Tuah A K, Danso Y N
Trop Anim Health Prod. 1985 May;17(2):114-20. doi: 10.1007/BF02360784.
The performance of N'Dama and West African Shorthorn cattle in the humid forest zone of Ghana was evaluated using records (1969-1979) on these breeds kept at the UST livestock farm. The mean age at first calving for N'Dama was 32.07 months. Calving intervals of 501.92 and 462.83 days were obtained for N'Dama and West African Shorthorn cattle respectively. The secondary sex ratio for N'Dama calves was not significantly different from the expected theoretical value of 50%; that of the West African Shorthorn was, however, significantly different from the expected theoretical value mainly due to the small size of the population. Average birth weight for the two breeds was not significantly affected by breed, season of birth, weight and age of dam. Sex significantly affected the birth weight of the N'Dama calves. Pre-weaning and post-weaning growth rates of N'Dama male calves were significantly greater than the pre-weaning and post-weaning growth rates of females. For the West African Shorthorn sex did not significantly (P greater than 0.05) affect these traits. Calf mortalities for the two breeds were 10.53% for N'Dama and 21.05% for the West African Shorthorn. Calving percentage was not affected by breed. The productivity indices per cow per year were 72.7 kg for N'Dama and 32.1 kg for the West African Shorthorn. The productivity indices per 100 kg cow maintained per year were 36.8 kg for N'Dama and 16.6 kg for the West African Shorthorn.
利用在UST畜牧场保存的关于N’Dama牛和西非短角牛的记录（1969 - 1979年），对这两个品种在加纳湿润森林地区的性能进行了评估。N’Dama牛首次产犊的平均年龄为32.07个月。N’Dama牛和西非短角牛的产犊间隔分别为501.92天和462.83天。N’Dama牛犊的次生性别比与预期理论值50%没有显著差异；然而，西非短角牛的次生性别比与预期理论值有显著差异，主要是因为群体规模较小。两个品种的平均出生体重不受品种、出生季节、母牛体重和年龄的显著影响。性别对N’Dama牛犊的出生体重有显著影响。N’Dama公牛犊断奶前和断奶后的生长速度显著高于母牛。对于西非短角牛，性别对这些性状没有显著影响（P大于0.05）。两个品种的犊牛死亡率分别为：N’Dama牛10.53%，西非短角牛21.05%。产犊率不受品种影响。N’Dama牛每头母牛每年的生产力指数为72.7千克，西非短角牛为32.1千克。每年每维持100千克母牛的生产力指数，N’Dama牛为36.8千克，西非短角牛为16.6千克。
