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ThesisItem Open Access EVALUATION OF APPARENT AND TRUE METABOLIZABLE ENERGY OF CERTAIN FEEDSTUFFS IN DUCKS AND CHICKEN(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 1996-12) CHINNI, VELUPULA; QUDRATULLAH, S(MAJOR); RAVINDRA REDDY, V; JANARDHANA REDDY, TThesisItem Open Access STUDIES ON THE NUTRITIVE VALUE AND UTILISATION OF PRAWN WASTE IN QUAIL DIETS(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 1996-11) GURAVA REDDY, P; SATYANARAYANA REDDY, P.V.V(MAJOR); SUDHAKARA REDDY, P; RAMAPRASAD, JThesisItem Open Access ENVIRONMENT FRIENDLY DISPOSAL OF POULTRY DROPPINGS BY ANAEROBIC FERMENTATION AND RECYCLING AS FEED INGREDIENT(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 1996-11) MADHU KUMAR, K; RAJASHEKER REDDY, A(MAJOR); ESHWARAIAH; SESHAGIRI RAO, AThesisItem 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.ThesisItem Open Access EFFECT OF ENCAPSULATION OF FEED ENZYMES ON PERFORMANCE OF BROILERS(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2011-09) SRINATH, K; RAVINDER REDDY, V(MAJOR); CHINNI PREETAM, V; REDDY, M.R; KONDAL REDDY, KABSTRACT: The effect of feeding encapsulated enzymes in corn soya pelleted diets on the performance of broilers was studied. The enzyme supplementations like phytase, xylanase and cocktail (cellulase, xylanase, pectinase, mannanase, glucanase, amylase, and protease) available in market were procured, encapsulatecUcoated with sodium alginate and included to corn-soya diet at recommended doses. The feed was then pelleted at 80°C in a steam conditioner of 0.6 MPa for 10 s. The enzyme combinations were offered to nine groups, each consist of 30 male broiler chicks (Vencobb) from day old to 6 weeks of age. The chicks were raised on wire floor electrically heated battery brooders; feed and water were provided ad libitum. The performance of broilers in terms of body weight gain, feed consumption, feed efficiency, livability, dressing yield, relative length of small intestine in centimeters, proventriculus weight, abdominal fat weight and relative weights of giblets. Lymphoid organs such as thymus, bursa and spleen weights, which were expressed as percentage of live body weight, were also In the present study broilers showed significantly (P(0.05) increased body weight gains on supplementation of uncda nd coated ~eto corsn-soya diet during finisher phase (4-6 weeks) and overall period (0-6 weeks) than the control diet. Coated enzyme supplemented diets yielded significantly (P<0.05) increased body weight gains over their respective uncoated supplemented diets during starter phase (0- 3 weeks) , finisher phase(4-6 weeks) and overall period (0-6 weeks) except in coated phytase supplemented diet which only resulted in significantly (P<0.05) increased body weight gain over uncoated phytase supplen~ented diet (T2) during finisher phase (4-6 weeks). Feed intake of broilers on supplementation of uncoated and coated enzymes to corn- soya diet showed no significant difference during 1-6 week of age when compared to control diet. Supplementation of uncoated and coated enzymes in pelletized corn soya diet yielded significantly (Pc0.05) efficient feed to weight gain values over the control diet during finisher phase (4-6 weeks) and overall period (0-6 weeks). Coated enzyme supplemented diets yielded significantly (Pc0.05) efficient feed to weight gain values over their respective uncoated enzyme supplemented diets during finisher phase (4-6 weeks) and overall period (0-6 weeks). Supplementation of uncoated or coated enzyme preparations to corn soya diet did not influence the livability, dressing percent, abdominal fat weight, proventriculus weight, visceral organ weights (liver, lleart, and gizzard), intestinal lengths (cm) and weights of immune organs (thymus, bursa and spleen) in broilers. In vitro feed analysis of release of total sugars (mg/gm diet) from uncoated and coated enzymes supplemented pelletized corn soya diets yielded higher values of total sugars (mglgm feed) in enzyme treated diets than control diet in both starter and finisher feed. Coated enzyme supplemented diets yielded higher values of total sugars (mg/grn feed) over their respective uncoated enzyme supplemented diets in both starter and finisher feed. In viho fced analysis of release of inorganic phosphorous (g/kg diet) from phytase enzyme supplemented corn-soya pelleted diets yielded higher values of inorganic phosphorous release in ooated phytase supplemented diets than uncoated phytase supplemented diets. However, both uncoated and coated phytase enzyme supplemented diets yielded higher inorganic phosphorous values than control diet. The returns over feed cost of Rs 48.31 to 50.94 per bird on uncoated enzyme supplemented diets as against Rs 44.05 on control diet. The