2Chesnais J P.The Canadian swine improvement system[C].Ontario,Canada:Proc NSIF Conference Ottawa,1996.
3Rydhmer L.Swine breeding programmes in the Nordic countries[C].Ontario,Canada:Proc NSIF Conference Ottawa,2005.
4Mathur P K,Sullivan B,Chesnais J.A practical method for estimating degree of connectedness in large livestock populations with application to Canadian swine herds[M].Chengdu:CCSI Training Course on Swine Genetic Improvement.1999,3:8-12.
5Haley C S.Considerations in the development of future pig programmes[J].Asian-Aust J Anim Sci,1991,4:305-328.
6Krueger C,Rath D.Intrauterine insemination in sows with reduced sperm number[J].Reprod Fertil,2000,12:113-117.
7Watson P F,Behan J R.Intrauterine insemination of sows with reduced sperm numbers:results of a commercially based field trial[J].Theriogenology,2002,57:1683-1693.
8Rozeboom K J,Reicks D L,Wilson M E.The reproductive performance and factors affecting on-farm application of low dose intrauterine deposit of semen in sows[J].Anim Sci,2004,82:2164-2168.
9Roberts P K,Bilkei G.Field experiences on post cervical artificial insemination in the sows[J].Reprod Domest Ani,2005,40:489-491.
10Martinez E A,Vazquez J M,Roca J,et al.Minimum number of spermatozoa required for normal fertility after deep intrauterine insemination in non-sedated sows[J].Reproduction,2002,123:163-170.
