Thomas R J, Starr J R
Vet Rec. 1978 Nov 18;103(21):465-8. doi: 10.1136/vr.103.21.465.
The pattern of sheep nematode infective larvae on pasture shows a marked midsummer peak arising largely from the ewe peri-parturient egg output. Records of larval pattern over a nine-year period were examined in relation to meteorological data, and a correlation was demonstrated between the time of the summer peak and cumulative rainfall. A "wet score" was allocated to 12-hourly rainfall figures, and a "critical index" of 440 units of wetness was shown to be necessary before the larval peak was reached. A "warning index" of 350 to 380 wetness units is suggested which would allow a prediction to be made of the onset of major infection in lambs.
牧场上绵羊线虫感染性幼虫的分布模式呈现出一个明显的仲夏高峰，这主要源于母羊围产期的排卵量。研究人员对九年期间幼虫分布模式的记录与气象数据进行了关联分析，结果表明夏季高峰时间与累积降雨量之间存在相关性。对每12小时的降雨量数据赋予一个“湿润分数”，结果显示在达到幼虫高峰之前，需要440个湿润单位的“临界指数”。建议设置一个350至380湿润单位的“预警指数”，以便能够预测羔羊重大感染的开始。
