Abstract: Blood gas index in venous blood of 12 Yili horses in different stages of 1000 m trot training (motionless, after the warming up, after the game instantly, 15 min, 30 min, 60 min) were detected by i-STAT blood gas analyzer, and the differences and correlation of the blood gas index were analyzed. The results showed that before and after exercise PvCO₂, PvO₂, HCO₃, TCO₂, SvO₂ and Glu of the venous blood did not change significantly (P>0.05). Blood pH, BE and Ca²⁺ were lower immediately after the game, but after 15 min rest basic rebounded to motionless level. K⁺, Hct and Hb immediately after the game were significantly increased (P<0.05), but after 15 min rest basic back down to motionless levels. Blood pH value was highly significant positive correlation with BE and HCO₃ (P<0.01), and significantly positive correlation with the TCO₂ concentration (P<0.05), Hct, Hb were highly significant negative correlation with pH, HCO₃(P<0.01),Hct, Hb were highly significant positive correlation with K⁺(P<0.01). The analysis showed that BE, HCO₃, TCO₂, Hct and Hb on acid-base balance all had certain adjustment, Na⁺, K⁺ and Ca²⁺ on the body movement had certain adjustment.

Key words: Yili horse; trot; blood gas index