen was evaluated for volume, appearance, individual motility, sperm concentration, 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) dye reduction test, and live, dead and abnormal sperm counts. The seminal plasma was separated and evaluated for protein, alkaline phosphatase, and lipid peroxidation. At the end of the experiment, blood from individual birds was collected, and serum was separated and evaluated for superoxide dismutase activity, lipid peroxidation, and ferric-reducing ability of plasma. Supplementation with EA had no effect (P > 0.05) on gross semen parameters. Seminal plasma protein and lipid peroxidation were different (P < 0.01) between the treatment groups. The group fed EA at 75 mg/kg had high (P < 0.01) seminal plasma lipid peroxidation and lower (P < 0.05) serum superoxide dismutase activity. In conclusion, dietary supplementation of EA in chickens had no effect on the gross semen qualities and increased lipid peroxidation in seminal plasma.

Effect of feeding diets based on coarse maize on productive performance, gizzard development and energy utilisation of laying hens

1. A total of 2200 White Leghorn layers were used to study the effect of feeding coarse maize on productive performance, gizzard weight, apparent metabolisable energy (AME) and egg quality parameters. 2. The experiment was a completely randomised design with 5 treatments, each being replicated 5 times (88 birds per replicate). Dietary treatments included a control diet with 600 g/kg of ground maize (6 mm sieve) and experimental diets with 150, 300, 450 or 600 g/kg coarse maize (10 mm sieve) replacing (w/w) ground maize. Diets, in mash form, were offered from 39 to 62 weeks of age. 3. Over the entire experimental period, dietary treatments had no effect on any of the production parameters, except on feed intake. A quadratic effect was observed for feed intake, where intake increased at 150 g/kg coarse maize inclusion. At higher inclusion levels of coarse maize, feed intake was similar to that of the control diet. But the differences in daily intake between dietary treatments were only around 1 g/bird and may not be of any biological significance. 4. Dietary treatments had no effect on gizzard weight, AME or egg quality. 5. The results indicate that coarse maize could completely replace maize in layer diets with no adverse effect on egg production, egg quality and dietary energy utilisation. In the current work, although the proportion of coarse particles (over 1 mm) increased with increasing inclusion levels of coarse maize, the differences in the percentage of particles above 1 mm between the fine control (0 g/kg coarse maize) and coarsest (600 g/kg coarse maize) diets was only 15%, and this may limit the value of the findings reported herein.

Influence of different concentrations of metabolisable energy at constant ratio to dietary protein, lysine, methionine, calcium and phosphorus on the performance of White Leghorn layers in the tropics

An experiment was conducted to study the effect of nutrient density on the performance (21–72 weeks of age) of White Leghorn layers reared in an open-sided poultry house in the tropics. Six diets with graded levels (9.62–11.72 MJ/kg) of metabolisable energy (ME) with an increment of 0.42 MJ were formulated. Concentrations of crude protein, lysine, methionine, calcium and non-phytate phosphorus were kept constant to ME in all diets (15.9, 0.73, 0.35, 3.19 and 0.31 g/MJ ME, respectively). At 21 weeks of age, a total of 5280 birds was distributed randomly in 4-bird colony cages and 22 such cages in a row constituted one replicate. Each diet was fed ad libitum to 10 replicates from 21 to 72 weeks of age and performance parameters were recorded at 28-day intervals (period, 1–13). Egg production (EP) increased (P < 0.05) with increasing dietary ME and maximum response in EP was observed when dietary ME levels ranged between 10.93 and 11.69 MJ/kg during the majority of periods, while in periods 6, 7 and 8 (summer, 28−37°C), maximum EP was observed at higher ME levels in diet (11.64–11.69 MJ/kg diet). Feed intake (P < 0.01) decreased, feed efficiency (P < 0.01), egg mass (P < 0.01) and weight gain (P < 0.05) improved quadratically with increase in dietary ME concentration. Maximum feed efficiency was observed at 11.36 MJ ME/kg diet during 21–72 weeks of age. Egg shell defects were not influenced (P > 0.05) by dietary nutrient density. Mortality reduced quadratically with increase in dietary ME concentration and mortality was minimum at 11.64 MJ ME/kg diet. Based on results from the experiment it was concluded that White Leghorn layers (21–72 weeks of age) require 11.36 MJ ME/kg diet for maximum egg production, feed efficiency and egg mass with better liveability. The calculated intake of metabolisable energy, crude protein, lysine, methionine, calcium and non-phytate phosphorus in layers fed 11.30 MJ ME/kg diet was 1.157 MJ, 18.42 g, 865 mg, 409 mg, 3.68 g and 358 mg per bird per day, respectively.

