用药条件下马胃蝇蛆排出动态模型的建立

Study on the discharge dynamics of Gasterophilus spp. larvae after administration of ivermectin

目的通过拟合马科动物服用伊维菌素后排出的马胃蝇蛆数量动态变化,建立马胃蝇蛆排出动态模型,根据模型预测排虫高峰,为新鲜蝇蛆的大量采集提供参考。方法随机选取家马和普氏野马各3匹,分别圈养在临时搭建的小围栏内;统计服用伊维菌素后单位时段各实验对象排出的马胃蝇蛆数,计算家马和普氏野马在各时段排出的平均马胃蝇蛆比率,采用Quadratic、Compound、Cubic模型对排虫动态进行拟合。结果在3种拟合模型中,Cubic模型拟合马科动物马胃蝇蛆排出动态的效果最好(家马R^2修正值为0.837,P=0.003;野马R^2修正值为0.940,P=0.000),家马和野马排虫动态拟合的回归方程分别为Y_(家马)=-1.302 766+0.075 436t-0.001 177t^2+0.000 006t^3(27.6≤t≤87.9),Y_(野马)=-1.178 999+0.071 902t-0.001 157t^2+0.000 006t^3(25.7≤t≤84.7)。由回归方程解出,家马和野马排虫高峰分别出现在服药后49.0和47.1 h。结论不同马科动物排虫动态的一致性说明驱虫效果与马科动物种类及其马胃蝇蛆感染量无关;所得回归方程量化了早期的观察结果,研究结论有助于提高马胃蝇蛆的采集效率和获取新鲜蝇蛆样本,为进一步研究奠定了基础。

Objective The discharge dynamic models of Gasterophilus spp. larvae were established by fitting the numberof larvaeshedding from the equids after taking ivermectin. According to the models, the peaks of larvae discharge werepredicted, which could help the collection of fresh maggots.Methods Three domestic horses and three Przewalski shorses were randomly selected and were kept in small enclosures separately. Maggots of each animal was harvested per unittime after taking ivermectin, the average rates of discharge larvae were calculated for both domestic and Przewalski shorses. Quadratic, Compound and Cubic models were used to fit the dynamics of larvae discharge.Results Among thethree fitting models, the Cubic models were the best models to fit the discharge rate of the larvae（domestic horses： adjusted R^2=0.837; Przewalski s horses： adjusted R^2=0.940）. The regression equations of the dynamic fitting of domestic andPrzewalski s horses were： Y_d=-1.302 766＋0.075 436t-0.001 177t^2＋0.000 006t^3（27.6≤t≤87.9）, Y_P=-1.178 999＋0.071 902t-0.001 157t^2＋0.000 006t^3（25.7≤t≤84.7）. According to the regression equations, the peak values of domesticand Przewalski s horses were 49.0 h and 47.1 h.Conclusion The efficacy was not related to the equine species andinfection intensity of Gasterophilus spp. larvae. The regression equation quantified the early observations, the conclusioncould help to improve the collection efficiency and obtain fresh maggot samples, which laid a foundation for further study.