The Effects of Various Levels of Sodium Citrate, Glycerol, and Equilibration Time on Survival of Bovine Spermatozoa after Storage at −79° C

Open Access
Publisher Website
Google Scholar
Abstract
The optimal combination of per cent sodium citrate, per cent glycerol (by volume), and equilibration hours which would allow maximum survival of bovine spermatozoa after being frozen for 5 days by use of dry ice was determined. The sodium citrate-yolk glycerol diluent contained approximately 24% yolk in the final dilution. A dilution rate of 20 million spermatozoa/ml of diluted semen was used. A three dimensional central composite experimental design was employed, involving the calculation of a response equation and the use of surface fitting techniques. The estimated optima were: sodium citrate, 2.9%; glycerol, 7.6%; equilibration time, 14.9 hours. As equilibration time was decreased, per cent survival decreased only slowly. An interaction between sodium citrate and glycerol was noted. Although semen from bulls was different, the pattern of response to treatments was the same with only absolute magnitude of response variable. An eosin-aniline blue live-dead stain was not satisfactory for estimating live spermatozoa when used on freshly thawed semen samples.