The Connectedness on Large White and Landrace in Regional Joint Breeding System in Beijing
Connectedness between herds plays a very important role in cross-herd genetic evaluation in pig breeding. The connectedness between herds in Beijing region was evaluated to assess the efficiency of regional joint breeding system in China. In current study, data on age at 100 kg in Large White and Landrace were collected and Connectedness Rating (CR) method was employed to measure the connectedness between herds. Results showed that most herds have genetic connection with other herds. There were 17 and 10 herds, out of totally 19 and 13 herds of Large White and Landrace, respectively were connected with at least one other herd within breed. However, the average CR in Beijing was relatively low (0-4.80%), the strong connectedness only existed among few herds; therefore, regional cross-herd genetic evaluation by far is not practicable. More intense efforts are needed to establish and enhance the connectedness between herds by means of extensive use of Artificial Insemination (AI), together with promotion of other activities on breed registration, performance test, etc.