Analysis of Improvement Effect on Imported Red Angus For Yunnan Yellow Cattle

【Objective】The imported Angus of quality beef breeds from abroad had been used to crossbreed and improve yunnan yellow cattle since 1974,1997 and 2003.The improvement effect was well.【Method】The birth weight and body weight of F1 crossbreed from Angus and Yunnan yellow cattle were measured at 6,12,24 and 48 months' age.【Result】 The result showed that the imported bulls could adapt the climate conditions of Yunnan Plateau well.The average birth weight of F1 crossbreds of Yunnan yellow cattle with Angus was 21.21 kg;and the body weight at 6,12,24 and 48 months old was 134.34 kg,187.18 kg,268.45 kg and 324.92 kg,respectively.Compaered with that of Yunnan yellow cattle,it increased 50.32%,57.45%,49.33%,38.89% and 37.27% under the rural feeding conditions.【Conclusion】The crossbreeding offspring showed up better economic prematureness and the improvement effect was significant.