Comparison of the effects of LONGRANGETM and DECTOMAXTM on grazing performance and parasite burden in stocker cattle

摘要

The efficacy of a single injection of an extended-release formulation of eprinomectin (LONGRANGETM) was evaluated against a single injection of doramectin (DECTOMAXTM) in 520, castrate male, crossbred feeder steers grazing native grass in the Flint Hills region of Kansas. Animals were randomly assigned to one of two treatment groups: extended release eprion-mectin (LONGRANGE.TM 50mg mL) or injectable doramectin (DECTOMAX.TM 10mg/mL), and were then allocated to one of nine different grazing units. Animals were weighed individually and a rectal fecal samples were collected from a randomly selected 25% of the study animals on study day 0 and at the end of the study (day 76). Initial body weight was not significantly different between treatments (P = 0.89): eprinomectin, 622 lbs and doramectin, 623 lbs. The final body weight of cattle recieve-ing eprinomectin was nummerically greater than doramectin at 819 and 796 lbs, respectively (P = 0.11). Cattle recieveing eprinomectin had a statistically signifincant higher average daily gain (2.59 lbs / day) than those recieveing doramectin (2.27 lbs / day) prior to pasture turnout (P = 0.02). No statistical differences in fecal egg counts were noted between treatment groups at treatment allocation (day 0, P =0.71), nor at the conclusion of the study (day 76. P = 0.87). The extended-release eprinomectin (LONGRANGETM) administered prior to pasture turnout resulted in increased average daily gain as compared to those cattle recieving doramectin (DECTOMAXTM) inthis study.