Survey of cellular mechanisms of nonspecific immunity in newborn calves with hypotrophy

The own immune defense in newborn calves is represented mainly by phagocytosis and lymphocytic reactions. The aim of the study was to investigate the cellular mechanisms of nonspecific immunity in hypotrophic calves. The material of the study was blood cells of newborn calves with hypotrophy (experimental). The results were compared with those of physiologically developed calves (control). The study was conducted using unified hematological, immunological and cytochemical methods. Hypotrophy was diagnosed by clinical and morphological signs. The content of WBCs, phagocytic reaction of neutrophils, myeloperoxidase, neutrophil cationic proteins and their general bactericidality (NBT) were determined. The results obtained in calves with hypotrophy were compared with similar data in healthy calves. Hypotrophics had more (p<0.05) banded neutrophils (%) on day 1 – by 27.7; day 3 – by 31.2, day 6 – by 22.0 and day 9 – by 25.6, as well as segmented neutrophils, on day 1 – by 26.1 and on day 6 – by 69.6. The number of phagocytic neutrophils in hypotrophics was lower (p<0.05), on day 1 – by 55.7; day 3 – by 58.2; day 6 – by 66.2; day 9 – by 67.5 and day 12 – by 40.3%. The maximum decrease in myeloperoxidase activity in hypotrophs was found on day 3 - by 40 % (p<0.05). The content of cationic proteins in both groups of calves was lower than the norms, and in hypotrophics it was lower (p<0.05) than in the control, respectively, on day 6 - by 33.3; on day 9 - by 57.1 and on day 12 - by 40 %. The values of the unstimulated NВT were significantly lower (p<0.05) on day 6 – by 35.9 and on day 9 – by 24.3 %. The minimal decrease was found on day 6 – 7.30.5 units, and on day 12 the index exceeded the relevant value in control animals by 30.9% (p<0.05). Indicators of the stimulated NВT in hypotrophs were lower (p<0.05) on day 3 – by 34.7; on day 6 – by 48.1; on day 9 – by 49.8 and on day 12 – by 36 %. Thus, the nonspecific resistance of hypotrophic calves is characterised by a decrease in the basic enzymatic activity of neutrophils and their stimulation reserves.