奶牛赘生乳头数遗传力的估计及其与产奶量的相关分析

ESTIMATION OF HERITABIL OF ACCESSORY TEATS AND CORRELATION OF MILK YIELD IN DAIRY COWS

奶牛赘生乳头数呈阈性状特点,本文采用阈性状分析法估测赘生乳头数的遗传力为0.33+0.04,因此,进行表型选择可获得较理想的选择效果。通过其对产奶量的相关分析表明,赘生乳头对产奶量虽无明显影响,但有遗传倾向。它不仅影响乳房的外形,也不利于机械化生产,无疑是一不合意性状,应在奶牛选种工作中予以重视。

Number of accessory teats in dairy cows might be studied as a threshold character.In the present study estimate of h2 for trait from threshold character analysis was 0.33±0.04.Accordingly, phenotypic selection on this trait could result in a desirable selection response. Correlation analysis indicated that accessory teats did not have a significant effect on milk yield. But they would have an effect on the shape of the udder and were not good for mechinized on milking. Since the trait had hereditary tendency, it is no doubt that accessory teat is an undesirable trait and should be paid much attention in dairy cow selection.