Jacobs D E, Fisher M A, Hutchinson M J, Bartram D J, Veys P
Department of Pathology and Infectious Diseases, Royal Veterinary College (University of London), Hatfield, Hertfordshire.
Vet Rec. 1995 Apr 15;136(15):386-9. doi: 10.1136/vr.136.15.386.
Two groups of 16 set-stocked calves were used to evaluate a new strategy for the prevention of parasitic bronchitis and parasitic gastroenteritis. One group was left untreated while the calves in the other were treated with abamectin at 0.2 mg/kg at turnout and again six weeks later. The treatment prevented the output of nematode eggs and lungworm larvae in faeces for at least 70 days. The number of infective larvae subsequently appearing on the pasture was reduced by 90.2 per cent and the infectivity of the pasture (as monitored by tracer calves) by 96.0 to 99.8 per cent in the case of Dictyocaulus viviparus, 88.2 to 99.2 per cent for Ostertagia ostertagi and 69.3 to 98.1 per cent for Cooperia oncophora. Parasitic bronchitis occurred in the control calves and both bronchitis and gastroenteritis in the tracer calves grazing the paddock grazed by the control calves, but no disease occurred either in any of the calves treated with abamectin or in the tracer calves grazing the paddock grazed by these calves.
两组各16头舍饲犊牛被用于评估预防寄生性支气管炎和寄生性胃肠炎的新策略。一组不进行治疗，而另一组的犊牛在放牧时以0.2毫克/千克的剂量使用阿维菌素进行治疗，并在六周后再次用药。该治疗方法至少70天内阻止了粪便中线虫卵和肺线虫幼虫的排出。随后牧场上出现的感染性幼虫数量减少了90.2%，对于胎生网尾线虫，牧场的感染性（通过示踪犊牛监测）降低了96.0%至99.8%；对于奥斯特他线虫，降低了88.2%至99.2%；对于牛古柏线虫，降低了69.3%至98.1%。对照犊牛发生了寄生性支气管炎，在放牧对照犊牛所使用牧场的示踪犊牛中，支气管炎和胃肠炎均有发生，但在任何接受阿维菌素治疗的犊牛中以及在放牧这些犊牛所使用牧场的示踪犊牛中均未发生疾病。
