Browsing by Author "RAMA RAO, S.V."
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ThesisItem Open Access EFFECT OF GRADED LEVELS OF ORGANIC AND INORGANIC CHROMIUM ON THE PERFORMANCE AND IMMUNE COMPETENCE IN BROILERS(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2010-08) SRINIVASA RAO, G; RAVINDER REDDY, V(MAJOR); BINDU MADHURI, S; RAMA RAO, S.V.ABSTRACT : The present experiment was conducted to study the effects of graded levels of organic (0, 300, 600, 900, 1200 and 1500 μg/kg) and inorganic chromium (0, 300, 600, 900, 1200 and 1500 μg/kg) in a 5 x 2 factorial manner on the performance, slaughter variables and immune response of broilers. A total of 330 day-old commercial broiler males were divided into 11 treatments with 6 replications (5 broilers in each) and fed test diets adlibitum from one to six weeks of age (pre-starter 0-14 d, starter 15-28 d and finisher 29-42 d). Body weight gain of broilers significantly (P<0.05) higher in groups fed diets with organic Cr during pre-starter and finisher phases than control and inorganic Cr group. During starter phase, body weight gain was significantly (P<0.05) higher for inorganic Cr compared to the control and organic Cr. Body weight gain was not influenced by source of Cr during overall period. Supplementation of Cr at 600 μg/kg to the diet had significantly (P<0.05) higher body weight gains during pre-starter, starter, finisher and overall period. Whereas, during finisher and overall period 1500 μg/kg Cr was superior to other levels. The interaction effect between source and level of Cr was significantly (P<0.05) improved the body weight gains than the control. Feed intake increased significantly (P<0.05) in proportion to growth rate by organic Cr during pre-starter, starter, finisher and overall period. At 600 μg/kg Cr the feed intake increased significantly during pre-starter, starter, finisher and overall period. Feed conversion ratio was not significantly influenced by source of Cr during pre-starter and finisher phases. Supplementation of inorganic Cr significantly (P<0.05) improved the FCR compared to control or organic Cr during starter and overall period. During finisher and overall period supplementation of Cr at 1500 μg/kg significantly improved the feed efficiency. The Cr level did not influence the FCR during starter phase. The FCR was poor in Cr supplemented diets during pre-starter phase. The dressing yields, breast yield and weights of liver, heart and gizzard were not influenced by source and level of Cr. Supplementation of inorganic Cr significantly (P<0.05) reduced abdominal fat percentage. Interaction between source and level of Cr did not influence the slaughter variables except dressing yield. Shrinkage loss was not influenced by either source, level of Cr or their interaction. The source of Cr did not influence the relative weight of lymphoid organs. Supplementation of Cr at 300 μg/kg significantly (P<0.05) increased the thymus weight compared to the control and other levels of Cr. Interaction did not affect the lymphoid organ weights. The humoral immune response to NDV at 28th and 42nd day of age was not influenced by source of Cr. Dietary Cr at 1500 μg/kg significantly (P<0.05) increased antibody titers against NDV at 28th and 42nd day of age. Cell mediated immunity in terms of CBH response was not affected by addition of Cr to the diet. The source of Cr did not influence the lipid peroxidation in broilers. Inclusion of Cr reduced MDA levels compared to the control. Interaction effect of Cr source and level was significantly (P<0.05) decreased the lipid peroxidation. Supplementation of Cr decreased the GSH-Px activity. Heterophil to Lymphocyte (H/L) ratios were significantly (P<0.05) decreased by the organic and inorganic Cr inclusion and all levels of inclusion than the control. The diet supplemented with Cr source had significantly (P<0.05) increased triglyceride concentration than the control diet. The effect of different levels of Cr had significantly (P<0.05) higher triglyceride concentration than the control diet. Glucose and cholesterol concentration in serum were significantly (P<0.05) decreased on source and level of Cr diets than the control. Based on the data of the present experiment it can be concluded that supplementation of organic or inorganic Cr at 600 μg/kg diet for improved growth performances, antioxidant status and reduced the total cholesterol and glucose concentration in serum of broilers.ThesisItem Open Access EFFECT OF MICROBIAL PROTEASES AND CRITICAL AMINO ACIDS MODULATION ON THE DIETARY REQUIREMENT OF PROTEIN IN COMMERCIAL BROILERS(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2011-11) SRILATHA, T; RAVINDER REDDY, V(MAJOR); CHINNI PREETHAM, V; RAMA RAO, S.V.; RAMANA REDDY, YABSTRACT: Protein is the second largest nutrient which determines the feed cost of poultry production. By optimizing the nutrient allowances of dietary crude protein (CP) through supplementation of the most critical amino acids and supplementation of microbial proteases in at sub-optimal concentrations of dietary CP we can reduce the cost of feeding besides minimizing environmental pollution from broiler farming. To fulfill these objectives, a total of 5 experiments were conducted including an in vitro protein digestibility of compounded broiler feeds. All experiments were conducted with commercial broilers reared in battery brooders from 1 to 42 d of age. The primary objective of the Experiment 1 was to find out the optimum concentrations of CP in broiler diet during different phases i.e., pre starter (0-10d), starter (11-21d) and finisher (22-42d). Two levels of CP during pre starter (23 and 21%) and starter (21 and 19%) phases and three levels in finisher phase (19.5, 18 and 16.5%) were tested. The experimental design includes 2 x 2 x 3 levels of CP during pre-starter, starter and finisher phases respectively. The concentrations of lysine, threonine and tryptophan were maintained at the same ratio considering the ideal amino acid ratio (Baker 1996), except