Charlier Johannes, Duchateau Luc, Claerebout Edwin, Vercruysse Jozef
Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
Vet Parasitol. 2007 Feb 28;143(3-4):322-8. doi: 10.1016/j.vetpar.2006.08.015. Epub 2006 Sep 20.
The objectives of this study were (1) to determine the effect of a treatment with eprinomectin in autumn of pastured dairy herds on the anti-Ostertagia ostertagi bulk-tank milk antibody level, (2) to determine the overall effect of this treatment on three milk-production parameters (milk yield, protein % and fat %) and (3) to investigate the value of the pre-treatment Ostertagia-specific bulk-tank milk antibody level to predict the production response after anthelmintic treatment. One hundred and nineteen herds in Flanders (Belgium) were randomly assigned to a treatment with eprinomectin or a placebo in October 2004. Bulk-tank milk samples were collected monthly from August 2004 until April 2005, and the antibody levels against O. ostertagi were determined as optical density ratios (ODRs) with an ELISA. The treatment effect over the 4 months following treatment on three production parameters (milk yield, milk-protein %, milk-fat %) was estimated by mixed models with herd as a random effect. The treatment effect on milk yield was also investigated within six categories of the pre-treatment ODR. The ODR values were lower in the eprinomectin group than in the control group at each time point after treatment. The overall effect on milk yield was estimated at 1.2 kg/cow/day, whereas no effect on the milk-protein % and milk-fat % was observed. Herds in the highest pre-treatment ODR category (>0.84) had a positive milk-yield response of 4.0 kg/cow/day (95%-confidence interval: 1.0; 7.0), while the 95%-confidence intervals of the milk-yield responses in the other categories all included zero. This study demonstrates that treatment with eprinomectin of pastured dairy cows in autumn will lower the Ostertagia-specific bulk-tank milk antibody level during the stabling period and can result in a consistent increase in milk yield. The results indicate that an O. ostertagi bulk-tank milk ELISA can be used to identify the herds where the greatest milk-yield response after an anthelmintic treatment is expected.
（1）确定秋季对放牧奶牛群使用伊维菌素治疗对牛结节性皮肤病大容量储存罐牛奶抗体水平的影响；（2）确定该治疗对三个产奶参数（产奶量、蛋白质百分比和脂肪百分比）的总体影响；（3）研究治疗前牛结节性皮肤病特异性大容量储存罐牛奶抗体水平对预测驱虫治疗后生产反应的价值。2004年10月，比利时弗拉芒地区的119个牛群被随机分配接受伊维菌素或安慰剂治疗。从2004年8月到2005年4月每月采集大容量储存罐牛奶样本，并用酶联免疫吸附测定法（ELISA）将抗牛结节性皮肤病的抗体水平测定为光密度比（ODR）。通过以牛群为随机效应的混合模型估计治疗后4个月内对三个生产参数（产奶量、乳蛋白百分比、乳脂百分比）的治疗效果。还在治疗前ODR的六个类别中研究了对产奶量的治疗效果。治疗后每个时间点，伊维菌素组的ODR值均低于对照组。估计对产奶量的总体影响为1.2千克/头/天，而未观察到对乳蛋白百分比和乳脂百分比的影响。治疗前ODR最高类别（>0.84）的牛群产奶量有4.0千克/头/天的正向反应（95%置信区间：1.0；7.0），而其他类别的产奶量反应的95%置信区间均包含零。本研究表明，秋季对放牧奶牛使用伊维菌素治疗将在圈养期间降低牛结节性皮肤病特异性大容量储存罐牛奶抗体水平，并可导致产奶量持续增加。结果表明，牛结节性皮肤病大容量储存罐牛奶ELISA可用于识别预期驱虫治疗后产奶量反应最大的牛群。
