The effect of gestation and lactation of dairy cows on lipid and lipoprotein patterns and composition in serum during winter and summer feeding

Abstract

Studies were carried out on lipid and lipoprotein fractions in the serum of cows during summer and winter feeding. The experimental group comprised 32 Black-and-White cows in the final stage of pregnancy (2-3 weeks before calving) or in the 6th week of lactation. Total serum lipid (2.51 g/1) and cholesterol (2.51 mmol/1) concentrations were significantly lower (P<0.01) in cows subjected to drying than in lactating animals (3.29 g/1 and 3.86 mmol/1, respectively), irrespective of the feeding period. In contrast, the serum triglycerides concentration was 0.34 mmol/1 in cows before calving and twice as high than during lactation. It was also shown that HDL constituted the main fraction, and that HDL in cows prior to calving represented about 74% of serum lipids, increasing to about 80-85% during lactation. The LDL concentration was lower, representing, on average, 22% in dry cows, and 13-15% in the 6th week of lactation. Prior to calving, triglycerides represented over 40% of LDL, 32% was represented by cholesterol. In the peak of lactation the TG fraction in LDL decreased to 14-19%, while that of cholesterol increased to over 45%.

The Effect of Seasonal Thermal Stress on Lipid Mobilisation, Antioxidant Status and Reproductive Performance in Dairy Cows

“…). In addition, low cholesterol and HDL‐C concentrations from 1 week prior to calving until 1 week after calving could be a consequence of higher nutrient demands of the foetus for its growth and development, as well as of maternal reproductive glands for steroid hormone synthesis (Grummer ; Pysera and Opalka ; Turk ).…”

“…These changes are typical patterns during NEB where dietary and tissue-derived nutrients are allocated to the mammary gland to support milk production (Mazur et al 1988;Turk et al 2008). In addition, low cholesterol and HDL-C concentrations from 1 week prior to calving until 1 week after calving could be a consequence of higher nutrient demands of the foetus for its growth and development, as well as of maternal reproductive glands for steroid hormone synthesis (Grummer 1993;Pysera and Opalka 2000;Turk 2009). In the present study, bilirubin concentration significantly increased only in the summer group from calving to 2 weeks post-partum compared to the basal value, and those values were significantly higher compared to the winter group.…”

Biochemical and Haematological Blood Parameters at Different Stages of Lactation in Cows

“…Cholesterol presented the lowest average values on day 3 post-partum (106.3 mg/dl) and the highest on day 7 post-partum (126.4 mg/ dl). Cholesterol is influenced by the state of pregnancy, the time and number of lactations according to studies by Pysera et al (2000) and Nath et al (2005 Total protein presented the lowest average values at day 1 post-partum (6.62 g/dl) and increased in the coming days post-partum reaching the highest values on day 7 (7.88 g/dl). High levels of total proteins may be caused by various diseases, mastitis, the influence of the metabolism, and nutrition and lactation (Rowland et al, 1975 …”

Effects of Dietary Sodium Monensin on the Metabolic and Hormonal Profiles of Dairy Goats During the Peripartum Period

“…Some studies in goats and dairy cows show a decrease in prepartum cholesterol levels due to its requirements for fetal growth and steroid hormone synthesis. In turn, in the postpartum period, concentrations of cholesterol in dairy animals reach their maximum, as there is a gradual increase due to glucagon influence and the synthesis of plasma lipoproteins (22,27,28,29) . In the present study, this increase was not verified, possibly because of the variability of factors such as milk production, lactation period, and the diet provided.…”