Use of different nonglycolysable sugars to maintain stallion sperm viability when frozen or stored at 37 degrees C and 5 degrees C in a bovine serum albumin medium.

Bovine serum albumin (BSA) diluents containing lactose, raffinose or sucrose were not different (P greater than 0.05) in their ability to maintain stallion sperm viability, as determined by percentage motile spermatozoa (PMS) and their rate of forward movement (RFM), when stored at 37 or 5 degrees C for 24 h. These diluents did promote a higher (P greater than 0.05) PMS and RFM, when compared with BSA diluents containing arabinose or galactose. The BSA-arabinose and BSA-galactose diluents did not differ (P less than 0.05) in their ability to support sperm viability and were detrimental to spermatozoa. The fertility of freshly collected and diluted spermatozoa was not different (P greater than 0.05) when extended in BSA diluents containing lactose, raffinose or sucrose. There was no difference (P greater than 0.05) in PMS and RFM of frozen-thawed stallion spermatozoa when the spermatozoa were frozen, thawed and incubated at 37 degrees C for 180 min in BSA diluents containing lactose, raffinose or sucrose. Spermatozoa from 6 of 8 stallions did not survive the freezing process. A one-cycle conception rate of 32% was obtained from frozen-thawed spermatozoa extended in BSA diluents containing lactose, raffinose or sucrose. This rate was 78% of the conception rate obtained when the same mares were inseminated with fresh semen in a subsequent study (41%).