3BRACKETT B G,ZUELKE K.Analysis of factors involved in the vitro production of bovine embryos[J]. Theriogenology, 1993,39:43 - 64.
4WANG W L,JIANG L H,LU K H,et al.Effect of condition medium and glucose concentration on the in vitro development of early bovine embryos[J].Theriogenology,1990,33:343.
5COSKUN S, LIN Y C. Mechanism of action of epidermal growth fartor induced porclne oocyte maturation[J] .Mol Reprod Dev,1995,42:311-317.
6DOWNS S M. Specificity of epidermal growth factor action on maturation of the murine oocytes and cumulus oophorus in vitro[J] .Biol Reprod, 1989,41:371- 379.
7PALMA G A,BERM G. Effect of gowth factors IGF-1, IGF-2, EGF and PDGF on development of in votro produced bovine blastocysis[ J ]. Theriogenology, 1995,43:291.
