Acevedo-Ramírez P M C, Quiroz-Romero H, Cruz-Mendoza I, Ulloa-Arvizu R, Ibarra-Velarde F
Universidad Nacional Autónoma de México, Facultad de Medicina Veterinaria y Zootecnia, Av. Universidad 3000, Coyoacan, CP 04510, México DF, México.
J Helminthol. 2013 Mar;87(1):108-14. doi: 10.1017/S0022149X12000132. Epub 2012 Mar 2.
The aims of this study were to determine the frequency of egg shedding (percentage of egg-positive faecal samples) and faecal egg counts (FEC) over 13 months in two different breeds of ewes, both pregnant and non-pregnant, in a mountainous region of central Mexico. Additionally, the effect of ivermectin and albendazole treatments on FEC reduction was recorded. The study also aimed to relate temperature and rainfall to FEC. The gastrointestinal nematode (GIN) third-stage larvae genera recovered from both faeces and grassland pastures in a temperate region were also assessed. Faecal samples were collected from ewes at monthly intervals for 13 months to investigate the FEC population of GIN larvae, their concentration and genera in grass samples collected from grazed and rested pastures. Egg-shedding frequency ranged from 0 to 92% and FEC from 0 to 12,000 eggs per g faeces (epg), with counts in Suffolk higher than in Dorset ewes. The identified genera were Haemonchus, Trichostrongylus, Teladorsagia, Cooperia, Oesophagostomum, Bunostomum, Nematodirus and Strongyloides. Haemonchus and Trichostrongylus were the most common genera. The number of L3 was higher in grazing lands than in those at rest. The highest FEC were recorded in the dry season due to peripartum, but the highest L3 counts were recorded in the rainy season. The coexistence of species of different geographical distributions at this site may be because there is a confluence of Nearctic and Neotropical geographic regions; thus, despite the temperate climate, tropical species can be found. Additionally, this study suggests that increasing temperatures could favour the presence of different tropical GIN species together with typical temperate-zone GIN species.
本研究的目的是确定墨西哥中部山区两种不同品种的怀孕和未怀孕母羊在13个月内的排粪虫卵频率（粪样虫卵阳性百分比）和粪虫卵计数（FEC）。此外，记录了伊维菌素和阿苯达唑治疗对FEC降低的影响。该研究还旨在将温度和降雨量与FEC联系起来。对从温带地区的粪便和草原牧场中回收的胃肠道线虫（GIN）第三期幼虫属也进行了评估。在13个月内每月从母羊采集粪便样本，以调查GIN幼虫的FEC数量、其在从放牧和休牧牧场采集的草样中的浓度和属。排粪虫卵频率为0至92%，FEC为每克粪便0至12000个虫卵（epg），萨福克母羊的计数高于多塞特母羊。鉴定出的属有血矛线虫属、毛圆线虫属、细颈线虫属、古柏线虫属、食道口线虫属、牛仰口线虫属、细颈线虫属和类圆线虫属。血矛线虫属和毛圆线虫属是最常见的属。放牧地的L3数量高于休牧地。由于围产期，旱季记录到最高的FEC，但雨季记录到最高的L3计数。该地点不同地理分布的物种共存可能是因为新北区和新热带区地理区域交汇；因此，尽管气候温和，但仍能发现热带物种。此外，本研究表明，温度升高可能有利于不同热带GIN物种与典型温带GIN物种共同存在。
