Effect of ethionine on hematologic and serum biochemical values in fasted calves.

DL-Ethionine (0.87 g/kg of body weight) was administered IV to 6 fasted (12 hour) Holstein bull calves (4.5 months old). Fasting, which was continued for an additional 48 hours, caused a body weight loss (10.82% to 11.96%), a mild increase in PCV, and an increase in the serum free fatty acids (1.204 mmole/L, fasted; 0.949 mmole/L, fasted ethionine-treated calves). Ethionine caused a decrease in the total plasma proteins from 6.5 g/dl to 5.5 g/dl and total serum lipids from 493.9 mg/dl to 307.8 mg/dl. The decrease in the serum esterified fats included all the lipid fractions (triglycerides, cholesterol, and phospholipids). The calves' WBC and serum enzymes aspartate aminotransferase and L-alanine aminotransferase remained within normal range.