Research On Heteosis, Combining Ability And Behavior Characters Among Three Foreign Mutton Breeds And Mongolian Sheep

Twelve combinations of reciprocal two-way crossing experiments were conducted among 4 sheep breeds, including Germen Mutton Merino (G), Poll Dorset (D), Suffolk (S) and Mongolian Sheep (M), under the condition of mainly grazing in Xilinguole Paraire of Inner Mongolia Autonomous Region, and minorly supplying concentrate in winter and spring time, by checking the performances, such as birth weight, weight gain, effects of heterosis and combining abilities on different experimental stages, to choose the best combination and improve the performance of mutton sheep, and to observe the specific behaviors and characteristics of different mutton sheep breeds when house feeding in winter and grazing condition during summer and fall, respectively. In addition, dual two-way crossing experiments were conducted among the descendants of two-way crossing sheep, to provide species for factory and intensive raising, and to provide overall data for the breeding of new specialized mutton sheep strain in China. The results shown that the general combining ability of birth weight (-0.65 kg), 120 d weight (1.87 kg), and 120 d weight gain (12.60 g) of Suffolk sheep were the best among the 4 breeds. The results were also shown that the specific combining ability of M×S combination was the best one among the 12 crossing groups; the specific combining ability indices for heterosics effects , such as birth weight (1.26 kg), 120 d weight (11.61 kg), and 120 d weght gain (69.45 g) in M×S combination were significant higher than that of other combinations. Furthermore, the results were shown that Mongolian Sheep, being a famous local breeds in Inner Mongolia, was of great value as a sire line in the breeding of Specialized Line Mutton Sheep, and in the crossing of merchandised sheep. In addition, the results of dual two-way crossing experiments were shown that the brith weight and weight gain indices in 4 dual two-way crossing combinations were all higher than that in two-way crossing. The average birth weight in dual two-way crossing was 0.68 kg higher than that in two-way crossing, the average weight in 4 combinations of dual two-way crossing could be amounted to 27.11 kg on 60-80 d, and 44.64 kg on 120-140 d.