Roberts J A
Faculty of Veterinary Medicine and Animal Science, University of Peradeniya, Sri Lanka.
Vet Parasitol. 1990 Oct;37(2):113-20. doi: 10.1016/0304-4017(90)90066-k.
The egg production of Toxocara vitulorum in Asian buffalo has been studied. Eggs were first present in the faeces of calves when they were 22.3 +/- 1.6 days old. In calves treated with pyrantel when 3 days old, the age at first patency was extended by 3.5 days indicating that there was no pre-natal transmission. Calves on only half the milk of the cow had a significantly longer prepatent period of 27.7 +/- 2.2 days. The peak egg output occurred in calves 35.7 +/- 2.6 days old and had a duration of 5.5 +/- 2.5 days with 98,000 +/- 63,700 eggs g-1 of faeces. The duration of the patent period was 35 +/- 12 days. The average lengths of populations of mature female parasites from different hosts at the time of peak egg output or older, ranged from 15.0 to 31.0 cm and was correlated with those of the males in the same populations (10.6-20.4 cm). The size of females was not affected by intraspecific competition. The proportion of males in the populations was 0.39 +/- 0.11. The egg output per female per day at the peak was 110,000 +/- 58,000 and was correlated with the size of the females at autopsy, but the egg output per female per day at the time of autopsy was lower and was not correlated, so it was concluded that the drop in egg counts was the result of reduced fecundity. The fertility of the eggs from faeces was greater than 92% throughout.(ABSTRACT TRUNCATED AT 250 WORDS)
对亚洲水牛体内牛弓首蛔虫的产卵情况进行了研究。虫卵首次出现在22.3±1.6日龄犊牛的粪便中。3日龄时用噻嘧啶治疗的犊牛，首次排虫的年龄延长了3.5天，这表明不存在产前传播。仅食用母牛一半乳汁的犊牛，其潜伏期显著延长，为27.7±2.2天。虫卵排出高峰出现在35.7±2.6日龄的犊牛中，持续时间为5.5±2.5天，粪便中虫卵含量为98,000±63,700个/克。排虫期持续35±12天。在虫卵排出高峰或更晚时，来自不同宿主的成熟雌虫群体的平均长度在15.0至31.0厘米之间，且与同群体雄虫的长度相关（10.6 - 20.4厘米）。雌虫大小不受种内竞争影响。群体中雄虫比例为0.39±0.11。高峰时每头雌虫每天的产卵量为110,000±58,000个，且与尸检时雌虫大小相关，但尸检时每头雌虫每天的产卵量较低且无相关性，因此得出虫卵计数下降是繁殖力降低的结果。粪便中虫卵的受精率始终高于92%。（摘要截选至250字）
