Bremner K C, Keith R K, Winks R
Res Vet Sci. 1976 May;20(3):350-1.
Two groups of seven castrated male calves, aged three and 13 months respectively, which had been reared worm-free, were infected with 5000 larvae of Oesophagostomun radiatum. At autopsy six weeks later a mean of 403 +/- 398 adult worms were recovered from the older animals and a mean of 1174 +/- 484 from the younger. This significant difference (P less than 0-01) indicates that the resistance of cattle to initial infection with O radiatum increases with age.
两组分别为7头去势雄性犊牛，年龄分别为3个月和13个月，此前饲养过程中未感染蠕虫，给它们接种5000条辐射食道口线虫幼虫。六周后进行解剖，从年龄较大的犊牛中平均检获403±398条成虫，年龄较小的犊牛中平均检获1174±484条。这一显著差异（P<0.01）表明，牛对辐射食道口线虫初次感染的抵抗力随年龄增长而增强。
