The effect of recombinant colicin E2 on some geriatric markers in the blood of lactating cows aged 5-6 years

The increase of productive longevity of dairy cows is a current problem in the animal breeding. In this regard, the study of changes of geriatric parameters in elderly cows and the evaluation of preparations affecting gerontological processes is an important scientific and practical task. The effect of recombinant colicin E2 on some geriatric parameters of lactating cows aged 5-6 years over a period of eight months has been studied. Two groups of healthy lactating cows (control and experimental) of eight heads each were formed. During the experiment the medicine was introduced to the cows of the experimental group intramuscularly in the dose of 500 mg twice a month. During the experimental period the blood of the control group showed a 40 % decrease in the telomere length of lymphocytes and an 8 % decrease in the amount of melatonin. The amount of inflammatory mediators increased significantly in the blood of control animals - prostaglandin E2 from 86.4±7.1 pg/ml to 124.5±5.2 pg/ml (P<0.05) and matrix metalloproteinase from 14.8±0.2 ng/ml to 34.2±0.5 ng/ml (P<0.05). By using the recombinant colicin E2 in cows of the experimental group, no decrease in the telomere length of lymphocytes was detected. Increase in the quantity of interleukin 4 and interferon alpha in the blood was noted. Stimulation of cytokine production of interleukin 4 and interferon alpha by recombinant colicin E2 in the blood of cows of the experimental group regulated the activation of lymphocytes having receptors to melatonin. The quantity of melatonin in the blood of experimental cows increased from 28.6±0.8 pg/ml to 38.5±1.4 pg/ml (P<0.05), and the quantity of matrix metalloproteinase remained stable.