Attempts at storage of sheep ova at low temperatures

Abstract

Eighty-three fertilized sheep ova were stored at 0–8° C. for 6–72 hr. in sterile sheep serum or Ringer's solution and subsequently transferred to suitable recipient ewes in order to determine their viability following storage.In Exp. 1, nine out of twelve ova stored in sheep serum, but none out of five ova stored in Ringer's solution, continued development after subjection to storage at 5–8° C. for 6–9 hr. Seven out of fifteen, none of nineteen, and none of nine ova were found developing in recipients after subjection to 5–8° C. in serum for 24, 48 and 72 hr., respectively.In Exp. 2, lambs were born to recipients of four out of six ova stored for 24 hr. at 4·5–7° C, and of two out of five ova stored for 72 hr. at these temperatures. None of the recipients of twelve ova stored for 24, 48 and 72 hr. (four ova of each duration) at 0·4° C. produced live lambs.In Exp. 3, none of thirty-four ova developed after subjection to freezing to −79° C. in 12·5% glycerol in serum.