Evaluation of the efficacy of trace element supplementation of an anthelmintic.

The efficacy of the selenium and cobalt contents of a trace element supplemented anthelmintic was evaluated in a series of trials with lambs in Scotland and Northern Ireland. The product was compared with other methods of supplementation and was found to be an adequate source of selenium when administered at monthly intervals. Its cobalt content was shown to be of some nutritional benefit on four of five sites but not as effective as the monthly 250 mg oral cobalt dose, vitamin B12 injection or intraruminal soluble glass bolus treatments also used. No growth responses were obtained and unsupplemented animals generally had an adequate cobalt and selenium status. No toxicity problems were encountered from either element.