1. Plasma urea, creatinine, bilirubin, glucose, cholesterol and total serum proteins were determined in Danish landrace goats from five herds in early and late gestation, during lactation and in dry goats. The purpose was to determine if there are sustained alterations in the levels of these parameters due to pregnancy and lactation and whether the changes are dependent on age, parity and environment. 2. Urea, creatinine and bilirubin were higher in young non-pregnant goats than in others. Urea decreased in goats at early and mid-lactation directly proportional to parity so that the higher the parity the more the decrease. 3. Creatinine was higher in young and adult non-pregnant goats than in others. There was an increase in late lactation that was greater in goats of higher parity than in others. 4. Bilirubin was higher in the mid-lactation stage, much more in goats of higher parity than in others. 5. Glucose concentration was lower in pregnant than in lactating goats and increased during lactation. The decrease during pregnancy was greater in higher parity goats than in others. 6. Plasma cholesterol and total serum proteins increased during lactation directly proportional to parity. 7. There were significant differences in biochemical parameters between goats from different herds (within similar physiological states). 8. Sustained alterations of these biochemical parameters occur during pregnancy and lactation in goats; the magnitude of changes depends on age and parity, and varies between herds.