Rocha Raquel Abdallah da, Bricarello Patrizia Ana, Rocha Gilberto Pedroso da, Amarante Alessandro Francisco Talamini do
Departamento de Zootecnia, Universidade de Ponta Grossa - UEPG, Ponta Grossa, PR, Brasil.
Departamento de Zootecnia e Desenvolvimento Rural, Centro de Ciências Agrárias, Universidade Federal Santa Catarina - UFSC, Florianópolis, SC, Brasil.
Rev Bras Parasitol Vet. 2014 Oct-Dec;23(4):463-72. doi: 10.1590/S1984-29612014075. Epub 2014 Dec 1.
The survival of infective larvae (L3) of Trichostrongylus colubriformis was evaluated on Brachiaria, Coast-cross and Aruana forage grasses. Feces of sheep parasitized exclusively by T. colubriformis were deposited in winter and spring on experimental plots whose grasses were cut at two heights: 5 cm and 30 cm. One, two, four, eight, 12 and 16 weeks after depositing the feces, fecal and forage samples were collected for the retrieval and quantification of L3. Retrieval of L3 from feces and forage was negligible in winter due to the dry weather, although a few larvae were retrieved in the last larval collections. However, L3 retrieval from fecal samples was greater in spring, especially two weeks after feces were deposited on 30 cm high grasses. At this time, the L3 retrieval rate from the three forage grasses differed significantly (P <0.05), with Aruana grass showing the highest average L3 retrieval rate, followed by Coast-cross and Brachiaria. In conclusion, the winter drought proved very unfavorable for the presence of L3 in the environment, and the microclimate of Aruana pastureland was generally the most favorable for the retrieval of infective larvae.
对蛇形毛圆线虫感染性幼虫（L3）在臂形草、海岸杂交草和阿鲁阿纳牧草上的存活情况进行了评估。仅感染蛇形毛圆线虫的绵羊粪便在冬季和春季被放置在试验地块上，这些地块上的草被修剪成5厘米和30厘米两种高度。在粪便放置后的1、2、4、8、12和16周，采集粪便和草料样本以检索和定量L3。由于冬季天气干燥，冬季从粪便和草料中检索到的L3数量可忽略不计，尽管在最后一次幼虫采集时检索到了一些幼虫。然而，春季从粪便样本中检索到的L3更多，尤其是在粪便放置在30厘米高的草地上两周后。此时，三种牧草上的L3检索率差异显著（P<0.05），阿鲁阿纳草的平均L3检索率最高，其次是海岸杂交草和臂形草。总之，冬季干旱对环境中L3的存在非常不利，阿鲁阿纳牧场的小气候总体上最有利于检索感染性幼虫。
