Treatment of dairy sheep with soluble glass boluses containing copper, cobalt and selenium

Abstract

The efficacy of soluble glass boluses in grazing dairy ewes was tested. Fifty-two Karagounico ewes were divided into two groups. The ewes of the first group were given a soluble glass bolus (COSECURE), containing copper, cobalt and selenium, while the ewes of the second group were left as controls. Blood and wool samples were taken prior to treatment, and subsequently at Days 103, 224 and 338 post-treatment. Blood samples were analysed for copper, selenium and vitamin B 12 concentrations, and wool samples only for copper concentration. The glass boluses released quantities of copper, cobalt and selenium sufficient to raise and maintain plasma copper, serum vitamin B 12, blood selenium and wool copper concentrations of treated ewes for about a year. Thus glass boluses appear to provide an efficient and practical method of supplying the three elements, involve the minimum amount of collection and handling of livestock, and cause no systemic toxicity and tissue damage to the animal.