Lasalocid for improved weight gains and control of Coccidia in lambs.

Lasalocid at 25 mg/kg of feed was highly effective in reducing numbers of oocysts in feces of naturally infected ewes and lambs. Treated ewes were fed lasalocid-medicated feed before and after parturition, and the 17 lambs from these ewes also were fed medicated feed gained 5.26 kg more (P less than 0.05) than did the 17 nontreated lambs from nontreated ewes. Naturally infected lambs maintained in semiconfinement acquired coccidia infections between 23 and 64 (mean of 38) days after birth. A coccidiostat given before and during the time coccidia-naive lambs were first exposed to coccidia was necessary to achieve the greatest production response to treatment. When naturally infected feeder lambs (30.9 kg) maintained in semiconfinement were fed lasalocid-medicated feed at 25 mg/kg of feed or unmedicated feed for 91 days, no significant difference (P greater than 0.05) in rate or efficiency of gain was detected, even though lasalocid was highly effective against coccidia.