Henriksen S A, Bentholm B R, Nielsen-Englyst A
Nord Vet Med. 1976 Apr-May;28(4-5):201-9.
Ecological studies of bovine gastro-intestinal trichostrongylide larvae have been carried on during a three-year period (1972-1974). The studies mainly included pastures grazed by heifers (2nd time grazing cattle). Examination of the herbage samples was based on washing and filtration (sieve mesh-size 36 and 28 mu) followed by Baermann test on the debris. The pasture infestation with infective larvae (L3) followed a nearly stereotype seasonal pattern (cf. fig. 2 and fig. 3): A considerable larval population survived on the pasture during the winter, the infestation decreased strongly during April-May, was low during June and beginning of July, and increased from the middle of July to reach a peak in September-October. The infestation was usually much higher just around the faecal pats than in the rest of the pasture area (cf. fig. 3). The observed populations of trichostrongylide larvae were dominated by Ostertagia (ostertagi), but included other species as well, e.g. Cooperia (oncophora), Nematodirus spp., etc.
在1972年至1974年的三年期间，对牛胃肠道毛圆线虫幼虫进行了生态学研究。这些研究主要包括小母牛放牧的牧场（第二次放牧牛群）。对牧草样本的检测基于洗涤和过滤（筛网孔径为36和28微米），然后对残渣进行贝尔曼氏试验。感染性幼虫（L3）在牧场上的感染情况遵循几乎固定的季节性模式（见图2和图3）：冬季有相当数量的幼虫存活在牧场上，4月至5月感染率大幅下降，6月和7月初较低，7月中旬开始上升，9月至10月达到高峰。粪便堆周围的感染率通常比牧场其他区域高得多（见图3）。观察到的毛圆线虫幼虫种群以奥斯特他线虫（奥斯特他线虫）为主，但也包括其他种类，如古柏线虫（瘤形古柏线虫）、细颈线虫属等。