return over feed cost was Rs 55.32 to 51.58 on coated enzymes supplemented diets. It is concluded that supplementation of coated enzymes offered better protection against pelletization temperature and gastric conditions in the gut there by retaining maximum efficacy over uncoated enzymes. Hence, coating of enzymes is suggestedThesisItem Open Access RELATIVE EFFICIENCY OF ORGANIC ACIDS (in vitro and in vivo) ON THE EXCLUSION OF ANTIBIOTIC (Virginiamycin) FROM DIETS AND ENHANCEMENT OF CALCIUM AND PHOSPHOROUS IN BROILERS(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2011-08) VIJAYA LAKSHMI, K; Raja Sekhar Reddy, A(MAJOR); Ravinder Reddy, V; Shyam Sundar, G; Naga Lakshmi, D; Reddy, Y.NABSTRACT : Antibiotics are used in poultry feeds for antimicrobial effect, and also for growth promotion, but are now banned because of drug resistance and residual effects through egg and meat consumption. As feed acidifiers, organic acids (C1-C7) are associated with antimicrobial activity and growth promotion, and therefore considered as valuable replacers for antibiotics. However, the studies conducted so far on organic acids projected variable results, primarily due to pKa values and molecular weights that determine the antimicrobial and growth promoting effects. In order to examine the expression of organic acids, a series of trials in vitro and in vivo were under taken with closely (Propionic acid -PA and Butyric acid-BA) and remotely related (Lactic acid -LA and Citric acid-CA) acids to decipher information on their utility in broiler chicken. PA and BA with relatively high pKa and low molecular weight, were expected to possess higher antimicrobial effect and hence, their inclusion levels were kept low (0.1% - 0.3%) in diets, and conversely for LA and CA (1-3%). In vitro experiments exhibited growth inhibition of E.coli (serotype O: 109 at 106CFU/ml) with all levels of PA and BA (0.1, 0.2 or 0.3%) and, LA and CA (1, 2 or 3%) inclusion in diets compared to the control. The antimicrobial effect was more pronounced at pH 4 within 5 h, which continued up to 24 h, and the vice versa at pH 7.4, indicating a complimentary effect between the organic acids and low pH in reducing the E.coli count. Oral administration of E.coli culture into the crop at 21d of age reduced body weight, FCR and livability of broilers at 42 d, which was effectively corrected by organic acids. These organic acids significantly reduced the bacterial load in duodenal digesta by 3.6 -7.7% compared to antibiotic and control diets, the maximum decline was observed with PA. The in vivo trials with PA or BA inclusion in diets significantly (P<0.05) enhanced broiler body weights (8-10%), FCR, tibia weight, tibia length, breast muscle, intestinal growth, immune response, lymphoid organ weights, and reduced abdominal fat (7.5%) compared to AB and control diet. PA or BA at 0.2% level was either more effective or equivalent to 0.3% level and hence, the former can be used in broiler diets. Organic acids stimulated the growth of small intestine, increased villi length, crypt width and improved goblet cell activity (duodenum), the maximum being with BA, which enhanced nutrient absorption and growth over antibiotic and control diets. Similarly, LA or CA at 2% level improved body weight (9.6-10.9%) and FCR (7.75 - 8.9%) compared to AB and control diets. LA produced higher meat yield (3.1%), breast meat (9.7%) and small intestine weight (45%) compared to control, and decreased abdominal fat. LA or CA in diets maintained significantly low pH in the crop (4.45), proventriculus (3.15) and gizzard (2.38) than the AB diet implying better absorption of nutrients from the gut, due to acidification. The histological studies of duodenum revealed a moderate mono nuclear cell infiltration in duodenal villi and intense activity of goblet cells due to dietary acidification. Further, the feeding trials involving different levels of Ca: P (0.9:0.45%; 0.7:0.35%; 0.5:0.25%) with organic acids, antibiotic and control diets revealed a complementary effect between moderately low level of Ca: P (0.7:0.35%) and organic acids measured in terms of broiler growth, FCR and leg scores, serum Ca: P concentrations and protein deposition in breast muscle that were on par with Ca: P at 0.90:0.45%. Diets with Ca: P at 0.90:0.45% level and BA produced maximum Ca retention in tibia, while PA influenced higher P retention. The extent of decline in bone measures and mineralization due to low Ca: P (0.5:0.25%) was considerably reduced by the intervention of organic acids compared to AB and control diets. The influence of organic acids was also reflected from the sustained higher serum Ca (21%) and P (32.1%), besides that in bone (Ca>4.6% and P>10.5%) compared to antibiotic and control diets. The apparent digestibility of