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 withdrawal influences egg production, egg quality and antioxidant 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 hens (67 to 80 weeks) reared in open-sided poultry houses 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 layers 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 hens reared during summer in the tropical region.

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.

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.

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.

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.

Backyard poultry farming for sustained production and enhanced nutritional and livelihood security with special reference to India: a review.

A comprehensive review on backyard poultry farming (BYPF) was carried out with respect to history, status, production systems, management practices, role in socio-economic development, etc., considering the Indian scenario in particular. Backyard poultry is an age-old traditional practice where small numbers of native chickens are reared with or without inputs under the free-range scavenging conditions. Currently, BYPF contributes about 17.8% (18.41 billion) of the total egg production (103.32 billion) of India. The introduction of high yielding chicken varieties, which resemble the native chicken, transformed the BYPF into a highly remunerative farming activity. The BYPF has a proven potential to alleviate poverty, eradicate malnutrition, empower women, and provide subsidiary income, and gainful employment in rural and tribal areas. In India, four types of backyard poultry farming are practiced, i.e., traditional, small-scale rural, small-scale intensive, and native chicken farming. The aspects of breeding and nutritional strategies in the nursery, and free-range conditions, besides the housing and health care practices that are followed in India, are discussed in detail. Backyard poultry farming has huge potential for further expansion as the produce from this system is preferred across the country.

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.

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 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.

Comparative evaluation of carcass traits and meat quality in native Aseel chickens and commercial broilers.

A comprehensive study was conducted to analyse the meat quality attributes, composition and carcass traits in Aseel chickens and commercial broilers at market age on the basis of physiological age. A total of 20 Aseel (26 and 56 weeks) and 20 broiler (6 weeks) chickens were divided into two groups on a live weight basis, i.e. large (≥2.5 kg) and small (<2.5 kg) with 10 birds in each subgroup. The pH of meat did not show any significant variation between Aseel and broiler chickens. The meat from heavier birds had significantly higher pH. Shear force value and hydroxyproline contents were significantly higher in Aseel chickens. Aseel birds had significantly higher red (a*) colouration and lower lightness (L*) than broiler chickens. The texture and acceptability of Aseel meat were significantly higher. Scanning electron microscopy revealed that muscle fibres in Aseels were arranged in a more coiled pattern making the muscle tough. A larger amount of connective tissue was also observed between the muscle fibres compared with the broiler chickens. The dressing percentage was significantly higher in larger chickens. Commercial broilers recorded significantly higher meat proportion and lower proportion of bone. The meat:bone ratio was 1.07:1.0 in Aseel and 1.31-1.0 in broiler chicken. Breast muscle content was significantly lower in smaller Aseel chickens. Aseel chicken had stronger and heavier backs and shanks. Abdominal fat percentage was significantly lower in Aseel (0.73-0.78%). The study concluded that the firm texture of Aseel meat was due to the high collagen content and interlocking connective tissue between the muscle fibres. The texture and acceptability of Aseel meat was higher. Aseel cocks had strong legs, lean meat and less abdominal fat, making them a high-value meat bird in addition to their aggressive fighting ability.

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 different concentrations of metabolisable energy and protein on performance of White Leghorn layers in a tropical climate.

1. An experiment was conducted to study the effects of feeding graded concentrations of metabolisable energy (ME) and crude protein (CP) on the performance of layers. Nine diets with three concentrations each of ME (10.04, 10.67 and 11.30 MJ/kg) and CP (150, 165 and 180 g/kg) in a 3 × 3 factorial arrangement of treatments were formulated. 2. A total of 5544 White Leghorn (WL) pullets (20 weeks of age) were housed in 4-bird colony cages and 22 adjacent cages constituted a replicate. Each diet was fed ad libitum to 7 replicates from 21 to 72 weeks of age. Production variables were recorded in 13 laying periods of 28 d each, and the data were pooled into three production phases, namely initial (21-32 weeks), peak (33-52 weeks) and post-peak (53-72 weeks). 3. No interaction was observed between ME and CP for egg production (EP), food intake (FI), food efficiency (FE), egg weight (EW), egg mass (EM) and body weight gain. 4. The EP, EW and EM during the initial phase of production were not affected by dietary ME concentrations, while the EW and EM improved with increasing concentrations of dietary CP from 150 to 165 g/kg. 5. During the peak production phase, improvements in EP (ME and CP), FI (ME), FE (ME, CP), EW (ME) and EM (ME, CP) were observed with increasing concentrations of energy and protein to 11.30 and 180 g/kg diet, respectively. 6. EP, EW and EM were unaffected by dietary variation in concentrations of ME and CP during post-peak production phase, but the FE improved and FI reduced with increasing dietary concentrations of these nutrients. 7. It is concluded that the optimum concentrations of ME for WL layers during the 21-32, 33-52 and 53-72 weeks of age are 11.30, 11.30 and 10.04 MJ/kg diet, respectively. The corresponding values for CP in diets are 180, 180 and 150 g/kg.

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.

Synergistic effect of probiotic, chicory root powder and coriander seed powder on growth performance, antioxidant activity and gut health of broiler chickens.

Gut health plays an important role on production and performance of broilers. This trial was undertaken with an aim to evaluate the synergistic effect of probiotic, chicory root powder and coriander seed powder on the performance and gut health of broiler chicken. For this purpose, a total of 240 day-old broiler chicks were randomly allotted to six dietary treatments with 8 replicates of 5 birds in each. Treatment groups included T1 as control i.e., basal diet (BD) without any growth promoter and T2-BD + antibiotic (BMD 0.05%). In the remaining experimental diets, T3-probiotic (@ 0.01%) + chicory root powder (@ 1.0%), T4-probiotic (@ 0.01%) + coriander seed powder (@ 1.5%), T5-chicory root powder (@ 1.0%) + coriander seed powder (@ 1.5%) and T6-probiotic (@ 0.01%) + chicory root powder (@ 1.0%) + coriander seed powder (@ 1.5%). The results indicated that supplementation of probiotic + chicory (T3), probiotic + coriander (T4), chicory + coriander (T5) and probiotic + chicory + coriander (T6) in combination resulted in significantly (P<0.05) higher weight gain and better FCR compared to control and antibiotic groups at 42 d of age. Supplementation of different dietary groups did not show any significant (P>0.05) effect on feed intake of broilers. Supplementation of all the test diets (T3 to T6) significantly (P<0.05) increased the glutathione peroxidase (GSHPx), glutathione reductase (GSHRx) and superoxide dismutase (SOD) enzyme activity when compared to control and antibiotic groups at 42 d of age. Supplementation of all the test diets (T3 to T6) significantly (P<0.05) lowered the pH in the gut, increased Lactobacillus counts, and reduced E. coli and Salmonella counts in the ileum compared to control and antibiotic groups. Supplementation of all the test diets (T3 to T6) significantly (P<0.05) increased the villus height (VH), crypt depth (CD), VH:CD ratio and villus width (VW) in the duodenum and only VH and CD in the ileum compared to control and antibiotic groups. Significantly (P<0.05) higher jejunal VH and VW and increased the goblet cell number in duodenum, jejunum and ileum was recorded in all test diets (T3 to T6) compared to control and antibiotic groups. Therefore, combinations of probiotic (0.01%), chicory root powder (1.0%) and coriander seed powder (1.5%) can be used as feed additive for improving performance and gut health of broiler chicken.

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.

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.