Centre for Integrative Genetics, National Dairy Research Institute, Karnal, India.
J Anim Breed Genet. 2011 Apr;128(2):133-40. doi: 10.1111/j.1439-0388.2010.00882.x. Epub 2010 Oct 28.
Breed additive and non-additive effects, and heritabilities of birth weight (BWT), weaning weight (WWT), 6 months weight (SMWT), yearling weight (YWT), eighteen months weight (EWT), 2 years weight (TWT) and average daily weight gain from birth to 6 months (ADG1) and from 6 months to 2 years (ADG2) were estimated in Ethiopian Boran (B) cattle and their crosses with Holstein Friesian (F) in central Ethiopia. The data analysed were spread over 15 years. Ethiopian Boran were consistently lighter (p < 0.01) than the B-F crosses at all ages. Ethiopian Boran also gained lower weight than all the crosses. At birth, 50% F crosses were significantly (p < 0.01) lighter than all the other crosses. However, the differences in SMWT, YWT, EWT, TWT, ADG1 and ADG2 were all non-significant among the crosses. The individual additive breed differences between B and F breeds were positive and significant (p < 0.01) for all traits. The individual heterosis effects were significant (p < 0.05) for all traits except WWT for which the effect was non-significant. The maternal heterosis effects were significant (p < 0.01) for BWT (2.5 kg) and WWT (-3.0 kg). The heritability estimates for all traits in B and crosses were generally moderate to high indicating that there is scope for genetic improvement through selection. Selection within B and crossbreeding should be the strategy to enhance the growth performance under such production systems.
在埃塞俄比亚博兰牛(B)及其与荷斯坦弗里生牛(F)的杂交后代中,评估了初生重(BWT)、断奶重(WWT)、6 月龄重(SMWT)、1 岁重(YWT)、18 月龄重(EWT)、2 岁重(TWT)和从出生到 6 月龄(ADG1)以及从 6 月龄到 2 岁(ADG2)的日增重的品种加性和非加性效应以及遗传力。分析的数据分布在 15 年中。在所有年龄段,埃塞俄比亚博兰牛都比 B-F 杂交后代轻(p < 0.01)。埃塞俄比亚博兰牛的增重也低于所有杂交后代。在出生时,50%的 F 杂交后代明显(p < 0.01)比所有其他杂交后代轻。然而,在 SMWT、YWT、EWT、TWT、ADG1 和 ADG2 方面,杂交后代之间的差异均无统计学意义。B 和 F 品种之间的个体加性品种差异在所有性状上均为正且显著(p < 0.01)。除 WWT 外,所有性状的个体杂种优势效应均显著(p < 0.05),而 WWT 的效应不显著。母本杂种优势效应在 BWT(2.5 公斤)和 WWT(-3.0 公斤)方面显著(p < 0.01)。B 和杂交后代的所有性状的遗传力估计值通常为中度到高度,表明通过选择可以在遗传上进行改进。在这种生产体系下,应通过选择和杂交来提高生长性能。