Enhancement of performance and anti-oxidant variables in broiler chicken fed diets containing sub-optimal methionine level with graded concentrations of sulphur and folic acid.

OBJECTIVE: An experiment was conducted to determine the effects of supplementing graded concentrations of inorganic sulphur (S) without and with folic acid (FA) in maize-soybean meal diets on performance, slaughter and anti-oxidant variables, immune responses and serum protein fractions in broiler chicken. METHODS: Inorganic S was supplemented at 0.05%, 0.10%, 0.15%, and 0.20% alone or in combination with FA (4 mg/kg) in basal diet (BD) containing no supplemental methionine (Met) and FA. A control group was fed with the recommended concentration of Met. Each diet was offered to 10 pens of 5 male broiler chicks (Cobb 400) and fed ad libitum from day 1 to 42. RESULTS: The broilers fed the BD had lower body weight gain (BWG), feed efficiency (FE), higher lipid peroxidation (LP), lower activity of glutathione peroxidase (GSHPx), lower lymphocyte proliferation ratio (LPR), and reduced concentrations of total protein, albumin, and globulin in serum. Supplementation of FA and S to the BD improved the BWG (all concentrations of S) and FE (0.20% S) similar to the control group. Similarly, the combination of S and FA significantly improved the concentrations of total protein, albumin, and globulin in serum, reduced the LP and increased the activity of GSHPx and LPR. However, responses in the above parameters were related to the concentration of S in the diet. The slaughter variables and antibody titres against the Newcastle disease were not affected with the treatments. CONCLUSION: Based on the results, it is concluded that the combination of S (0.2%) and FA (4 mg/kg) improved the BWG and FE, similarly supplementation of these nutrients improved the concentration of protein fractions and reduced the stress (reduced LP and improved GSHPx) variables in serum and improved the cell mediated immune response (LPR) in broilers fed sub-optimal concentrations of Met in diet.

Effect of methyl donors supplementation on performance, immune responses and anti-oxidant variables in broiler chicken fed diet without supplemental methionine.

OBJECTIVE: Methionine (Met) is involved in methyl group transfer besides protein synthesis. As the availability is limited and cost is high for synthetic Met, reductions in its inclusion in broiler diet may be possible by supplementing the low Met diets with methyl donors (MD) like betaine (Bet), folic acid (FA), vitamin B12 (B12), and biotin (Bio). An experiment was conducted to study the effects of supplementing the MD on performance (average daily gain [ADG], daily feed intake, feed efficiency [FE]), anti-oxidant variables, immune responses and serum protein concentration in broilers fed sub-optimal concentrations of dietary Met. METHODS: Maize-soybean meal diet was used as control (CD). Different MD like Bet (0.2%), B12 (0.1 mg), FA (4 mg), or Bio (1.5 mg/kg) were supplemented to basal diet (BD) having no supplemental Met. The BD without MD was kept for comparison. Each diet was fed ad libitum to 10 replicates of 25 chicks in each from 1 to 42 d of age. RESULTS: At the end of experiment, the ADG in MD group was higher than BD and lower than CD. The FE improved with FA or Bet compared to the BD. Breast meat weight was higher in Bet compared to the BD, while it was intermediate between BD and CD in other groups. The lipid peroxidation reduced with Bio, B12, or Bet, while the glutathione peroxidase activity improved with Bio or B12 compared to the BD. Lymphocyte proliferation improved with Bet compared to the BD. The serum protein concentrations increased with FA, Bio, or Bet compared to those fed BD. CONCLUSION: It can be concluded that the ADG can be improved partially with supplementation of MD while the FE improved with FA or Bet. Some MD also reduced the stress indices and improved immune responses compared to the BD fed broilers.

Graded concentrations of digestible lysine on performance of White Leghorn laying hens fed sub-optimal levels of protein.

OBJECTIVE: An experiment was conducted to study the effect of graded concentration of digestible lysine (dLys) on performance of layers fed diets containing sub-optimal level of protein. METHODS: Five diets were formulated to contain graded concentrations of dLys (0.700%, 0.665%, 0.630%, 0.593%, and 0.563%), but similar levels of crude protein (15% CP), energy (10.25 MJ ME/kg) and other nutrients. A total of 3,520 hens (26 wk of age) with mean body weight of 1,215+12.65 g were randomly divided into 40 replicate groups of 88 birds in each and housed in an open sided colony cage house. Each diet was offered ad libitum to eight replicates from 27 to 74 wk of age. The performance was compiled at every 28 d and the data for each parameter were grouped into three phases, that is early laying phase (27 to 38 wk), mid laying phase (39 to 58 wk), and late laying phase (59 to 74 wk of age) for statistical analysis. RESULTS: Egg production, egg mass and feed efficiency (feed required to produce an egg) were significantly improved by the dLys level during the early and mid laying phases but not during the late phase. Whereas feed intake was significantly reduced by dLys concentration during mid and late laying phases but not during early laying phase. The egg weight was not affected by dLys concentration in any of the three phases. CONCLUSION: Based on best fitted statistical models, dietary requirements of dLys worked out to be 0.685%, 0.640%, and 0.586% during early phase, mid phase, and late egg laying phase, respectively. The calculated requirement of dLys for the respective production phases are 727 mg/b/d during the early and mid laying phases and 684 mg/b/d during the late laying phase in diets containing 15% CP.

Effect of Dietary Supplementation of Organic Trace Minerals at Reduced Concentrations on Performance, Bone Mineralization, and Antioxidant Variables in Broiler Chicken Reared in Two Different Seasons in a Tropical Region.

Two experiments were conducted to study the performance, antioxidant activity, and bone mineral variables in broilers fed organic trace minerals (OTM) at lowered concentrations in the diet. In experiment 1, a total of 1500 day-old broiler male chicks were randomly distributed into six groups with 10 replicates of 25 chicks each and housed in floor pens (1.90 × 1.22 m). One group was fed the maize-soybean meal-based control diet, supplemented with inorganic trace mineral (ITM) premix containing Mn, Zn, Fe, Cu, Se, and Cr at 50, 45, 40, 7.5, 0.30, and 0.25 mg/kg, respectively. The remaining groups of chicks were fed the diets, where the ITM premix was replaced with OTM mix so as to provide the respective minerals at graded levels in the diet (100, 75, 50, 40, and 30% of the control diet). Similarly, in experiment II, a total of 1350 day-old male broiler chicks were divided at random into six groups with 9 replicates of 25 chicks each and fed the maize-soybean meal-based control diet having ITM at levels similar to those of experiment I or the test diets, where the ITM was replaced with OTM so as to provide the minerals at 100, 80, 60, 40, and 20% of the ITM-based control diet. Each diet was fed ad libitum from 0 to 42 days of age. The body weight gain, feed intake, and feed efficiency were not affected by supplementing OTM at 30 and 20% in experiments I and II, respectively. Slaughter variables, activities of glutathione peroxidase and super oxide dismutase, and lipid peroxidation and ferric reducing activity in serum were not affected by supplementing OTM at the lowest level of 20% in the diet. Similarly, bone-breaking strength, ash, and Mn contents were not affected by supplementing OTM at 20% of the mineral concentration in control diet containing ITM. Deposition of Ca, P, Cu, and Fe in tibia ash increased with increased concentration of OTM in the diet. However, Zn content in tibia ash reduced with reduction in OTM level in the diet. Based on the results, it is concluded that trace mineral supplementation in organic form even at 20% of the concentration recommended for ITM may be sufficient in maize-soybean meal-based diet to support the optimum growth, bone ash, bone strength, and serum antioxidant status in commercial broilers.