Malczewski A, Jolley W R, Woodard L F
W. Stefański Institute of Parasitology, Polish Academy of Sciences, Warsaw, Poland.
Vet Parasitol. 1996 Sep 16;64(4):285-97. doi: 10.1016/0304-4017(95)00924-8.
During 1988, monthly collections of abomasa and the cranial portion of the small intestine of 208 native Wyoming cattle were examined for adult and larval helminth parasites. Egg counts were performed on colonic faecal specimens. The animals ranged from 7 months to 8 years of age and were sampled at slaughter houses or diagnostic laboratories from five different counties in the State. Most of the cattle had ranged for a long time on non-irrigated, high altitude grass plains from about 1250 to 2500 m above sea level. All animals examined were found infected. Nematode genera (and number of species) found included Ostertagia (4), Trichostrongylus (2), Haemonchus (1), Cooperia (4) and Nematodirus (2). One trematode, Fasciola hepatica, and a cestode, Moniezia benedeni, also were found. Trichostrongylus axei, Trichostrongylus longispicularis and Cooperia lyrata were found for the first time in Wyoming, Ostertagia circumcincta was found for the first time in cattle in Wyoming, and Haemonchus placei, tentatively identified in a previous survey, was definitively confirmed. Predominant species (and prevalence) were Ostertagia ostertagi (98%), Cooperia oncophora (60.6%), Ostertagia bisonis (41.8%), Cooperia bisonis (33.6%) and T. Axei (27.9%). One or more of the four species of Ostertagia were found in all animals. Inhibited O. ostertagi and O. bisonis larvae predominated from November to April and reached a peak in January to comprise 88% of the total nematode burden for that month. The adult population of abomasal nematodes peaked in April and predominated thereafter until October. Haemonchus placei also spent the autumn-winter period in an inhibited state of development. Faecal egg counts were lowest during winter months, when the highest number of worms were present as L4 larvae, as determined by luminal and mucosal counts. Nematode populations in the small intestine peaked in June and persisted until November. The results of this study showed the magnitude and species composition of nematode parasitism in cattle raised on high altitude grass plains, underscored the inaccuracy of faecal egg counts as an indicator of worm burden during fall and winter seasons, and provided information on which anthelmintic treatment timing would be most efficacious.
1988年期间，对208头怀俄明本地牛的皱胃和小肠前段进行了月度采集，检查其中的成虫和幼虫期蠕虫寄生虫。对结肠粪便样本进行了虫卵计数。这些动物年龄从7个月到8岁不等，在该州五个不同县的屠宰场或诊断实验室进行采样。大多数牛长期在海拔约1250至2500米的非灌溉高海拔草原上放牧。所有检查的动物均被发现感染。发现的线虫属（及物种数量）包括奥斯特线虫属（4种）、毛圆线虫属（2种）、血矛线虫属（1种）、古柏线虫属（4种）和细颈线虫属（2种）。还发现了一种吸虫，即肝片吸虫，以及一种绦虫，即贝氏莫尼茨绦虫。艾氏毛圆线虫、长刺毛圆线虫和莱氏古柏线虫在怀俄明州首次被发现，环形奥斯特线虫在怀俄明州的牛中首次被发现，在之前的一项调查中初步鉴定的牛血矛线虫得到了明确确认。优势种（及感染率）为奥氏奥斯特线虫（98%）、牛古柏线虫（60.6%）、野牛奥斯特线虫（41.8%）、野牛古柏线虫（33.6%）和艾氏毛圆线虫（27.9%）。在所有动物中均发现了四种奥斯特线虫中的一种或多种。受抑制的奥氏奥斯特线虫和野牛奥斯特线虫幼虫在11月至4月占主导，1月达到峰值，占该月线虫总负荷的88%。皱胃线虫成虫数量在4月达到峰值，此后占主导地位直至10月。牛血矛线虫在秋冬季节也处于发育受抑制状态。冬季粪便虫卵计数最低，此时通过肠腔和黏膜计数确定存在数量最多的L4期幼虫。小肠中的线虫数量在6月达到峰值，并持续到11月。本研究结果显示了在高海拔草原上饲养的牛体内线虫寄生的规模和物种组成，强调了粪便虫卵计数作为秋冬季节蠕虫负荷指标的不准确之处，并提供了驱虫治疗最有效时机的相关信息。
