Reduction of inbreeding in commercial females by rotational mating with several sire lines

Genetics Selection Evolution

Fumio Mukai¹  Tetsuro Nomura²  Takeshi Honda³ 

[1] Faculty of Agriculture, Kobe University, Kobe, Japan;Faculty of Engineering, Kyoto Sangyo University, Kyoto, Japan;Graduate School of Science and Technology, Kobe University, Kobe, Japan

关键词: commercial females;    rotational mating;    coancestry;    inbreeding;   

Others  :  1094302
DOI  :  10.1186/1297-9686-36-5-509

 received in 2003-11-17, accepted in 2004-04-27,  发布年份 2004

【 摘 要 】

A mating system to reduce the inbreeding of commercial females in the lower level was examined theoretically, assuming a hierarchical breed structure, in which favorable genes are accumulated in the upper level by artificial selection and the achieved genetic progress is transferred to the lower level through migration of males. The mating system examined was rotational mating with several closed sire lines in the upper level. Using the group coancestry theory, we derived recurrence equations for the inbreeding coefficient of the commercial females. The asymptotic inbreeding coefficient was also derived. Numerical computations showed that the critical factor for determining the inbreeding is the number of sire lines, and that the size of each sire line has a marginal effect. If four or five sire lines were available, rotational mating was found to be quite an effective system to reduce the short- and long-term inbreeding of the commercial females, irrespective of the effective size of each sire line. Oscillation of the inbreeding coefficient under rotational mating with initially related sire lines could be minimized by avoiding the consecutive use of highly related lines. Extensions and perspectives of the system are discussed in relation to practical application.

【 授权许可】

   
2004 INRA, EDP Sciences