Study on the breeding objective traits and selected traits for beef line of Luxi cattle

chinois. 为了选育鲁西黄牛肉用品系，结合鲁西黄牛肉用品系育种实际，经过系统分析，确定了鲁西黄牛肉用品系近期的育种目标性状和相应的选择性状，并采用差额法计算了各选择性状的边际效益。结果表明，鲁西黄牛肉用品系近期的育种目标性状有3类，分别为生长发育性状、胴体性状和繁殖性状，包括有周岁质量、育肥期日增质量、生长能力、胴体等级、屠宰率、初产年龄、产犊间隔和射精量8个选择性状。在预期的市场和生产条件下，对于上述各选择性状的边际效益分别为：5.71元/kg，0.90元/g，2.84元/kg，402.00元/级，60.30元/%，-3.52元/d，-6.16元/d，55.23元/mL；通过遗传标准差校正，3类性状中生长发育、胴体性状和繁殖性状的经济权重之比为_0.55∶_0.21∶0.24，近似于2∶1∶1。说明鲁西黄牛向肉用方向发展过程中，需要加强生长发育性状的选择力度，同时要兼顾胴体性状和繁殖性状的选择。

anglais. In order to breed a beef line in Luxi cattle, breeding objective traits and selected traits were defined in the near future by systematic analysis according to real breeding condition of Luxi cattle in the paper. The marginal profit of breeding objective traits was calculated by WEU. The result showed that breeding objective traits were grouped into three kinds of traits: growth, carcass and reproduction, including eithgt economic traits which are yearing weight, feed gain, growth capacity carcass quality, age of first calving interval and ejaculate volume. In the situation of predicted market and productive condition, the marginal profits of eight objective traits were 5.71 yuan/kg, 0.90 yuan/g, 2.84 yuan/kg, 402.00 yuan/grade, 60.30 yuan/%, -3.52 yuan/d, -6.16 yuan/d, 55.23 yuan/mL respectively. And the ratio of relative economic weights of three kinds of traits was 0.55∶0.21∶0.24 after standardization, similar to 2∶1∶1.It also showed completely that growth traits should be mainly strengthened to select for beef purpose direction, and that attention should be given to reproduction and carcass traits simultaneously.