Age dynamics of biochemical parameters of the blood of deep-calving cows

Abstract

The study of changes in the system of metabolichomeostasis of dry-lasting cows in the winter-stable periodis important in maintaining their productive and reproductivestate whereas this periodis one of the most difficult for thebody, as the most stressful factors: lack of exercise and solarinsolation; the action of potentially pathogenic microflora andincreased level of gassiness in livestock premises; possibleinsufficiency in the nourishment of vitamins and macromicroelements. The action of stress factors causes metabolic disorders,which often occur without visible clinical features.The indicators, which changing of the state of energy,protein, vitamin and mineral nutrition of the animal body,are necessary to determine during monitoring.The dynamics of total protein content was determined bythe biuret method, albumin – by the reaction of bromocresolgreen, the activity of alanine and aspartate aminotransferases(ALT and AST) – by the Reitman-Frenkel method, theactivity of alkaline phosphatase and phosphate phosphatasecarotene content – photometric method, total calcium content– complexometric method and carotene content – photometricmethod in the blood of deep-boiled cows during the winterstable content.A decrease in total protein content was indicated incows with fourth calving in a month before calving up to76.08±2.47 g/l. Incowswiththe 4th and 6th calving, theprotein level was the lowest, in relation to other experimentalgroups of animals, and was 76.08±2.47 and 76.43±2.97 g/l,respectively. The fractional spectrum of globulins tendedto decrease in cows from the second to the fourth calving.Absolute values of ALT activity in animals with 3rd,4 rd and6th calving were 2-fold (p<0.01) lower than in the 2nd and5rd. There was also a tendency to reduce AST in older cows,but a significant decrease compared to the second pregnancywas found only in animals of the sixth calving (about 20 %).The content of total calcium in the serum of drylasting cows of all experimental periods of calving wasbelow the normal line and ranged from 2.15±0.29 mmol/lto 2.30±0.19 mmol/l. The content of inorganic phosphoruswith an increasing number of calving in dry-lasting animalsgradually decreased from 1.83± 0.19 mmol/l to 1.63±0.16mmol/l and approached the minimum limit of normal. Thecalcium-phosphorus ratio in animals in the second and thirdcalving corresponded to the minimum allowable values(1.2: 1). Increases in carotene content were observed at thefourth (0.46±0.09 μM/l), fifth (0.53±0.08 μM/l) andsixth(0.74±0.10 μM/l) calving. The index of acid capacity tendsto increase in cows with the third (412.73±15.37 mm/l)andfourth (385.00±12.17 mm/l) pregnancy. Key words: dry-lasting cows, winter-stable and drylasting period, blood serum, biochemical research.