nutrients, particularly that of protein, Ca and P was higher with acidified diets. Interestingly, the digestibility of protein, Ca and P was inversely related to the levels of Ca: P in diet. Organic acids in combination with Ca and P at 0.9:0.45% level supported more protein accretion and less fat deposition in breast muscle and liver tissue. LA and CA in diets enhanced breast meat yield (5.6%), reduced abdominal fat (18.7%) and serum cholesterol (11%) compared to the control diet. It can be concluded that individually all organic acids (Propionic, Butyric, Lactic and Citric acids) effectively sanitized the upper GI tract from E.coli, better than antibiotics, and significantly enhanced broiler performance at 35 and 42 d of age. The ideal inclusion levels of PA or BA (0.2-0.3%) were low compared to LA and CA (2-3%), primarily due to pKa values and molecular weights. Organic acids maintained suitable environment in the intestine and stimulated its morphological and histological growth, which supported higher nutrient absorption, broiler growth, breast meat with more percentage of protein, less water and low fat content and higher Ca and P retention. The antibiotics can be effectively replaced from feed with organic acids.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 THE EFFECT OF SINGLE OR COMBINED DIETARY SUPPLEMENTATION OF PROBIOTIC, PREBIOTIC AND ACIDIFIER IN COMPARISON TO ANTIBIOTIC ON PERFORMANCE AND IMMUNE STATUS OF BROILERS(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2010-06) SRINIVAS, G; QUDRATULLAH, S(MAJOR); Chinni Preetham, V; Raju, M.V.L.N; Reddy, M.RABSTRACT : The aim of the present study was to investigate the effect of dietary supplementation of a probiotic, a prebiotic and an acidifier either individually or in combination for comparing the performance and immune status of broiler chickens with antibiotic and control. For this purpose, 270 day-old commercial male broiler chicks were randomly divided into 9 treatment groups with 6 replications of 5 birds each. The experimental design consisted of; a control diet (maize-soya based) without supplementation, Antibiotic (Virginiamycin @ 500 g/ton), Probiotic (Protexin @ 500 g/ton), Acidifier (Biotronic SE @ 3 kg/ton), Prebiotic [Mannanoligosaccharide (Mos) 500 g/ton], and combinations of Probiotic + Acidifier, Probiotic + Mos, Acidifier + Mos, Probiotic + Acidifier + Mos at their respective inclusion rates. The broilers were fed with prestarter (0-14 d), starter (15-28 d) and finisher diets (29-42 d). The birds were maintained under similar management conditions in battery brooders. The feed and water were offered ad libitum. The ANOVA indicated that body weight gain of broilers was significantly (P<0.05) influenced by all dietary treatments in comparison to control and antibiotic throughout the course of the study. Acidifier alone had significantly (P<0.05) higher body weight (2059 g) gain followed by probiotic + Mos combination (2039 g) during the overall experimental period (0-42 d) compared to control and antibiotic treatments. No significant (P>0.05) difference was recorded among other groups at 42 d of age except probiotic + acidifier group (1939 g) which recorded the lowest body weight gain. During the overall experimental period, no significant (P>0.05) difference was observed on feed intake with all the treatment groups. But, feed efficiency was significantly (P<0.05) improved in all test groups during the overall experimental period compared to control. No significant (P>0.05) differences were observed among probiotic, acidifier, Mos, acidifier + Mos, probiotic + Mos, probiotic + acidifier, probiotic + Mos + acidifier and antibiotic groups which ranged from 1.62 to 1.67 compared to control diet (1.71). All dietary supplements did not have significant (P>0.05) effect on various carcass parameters studied, except for abdominal fat percentage, which was significantly (P<0.05) lower in probiotic, acidifier alone and acidifier + Mos groups at 42 d of age, while the rest of the treatment groups did not differ from control. Mortality was less and in normal range in all the dietary treatment groups. The bursa and spleen weights were significantly (P<0.05) influenced by all dietary treatments. Bursa weight was significantly (P<0.05) high in probiotic, acidifier alone and combination of probiotic + Mos + acidifier groups, similarly higher spleen weight was noticed in Mos alone and probiotic + Mos + acidifier combination in comparison to control. The humoral immune response to SRBC was increased significantly (P< 0.05) in all dietary treatments compared to control at 42 days of age. The higher titer values were recorded in Probiotic + Mos + acidifier combination group followed by acidifier alone and acidifier + Mos. Supplementation of probiotic, Mos and acidifier