Guichon P T, Jim G K, Booker C W, Schunicht O C, Wildman B K, Brown J R
Feedlot Health Management Services, Okotoks, AB, Canada.
J Am Vet Med Assoc. 2000 Jun 15;216(12):1965-9. doi: 10.2460/javma.2000.216.1965.
To compare growth performance, animal health characteristics, and carcass characteristics of feedlot calves treated with ivermectin topically with that of feedlot calves treated with a combination of fenbendazole orally and permethrin and fenthion topically.
Clinical trial.
14,184 British crossbred steer calves (mean weight, 286 kg [630 lb]) in 30 pens at a commercial feedlot in Nebraska.
On arrival at the feedlot, calves were randomly assigned to be treated with ivermectin topically or with a combination of fenbendazole orally and permethrin and fenthion topically (control). At the time of assignment to treatment groups, fecal samples were collected from 5% of the calves. Growth performance, carcass characteristics, and health information were recorded.
Geometric mean fecal egg counts at the time of arrival at the feedlot were not significantly different between groups. Final weight, weight gain, average daily gain, and the dry matter intake-to-gain ratio were significantly improved for calves in the ivermectin group. The percentage of carcasses classified as quality grade choice was higher for the ivermectin group than the control group; however, the percentage of carcasses classified as yield grade 1 and the dressing percentage were higher for the control group than for the ivermectin group.
Results suggest that topical administration of ivermectin to feedlot calves is relatively more cost-effective than administration of a combination of fenbendazole orally and permethrin and fenthion topically.
比较经伊维菌素局部治疗的饲养场犊牛与经芬苯达唑口服及氯菊酯和倍硫磷局部联合治疗的饲养场犊牛的生长性能、动物健康特征和胴体特征。
临床试验。
内布拉斯加州一家商业饲养场30个围栏中的14184头英国杂交阉牛犊牛（平均体重286千克[630磅]）。
犊牛抵达饲养场时，随机分配接受伊维菌素局部治疗或芬苯达唑口服及氯菊酯和倍硫磷局部联合治疗（对照组）。在分配到治疗组时，从5%的犊牛中采集粪便样本。记录生长性能、胴体特征和健康信息。
两组犊牛抵达饲养场时粪便虫卵计数的几何平均数无显著差异。伊维菌素组犊牛的最终体重、体重增加、平均日增重和干物质摄入增重比均显著提高。伊维菌素组胴体被评为优质级的百分比高于对照组；然而，对照组胴体被评为1级产量级的百分比和屠宰率高于伊维菌素组。
结果表明，对饲养场犊牛局部应用伊维菌素比口服芬苯达唑及局部应用氯菊酯和倍硫磷联合治疗相对更具成本效益。
