In this study, the effects of zinc bacitracin supplementation into iamb fattening diets on live weight gain, feed consumption, feed conversion, carcass traits and lamb cost were investigated and it was aimed to determine the possibilities of using zinc bacitracin in the intensive lamb fattening programmes.
A total of 24 twin-male Kıvırcık lambs which were weaned at 3 months of age were used as the material of the research. Lambs were divided into 3 groups each of which comprised 8 heads. Lambs in control, experimental 1 and experimental 2 groups were fed with forages and concentrates ad libitum, during fattening period.
Zinc bacitracin used as antibiotic was supplemented 200 mg/kg (30 ppm) concentrate into experimental 1 group's rations and 400 mg/kg (60 ppm) concentrate into experimental 2 group's rations. No antibiotic was supplemented into control group's diet.
At the end of the study which was continued 56 days, the lambs live weight of control, experimental 1 and experimental 2 groups were determined to be 30.69 kg, 30.91 kg and 30.22 kg respectively (P>0.05). The means of daily live weight gain during fattening period in the groups were found as 230.4 g, 136.8 g and 198.5 g respectively (P>0.05).
When the amounts of the concentrates and forages consumed per kg of live weight gain were investigated, feed conversion of control group which had no antibiotic in their diet, was found to be better than the experimental groups. Cold carcass weight of control, experimental 1 and experimental 2 groups were found to be 14.88 kg, 15.48 kg and 15.09 kg respectively and dressing percentage were calculated to be 46.31%, 45.37 % and 44.37% respectively.
The research concluded that supplementation of zinc bacitracin into concentrates for intensive lamb fattening programme would not positively affect fattening performance, carcass traits and fattening profitability positively.