Trail J C, d'Ieteren G D, Feron A, Kakiese O, Mulungo M, Pelo M
International Livestock Centre for Africa, Nairobi, Kenya.
Acta Trop. 1990 Oct;48(1):37-45. doi: 10.1016/0001-706x(90)90063-6.
One hundred and forty six calving interval records were built up from 64 N'Dama cows maintained for 3.5 years under a high natural tsetse challenge in Zaire. Matching health and performance data were recorded monthly to allow simultaneous evaluation of the effects of different criteria of trypanotolerance represented by time detected parasitaemic, parasitaemia score and packed red cell volume percent (PCV) on reproductive performance, calf weaning weight and cow productivity. Control of development of anaemia, measured by PCV value during trypanosome infection, had the major effect on all three performance traits. The repeatability of this criterion (0.33) was almost equal to that of calf weaning weight, indicating PCV measurement might be suitable for identification of more trypanotolerant animals. Simultaneous evaluation of the relative effects of control of development of anaemia in both the pre-weaner calf and its dam, on calf performance, suggested that its measurement in an animal might be feasible at an early post-weaner stage. Guidelines for work to develop practical field tests for trypanotolerance involving post-weaners maintained for varying lengths of time in high natural challenge situations are suggested.
在扎伊尔，对64头恩达马母牛进行了3.5年的饲养，这些母牛处于高自然采采蝇挑战环境下，据此建立了146条产犊间隔记录。每月记录匹配的健康和生产性能数据，以便同时评估由检测到寄生虫血症的时间、寄生虫血症评分和红细胞压积百分比（PCV）所代表的不同耐锥虫标准对繁殖性能、犊牛断奶体重和母牛生产力的影响。通过锥虫感染期间的PCV值来衡量的贫血发展控制，对所有这三个生产性能性状都有主要影响。该标准的重复性（0.33）几乎与犊牛断奶体重的重复性相同，这表明PCV测量可能适用于识别更耐锥虫的动物。同时评估断奶前犊牛及其母牛的贫血发展控制对犊牛性能的相对影响，表明在断奶后早期阶段对动物进行该测量可能是可行的。建议开展相关工作，为耐锥虫性制定实际的现场测试指南，这些测试涉及在高自然挑战情况下饲养不同时长的断奶后动物。
