The increasing number of breeding Dorset Down which was reproduced with now available Dorset Down by means of technology of embrgo transfer was fast and low cost in the breeding farm which belongs to the institute of Animal and Veterinary sciences of Hoibei Prefecture.

Ecological adaptation analysis of Small-tail Han sheep and Dorset Sheep introduced to Huangyuan county in Qinghai Province;

The semen quality,semen freezing-storage-diluent and the preparation technique of frozen semen for the semen in two Dorset sheep at the age of one and two years introduced from new Zealand were scudied.

Determination of Boby Weight of Dorset F_1;

The contemporary ram lamb of first filial generation of Dorset and Han-sheep with small-tail,Dorset and local sheep,Han-sheep with small-tail,local sheep were selected and used to determine the slaughter weight,the dressed weight,the meat weight and the ratio of meat to bone and to compare and analyse under same feeding and managment and fattening.

The body weight of hybrid offsprings of Dorset mutton sheep to local four breeds of sheep at the birth,the age of three-months,sex-months and twelve-months were determined and compared with that in the local valley type of Tibetan sheep.

Crossbreeding Effect of Poll Dorset with Qinghai Semifine Wool Sheep;

The DNA samples were purified from the blood samples taken from 53 Small Tail Han sheep ewes in Shandong and 25 Poll Dorset ewes from Yongchang of Gansu,35 Mongolia ewes from Wuwei of Gansu.

Studies on the Adaptability and Crossbred Effects of Poll Dorset Sheep in the Northwest of Gansu Province;