Influence of modified Tyrode's media on motility of cold-stored stallion spermatozoa


Two experiments were conducted to determine if the nonelectrolyte components of a modified Tyrode's media could be eliminated without affecting the percentage of stallion spermatozoa which recovered motility after storage at 5°C. In the first experiment, diluents tested included the traditional 2.4% skim milk-5% glucose extender frequently used in the industry or that same extender supplemented at a 65:35 (vol/vol) basis with either the modified high-potassium Tyrode's media (MT) or that same media minus lactate and pyruvate (MT-LP), bovine serum albumin (MT-BSA) or lactate, pyruvate and bovine serum albumin (MT-BSA,LP). Three ejaculates were collected from each of 4 stallions. For each ejaculate and test diluent combination, two aliquots of semen were cooled in a static cooling device. One aliquot was diluted and cooled after the seminal plasma was removed by centrifugation and the second aliquot was diluted and cooled without removing the seminal plasma. The percentage of motile sperm was higher (P < .05) following 24 and 48 hours of cold storage for spermatozoa cooled in MT or MT-BSA compared with spermatozoa stored in SKMG, MT-LP or MT-BSA, LP. Removal of seminal plasma was beneficial (P < .01) when spermatozoa were stored for 48 hours in MT and MT-BSA. In the second experiment, all aliquots were centrifuged to remove seminal plasma prior to resuspension in one of four test diluents which consisted of MT-BSA and SKMG with and without the HEPES buffer (MT-BSA+HEPES, MT-BSA-HEPES, SKMG+HEPES and SKMG-HEPES). Exclusion of HEPES buffer from the Tyrode's media was not detrimental to the recovery of motile spermatozoa (P < .05). There was no advantage (P < .05) to the inclusion of HEPES in the skim milk; motility of spermatozoa stored in the media supplemented with the modified Tyrode's was superior (P < .05) to those which were not stored in diluents supplemented with Tyrode's. © 1995 William E. Jones.

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Journal of Equine Veterinary Science