Effect of dietary supplementation of organic chromium on performance, carcass traits, oxidative parameters, and immune responses in commercial broiler chickens

An experiment was conducted to study effect of supplementing graded concentrations (0, 100, 200, 300, or 400 μg/kg diet) of organic chromium (Cr) on performance, carcass traits, oxidative stress, and immune responses in commercial broiler chickens reared in open-sided poultry house under tropical climatic conditions. Each diet was fed ad libitum to eight replicates consisting of six birds in each pen from 1 to 42 days of age. Body mass gain and feed efficiency at 21 and 42 days of age and relative mass of liver, abdominal fat, and ready to cook yields at 42 days of age were not affected (P > 0.05) by supplementing organic Cr in broiler diet. Body mass loss during pre-slaughter holding period (12 h) reduced and relative breast mass increased nonlinearly (P < 0.01) with concentration of Cr in diet. Lipid peroxidation decreased, while activities of glutathione peroxidase and glutathione reductase in plasma increased nonlinearly with Cr supplementation. The ratio between heterophyl and lymphocyte was not affected (P > 0.05) with Cr supplementation in broiler diet. Relative mass of lymphoid organs (bursa, spleen, and thymus) and antibody production to Newcastle disease vaccination were not affected (P > 0.05) by the treatments employed. The cell-mediated immunity (lymphocyte proliferation ratio) increased nonlinearly with dietary Cr concentration. The results of the present study indicated that supplementation of organic Cr did not influence body mass and feed efficiency. However, supplementation of the Cr reduced pre-slaughter holding losses, increased the relative mass of breast, and increased antioxidant status and lymphocyte proliferation in broilers reared in tropics.

Effect of age on semen quality in naked neck and dwarf chicken under tropical climatic conditions

The present study was undertaken to elucidate the effect of age on semen quality of naked neck and dwarf chicken lines under tropical climatic conditions. Semen collected by abdominal massage at 4-week intervals from 24 to 48 weeks of age was evaluated for different semen quality parameters. Except sperm concentration and appearance, all other parameters were significantly (P < 0.05) affected by the age of the birds. The semen volume, motility, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide dye reduction test and percentage of live sperm were significantly (P < 0.05) lower at 24 weeks of age compared with 40 weeks of age. At 24 weeks of age the dead sperm percentage was significantly (P < 0.05) high and with advancing age it decreased. There was a significant difference (P < 0.05) between the gene lines for volume, appearance, motility, sperm concentration, and percentage of live and dead sperm. Except for sperm concentration, significant (P < 0.05) interaction between gene lines and age was observed in other parameters. In conclusion, semen quality was different between naked neck and dwarf line males and age affected semen quality of the gene lines studied in different manners.

Nutritional evaluation and utilisation of quality protein maize, Nityashree hybrid maize, and normal maize in broiler chickens

Three experiments were conducted to determine the apparent metabolisable energy, apparent digestible amino acid values, and utilisation of three maize varities in chickens: quality protein maize (QPM), hybrid maize Nityashree (HMN) and normal maize (NM). There was no significant difference in the apparent metabolisable energy (AME) content amongst the three varieties of maize. Lysine and threonine digestibilities were significantly higher in QPM compared to either HMN or NM. No difference in the digestibilities of other amino acids occurred among the three different maize varieties. There was no difference between diets containing NM or HMN for body weight gain (21 and 40 d of age) and overall feed conversion ratio (0-40 d), but values were significantly higher for QPM (and Lys-supplemented NM) diets. The relative weights of dressed meat yield and giblets were unaffected by dietary replacement of NM with QPM, HMN, or Lys supplementation of the NM diet. However, abdominal fat content decreased and breast meat yield increased with both dietary replacement of NM with QPM and Lys supplementation of the NM diet. The concentration of protein in serum was significantly increased by dietary replacement of NM with QPM. Adding Lys to the NM based diet significantly increased the Ca concentration in serum compared with NM or HMN diets. However, the highest concentration of Ca in serum was found in the QPM diet. The concentration of total cholesterol in serum significantly decreased by either replacing NM with QPM or adding Lys to the NM based diet, compared with the NM diet. These results suggested that the feeding value of quality protein maize was superior to normal maize, while the feeding value of hybrid maize Nityashree was similar to that of normal maize.

