Abstract
To evaluate the effect of Boldenone Undecylenate (BOL) injection, on growth performance, some blood parameters and concentration of residual testosterone in raw, fried, grilled and boiled meat, twelve beef bulls were divided randomly into three equal groups (4 animals each group). Group 1 (G1) was injected intramuscularly (im) with saline as control group. G2 and G3 were injected im with BOL1 ml/45 kg and 1 ml/90 kg BW, respectively. BOL was given three times with three weeks interval. Blood samples were collected at day 0, 60th and 120th for assays of total protein, cholesterol, testosterone and estradiol concentrations Final body weight, total body gain, daily gain and feed efficiency were significantly (P<0.05) increased in G2 in compression with G1 and G3. In addition, total protein, cholesterol, testosterone and estradiol concentrations were significantly (P<0.05) higher in G2 than G1 and G3 at the 60th and 120th days of experiment. The average pre slaughter body weight, dressing percentage, and testes, eye muscle and bone weights as well as protein concentration in meat were significant higher in G2 than those of G1 and G3. The concentrations of testosterone in the raw and cocked (using different cooking methods) were higher in G2 and G3 than those of G1, but the residual concentrations were safe for the human consumers. Boldenone undecylenate injection (1 ml/45kg or 1 ml/90 kg) in fattening bull improved growth performance without adverse effect on the residual concentrations of testosterone in meat.