Fernández A S, Larsen M, Henningsen E, Nansen P, Grønvold J, Bjørn H, Wolstrup J
Danish Centre for Experimental Parasitology, Royal Veterinary and Agricultural University, Frederiksberg, Denmark.
Parasitology. 1999 Jul;119 ( Pt 1):105-11. doi: 10.1017/s0031182099004369.
The efficacy of an isolate of the nematophagous fungus Duddingtonia flagrans against gastrointestinal nematodes of cattle was examined at 2 dose levels on 2 permanent pastures, with high and low stocking rates, respectively. Thirty calves, experimentally infected with Ostertagia ostertagi, were divided into 3 comparable groups and allocated to 3 similar paddocks in each of the 2 trials. Two of the 3 groups received fungal material once per day during the initial 2 months, either at high dose (10(6) fungal spores/kg body weight) or low dose (5 x 10(5) or 2.5 x 10(5) fungal spores/kg body weight). The third group remained as an untreated control group. Faecal, blood, and herbage samples were collected and animals were weighed every month from May to September. The pasture grazed at a high stocking rate had a large number of overwintering infective larvae, while the pasture grazed at a low stocking rate had a low overwintering herbage larval infectivity. The results showed that, at a high stocking rate, the recovery of infective larvae on pasture was diminished and calves were prevented from clinical ostertagiosis by using the D. flagrans Troll A-isolate. At low stocking rate, the parasite burden seemed not to be very heavy, and a conclusive effect of the fungi at the dose-level used could not be detected.
在两个分别具有高载畜率和低载畜率的永久性牧场上，以两种剂量水平对食线虫真菌弗氏节丛孢菌的一个分离株针对牛胃肠道线虫的功效进行了检测。三十头经实验感染奥斯特他线虫的犊牛被分成3个可比组，并在两项试验的每一项中被分配到3个相似的围场。3组中的两组在最初2个月期间每天接受一次真菌材料，剂量要么高（10⁶个真菌孢子/千克体重）要么低（5×10⁵个或2.5×10⁵个真菌孢子/千克体重）。第三组作为未处理的对照组。从5月到9月每月采集粪便、血液和牧草样本并对动物称重。以高载畜率放牧的牧场有大量越冬感染性幼虫，而以低载畜率放牧的牧场越冬牧草幼虫感染性较低。结果表明，在高载畜率情况下，使用弗氏节丛孢菌Troll A分离株可减少牧场上感染性幼虫的数量，并防止犊牛出现临床奥斯特他线虫病。在低载畜率情况下，寄生虫负担似乎不太重，且未检测到所用剂量水平的真菌有决定性效果。
