2020-03-172020-03-172015-06FRANCISCO JÚNIOR, A.; OLIVEIRA, R. A.; OLIVEIRA, F.; OLIVEIRA FILHO, B. D.; GAMBARINI, M. L. Cisteína como antioxidante para a criopreservação de sêmen de garanhões considerado de baixa congelabilidade. Revista Brasileira de Reprodução Animal, Belo Horizonte, v. 39, n. 2, p. 301-306, abr./jun. 2015.e- 1984-3143http://repositorio.bc.ufg.br/handle/ri/18852The aim of this experiment was to evaluate the effect of in vitro addition of cysteine (CIS) as antioxidant used for frozen semen of "bad freezer" stallions. Three semen samples from seven stallions were obtained by artificial vagina, diluted in commercial extender (Botusêmen) and splited in two treatments: control and CIS (2.5 mM of cysteine) and cryopreserved. After post-thaw, the analyzed parameters were: computerized analysis of sperm movement characteristics and acrosmal and plasma membrane integrity by fluorescent probes. Total and progressive motility were higher (P < 0.01) in CIS group (23.95 ± 3.33; 4.66 ± 0.84) when compared with control group (11.38 ± 2.35; 2.04 ± 0.36), respectively. Regarding plasma and acrosomal membrane integrity there was no difference (P > 0.05) (12.5 ± 2.6 x 15.1 ± 2.6 and 24.2 ± 3.6 x 25.4 ± 3.85, respectively) between the control and cysteine group. It is known that the motility is highly correlated with fertility so these results suggest that the addition of 2.5 mM of cysteine in the frozen extender medium before cryopreservation increases the seminal quality of "bad freezer" stallions.porAcesso AbertoAntioxidantesCongelabilidadeEquinoMangalarga marchadorSêmenAntioxidantsEquineFreezabilityArtigo