Van Wyk, Jan Aucamp; Stenson, M.O.; Van der Merwe, J.S.; Vorster, R.J.; Viljoen, P.G.; Verwoerd, Daniel Wynand(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute, 1999)
Surveys to determine the prevalence and degree of resistance of Haemonchus spp. of sheep and
goats to the available anthelmintics in South Africa indicate that small ruminant production is entering
a crisis situation ...
