Programa de Pós-graduação em Zootecnia, Universidade Estadual de Ponta Grossa - UEPG, Ponta Grossa, PR, Brasil.
CONSIPA - Consultoria em Sistemas Integrados de Produção Agropecuária, Ponta Grossa, PR, Brasil.
Rev Bras Parasitol Vet. 2021 May 28;30(2):e028120. doi: 10.1590/S1984-29612021032. eCollection 2021.
The resistance of gastrointestinal nematodes (GIN) of sheep to anthelmintic treatment has motivated researchers to seek alternatives to reduce the use of these drugs in sheep farming and decontaminate pastureland based on knowledge about the survival dynamics of larvae. The aim of this work was to evaluate the migration of the infective larvae (L3) of Haemonchus contortus at different times of the day, strata, and sward heights, with and without shade after the deposition of contaminated sheep feces. The grass species used here was Cynodon dactylon cv. Tifton 85 in four treatments: low sward height shade; low sward height sunshine; high sward height shade; and high sward height sunshine. The number of L3 recovered from the pasture at different times of the day did not differ. The highest number of L3 recovered was in shade. The number of L3 at different times and strata occurred uniformly, confirming that L3 remain in the same place after migrating from dung at the hottest times of the day. Infective larvae of H. contortus were able to migrate across all the strata regardless of the time of day in the summer season in humid subtropical climate.
绵羊胃肠道线虫（GIN）对驱虫治疗的耐药性促使研究人员寻求替代方法，以减少绵羊养殖中这些药物的使用，并根据幼虫生存动态的知识来净化牧场。本研究旨在评估在绵羊粪便污染后不同时间、层次和草丛高度以及有无遮荫条件下，感染性幼虫（L3）向哈蒙属线虫的迁移。这里使用的草种是蒂夫顿 85 号狗牙根，分为四个处理：低草丛高度遮荫；低草丛高度阳光；高草丛高度遮荫；高草丛高度阳光。不同时间从牧场上回收的 L3 数量没有差异。在遮荫下回收的 L3 数量最多。不同时间和层次的 L3 数量均匀发生，这证实了 L3 在一天中最热的时候从粪便中迁移出来后，仍然留在原处。在潮湿亚热带气候的夏季，哈蒙属线虫的感染性幼虫能够穿过所有层次，无论白天的时间如何。
