Dynamics of biochemical parameters of blood of cows during the dry period for stall keeping

Abstract

The period of stable keeping of cows is one of the most difficult periods for the body, as it is the most saturated with stressful influences, and precisely due to the lack of solar insolation and exercise, the action of potentially pathogenic microflora and increased gassing of livestock premises, shortage vitamins, micro- and macroelements in feed. Deep calving animals have metabolic disorders without clinical signs. Such a form pathologies can be detected only through biochemical research.The content of total protein was determined by biuret`s method, albumins ‒ by reaction with bromocresol green, activity alanine and aspartate aminotransferase ‒ by the Reitman-Frenkel method, activity alkaline phosphatase ‒ with disodium phenyl phosphate, acid capacity ‒ by Bolshakov-Belyaev technique, carotene content ‒ by photometric method, content of total calcium ‒ by the complexometric method, the content of carotene ‒ photometric method. The purpose of our work was to study the dynamics of protein and mineral meabolism in cows during the dry period for stall keeping. The object of the study was cows (15 heads) of the Holstein breed with a milk yield of 5‒6 thousand kg per lactation for 8‒9 months of pregnancy. It was found that the total protein of the cows organism decreased in the last months of pregnancy during the dry period from 87.25 ± 1.20 to 81.60 ± 1.20 g/l (Р < 0.05), including the globulin fraction from 51.96 ± 2.08 to 43.75 ± 2.07 g/l (Р < 0.05) and other indicators of protein metabolism changed. The g-globulin fraction significantly decreased from 28.53 g/l to 22.97 g/l (Р < 0.01). In our opinion, this is due to a decrease in the activity of the mother's body defenses to prevent the development of a reaction to the fetal tissue, which is a foreign organism. The activity of aspartate aminotransferase decreased by 8.5 months of pregnancy to 150.26 ± 13.59 nM/s·L (Р < 0.01), and then tended to increase to 187.19 ± 9.21 nM/s·L (Р < 0.05). Such a change in the activity of this enzyme in late pregnancy is associated with an increase in the processes of self-renewal of proteins due to transamination, which can be used more intensively by the fetus. The calcium content decreased by 1.14 times during the dry period. This fact, in our opinion, is associated with the intensive development and formation of the fetal skeleton. This is also evidenced by a significant increase in the activity of alkaline phosphatase (1.29 times, Р < 0.01). Changes in total calcium and inorganic phosphorus were strongly correlated (r = 1.0). The results obtained allow us to point out the causes of the identified deviations and offer recommendations for their elimination and correction of animal feeding.