Abstract: To discuss the effects of calcium ion concentration on ovine sperm capacitation. The sheep spermatozoa were incubated in the ovine oviduct synthesis fluid with different calcium ion concentration, then induced by calcium ionophore A23187. The results showed that the sperm capacitation was not significantly affected by adding with different concentrations of calcium ion, but the acrosome reaction rates induced by 1.7, 2 mmol/L were significantly higher than the others. The appropriate sperm enduring period of 1.7, 2 mmol/L were 16 h and 10 h respectively. It suggested that the suitable concentration of calcium ion for ovine sperm capacitation in vitro is 1.7 mmol/L, and this process should accompany with calcium ion.

Key words: ovine; sperm; calcium ion concentration; capacitation