Rehbein S, Knaus M, Visser M, Winter R, Yoon S, Anderson A, Cramer L
Merial GmbH, Kathrinenhof Research Center, Walchenseestr. 8-12, 83101, Rohrdorf, Germany,
Parasitol Res. 2015 Jan;114(1):47-54. doi: 10.1007/s00436-014-4158-4. Epub 2014 Oct 4.
The persistent activity of ivermectin long-acting injection (IVM LAI; IVOMEC® GOLD, Merial; 3.15% ivermectin w/v) against nematode infections of cattle was evaluated under natural challenge conditions. Seventy nematode-free Brown Swiss calves were blocked by pre-treatment bodyweight and allocated randomly to seven groups of 10 animals each: saline (control) at 1 mL/50 kg bodyweight once on day 0 or IVM LAI at 1 mL/50 kg bodyweight (630 mcg IVM/kg) on either days 0, 7, 14, 21, 28, or 35. After housing until day 35, calves were grazed as one herd on a naturally contaminated pasture for 42 days. Calves were then weighed and housed for 4 weeks before being necropsied for parasite counting. Treatment with IVM LAI prevented the establishment (>90%, p < 0.05) of Dictyocaulus viviparus (100%), Bunostomum phlebotomum (100 %), Haemonchus contortus (98.6%), Ostertagia ostertagi/lyrata (94.9%), and Oesophagostomum radiatum (93.3%) for at least 77 days; Ostertagia leptospicularis (99.1%) for 63 days; Cooperia punctata (97.7%), Trichostrongylus axei (96.5%), and Ostertagia spp. inhibited larvae 4 (93.3%) for 56 days; Cooperia oncophora/surnabada (96.9%), Trichuris discolor (93.6%), and Cooperia spp. inhibited larvae 4 (98.8%); and Nematodirus spp. inhibited larvae 4 (97.1%) for 42 days. Calves of groups treated with IVM LAI had significantly (p < 0.001) higher days 0 to 77 weight gains than the saline-treated controls (28.40-39.25 vs 2.60 kg); the weight gains of the IVM LAI-treated groups, however, were not different from one another (p > 0.3). This study demonstrated a very high efficacy of IVOMEC® GOLD in preventing the establishment of a wide range of bovine nematodes for extended periods of time which was associated with a significant benefit to productivity in terms of weight gain.
在自然感染条件下，对伊维菌素长效注射液（IVM LAI；伊维菌素长效注射液，默克动物保健公司生产；含3.15%伊维菌素，重量/体积比）对牛线虫感染的持续作用进行了评估。70头未感染线虫的瑞士褐牛犊按预处理体重进行分组，并随机分为7组，每组10头动物：在第0天以1 mL/50 kg体重的剂量注射一次生理盐水（对照组），或在第0、7、14、21、28或35天以1 mL/50 kg体重（630 mcg伊维菌素/kg）的剂量注射IVM LAI。在圈养至第35天后，将犊牛作为一个牛群在自然污染的牧场上放牧42天。然后对犊牛进行称重，并圈养4周，之后进行剖检以计数寄生虫。IVM LAI治疗可预防胎生网尾线虫（100%）、牛血矛线虫（100%）、捻转血矛线虫（98.6%）、奥斯特他线虫/叶氏奥斯特他线虫（94.9%）和辐射食道口线虫（93.3%）的感染达90%以上（p < 0.05），至少持续77天；预防细颈奥斯特他线虫（99.1%）感染达63天；预防点状库珀线虫（97.7%）、斧形毛圆线虫（96.5%）和奥斯特他线虫属抑制期幼虫4（93.3%）感染达56天；预防牛仰口线虫/苏纳巴达仰口线虫（96.9%）、变色毛首线虫（93.6%）和库珀线虫属抑制期幼虫4（98.8%）感染；预防类圆线虫属抑制期幼虫4（97.1%）感染达42天。与生理盐水治疗的对照组相比，接受IVM LAI治疗的犊牛在第0至77天的体重显著增加（p < 0.001）（28.40 - 39.25千克对2.60千克）；然而，IVM LAI治疗组之间的体重增加没有差异（p > 0.3）。本研究表明，伊维菌素长效注射液在长时间预防多种牛线虫感染方面具有非常高的疗效，这与在体重增加方面对生产力的显著益处相关。
