A cost-benefit analysis of pre- and post-lambing anthelmintic treatments to twin-bearing ewes on commercial farms in the southern North Island of New Zealand

Abstract

A positive financial return resulting from the anthelmintic treatment of adult ewes around lambing is neither consistent nor predictable, and is often not achieved. Given that the additional costs of accelerating the development of anthelmintic resistance were not included in these calculations, farmers need to consider carefully the merits of administering anthelmintics to ewes around lambing.