Changes in the biochemical composition of fetal fluids and maternal blood serum during different days of gestation in cattle

The aim of this study was to determine the values of some metabolites, ions, and enzymes in maternal blood serum and fetal fluids in relation to gestation day in cattle. Gravid uteri of cattle were collected after slaughter. The allantoic and amniotic fluids as well as maternal blood samples were collected. Fetal ages were determined according to crown–rump length by applying the age estimation formula that previously was presented for cattle. The pregnancies were divided according to gestation days into four groups: 0–50, 51–100, 101–150, and 151–200?days. With the progress of pregnancy, the biochemical levels of fetal fluids and maternal serum changed as follows: there was a rise of total protein, urea, creatinine, and alkaline phosphatase values in fetal fluids and serum; the levels of glucose in maternal serum and potassium in fetal fluids increased; cholesterol, triglyceride, phosphorus, and sodium contents of fetal fluids and serum decreased; the concentrations of glucose and calcium in fetal fluids, lactate dehydrogenase (LDH) in serum and allantoic fluid, potassium in serum, and aspartate aminotransferase (ASAT) in amniotic fluid and serum dropped. The values of LDH in amniotic fluid, ASAT in allantoic fluid, alanine aminotransferase in amniotic and allantoic fluids, and calcium in maternal serum remained unchanged.