西门塔尔牛对蒙古牛改良后代线性体型性状的影响

IHE EFFECT OF SIMMENIAL AS FATHERLINE ON THE LINER TYPE TRAITS OF CROSSBREEDING WITH MONGOLIAN CATTLE

１９９３年对５０头杂种公牛的线性体形性状进行了评定，同时划分了父母系和年龄段。统计分析结果表明，线性性状评定方法对兼用牛是有效的。西门塔尔牛在乳用性性状上具有很好的改良效果（Ｐ＜０．０５），其它线性性状没有发现显著作用（Ｐ＞０．０５）。级进杂交三代牛对后代体高、强壮度和腰部厚具有显著影响，对后腿曲直度具有极显著影响。鉴于有些线性体形性状同产肉性能密切相关，在肉用杂交改良中，应选择那些线性体型性状好的个体。在西门塔尔－蒙古牛杂交体系中，父母与膘情无关。

The liner type traits scores of fifty crossbreeding males were observed in 1993.Emphasis was put on the parent lines,grades of crossbreeding and ages on the linertype traits of the crossbreding cattle. Results showed that the liner type traits methodwas suitable for the dual-purpose cattle evaluation. Simmental had good influenceon dairv charaiter(F=7. 12,P<0.01) and shoulder width(F=4.98,P<0.05)andother traits(P>0. 05).In grade-up crossing the third grade had signifecant influnce ondescendant for body statue,strenth and loin thickness with F values of 5.06,4.50 and5. 14, respectively(P<0.05) and for rear leg views with F value of 16.21(P<0.01),for beef crossing purpose the Simmental bulls were suggested to select the individualswith better liner type scores which were highly related to beef production performances-Fatness of animals was not related to parent line on simmental-Mongolian cattle crossbr-eeding system.