犊牛血液RNA含量用作奶牛遗传标记的研究

STUDIES ON THE BLOOD RNA CONTENT OF CALVES TREATED AS BIOCHEMICAL CENETIC MARKERS IN DAIRY COWS

本研究采用作者试验改进的脲─酚─氯仿─醇─ＳＤＳ系统方法［１］，对江西畜牧良种场奶牛一分场的黑白花奶牛群的５头公牛家系的１９１对母女牛进行了血液ＲＮＡ的测定，分析了被测奶牛血液ＲＮＡ含量的变化的规律性及其与产奶量的关系，建立了利用血液ＲＮＡ含量估测产奶量的回归方程。测定分析结果：试验牛血液ＲＮＡ遗传力（ｈ￣２）及其与产奶量的遗传相关（ｒＡ）分别为０．８５５８（Ｐ＜０．０５）与０．５８１７（Ｐ＜０．０５）；试验牛血液ＲＮＡ含量随月龄增加而降低，将试验牛６，９，１２，１６月龄对血液ＲＮＡ含量与其３月龄时血液ＲＮＡ含量相比，其血液ＲＮＡ含量降低率分别为６．３６％，２４．５％，３６．０％及４１．２６％；试验牛血液ＲＮＡ含量与其月龄数呈负相关（ｒ＝－０．９７３８，Ｐ＜０．０１），回归方程；试验牛泌奶３００ｄ时血液ＲＮＡ含量与其日平均产奶量呈正相关（ｒ＝０．５９２６，Ｐ＜０．０１），回归方程；试验牛泌奶３００ｄ时血液ＲＮＡ含量与其子代３月龄时血液ＲＮＡ含量呈正相关（ｒ＝０．４６４９，Ｐ＜０．０５），回归方程试验结果提示，犊牛血液ＲＮＡ含量有可能用来作为奶牛的遗传标记。

The modified method,urea-phenol-chlroform-ethanol-SDS,was adopted to determine the blood RNA content of191 calves and heifers which were born of five sires,and That of 65dams in Black and White dairy cattle.The results of determination indicate.Estimation onheritability of the blood RNA content of cows at 300 davs of lactation was 0.855 8(P<0.05),genetic correlation between the blcod RNA content of cows at 300 davs of lactationand their average daily milk yield was 0.5817(P<0.05).The blood RNA content of calvesdecreased at 6.36%,24.51%,36.00% and 41.36% respectively from 3 month of age to 6,9,12 and 16 month of age.Phenotypic correlation between the blcod RNA content of cows at300 days of lactation and their average daily milk yield was 0.592 5(P<0.01),and that oftheir female progeny at 3 month of age was 0.4649(P<0.05).As above indicate,We sug-gest that the blood RNA content of calves is possible to be treated as biochemical geneticmarker in the work of selecting dairy type of cattle indirectly.