5Chen S S, Wrathal A E. The importance of the zonal pellu- cid for disease control in livestock by embryo transfer[ J]. Br Vet J, 2003, 145(2) :129 -140.
6Eaglesome M D, Garcia M M. Disease risks to animal health from artificial insemination with bovine semen [ J ]. Rev Sci Tech, 1997,16( 1 ) :215 - 225.
7Wrathall A E, Wells D E, Cartwright S F, et al. An inacti- vated, oil -emulsion vaccine for the prevention of porcine parvovirus -induced reproductive failure[ J]. Res Vet Sci, 2004, 36(2) : 136 - 143.
8Singh V, Goh B T, Smith G W, et al. Penicillin concentra- tions in serum and cerebrospinal fluid after intramuscular injection of aqueous procaine penicillin 0.6 MU with and without probenecid [ J ]. Br J Veneer Dis, 2007,60 (6) : 371 - 376.
9Stringfellow D A,Wolfe D F, Lauerman L H, et al. Resist- ance of preimplantation bovine embryos to infection with Brucella abortus [ J ]. Am J Vet Res, 2008, 47 (9) : 1 924 - 1 927.