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.

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 (4mg/kg) low-methionine 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 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 3.39g/kg, respectively in pre-starter, starter and finisher phases) containing 4 mg/kg FA.

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.

Effect of Different Zinc Sources and Concentrations on the Biomass Yield of Saccharomyces cerevisiae Yeast.

Zinc incorporation and the growth of Saccharomyces cerevisiae were investigated in a culture supplemented with three inorganic zinc salts, i.e. zinc sulphate, zinc chloride and zinc nitrate. The cultivation was performed on a yeast extract peptone dextrose (YEPD) broth medium. The growth of yeast was carried out at different concentrations of zinc, i.e. 0, 30, 60, 90 and 120 mg 100 ml-1. It was found that the addition of different zinc sources at 30 mg 100 ml-1 concentration produced higher biomass yield ranging 1.00-1.03 g from 100 ml-1 of cultivation medium, while higher zinc concentration in the medium caused significantly lower yields of yeast biomass. The amount of zinc in yeast cells was determined by an atomic absorption spectrometer (AAS). The highest amount of zinc in yeast cells was achieved when added in the form of zinc sulphate at a concentration of 120 mg 100 ml-1. The increment of intracellular zinc was up to 9889.67 mg kg-1 of biomass.

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.

Effect of feeding diet with alternate protein sources and quality protein maize on performance and nutrient utilization in broiler chickens.

The experiment was conducted to study the effect of feeding diets with quality protein maize (QPM) along with cottonseed meal (CSM) and guar meal (GM) on nutrient utilization, body weight (BW) gain (BWG), feed efficiency, and antioxidant status in broiler chickens. The biological trial was conducted on day-old broiler chicks (n = 240), which were randomly distributed into 6 dietary groups having 8 replicates with 5 chicks. Six experimental diets were formulated to contain maize (diet I), QPM (diet II), maize+CSM80 g/kg + GM40 g/kg (diet III), maize + CSM120 g/kg + GM60 g/kg (diet IV), QPM+CSM80 g/kg + GM40 g/kg (diet V), and QPM+CSM120 g/kg + GM60g/kg (diet VI). The BWG and feed intake were recorded at weekly intervals. Supplementation of CSM and GM along with QPM or maize depressed (P < 0.05) BWG, feed conversion ratio, and slaughter variables in commercial broilers. Improvement of BWG and breast weight was recorded among the groups supplemented 80 g/kg CSM and 40 g/kg GM with a QPM-based diet compared with those groups fed 120 g/kg CSM and 60 g/kg GM with maize or QPM. The energy and protein utilization decreased among the groups supplemented CSM and GM. However, protein and energy utilization was increased (P < 0.05) among the groups fed QPM-based diets compared with those groups fed CSM and GM with maize or QPM. Therefore, it has been concluded that the performance and other parameters did not differ between the groups fed maize- and QPM-based diets in the present experiment. However, QPM with CSM and GM improved the performance, slaughter parameters, and nutrient utilization over CSM and GM with maize.

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.

Effect of feeding higher concentrations of limiting amino acids on performance, slaughter variables and nitrogen retention in broiler chicken fed graded levels of toasted guar (Cyamopsis tetragonoloba) meal.

1. An experiment was conducted to study the effect of supplementing higher concentrations (100% vs. 110%) of critical amino acids (CAA) on performance (body weight gain - BWG, feed efficiency - FE), slaughter variables and nitrogen retention in broiler chicken (1-6 weeks of age) fed graded levels of toasted guar meal (TGM) as a protein source in diets. 2. The TGM was included at five graded concentrations (0, 50, 100, 150 and 200 g/kg) in iso-caloric and iso-protein diets with either the recommended concentration (100%) of CAA (lysine, total sulphur amino acids, threonine, tryptophan and valine) or at 10% higher (110%) concentration. A metabolism trial of 3-day duration was conducted during 6th week of age to study nitrogen retention. 3. The TGM levels and CAA concentration at 21 or 42 d of age did not influence BWG, FI and FE. BWG was not affected with inclusion of TGM up to 100 g/kg in starter and overall production (1-42 d of age) phases. The FE improved with TGM supplementation during starter phase, while at the end of experiment (42 d), FE was depressed by inclusion of TGM in dose dependant manner. All performance variables improved with increase in concentration of CAA from 100% to 110%. 4. Breast meat weight improved and abdominal fat weight reduced with higher levels of CAA in diet. Retention of nitrogen reduced with increase in level of TGM in broiler diet. Increasing concentrations of CAA in diet improved nitrogen retention. 5. It was concluded that TGM could be incorporated up to 100 g/kg with 100% CAA and up to 150 g/kg with 110% CAA without affecting performance. Increasing CAA concentration (110%) in diets significantly improved BWG and FE (21 and 42 d), breast meat weight and nitrogen retention in broiler chicken.

