عنوان مقاله [English]
To evaluate the effects of cobalt source and level on blood parameters and performance, 30 indigenous breed male goat kids of 3-5 months age, with an average BW of 17.8±2.5 kg were assigned to five treatments in a completely randomized design: 1) Basal diet containing 0.076 mg Co/kg DM (Control); 2) basal diet + 0.25 mg Co/kg DM as Co-sulphate (sulphate 0.25); 3) basal diet + 0.5 mg Co/kg DM as Co-sulphate (sulphate 0.5); 4) basal diet + 0.25 mg Co/kg DM as Co-glucoheptonate (glucoheptonate 0.25); 5) basal diet + 0.5 mg Co/kg DM as Co-glucoheptonate (glucoheptonate 0.5). Goat kids receiving 0.5 ppm of Co from glucoheptonate had higher DMI compared to control. Final body weight and average daily gain was affected by the level of Co supplement and was significantly higher in 0.5 ppm receiving treatments. However, feed conversion ration did not differ significantly between treatments and differences were only numerical. Cobalt supplements affected serum glucose and vitamin B12 and the highest difference was for glucoheptonate 0.5 treatment. Although the glucoheptonate 0.5 treatment differed significantly with control, there were no significant differences with other treatments. Cobalt treatments had no significant effect on serum biochemical and hematological parameters. In general, the level of cobalt had a significant effect on goat performance given that higher levels of cobalt caused greater dry matter intake and average daily gain. The results of the present study showed that the requirement level of 0.07 mg/d for goats is marginally adequate and the organic Co source performed better in the rumen for vitamin B12 synthesis and consequently glucoseand goat performance was better at 0.5 as compared to 0.25mg Co/Kg DM.