EFFECT OF COBALAMIN ON GROWTH PERFORMANCE, CARCASS TRAITS ANDSOME RELATED PHYSIOLOGICAL PARAMETERS IN GROWING RABBITS

The experiment was carried out in Intensive Rabbit Production Unit; belonging to the Agriculture Studies and Consultations Center; Faculty of Agriculture, Ain Shams University; on 60 weaned male New Zealand White (NZW) rabbits. four weeks of age, in order to determine the effect of Cobalamin (vitamin B12J on growth performance, carcass characteristics and some related physiological parameters. Rabbits were randomly distributed into two comparable groups of 30 kids. The animals housed in cages provided with continues feeder and automatic waterers facilities during the experimental period, which lasted for 8 weeks. The basal diet (commercial pellets) was fed to the control animals (group I) without Cobalamin supplementation, while the treated animals (group II) was orally supplemented daily with 2 pg Cobalamin /kg body weight. Growth was assessed by measuring body weight gain (BWG). At 12 weeks of age ten animals from each group were slaughtered for carcass evaluation. Results showed that kids in group (II) were significantly (P 0.005) heavier in body weight than those not received Cobalamin. Average daily gains during the study were 21 .14 ± 1.16 and 25.40 ± 1.16 gm for groups I and II, respectively. Supplementation with Cobalamin improved (P 0.05) the dressing percentage by 3.58%; middle part by 10.09 % as compared with the control group. However, the hind part increased insignificantly by 4.94 %. The percentage of bone less meat increased (P 0.01) in front leg and middle part for Cobalamin treated rabbit. Meat protein increased (P 0.05) in Cobalamin supplemented rabbit; however ether extract decreased (P 0.01). Rabbit received Cobalamin showed. higher (P 0.05) values of RBCs, Hb, PCV, plasma glucose, globulin and lower (P 0.05) plasma cholesterol as compared with control group.