Effect of monensin, laidomycin, and lasalocid on coccidiosis control weight gain and feed intake in young calves
Thomas, E.E.; Parrott, J.C.; Speer, C.A.; Lechtenberg, K.F.
Journal of Dairy Science 81(4): 1200, April
Eighty Holstein male calves were purchased at 1 to 2 d of age and fed non-medicated milk replacer (weaned at 6 wks) and starter feed until 8 wks of age (Trial 1) or 12 wks. Feeding of treatment diets was then initiated that contained monensin (24.4 and 36.6), laidlomycin (12.2), and lasalocid (36.6) ppm DMB. Three days later calves were inoculated orally with approximately 500,000 oocysts (82% E. bovis, 10% E. zuernii, 9% other E. species). Calves remained on treatment 4 wks post challenge, during which daily gain, daily feed intake, and oocyst counts were determined. Weight gain was increased by monensin 36.6 ppm (P<.05) compared to controls. Although not significant (P>.05), total oocyst counts tended to be lowest for monensin 36.6 ppm and feed intake was highest for the monensin treatments. Calculated feed/gain was improved most with the monensin 36.6 ppm treatment.