Abstract: The aim of the present study were to assess the production performance of the F1 hybrid progeny of Dorper sheep and Bayannur prolific sheep, and to provide a basis for introduction of Bayannur prolific sheep in Korla region of Xinjiang for fattening lambs production as well as cross-breeding and utilization of mutton sheep. The differences in growth performance and slaughter performance between the F1 hybrid lambs of Dorper sheep （male parent） and Bayannur prolific sheep （female parent） and the lambs （control group） produced by local female and male sheep by natural mating were statistically analyzed. Furthermore, the reproductive performance of Bayannur prolific ewes and local ewes was compared. The results showed that the 3-month-old and 6-month-old weight of the F1 crossbred lambs in 2017 and 2018 was extremely significantly higher （P<0.01） than that of the control group, and the daily weight gain was significantly higher （P<0.05） than that of the control group; the F1 crossbred lambs aged 6 months had extremely significantly higher （P<0.01） body length and chest width compared to their counterparts in control group in 2018; the F1 crossbred lambs aged 6 months had significantly higher （P<0.05） body height, chest depth, chest circumference and tube circumference compared to the control group in 2017 and 2018; the carcass weight of the F1 crossbred lambs was extremely significantly （P<0.01） elevated by 21.07% and 22.90% than that of the control group in 2017 and 2018, respectively; the net meat weight and net meat rate of the F1 crossbred lambs was extremely significantly higher （P<0.01） than that of the control group in 2017 and 2018; the conception rate and dystocia rate of Bayannur prolific ewes was significantly higher （P<0.05） and extremely significantly higher （P<0.01） than that of the local ewes, respectively, but the survival rate of their lambs was extremely significantly reduced （P<0.01）; the lambing rate and twin-lamb rate of the Bayannur prolific ewes was 24.72% and 3.41 times higher than that of the local ewes, respectively, and the difference was both extremely significant （P<0.01）. The combined data suggested that the F1 crossbred lambs of Dorper sheep and Bayannur prolific sheep had better growth performance and slaughter performance compared to the local lambs, indicating that they inherited the superior growth and development performance of their male parent of Dorper sheep; the female parent of Bayannur prolific ewes maintained their good adaptability to the environment and prolificacy. The hybridization of the introduced Bayannur prolific sheep with the Dorper sheep fully exerted the heterosis of the F1 crossbred lambs, which would obviouly improve the economic benefits of mutton sheep farming in this region.

Key words: Dorper sheep Bayannur prolific sheep hybrid F1 generation meat production performance heterosis