Blood biochemical parameters of simmental cows in different phases of reproductive cycle

This paper presents the values of blood biochemical parameters of Simmental cows (n = 60), divided into five groups (dry cows, early puerperium, late puerperium, the fifth month of lactation, and cows with an extended service period). The ration for lactating cows contained an insufficient amount of dry matter, a third less than the lower limit of their requirements. In all examined groups of cows, a strong protein deficiency and excess calcium was found in the diet. Total protein concentration in all groups of cows were on the upper physiological limit, and the concentrations of bilirubin, carotene, vitamin A and total lipids were within the normal range. Low concentrations of urea in the third, fourth and fifth group of cows (3.1?0.39 mmol/l, 2.9?0.38 mmol/l and 3.3?0.43 mmol/l, respectively) indicate the imbalance of protein and energy in the diet. The presence of an energy deficit is also indicated by the low blood glucose in all groups of cows, especially the second and fifth groups of cows (2.2?0.04 mmol/l and 2.3?0.07 mmol/l, respectively). The unfavorable ratio of calcium and phosphorus in the diet resulted in the narrowing of the calcium:phosporus ratio in blood serum, which is particularly evident in cows with an extended service period (2.1?0.07 mmol/l compared to 1.9? 0.11 mmol/l). Based on these results,we conclude that the tested herd exhibits subclinical health disorders, caused by an inadequate diet and with adverse effects on the productive and reproductive parameters.