RAVI, A(MAJOR)RAMANA, J.VGANGA RAJU, GMUNAIAH, B2017-09-042017-09-042015-04http://krishikosh.egranth.ac.in/handle/1/5810030375THESESABSTRACT : The research work was carried out to study the impact of calf feed supplementation to growing crossbred and graded Murrah calves under the Sunandini calf rearing programme of the Animal Husbandry Department of A.P. The study was conducted for a period of 9 months i.e. winter (Dec 13 to Feb 14), summer (Mar14 to May 14) and Monsoon (June 14 to Aug 14) seasons. A total of 60 crossbred calves born of AI and belonging to farmers of 6 villages in TsundupallimandalofKadapa district were divided into two groups of 30 each.Thirty graded Murrah buffalo calves belonging to farmers of Thallamapuram village ofProdduturmandal were divided into two groups of 15 each. In both the species, the control group represented farmers feeding practices while in the treatment group calf feed was provided to the calves as per the schedule of the Animal husbandry department. The initial and monthly body weights of the calves were recorded as per theSheiffer’s formula by measuring the heart girth and length of the calves at monthly intervals. A digestion trial was conducted by the indicator method using six animals per treatment to know the plane of nutrition of the calves. The serum metabolites (Glucose, Total protein and BUN) and hormonal profile (Growth hormone, leptin, insulin, T3 and T4) was studied by collecting serum from the six animals in each group during winter, summer and monsoon seasons. The data on body weight changes was interpreted for the overall period and also season wise to account for the effect of seasons and treatments. The chemical composition of the feedstuffs used by the farmers for feeding the calves including the calf feed supplied by the AH department was found to be within the range of values reported by various authors. The chemical composition (%DM) of calf feed fed to Crossbred and graded Murrahbuffalo calves was 20.86 and 20.13 (CP); 3.14 and 3.2 (EE); 11.16 and 9.3 (CF); 14.82 and 13.98 (TA); 35.69 and 38.4 (NDF); 12.5 and 15.18 (ADF); 20.9 and 17.61 (cellulose); 6.73 and 5.19 (lignin), respectively. The digestibility of CP, CF, NFE, NDF and cellulose was not significantly different between treatments in both the crossbred and graded Murrah buffalo calves. The EE digestibility was significantly higher (p<0.01) in the treatment group of buffalo calves than in the control group. The body weight of the crossbred calves increased from the initial weight of 63.57 to 118.81 kg in the control group and than 59.44 to 137.64 kg in the treatment group. The overall body weight gain of 69.19 kg with an ADG of 256.27 g in the treatment group was significantly higher (p<0.01) than the corresponding values of 55.80 kg and 200 g in the control group. The body weight gain and ADG were significantly lower (P<0.01) during summer than during monsoon and winterseasons and the effect of seasons on body weight gain was in the order of monsoon>winter> summer. The body weight of the graded Murrah buffalo calves increased from the initial weight of 38.03 to 71.0 kg in the control group and from 49.98 to 99.82 kg in the treatment group. The overall body weight gain of 49.8 kg with and ADG of 184.5 g in the treatment group was significantly higher (p<0.01) than the corresponding values of 34.50 kg and 127.6 g in the control group. Similar to the trend observed in the crossbred calves, the effect of season on body weight gain of graded Murrah buffalo calves was in the order of monsoon>summer> winter. The overall effect of seasons on the serum biochemical profile (protein, glucose and BUN) was in the order of monsoon> winter > summer for protein and glucose and winter> summer> monsoon for BUN in both the species. The effect of treatments on the serum biochemical profile was not significant in both the species. The hormonal profile of crossbred calves revealed no significant effect of seasons on the concentration of GH and T3. The leptin concentration was significantly higher (P<0.01) during monsoon followed by winter season than during summer season in both the control group and treatment groups. The insulin concentration in the treatment group and T4 concentration in the control group was significantly higher (p<0.01) during monsoon and winter seasons than during summer season. The concentration of GH (ng/ml), Insulin (μIU/ml), T3 (ng/ml) and T4 (μg/ml) in the control and treatment group was 4 and 4.8; 9.97 and 9.04; 5.1 and 5 and 0.25 and 0.13, respectively and were not significantly different between the groups. However, the leptin concentration of 3.7 ng/ml in the control group was not significantly higher (P<0.01) than 2.98 ng/ml in the treatment group. In the graded Murrah buffalo calves, the GH concentration was significantly higher (P<0.01) during monsoon than during other two seasons in the control and treatment groups. The leptin concentration was higher (P<0.01) during monsoon and winter than during summer season in the control group. There was a trend to a higher concentration of insulin, T3 and T4 during monsoon followed by winter than during summer seasons. The GH and T4 were significantly higher (P<0.01) in the treatment group whereas the concentration of leptin, insulin and T3 were comparable between the groups and the values were 2.62 and 5.6, ng/ml (GH); 2.6 and 2.78, ng/ml (Leptin); 9.16 and 8.3, μIU/ml (insulin); 6.1 and 7.6, μg/dl (T4) and 0.15 and 0.15ng/ml (T3) in the control and treatment groups of graded Murrah calves respectively. The results of the present study indicated that supplementation of calf starter was beneficial in promoting better growth rate and in reducing calf mortality. The calf mortality during the study period was 17 and7 % (Crossbred calves) and 7 and 0 % (graded Murrah calves) in the control and treatment groups, respectivelyennullThesis