Reinecke R K, De Villiers I L, Joubert G
Onderstepoort J Vet Res. 1982 Sep;49(3):159-61.
Twelve calves were dosed with 40 000 and a further 12 with 80 000 infective larvae of Trichostrongylus axei respectively. These 2 groups and a control group were subsequently dosed with 50 000 infective larvae of Haemonchus placei. Predosing with T. axei had no effect on the establishment of H. placei. It is postulated that the numbers of T. axei worms present were below the 'threshold' value necessary to protect the calves against challenge with H. placei.
分别给12头小牛接种40000条和另外12头小牛接种80000条艾氏毛圆线虫感染性幼虫。随后给这两组以及一个对照组接种50000条捻转血矛线虫感染性幼虫。预先接种艾氏毛圆线虫对捻转血矛线虫的定植没有影响。据推测，所存在的艾氏毛圆线虫数量低于保护小牛免受捻转血矛线虫攻击所需的“阈值”。
