VARIATIONS OF LIPID CONCENTRATIONS IN THE BLOOD-PLASMA OF PREGNANT SOWS

Variations of plasma volume (PV) and variations of triglyceride, cholesterol, total lipid, beta-lipoprotein and phospholipid concentrations in the blood plasma were investigated in trials with ten sows, crossbreds of the White Thoroughbred and Landrace breeds, at the age of 2-3 years, kept on a defined diet; the trials were performed before the sows became pregnant and during their pregnancy (days 1-40, 41-60, 61-80, 81-100 and 101-120). The PV in nonpregnant sows is 9.8 +/- 0.33 1. Following a decrease to the values of 7.8 +/- 0.33 1 (p < 0.01) in the first 40 days of pregnancy the plasma volume increases in the successive periods and it makes 15.4 +/- 0.19 1 at the end of pregnancy (p < 0.001). Total lipaemia decreases during pregnancy from 2.80 +/- 0.054 in nonpregnant sows to 2.49 +/- 0.245 g per 1 in sows at the end of pregnancy. Cholesterol concentrations in the blood plasma also decrease from 2.48 +/- 0.53 in nonpregnant ones to 1.88 +/- 0.173 mmol per 1 (p < 0.001) in sows at the end of pregnancy, beta-lipoprotein concentrations from 3.95 +/- 1.134 in nonpregnant ones to 3.47 +/- 0.199 g per 1 in sows on days of pregnancy 81-100 (p < 0.05), phospholipid concentrations in the first 60 days of pregnancy from 1.62 +/- 0.079 before insemination to 1.29 +/- 0.05 mmol per 1 in sows of 41-60 day pregnancy. Triglyceride concentrations in the blood plasma increase during the pregnancy period from 0.42 +/- 0.016 mmol per 1 in nonpregnant sows to 0.57 +/- 0.098 mmol per 1 in highly pregnant sows (p < 0.02). But in the first 40 days of pregnancy triglyceride concentrations decrease to 0.39 +/- 0.036 mmol per 1, in the following period of pregnancy they increase and reach the highest concentrations in sows on days of pregnancy 101-120. Increases in the absolute amounts of total lipids on the one hand, and of cholesterol, beta-lipoproteins and phospholipids at a rate of 1.2-1.4 times and in those of triglycerides at a rate of 2.1 times on the other hand are related to the increase in PV of sows at the end of pregnancy. The variations of fatty components in the blood plasma of sows during their pregnancy are compared with findings concerning these variations in the blood plasma during the pregnancy of females of other animal species.