الملخص الإنجليزي
Seventy three, ten weeks old newly weaned Omani goats were randomlyallocated to two groups, namely control (n=38) and treated (n= 35). Kids in both groups were fed Rhodegrass hay ad libitum that contained less than 0.1mg/kg Dry matter cobalt and 150 grams per day of a commercially preparedruminant concentrate that contained approximately 0.12 mg/kg DM cobalt.
This diet provided the minimum daily requirement of cobalt as specified forsheep. The treated goats were supplemented with monthly subcutaneousinjections of 2000 ug of hydroxycobalamin. In order to prevent parasiticinfections, all animals were treated for ectoparasites by dipping them inGamatox solution and subcutaneously injecting them every two monthsduring the experiment with 1% Ivermectin. All goats were weighed and bloodsamples collected monthly for haematolgical, clinical, biochemical and serumvitamin B12 analysis for a ten-month experimental period.
The control animals exhibited significantly (p<0.05) lower weight gains, palemucus membranes and had dry scruffy hair coats. In addition, there was adecline in erythrocyte counts, mean haemoglobin level, pack cell volume,mean corpuscular volume, mean corpuscular haemoglobin and meancorpuscular haemoglobin concentration. On day 0 of the experiment, thecontrol and treated groups had average serum vitamin B12 levels of 521.9and 519.7 pg/ml, respectively (p>0.05) in all three breeds. Over the tenmonth period the serum vitamin B12 values of the control animals dropped to142 pg/ml (p<0.05). In contrast, the treated group, maintained levels thatwere not significantly different (p>0.05) from their values on day 0.Control animals also exhibited significantly (p<0.05) lower levels of totalserum proteins and elevated levels of serum alkaline phosphatase andaspartate aminotransferase compared to treated goats. Twenty two malegoats slaughtered at the end of the experiment exhibited gross and histopathological evidence of hepatic lipidosis. Conclusive evidence has therefore been presented that contrary to the popular belief that goats aremore resistant to cobalt deficiency than sheep that this does not apply to Omani goats.
