Sucrose and bovine serum albumin in association with dimethylformamide improved sperm parameters of frozen stallion semen

Postthaw stallion sperm integrity was determined after freezing semen in an extender supplemented with several sucrose concentrations, bovine serum albumin (BSA), and with and without dimethylformamide (DMF). Two ejaculates from 6 stallions (n =12) were diluted and aliquots (n = 7) were made for treatment groups (25 mM sucrose + BSA [S25], S25 + DMF [S25DMF], 50 mM sucrose + BSA [S50], S50 + DMF [S50DMF], 100 mM sucrose + BSA [S100], S100 + DMF [S100DMF], and Control (only DMF). Semen was frozen in a computer-controlled freezer. Sperm postthaw motility (total and progressive) and kinetics were assessed using CASA. Postthaw sperm plasma membrane and acrosomal integrity were evaluated using SYBR-14/PI and FITC-PNA, respectively. Sperm motility was higher in S100DMF and S50DMF. Plasma membrane integrity was higher in S100DMF, S50DMF, and S100. As sucrose concentration increased, plasma membrane integrity increased. Treatment groups with sucrose and BSA, regardless of DMF, had higher acrosome integrity than Control. Sucrose and BSA in association with DMF in a freezing extender protected sperm integrity during freezing and thawing.