A comparison of production responses in lambs drenched with moxidectin or ivermectin

Abstract

Abstract The weight gains of 164 3–4‐month‐old Romney ewe lambs following treatment with either moxidectin (Cydectin®) or ivermectin (Ivomec®) oral drenches in a cross‐over design experiment were compared. In the experiment, one group of 79 lambs was drenched initially with moxidectin and 29 days later with ivermectin. A second group, comprising 85 lambs, had similar treatments but given in the reverse order. On both treatment occasions the dose for each group was calculated to provide the recommended minimum dose of 0.2 mg/kg for the appropriate anthelmintic to the heaviest animal in that group and all animals were given the same dose. The two groups were run together as a single mob ensuring similar feeding levels and parasite challenge. Group 1 lambs achieved an average daily bodyweight gain (ADG) of 161.7 g/day after moxidectin treatment and 135.4 g/day after ivermectin treatment. Group 2 lambs achieved an ADG of 100.4 g/day after ivermectin treatment and 222.6 g/day after moxidectin treatment. These ...