The effect of ruminoreticulum bypass in yarded lambs on the ef®cacy of oxfendazole against resistant Trichostrongylus spp. helminths
نویسندگان
چکیده
An observational study was performed to investigate the effects of yarding and ruminoreticulum bypass on the ef®cacy of oxfendazole against resistant Trichostrongylus spp. helminths. Ruminoreticulum bypass was observed in 9-month old Perendale lambs using video-taped ̄uoroscopy and the ef®cacy of oxfendazole was estimated using the faecal egg count reduction test. Yarding and withholding feed for 24 h before drenching with oxfendazole signi®cantly enhanced the faecal egg count reduction for resistant Trichostrongylus spp. parasites (p < 0.05), but ruminoreticulum bypass of the drench in the yarded animals had no negative effect on anthelmintic ef®cacy (p > 0.05). The effect of ruminoreticulum bypass on the ef®cacy of oxfendazole may depend on the resistant parasite species present. The positive effects of yarding sheep for 24 h before drenching, on the ef®cacy of oxfendazole against resistant Trichostrongylus spp., probably outweigh any negative effects of ruminoreticulum bypass. However further studies are required, with different resistant parasite genera present, before ®rm recommendations can be made. # 2000 Elsevier Science B.V. All rights reserved.
منابع مشابه
Ruminoreticulum bypass in goats and its possible effect on the ef®cacy of oxfendazole against resistant gastrointestinal parasites
Ruminoreticulum bypass was observed in 9±12-month old Angora goats using video-taped ̄uoroscopy. For experimental purposes, ruminoreticulum bypass was stimulated by yarding animals for 19±24 h before drenching, or by yarding and oral premedication with 2% cobalt sulphate solution. When bypass occurred, 50±100% of the drench was deposited in the abomasum. Ruminoreticulum bypass had no apparent e...
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