Effect of supplementing germinated sprouts of pulses on performance, carcass variables, immune and oxidative stress indicators in broiler chickens reared during tropical summer season.

An experiment was conducted to study the effects of supplementing sprouts of pulses on performance, carcass variables, immune responses, and anti-oxidant variables in broiler chicken (day 1 to 6 weeks of age) reared during summer season in tropical region. Sprouts of black gram (BG, Vigna mungo), green gram (GG, Vigna radiata), and wild gram (WG, Vigna trilobata) were produced by soaking the pulses in water for 16 h and incubating at 37 °C for 24 h. Total phenolic content in sprouts of WG, BG, and GG was 102, 96.1, and 79.2 mg GAE/g, respectively, while the anti-radical activity in the sprouts was 61, 58, and 52%, respectively. A total of 200-day-old broiler male chicks were equally and randomly distributed in to 4 groups, each having 10 replicates of 5 chicks and housed in battery brooders in open-sided poultry house. Each of these groups was fed sprouts of BG, GG, or WG at 5% of feed intake, while the control group without feeding sprouts was kept for comparison. The trial was conducted during mid summer season (April and May, 2017). Feed conversion ratio (FCR) was reduced (P < 0.05) in broilers fed sprouted pulses compared to the control group at day 21. However, the body weight gain and FCR at 42 days of age, slaughter variables, and immune responses were not affected due to feeding of sprouted pulses. Feeding of sprouts significantly (P < 0.05) reduced lipid peroxidation and increased (P < 0.05) the activities of glutathione peroxidase, glutathione reductase, and superoxide dismutase in liver and spleen of broilers compared to the control group. Based on the results, it is concluded that oxidative stress in broiler chicken reared in tropical summer could be reduced by supplementing sprouted pulses without affecting performance, carcass variables, and immune responses.

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 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.

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.

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.

Rice bran lysolecithin as a source of energy in broiler chicken diet.

1. Rice bran lysolecithin (RBL) was evaluated in broiler chicken diets. In the first experiment, RBL was included in diet at 0, 0·5, 2, 8 and 32 g/kg and fed to 250 broiler chickens from 0 to 42 d of age. In the second experiment, RBL was fed at 0, 25 and 50 g/kg diet to 405 day-old broiler chickens until 21 d of age, while during the finisher phase (22-35 d of age) chickens receiving each concentration of RBL were given all three concentrations of RBL in a 3 × 3 factorial manner. The diets were isocaloric. 2. Body weight, food consumption and food conversion efficiency were unaffected by feeding RBL, while the weight of pancreas increased at ≥2 g/kg of RBL in diet (experiment 1). In experiment 2, body weight was greater in the chickens receiving RBL at either 25 or 50 g/kg (21 d) and 50 g/kg (35 d of age). At 21 d of age, food consumption was greater at 25 or 50 g RBL/kg diet, while food conversion efficiency improved with 50 g RBL/kg diet. 3. Fat digestibility increased with RBL at 32 g/kg (experiment 1) and ≤25 g/kg (experiment 2). Rice bran lysolecithin increased ready to cook weight at 50 g/kg during starter phase and decreased abdominal fat at 25 and 50 g/kg during finisher phase (experiment 2). Liver and meat fat content were not affected. 4. It is concluded that lysolecithin from rice bran oil could be used as energy supplement in broiler chicken diet.

Effect of dietary supplementation with vitamins E and C on production performance, immune responses and antioxidant status of White Leghorn layers under tropical summer conditions.

1. The effects of vitamin E (DL-alpha-tocopheryl acetate) and vitamin C (ascorbic acid) supplementation on performance, some immune variables and antioxidant status of White Leghorn layers (aged 44-56 weeks) exposed to tropical summer conditions were investigated. 2. Both vitamins E and C significantly improved the egg production, food conversion efficiency, antibody responses to inoculated sheep red blood cells (SRBC) and Newcastle disease virus (NDV) vaccine, lymphocyte proliferation in response to mitogen and activities of antioxidant enzymes red blood cell catalase (RBCC) and glutathione peroxidase (GSH-PX) in layers. Vitamin C increased the inflammatory response to phytohaemagglutinin-P (PHA-P) inoculation. 3. Supplemental vitamin C at 200 mg/kg diet significantly increased eggshell weight, eggshell thickness, and shell breaking strength. However, no effect of supplemental vitamin E on eggshell quality was observed. 4. Vitamins E and C, as well as interactions between them, significantly influenced the activities of glutathione reductase and lipid peroxidase. A combination of vitamin E at 125 IU/kg with vitamin C at 200 mg/kg diet had an additive effect on reducing the activity of oxidative enzyme lipid peroxidase (LP) and increasing the activity of antioxidant enzyme glutathione reductase (GSHR). 5. It is concluded that vitamin E (125 IU/kg) and vitamin C (200 mg/kg) could independently alleviate the effects of heat stress on production performance and immunological variables of layers. However, combination of both the vitamins at the above-mentioned concentrations is beneficial in eliciting higher antioxidant status in laying hens exposed to tropical summer conditions.

