Abstract: | The indices of the acid-base homeostasis of the blood were studied in 99 sows of the Large White, English Large White, Belgian Landrace, and Hampshire breeds. The blood pH ranged from 7.32 to 7.45, and no significant differences were found between the breeds. The highest pCO2 value of 6.4 kPa was found in the LW breed; in the remaining breeds it was lower. As to base excess values, positive average values ranging from +0.3 to +1.4 mmol .1-1, were found in all the breeds. The values of the buffering stage were fairly balanced and the means ranged from 48.7 to 50.0 mmol .1-1. Balanced average values were also found in standard bicarbonate, where the values ranged from 24.6 to 25.5 mmol .1-1. Actual bicarbonate showed similar values in the Large White breed (27.3 mmol .1-1), English Large White, and Hampshire (26.2 and 26.3 mmol 1-1, respectively). In the Landrace breed the average was only 25.9 mmol .1-1. The average values of CO2 in the blood plasma ranged from 27.1 to 28.7 mmol .1-1. |