methionine which was maintained at 45, 45 and 38% of lysine during pre starter, starter and finisher phases, respectively. The results showed that the broilers fed low levels of CP ( 21 and 19 %) showed significantly higher body weight gain (BWG) and feed intake (FI), and better feed efficiency as compared to the diets with high levels of CP during pre-starter and starter phases (23 and 21%, respectively). The birds fed on higher (19.5%) level of protein in the finisher phase showed higher body weight gain and best feed conversion ratio (FCR) compared to the lower levels (16.5 and 18%). Carcass characters were not influenced by the variation in dietary CP level tested except the abdominal fat weight which was significantly higher in broiler fed low CP diet either all through 1 to 42 d of age or the lower levels of CP during starter and finisher phases compared to those fed higher levels of CP during all three phases. The results showed that the broilers fed low CP had significantly higher protein digestibility compared to the high CP fed birds. Experiment 2 was conducted to test the feasibility of further reducing the dietary CP below the optimum levels determined in Experiment 1, by modulating the levels of critical amino acids without affecting the broiler performance. The control diet (CD) formulated to contain optimum requirements of CP 21, 19 and 19.5% during pre-starter, starter and finisher phases, respectively. The optimum CP levels were further reduced by 1.5% in the basal diet (BD) during all the 3 phases (19.5, 17.5 and 18%, respectively), Four different concentrations of critical amino acids (lysine-Lys, methionine-Met, threonine-Thr and tryptophan-Try) were added to the diet containing sub-optimal levels of CP by maintaining constant ratio in relation to the dietary Lys level as detailed in Experiment 1. In addition to these levels, a diet with CP recommended by NRC was maintained. A diet with CP levels being followed by the broiler industry was maintained (23, 21 and 19.5% in PS, S and F diets respectively) as the reference diet (RD). The performance of broilers fed the CD (21, 19 and 19.5% CP, in PS, S and F, respectively) was similar to those fed the RD or NRC diet. Reduction of CP content by 1.5% (19.5 and 17.5%) than the CD decreased the performance as compared to those fed on CD during pre-starter and starter phases. But the reduced CP during finisher phase (18%) supported the BWG, which was statistically similar to those fed the CD. Increasing levels of critical amino acids (Lys, Met, Thr and Try) in the BD resulted in progressive and significant reduction in the performance. Broilers fed diet with sub-optimal CP had significantly higher abdominal fat compared to those fed with CD, RD and NRC diet. Supplementation of critical amino acids to the sub-optimal protein diet did not influence the abdominal fat deposition. Effect of supplementing three variants of protease (acid, neutral and alkaline) on in vitro digestibility of CP was tested with various graded concentrations of the enzyme in the Experiment 3.Results showed that the individual proteases at 66.66 u/g soybean meal / meat and bone meal had shown maximum protein digestibility. In the maize-soy bean based diets supplemented with alkaline protease had higher protein digestibility. Highest protein digestibility was observed in groups containing 2:1:1 (33.33:16.66:16.66 u/g diet) and 1:1:2 (16.66:16.66:33.33 u/g diet), acidic, neutral and alkaline proteases, respectively. In maize-soya – meat and bone meal based diet, supplementation with acidic (66.98%), alkaline (64.66%) and neutral (60.20%) proteases significantly improved the protein digestibility compared to the control group. Highest protein digestibility was observed in groups containing 2:1:1 (33.33:16.66:16.66 u/g diet) and 1:1:1 (22.22:22.22:22.22 u/g diet), acid, neutral and alkaline proteases, respectively. Based on the in vitro protein digestibility coefficients, 3 effective levels of proteases (2000, 4000 and 6000u/kg) were selected. These effective combinations and concentrations of proteases were supplemented to low CP maize-soybean based diet (1:1:2 and 2:1:1) in Experiment 4 and low CP maize-soybean-meat cum bone meal based diet in Experiment 5 (1:1:1 and 2:1:1) to find out the possibility of reducing the dietary CP (1.5%) below the optimum levels. The results of Experiment 4 showed that the broilers fed high protein diet (CD) had significantly higher BWG and FI as compared to those fed sub optimal CP diets (BD). The feed efficiency was not affected due to the treatments employed. Proteases (acid, neutral and alkaline) supplementation to the BD had no effect on the performance. The relative weight of abdominal fat was significantly (P<0.05) higher in low CP fed birds compared to those fed the CD, but proteases supplementation to BD did not influence the abdominal fat content. The results of Experiment 5 showed that the broilers fed CD had significantly higher BWG compared to those fed BD. Supplementation of proteases to the BD significantly improved the BWG and feed efficiency during 1-21 and 1-28 d of age, but not during the latter phase (35 and 42 d of age) of growth. The broilers fed on CD had significantly higher ready to cook and breast yields compared to those fed the BD or BD the protease supplementation. The relative weight of abdominal fat was significantly reduced in broilers fed with 1:1:1 (acidic, neutral and alkaline proteases) at 4000 u protease / kg diet as compared to BD. In conclusion, the overall picture of study suggested that the dietary CP levels could be reduced below NRC recommended levels by 2-4% in pre-starter, starter diets and to an extent of 0.5% in finisher diet provided that levels of critical amino acids are closely looked after. Addition of proteases to low protein diets did not influence the growth performance of broilers fed maize-soybean meal based diet but it had a significant positive effect on in young chicken fed on maize-soybean meal based-meat and bone meal based diets.