Total of 20 New Zealand White (NZW) male bunnies weaned at 5 weeks of age having average live body weight of 620±20.2 g were used in experiment study to study the effect of daily treatment of chromium picolinate (CrP) on growth performance in relation to blood parameters, carcass traits, chemical analysis of meat and economic efficiency. Rabbits were divided into 2 groups, 10 animals in each. Rabbits in the 1st group were served as control (G1) without any treatment. However, those in the 2nd group (G2) were given daily oral dose from CrP at levels of 9 μg/kg body weight from 5 up to 10 weeks of age. All growing rabbits were kept under similar feeding and managerial conditions. Blood samples were collected biweekly for Cr determination and at slaughtering for biochemical determination. Three males from each group were randomly taken and slaughtered at 13 weeks of age for carcass traits and chemical composition of meat. Results show a tendency of slight improvement in growth performance of treated than in control rabbits, but the differences were not significant. Treatment with CrP decreased (P<0.05) concentration of albumin, albumin/globulin ratio, glucose, cholesterol, urea and creatinine, and activity of AST and ALT in serum. The group differences in concentration of total protein and globulin concentration were not significant. An increase (P<0.05) in net carcass weight and total weight of edible organs was observed in treated compared with control rabbits, reflecting impact of CrP treatment on dressing percentage (61.1 and 56.6%, respectively). Absolute and relative weights of heart were almost higher in treated than in control group. Weight of skin and legs was heavier in control than in treated group (433.3 vs. 369.7 g). Crude protein content in meat was higher (P<0.05) in G2 than in G1 (70.7 vs. 63.8%). Content of EE tended to decrease from 31.5% in G1 to 24.5% in G2. Chromium concentration was higher (P<0.05) in serum of G2 than in G1 by about 15%. Rabbits in G2 had higher Cr concentration in serum at all sampling times and in meat after slaughter (1.53 vs. 1.36 ppm) in G2 than in G1. Viability rate was 100 in G1 and G2 during the experimental period.
Based on the foregoing results of the current study, treatment of growing rabbits with daily oral dose of chromium piclonate at a level of 9 µg/kg LBW improved growth performance, feed conversion, carcass quality and net revenue. The obtained high CP and Cr contents and low fat content in meat of rabbits treated with Cr may suggest the possibility of its consumption for diabetic patients and as anticholesteroleamic meat.