Plasma Standard Bicarbonate and Chloride Concentrations in Cattle and Sheep

Abstract

SUMMARY The mean concentration of plasma standard bicarbonate in 168 venous blood samples from 144 cattle was 23 · 4 m-equiv./l. ( sd 1 · 59). Plasma chloride was determined in 127 of these samples and the mean concentration was 104 · 2 m-equiv./l. ( sd 3 · 92). The cattle sampled were of various beef and dairy breeds, males (castrated) and females, and were on diets varying from all-hay to high concentrate-low roughage mixtures. There was no evidence of systemic acidosis in the cattle fed high concentrate diets. A separate group of thirty-six steers had mean plasma contents of 28 · 0 ( sd 2 · 12)) m-equiv./l. standard bicarbonate and 97 · 6 m-equiv./l. ( sd 3 · 19) chloride, thus suggesting a mild metabolic alkalosis. The cause of this was not determined but could have been due to mild dehydration. Twenty miscellaneous sheep on a variety of diets had mean plasma standard bicarbonate levels of 25 · 8 m-equiv./l. ( sd 1 · 23) and 107 · 6 m-equiv./l. ( sd 2 · 78) plasma chloride and the respective values in nine sucking calves were 24 · 3 m-equiv./l. ( sd 1 · 09) and 99 · 3 m-equiv./l. ( sd 2 · 25). Repeated sampling at intervals of a few hours in a heifer and in a wether indicated only small short-term variations in plasma bicarbonate and chloride. Day-to-day variations were also quite small as indicated in five heifers sampled on five successive days.