Effects of media NaCl concentration and osmolarity on the culture of early-stage porcine embryos and the viability of embryos cultured in a selected superior medium.

One- and 2-cell porcine embryos were obtained from oviductal flushes and cultured for 96 hours in media with varied osmolarity that resulted from alterations in NaCl and sorbitol content. The viability of experimental embryos cultured to advanced stages was determined by comparison with that of the controls, noncultured embryos transferred to recipient gilts. The data suggest that variation in embryonic development in the experimental media is related to the NaCl concentration rather than to osmolarity. Increased NaCl concentration impairs development of the embryos to the advanced morula/blastocyst stages (P<0.001). There was no difference in the pregnancy rate between the recipients of cultured (45%) and noncultured (57%) embryos on Day 25. There was, however, a higher embryonic survival rate (P<0.05) within the control gilts.