6D. Marois, J. R. Brisbane, J.-P. Laforest. Accounting for lactation length and weaning-to-conception interval in genetic evaluations for litter size in swine. J. Anim. Sci., 2000,78:1 796-1 810
7Variey M A,Coie D J.Studies in sow reproduction: 5. The effect of lactation length of the sow on the subsequent embryonic development. Anita Prod,1976,22(1):79-85
8Hays V W, J. L. Krug, G.L. Cromwell, et al, Effect of lactation length and dietary antibiotics on reproductive performance of sows. J. Anim. Sci., 1978,46:884-891
9Beistra BA, Diekman MA, Richert BT. Effects of lactation length and an exogenous progesterone and estradiol-17beta regimen during embryo attachment on endogenous steroid concentrations and embryo survival in sows. Theriogenology, 2002,57(8):2 063-2 081
10H. J. Willis, L. J. Zak, G. R. Foxcroft. Duration of lactation, endocrine and metabolic state, and fertility of primiparous sows. J. Anim. Sci., 2003,81:2 088-2 102
