The effect of repeated intracistern administration of hyaluronidase on the mammary gland in cows

The aim of the research was to determine the effect of a five-fold intracistern injection of a solution containing 1,280 units of testicular hyaluronidase on the udder tissues of lactating cows. During the experiment, it was found that after the first dose of the drug, the electrical conductivity of milk increased by 0.8 ms/cm (P<0.05), and on the third day decreased to the initial values. As a result of the first infusion, a significant increase in the level of somatic cells in the secretion was recorded, which was 2.4 times (P<0.001). Subsequent administration of the enzyme potentiated the reactivity of the mammary gland, which led to a further increase in the cellular response. The maximum concentration of inflammatory response cells was reached after the fifth injection of the drug, which was more than three times higher than the baseline values before the start of the experiment (P<0.001). Discontinuation of intracistern hyaluronidase injections contributed to a decrease in the indicator. Morphological changes in the blood under the influence of the drug were characterized by a relative increase in the level of neutrophils by 8.3% (P<0.01), with a decrease in the absolute index of monocytes by 7.1 times (P<0.05). The data obtained demonstrate the need for further studies of the effect of hyaluronidase on breast tissue.