Heiskanen M L, Pirhonen A, Koskinen E, Mäenpää P H
State Horse Breeding Institute, Ypäjä, Finland.
J Reprod Fertil Suppl. 1987;35:103-7.
The role of various environmental conditions on sperm motility and ATP content was investigated by incubating raw and washed spermatozoa collected with an open-ended artificial vagina from 10 stallions in various biological and artificial media under different atmospheric conditions. Spermatozoa did not survive for more than 12 h when kept unextended in the original seminal fluid in any circumstances. The most favourable media tested for long-term sperm survival were Kenney's medium or Kenney's medium supplemented with 10 mM-theophylline and 10 mM-Hepes, pH 7.2. Centrifugation and slow cooling to 5-7 degrees C improved the survival as did incubation in atmosphere containing 5% CO2 or in a closed plastic bag with no air-space. In the most favourable circumstances, spermatozoa could stay alive, in some instances, for up to 4-5 days. The pregnancy rates 16 days after oestrus in mares inseminated with extended and cooled spermatozoa stored for 24 h were 82% (n = 11) and 70% (n = 10) per first oestrous cycle for Kenney's medium and the supplemented Kenney's medium, respectively.
