Serum bile acid concentrations in clinically normal cattle: comparison by type, age, and stage of lactation.

Serum total bile acid concentrations were determined for various types and ages of cattle. There was extreme variability among all the cattle, but the variance was twice as large (0.50 vs 0.22 in logarithmic scale) for beef cattle than for dairy cattle. There was no significant difference in serum total bile acid concentrations between beef cattle and dairy cattle in midlactation. Values for calves < 6 weeks old and for 6-month-old heifers were significantly (P = < 0.05) lower than values for lactating dairy cows. The 5th to 95th percentile range of values (mumol/L) for beef cattle was 9 to 126; for lactating dairy cattle, 15 to 88; and for 6-month-old dairy heifers, 11 to 64.