Physiological changes in hematological parameters of black-and-white cows at the beginning of lactation

Abstract

The onset of lactation can affect the condition of cows, affecting the metabolic processes throughout the body and hematological parameters. The blood parameters of high-milk cows after the first and after the second calving were evaluated in the work. 47 fully healthy pregnant cows were selected 3 weeks before the expected calving. These included first-heifers and re-calving purebred cows of a black-and-white breed. The animals were divided into two groups according to the number of pregnancies available in their lives: the group of first-born heifers consisted of 22 heads, the group of re-calves included 25 heads. The examination was performed 3 weeks before calving and 3 weeks after calving with taking blood samples. The first heifers after calving showed a decrease in the concentration of glucose, total protein and albumin with a significant increase in the concentrations of malondialdehyde, non-esterified fatty acids and globulin compared with the first study. Re-calved cows showed a significant decrease in the amount of glucose, total protein and albumin in the blood, combined with a significant increase in cholesterol and malondialdehyde levels compared to their pre-calving values. In re-calving cows, a significant decrease in non-esterified fatty acids was noted in comparison with calved first-calf cows. During the transition phase, control of the main hematological parameters is necessary for the timely prevention of pathology in first-heifers and re-lost cows.