Reversal of Cadmium-induced Oxidative Stress in Chicken by Herbal Adaptogens Withania Somnifera and Ocimum Sanctum

The present study was carried out to evaluate the herbal adaptogens Withania somnifera and Ocimum sanctum on cadmium-induced oxidative toxicity in broiler chicken. Cadmium administration at the rate of 100 ppm orally along with feed up to 28 days produced peroxidative damage, as indicated by increase in TBARS, reduction in glutathione (GSH) concentration in liver and kidney, and increase in catalase (CAT) and superoxide dismutase (SOD) of erythrocytes. Herbal adaptogens Withania somnifera roots and Ocimum sanctum leaf powder administration at the rate of 0.1% through feed reversed the antioxidant enzyme of RBC, i.e., CAT and SOD, nonenzymatic antioxidants GSH and lipid peroxidation marker TBARS of liver and kidney. Liver and kidney tissue repair and normal function was assessed by alanine aminotransaminase for liver and creatinine and blood urea nitrogen for kidney. In conclusion, oral administration of Withania somnifera root and Ocimum sanctum leaf powder prevented cadmium-induced peroxidation of tissues.

Effect of dietary α -tocopherol concentration on performance and some immune responses in broiler chickens fed on diets containing oils from different sources

1. An investigation was carried out into the effects of dietary α-tocopherol (α-T) concentration and source of supplemental oil on performance, activity of anti-oxidative enzymes and some immune responses in broilers from day-old to 41 d of age. 2. Three dietary concentrations of α-T (10, 50 and 100 mg/kg) with three sources of supplemental oil (sunflower - SFO, palm - PMO and safflower - SAO) were provided using a 3 × 3 experimental design. 3. Body weight gain and food conversion efficiency were not affected by either interaction or concentrations of α-T and sources of oil in diet. 4. Concentrations of total protein, globulin, triglycerides and cholesterol in sera increased significantly with dietary α-T concentration irrespective of the source of oil. Significantly higher concentration of serum albumin was evident in broilers fed on the SFO-based diet and the concentration of globulin was higher in groups fed on those diets containing PMO and SAO. 5. The lipid peroxidation (LP), measured as MDA release, decreased with the concentration of α-T in a dose-related manner with SFO- and SAO-based diets, although not with the PMO-based diet. With different oil sources, LP was significantly lower with the PMO-based diet compared to the others. Activities of glutathione peroxidase and RBC catalase increased and heterophil: lymphocyte ratio was reduced with concentration of α-T for each source of oil tested. 6. Assays for humoral and cell-mediated immune responses indicated no effect of the source of dietary supplemental oil or interaction, although an increasing concentration of dietary α-T improved cell-mediated immune responses. 7. It is concluded that sunflower oil, palm oil and safflower oil can be used as sources of oil for broiler diets without having any effect on performance, immune responses or the activity of anti-oxidizing enzymes. Higher concentrations of dietary α-tocopherol (50 or 100 mg/kg) reduced lipid peroxidation activity and enhanced activities of anti-oxidative enzymes, they also improved the cell-mediated immune responses in commercial broilers.

Effect of microbial phytase on production performance of White Leghorn layers fed on a diet low in non-phytate phosphorus

