Impact of the fetal age and litter size on the electrolytes levels in ovine fetal fluids

The main objective of this work is to study the influence of the fetal age and litter size on the mineral composition (Ca, P, Mg, Na, K and Cl) of fetal fluids and maternal plasma during pregnancy in ewes. Blood samples were collected from local abatttoir before slaughtering and a total of 102 gravid sheep uteri were collected agter evisceration. Amniotic and allantoic fluids are aspirated separately into plastic tubes and were subjected to biochemical analysis. The pregnancies were divided according to gestation days into 4 stages: S1 (0–60 days), S2 (61–90 days), S3 (91–120 days) and S4 (121–145 days). With the advancement of pregnancy, Ca levels decreased (p<0.001) in plasma and amniotic fluid, P and Na decreased significantly in fetal fluids. Plasma Mg decreased and Mg levels of fetal fluids increased in all groups. A significant increase (p<0.01) of plasma K was reported on S2 and then gradually decreased to S 4 of pragnancy. The litter size affected significantly plasma concentrations of Ca, Mg, Na, K and Cl. It also influenced the Ca of the amniotic fluid and the levels of P, Mg, Na, K and Cl of both fetal fluids. In conclusion, the influence of the fetal age and the litter size on the mineral profile was statistically significant; it can be used to predict metabolic problems before calving and during the postpartum period for the assessment of the nutritional status of the animals.