2SMITH A U,POLGE C.Storage of bull spermatozoa at low temperature[J].Vet Rec,1950,62:115-117.
3PURDY P H The post-thaw quality of ram sperm held for 0 to 48h at 5℃ prior to eryopreservation[J].Animal Reproduction Science,2006,93:114-123.
4POLGE C,SMlTH A U,PARHES A S.Revival of spermatozoa after vitrification and dehydration at low temperature[J].Nature,1949,164:666.
5FISHER P S,FAIRFULL R W,MARCUS G J.The effect of thawing velocity on survival and acrosomal integrity of ram spermatozoa frozen at optimal and suboptimal rates in straws[J].Cryobiology,1986,23:141-149.
6JANSEN H B.The influence of cool rates practiced in the Netherlands on the survival of bovine spermatozoa packaged in 0.25 mL French straws[C]//Proceeding of 11 Internationl Congress on Animal Reproduction and Artifieial Insemination,1988,3:258.
7PONTBRIAND D,HOWARD J G,SCHIEWE M C,et al.Effect of cryopmtective diluent and method of freeze-thawing on survival and acrozomal of ram spermatozoa[J].Cryobiology,1989,26:341-354.
