MAHENDER, M(MAJOR)RAGHUNANDAN, TRAMESH GUPTA, BGNANA PRAKASH, MKONDAL REDDY, KSARAT CHANDRA, A2018-11-132018-11-132011-08http://krishikosh.egranth.ac.in/handle/1/5810083373THESESABSTRACT : Studies were conducted on 144 weaned rabbits reared in cage and backyard rearing systems up to 16 weeks of age to study the influence of housing system and supplementation of probiotics and enzymes or both, on the productive and reproductive performance and health. A digestibility trial was conducted to assess the effect of different rations on digestibility of nutrients. Forty eight rabbits were slaughtered at 16 weeks of age and remaining rabbits were reared until first kindling to assess their reproductive performance. The overall least-squares mean body weights at 6, 8, 10, 12, 14 and 16 weeks of age were 568.29 ± 4.82, 690.34 ± 4.77, 963.44 ± 9.45, 1141.44 ± 7.69, 1322.17 ± 6.27 and 1499.15 ± 6.30 g, respectively with cage reared rabbits recording significantly (P≤0.05) higher body weights. In rabbits reared under cage and backyard systems, the effects of breed and ration were significant at most of the ages. In general, rabbits fed rations supplemented with enzymes and probiotics or both had significantly higher body weights at all ages. The overall least-squares mean ADGs were 18.21 ± 0.55, 20.72 ± 0.72, 18.19 ± 0.44, 13.15 ± 0.57, 10.89 ± 0.49 and 12.52 ± 0.62 g during 4 to 6, 6 to 8, 8 to 10, 10 to 12, 12 to 14 and 14 to 16 weeks of age, respectively. Cage reared rabbits recorded significantly higher ADG at most of the ages studied. Ration had significant (P≤0.05) effect on the ADGs during 4 to 6, 10 to12 and 12 to 14 weeks only. Backyard reared rabbits fed T4 and T2 rations recorded significantly higher ADG 4 to 6. The overall least-squares mean voluntary dry matter intake was 115.07 ± 4.48 g . Rabbits fed rations T3 and T4 recorded significantly (P≤0.05) higher DMI in both the systems of housing. The digestibility coefficients of dry matter, organic matter, crude protein, crude fiber, ether extract and nitrogen free extract were 72.64 ± 1.26, 73.10 ± 1.23, 78.61 ± 1.03, 71.59 ± 1.32, 81.12 ± 1.34 and 70.80 ± 1.46 respectively. In both the housing systems, rabbits fed experimental diets recorded significantly higher digestibility coefficients than control group. Significantly higher pre-slaughter weight (2014.29 + 47.21), dressed weight (994.40 + 26.01), fore and mid cut weights (296.25 + 10.36 and 230.63 + 6.48) and inedible offals (374.25 + 9.73 vs. 346.71 + 9.73) were recorded by cage reared rabbits. The overall mean dressing percentage and weights of hind cut, head and feet, pelt and edible offals and the length of caecum were 49.38 + 0.19, 457.13 + 10.14, 253.46 + 5.19, 198.21 + 3.91 and 67.85 + 0.84 g and 49.06 + 0.40 cm, respectively. Influence of experimental diets was significant on hind cut weight and length of caecum in cage system while all the carcass traits except pelt weight were significantly influenced in backyard system. Meat protein and fat percentage were significantly high in cage reared rabbits. The overall mean dry matter (%), total ash (%), protein (%), fat (%) and cholesterol (mg %) contents of meat were 20.66 + 0.08, 1.29 + 0.01, 21.29 + 0.12, 4.05 + 0.02 and 0.10 + 0.00, respectively. The protein content was significantly high in the rabbits fed ration 3 and 4 while the fat content was significantly high in the rabbits fed with control ration in cage reared and backyard reared rabbits. Rabbits housed in cages had lower AFK (217.25 + 1.69 days). The overall mean litter size and weight at birth were 6.83 + 0.26 bunnies and 337.64 + 12.73 g, respectively. Mean total erythrocyte count, leucocyte count, haemoglobin content, PCV, neutrophils, lymphocytes, eosinophils, monocytes, blood glucose, serum cholesterol, SGPT, SGOT, Serum protein, Albumin, Globulin and AG ratio were 7.52  0.12 x106/mm³, 6.29  0.08 x103/mm³, 10.77  0.06 g/dl, 34.25  0.37%, 35.71  1.03%, 60.27  1.38%, 1.35  0.14%, 1.92  0.13, 123.79  2.69 mg/dl, 123.67 ± 1.66 mg/dl, 18.17 ± 0.50 IU/dl, 28.04 ± 0.73 IU/dl, 6.20 ± 0.09 g/dl, 4.08 ± 0.08 g/dl, 2.11 ± 0.06 g/dl and 1.93 ± 0.09, respectively. The overall mean SRBC titre was 6.63 ± 0.20 log2 units. In both the housing systems, significantly high SRBC titers were recorded by rabbits fed rations 3 and 4. In general, it was observed that rabbits kept in backyard were more active, aggressive and burrowing was observed. Immediately after weaning and during nights, rabbits preferred to stay together in backyard system. Rabbits in the backyard preferred to stay on the cemented kerb. The cost of feed per kg gain was reduced by Rs. 1.20, 3.63 and 2.89 in cage reared rabbits and Rs. 1.10, 5.61 and 4.4 in backyard reared rabbits fed rations supplemented with enzymes (T1), probiotic (T2) and probiotic +enzymes (T3) over control ration, respectively. The present study recorded higher growth in broiler rabbits, but the difference in the body weight of broiler rabbits under two systems of housing was not significant, suggesting that rabbit farming for meat production can profitably be taken up under backyard system, which requires less capital investment and provides valuable animal protein and remunerative income to the farmers. The inclusion of enzymes and probiotics to the diets had a positive effect on the utilization of dietary nutrients and also reduced the cost per kg weight gain, which emphasizes that the cost of feeding in rabbit farming can be reduced by utilization of forages especially legumes and by products replacing the costly feed ingredients. Thus, rabbit farming as a small enterprise can be recommended for small and marginal farmers, to improve the quality of diet and as a steady source of income.ennullThesis