1. An experiment with 150 White Leghorn layers was conducted to examine the effect of microbial phytase supplementation of low non-phytate phosphorus (NPP) diets on egg production, eggshell quality, bone mineralisation and retention of nutrients at 32-48 weeks of age. 2. Four isonitrogenous and isocaloric diets were formulated to contain 1.2, 1.8, 2.4 and 3.0 g NPP/kg diet with the two lowest NPP (1.2 and 1.8) supplemented with microbial phytase (Biofeed Phytase, India) at 500 FTU per kg diet. Each diet was offered ad libitum to 5 replicates of 5 layers throughout the experiment. 3. Body weight gain was reduced significantly in the layers fed on the 1.2 g/kg NPP diet as compared to those given diets containing 1.8-3.0 g/kg. Addition of phytase to the 1.2 g/kg diet significantly enhanced the body weight and was comparable with those given diets containing 1.8-3.0 g/kg NPP. 4. No additional advantage resulted from enhancing the NPP levels beyond 1.8 g/kg or adding phytase to a diet containing 1.8 g/kg NPP. 5. Hen d egg production, food intake, food efficiency, shell weight, shell thickness, shell strength and tibia strength followed the same trends as above. However, adding phytase to the 1.8 g/kg NPP diet significantly enhanced tibia ash. Egg weight, specific gravity and Haugh units were influenced by neither NPP concentration nor phytase supplementation. 6. Adding phytase to the 1.2 g/kg NPP diet significantly enhanced nitrogen and phosphorus retention. 7. It was concluded that addition of 500 FTU of microbial phytase/kg diet can allow the reduction of NPP content to 1.2g/kg in the layer diet, eliminate inorganic phosphorus supplementation and results in significant reduction of nitrogen and phosphorus excretion without affecting the production performance of layers.

Performance and bone mineralisation in broiler chicks fed on diets with different concentrations of cholecalciferol at a constant ratio of calcium to non-phytate phosphorus

1. An experiment was conducted with broiler female chicks (720) to study the effects of graded concentrations (75, 15, 225 or 30 microg/kg) of cholecalciferol (CC) in diets containing varying levels of calcium (Ca) and non-phytate phosphorus (NPP) at a 2:1 ratio (4:2, 5:25, 6:3 or 7:35 g/kg, respectively), on the performance (2-35 d of age), bone mineralisation and mineral (Ca, P, Mn, Fe, Cu) concentration in excreta. 2. Body weight gain, food intake, tibia density and tibia ash increased, and leg abnormality score decreased with dietary increase of CC from 75 to 30 microg at 4 g Ca and 2 g NPP. However, this improvement was not comparable with the birds receiving the highest concentrations of CC, Ca and NPP (30 microg, 7 g and 3.5 g, respectively/kg diet). 3. Significant improvements in the majority of parameters noted with increasing CC up to 225 microg at 5 g Ca and 25 g NPP/kg, which was comparable to those fed the highest levels of CC, Ca and NPP. 4. Concentrations of Ca, P, Mn, Fe and Cu in excreta decreased significantly with increasing CC at all Ca:NPP ratios tested. 5. The predicted requirement of CC for most of the parameters ranged between 1625 and 25 microg/kg diet at 5 g Ca and 25 g NPP. 6. Considering the performance, bone mineralisation, and mineral concentration in excreta, it can be concluded that Ca and NPP levels in broiler diet could be reduced to 5 and 25 g, respectively, while maintaining CC at 25 microg/kg.

Incorporation of Cestrum diurnum leaf improves intestinal Ca transport in broilers

The economy of Ca utilization is under the control of vitamin D(3), particularly its active metabolite 1,25-dihydroxy cholecalciferol [1,25(OH)(2)D(3)]. In sufficient Ca absorption leads to tibial dyschondroplasia resulting in not attaining optimum body weight. Our earlier studies [T.P. Prema, N. Raghuramulu, Phytochemistry 37 (1994) 167] have shown that the Cestrum diurnum (CD) leaves contain vitamin D(3) metabolites. It was felt whether incorporation of CD as a source of 1,25(OH)(2)D(3) could improve the Ca absorption in broilers. Four groups of 60 birds each were fed with either normal diet or normal diet+0.25% CD or normal diet without vitamin D(3) or normal diet without vitamin D(3)+0.25% CD leaf powder for 45 days. In subsample of six birds it was observed that incorporation of CD leaves in the feed had the maximal effect on all the parameters studied. The results indicate that the intestinal Ca transport as represented by Serosa/Mucosa (S/M) ratio was found to be significantly (p<0.01) higher in broilers fed diet with CD leaf powder and the 1alpha hydroxylase activity in kidney is significantly (p<0.001) higher in negative controls. On the other hand the supplementation of CD leaves enhanced the serum Ca, body weight, tibia weight, density and strength resulting in the disappearance of tibial dyschondroplasia. No lesions of toxicity were observed in any of the soft tissue examined. The results suggest that the incorporation of CD leaf powder in poultry feed could be beneficial to the poultry.