Comparative evaluation of the influence of vaccinal stress on a number of physiological indicators, productivity and quality indicators of cows

The article presents the results of studies devoted to the influence of vaccination stress (stress related to the category of experimental stresses) on physiological indicators in terms of general clinical and biochemical blood analysis, productivity indicator and quality milk indicators of second lactation cows and first-calf cows. It has been found that in contrast to second lactation cows first-calf cows under the influence of a stress factor exhibited a longer adaptation process, which has been expressed in a significant increase in the number of erythrocytes in the blood 24 hours after the vaccination by 3.5 % to the values of the background sample, and also a decrease in the number of lymphocytes by 7.5 % against the background of a stable value of the total index of leukocytes, while an increase in the value of hematocrit observed by more than 10%. When studying the biochemical composition of blood plasma this state has been expressed by an increase in the value of glucose, and this is more pronounced on the first day after exposure to the stimulus (by 21.5 % to the background sample). 72 hours after vaccination the value of the change in the glucose index both in the group of first-calf heifers and in the group of second-lactation cows have been significantly less changed in comparison with the background indicators, in first-calf cows by 9.3 % 1.5 % in the group of cows. Regarding the effect of vaccination stress on productivity and milk quality indicators it is worth noting a decrease in milk yield in the first 2 days in both groups of animals, as well as a significant decrease in the content of fat mass in the milk of first-calf cows by 8.3 % percent.