Larsen M N, Roepstorff A
Danish Centre for Experimental Parasitology, Royal Veterinary and Agricultural University, Frederiksberg, Copenhagen, Denmark.
Parasitology. 1999 Aug;119 ( Pt 2):209-20. doi: 10.1017/s0031182099004503.
Pig faeces were deposited on experimental plots in the spring, summer, autumn and winter to study development and survival of Ascaris suum and Trichuris suis eggs under outdoor conditions. Faeces were placed either in short grass or 2 cm below the surface of bare soil, imitating pastures used by nose-ringed, grazing pigs or normally rooting pigs, respectively. The numbers and developmental stages of the eggs were recorded in faeces and soil for up to 50 weeks post-deposition. Embryonation took place only during the summer months and seemingly was independent of the microclimate. The majority of A. suum and T. suis eggs, which are generally considered to be extremely resistant and long-lived, seems to disappear rather fast. The disappearance rate for A. suum eggs was higher than for T. suis eggs, and both egg types disappeared significantly faster in the summer months than in the winter months, and when placed in short grass than when buried in soil (less exposed). We discuss how knowledge on egg development and survival may be used in the planning of pasture strategies for control of helminth infections in outdoor pigs.
春季、夏季、秋季和冬季时，将猪粪便放置在实验地块上，以研究猪蛔虫和猪鞭虫卵在户外条件下的发育和存活情况。粪便分别放置在矮草丛中或裸土表面以下2厘米处，分别模拟带鼻环放牧猪或正常拱土猪所使用的牧场。在粪便沉积后的50周内，记录粪便和土壤中虫卵的数量和发育阶段。胚胎发育仅在夏季进行，且似乎与小气候无关。大多数通常被认为极具抵抗力且寿命长的猪蛔虫和猪鞭虫卵，似乎消失得相当快。猪蛔虫卵的消失率高于猪鞭虫卵，并且两种虫卵在夏季的消失速度明显快于冬季，放置在矮草丛中的虫卵比埋在土壤中（暴露较少）的虫卵消失得更快。我们讨论了关于虫卵发育和存活的知识如何应用于规划户外猪蠕虫感染控制的牧场策略。