either alone or in combination did not have any significant (P>0.05) influence on the cell mediated immunity in terms of CBH response, but higher CBH response was noticed in all test diets compared to control. Supplementation of all dietary feed additives significantly (P<0.05) reduced the E. coli counts in the small intestine compared to control at 42 d of age. The lowest E. coli counts were recorded in probiotic, acidifier alone and probiotic + acidifier + Mos groups, whereas the other groups showed intermediate E. coli counts. Supplementation of all dietary feed additives (except probiotic + acidifier group) yielded higher returns over feed cost than the control and antibiotic groups. The highest return per bird was recorded with acidifier (Rs.4.96 / bird) followed by probiotic + Mos (Rs.4.54 / bird) groups.ThesisItem Open Access EFFECT OF EXOGENOUS ENZYMES IN HIGH FIBRE DIETS AND THEIR IMPACT ON BROILER PERFORMANCE(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2009-10) RAMBABU, D; RAVINDER REDDY, V(MAJOR); QUDRATULLAH, S; REDDY, V.R; KONDAL REDDY, KABSTRACT: Use of unconventional agro-industrial byproducts in poultry diets is restricted due to high level of crude fibre or presence of some deleterious fixtors. The principal components of dietary fibre are the structural carbohydrates which include cellulose, hemicellulose, P-glucans, arabinoxylans and pectins. Inadequate or non-availability of certain enzymes in the digestive tract of chicken reduces their nutrient utilization. A feeding trial of 6 weeks duration was conducted on 240 day-old commercial male broiler chicks procured and allotted randomly into eight treatments. Each treatment was divided into six replicates, with five chicks per replicate and raised in electrically heated battery brooders to evaluate tbe effect of exogenous enzymes on performance of broilers, fed with high and low fibre diets. Eight test diets were prepared by supplementing enzyme preparations to the reference diets i.e., TI, low fibre and T2 high fibre diets respectively. T3, T4 were low and high fibre diets supplemented with fibre degndng enzymes. Similarly, T5, T6 are low and high fibre diets supplemented with fibre degrading enzymes along with protease enzyme. TI. T6 arc low and high fibre diets supplemented with protease enzyme. Feed and water were provided ad libitum throughout the experimental period. The performance of broilers in terms of weight gain, feed intake, feed efficiency, livability, dressing percentage, visceral organs, abdominal fat, provenmculus weights and small intestinal lengths along with immune response to NDV and SRBC were studied. High fib diets (T4, T6, T6) supplemented with enzymes could record significantly l;p-.OS) improved body weight gains during finisher (5-6 week) and overall periods (0-6 weeks) with respect to the'i control diet (T2). Supplementation of protease enzyme to high fibre diet (Ts) resulted in significantly (P4.05) improved body weight gain during starter, finisher and overall periods compared to their correspoding control diet (G). The faad intake and feed-to-gain values were not affected by supplementation of exogenous enzymes either to high or low fibre diets. The livability was also unaffected on enzyme supplementation to both high and low fibre diets. The moisture content of litter values also were not affected by enzyme supplementation. Supplementation of enzymes to high and low fibre diets wuld recorded signific,antly (P4.05) improved dressing percentage, while the organ weights like of proventriculus, giblets, and abdominal fat and small intestine length were dected on enzyme supplementation. The lymphoid organ weights (thymus, spleen and bursa) expressed as percent on live body weight of bird were not affected on supplementation of enzymes either to high or low fibre diets. Humoral immune response to NDV in tenns of increased antibody production was found to be significant (Pc0.05) at 42d age on enzyme supplementation to high fibre diets. Antibody production on low fibre diets with enzyme supplementation was also not influenced. Humoral immune response to sheep RBC, on the antibody production with enzymes supplementation to either high or low fibre diets did not reveal any significant (Ps0.05) effect. However, antibody production was significantly (Pa.05) different among high or low fibre diets and enzyme supplemented diets. Economic calculation revealed that the returns over feed cost on high fibre enzyme supplemented diets were better over the unsupplemented diets and also low fibre enzyme supplemented diets. Supplementation of fibre degrading enzymes (cellulase-420 IU / kg, xylanasA025 IU / kg and pectinase-53 11J / kg) and proteolytic enzyme (protease-5000 U / kg) to high fibre diets wuld result in better weight gains of broilers.