Blood gas and acid-base values in the coccygeal artery of Holstein-Friesian cows.

The pH, Pco2, Po2, HCO3-, and CO2 content were determined in the blood of the coccygeal artery in l08 Holstein-Friesian cows. The mean values obtained at 39°C and 37°C (in parentheses) were: pH 7.464 (7.494), Pco2 39.1 (35.9) mmHg, Po2 107.2 (93.0) mmHg, HCO3- 27.4 (26.8) mEq/L and CO2 content 28.4 (27.9) mEq/L. Between blood samples from the coccygeal artery and those from the jugular vein of 35 of the total cows collected simultaneously, a correlation was observed in the pH, HCO3- and CO2 content, but no Correlation was found in the Pco2 and Po2 values. The correlation between the blood pH and the rumen fluid pH was not significant in 22 of the total cows examined.