Lipid metabolism in primiparous cows with a various state of the reproductive system

Abstract

Modified lipid metabolism has a negative effect on the fertility of cows. The aim of the research was to study lipid metabolism in the pre- and postpartum periods in primiparous cows with different signs of the impaired reproductive function. At 8, 6, 4 and 2 weeks before calving and 2 and 7 weeks after calving, the animals were bled to analyze the content of phospholipids and triglycerides. Based on the assessment of the functional state of the ovaries 7 and 9 weeks after calving, the cows were divided into three groups: I - without signs of ovarian hypofunction (n = 31), II - with moderate ovarian hypofunction (n = 13), III - with deep ovarian hypofunction (n = 14). After 12 months of lactation, animals without a diagnosis of deep ovarian hypofunction were divided into 3 groups: 1 - with an open days period of less than 125 days (n = 12), 2 - with an open days period of more than 125 days (n = 21), and 3 - cows that remained infertile (n = 11). The phospholipid concentration increased 1.6-1.9 times (p<0.001-0.05) between the 2nd and 7th weeks after calving in the blood of cows of all studied groups. Meanwhile, in groups II and 3, it decreased 1.4-1.5 times (p<0.05) between the 4th week before calving and the 2nd week of lactation. Seven weeks after calving, the phospholipid content in the blood of group I animals was 1.2-1.4 times higher (p<0.001-0.05) than in animals of groups II and III. In addition, this indicator after 2 and 7 weeks of lactation was 1.4-1.5 times higher (p<0.05) in group 1 than in group 3. The concentration of triglycerides decreased by 1.3 times (p<0.05) between the 2nd week before calving and the 2nd week after calving in the blood of group I cows and by 1.5-1.6 times (p<0.05) between the 6th week before calving and the 7th week after calving in groups II and III. In group 1, it increased 1.6 times (p<0.05) between the 8th and 2nd weeks before calving, and then decreased 1.5 times (p<0.05) by the 2nd week of lactation. This indicator decreased 1.4 times (p<0.01) between the 2nd week before calving and the 7th week of lactation in group 2 and did not change throughout the observation period in group 3. After 7 weeks of lactation, the content of triglycerides in the blood was 1.4 times higher (p <0.05) in group I than in groups II and III and was 1.3 times higher (p <0.05) in group 1 than in group 2. The data obtained suggest that the peculiarities of lipid metabolism during the pre- and postpartum periods are associated with various states of the reproductive system in primiparous cows.