Sunflower seed meal as a substitute for soybean meal in commercial broiler chicken diets.

1. An experiment was conducted to study the possibility of replacing soybean meal (SBM) with sunflower seed meal (SFM) in broiler chick diets. The SBM in broiler starter (317.9 g/kg) and finisher (275.4 g/kg) diets was replaced with SFM at 33, 67 and 100% on an iso-caloric and iso-nitrogenous basis using sunflower oil to balance the energy content of the diets. The metabolisable energy levels used in the diet were considerably less than the recommended levels for broilers. Each experimental diet was fed ad libitum from 2 to 42 d of age to 8 replicates of 5 birds. Parameters studied included amino acid and apparent metabolisable energy contents in food ingredients, body weight, food intake, food efficiency, leg abnormality score, dry matter digestibility, carcase traits, relative weight and length of intestine, fat and protein content in liver and serum biochemical profile. 2. SFM had higher concentrations of calcium, phosphorus, methionine and cystine and lower energy content than SBM. 3. Replacement of SBM with SFM up to 67% in starter and 100% in finisher diets did not affect weight gain. Total and 67% replacement of SBM with SFM depressed food efficiency at 21 and 42 d of age, respectively. Food intake was significantly higher in SFM-based diets than in the SBM reference diet at 21 and 42 d of age, except in groups given SFM100 at 21 d of age. In the latter group, the food intake was similar to that on the SBM reference diet. The digestibility of dry matter decreased with increased levels of SFM in the diet. 4. The relative weights of giblet, liver and abdominal fat, length of intestine, activity of alkaline phosphatase, concentrations of calcium and inorganic phosphorus in serum were not influenced by incorporation of SFM in the broiler diet. 5. The ready to cook yield and liver fat content decreased, while the relative weights of gizzard and intestine and protein content in liver increased, with increasing levels of SFM in the diet. 6. The concentration of HDL cholesterol increased while the concentration of LDL cholesterol decreased with increasing content of SFM (> or =67% of SBM) in diet. The serum protein concentration decreased progressively with increase in dietary SFM. The concentrations of protein and triglycerides in serum were lowest in groups receiving SFM100. 7. Body weight gain was not affected by total replacement of SBM with SFM at 42 d of age. However, considering food efficiency, carcase yields, serum lipid profile and level of supplemental fat in diet, it is concluded that SFM can replace up to two-thirds of soybean, corresponding to inclusion of 345 and 296 g SFM per kg for starter and finisher phases, respectively.

Effect of amount and source of supplemental dietary vegetable oil on broiler chickens exposed to aflatoxicosis.

1. Addition of sunflower oil (SFO) at 30 or 60 g/kg or three vegetable oils, namely SFO, soybean (SBO) or groundnut (GNO), at 30 g/kg to isocaloric and isonitrogenous broiler chicken diets were evaluated for possible counteractive effects against aflatoxin (AF) (0.3 microg B1/g diet) from 0 to 42 d of age. 2. Body weight, food intake and serum concentration of protein were lower in the AF group than in the control, whereas in the SFO and SBO supplemented groups they were comparable with those of the control. Sunflower oil at both concentrations exerted similar effects on growth. Groundnut oil did not improve growth or food intake in AF-fed birds. 3. The serum concentration of cholesterol and triglycerides decreased with AF feeding and was increased by supplementation of any of the three oils both in the control and in AF-fed groups. 4. Liver and giblet weight and liver fat content were increased by AF; these effects were countered by dietary oil inclusion, except for liver weight at 60 g/kg SFO. Weights of pancreas and gall bladder were increased by AF. Oil supplementation reduced the weight of pancreas in chickens given AF. 5. Humoral immune response was depressed by AF and dietary oil supplementation (particularly SFO or SBO) countered this effect. Other variables, namely, serum gamma glutamyl transferase activity, bone mineralisation, weights of lymphoid organs, kidney and adrenals, ready-to-cook yields and fat content in muscle and skin showed little or no effect of dietary oil supplementation. 6. It is concluded that dietary inclusion of SFO or SBO at 30 g/kg may alleviate the adverse effects of 0.3 microg/g of AF B1 in commercial broiler chickens. Groundnut oil, although showing beneficial effects on some biochemical variables, failed to improve growth performance.

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.