5Watson PF, Behan JR. Intrauterine insemination of sows with reduced sperm numbers: results of a commercially based field trial[J]. Theriogenology, 2002, 57, 1683 1693.
6Wongtawan T, Saravia F, Wallgren M, Caballero I, RodriguezMartinez H. Fertility after deep intra-uterine artificial insemi nation of concentrated low-volume boar semen doses[J]. Theriogenology, 2006, 65, 773 787.
7Alm K, Peltoniemi OAT, Koskinen E, Andersson M. Porcine field fertility with two different insemination doses and the effect of sperm morphology[J]. Reprod Domest Anim, 2006, 41, 210 213.
8Bathgate R, Eriksson B, Maxwell WMC, Evans G. Low dose deep intrauterine insemination of sows with fresh and frozenthawed[J]. Theriogenology, 2005, 63, 553 554.
9Bolarin A, Roca J, Rodriguez-Martinez H, Herna'ndez M, Va zquez JM, Martinez EA, Dissimilarities in sows' ovarian status at the insemination time could explain differences in fertility between farms when frozen-thawed semen is used[J]. Theriogenology, 2006, 65, 669 680.
10Day BN, Mathias K, Didion BA, Martinez EA, Caamano JN. Deep intrauterine insemination in sows: first field trial in USA commercial farm with newly developed device[J].Theriogenology, 2003, 59, 213 (abstract).
