Development of hypoxia in hens with dermanyssosis

The study object was industrial Hy-Line laying hens (Nizhny Novgorod Region, Russia). According to the results of the poultry building inspection for parasites, an extreme mite contamination with D. gallinae was found in the premises where the birds from the experimental group were kept. The control group was free of parasitic agents. Blood was taken from hens before morning feeding. We used classical morphophysiological, and physiological and biochemical methods of blood analysis. Hens with the D. gallinae parasitism have a pronounced anemia syndrome, and hemic hypoxia as a consequence. At the same time, they showed a significant decrease in erythropoietin concentration in the blood which is 3.9 (p < 0.001) lower than the control; and a significant decrease in hemoglobin concentration by 21.8 % (p < 0.01) and an erythrocyte count by 1.4 (p < 0.01) compared with healthy birds. Hens with dermanyssosis have disturbed oxidative homeostasis that is accompanied by the development of oxidative stress and hypo-energetic conditions. The stated above causes tissue hypoxia. At the same time, the carbohydrate and energy metabolism intensity changes in sick hens towards stimulation of anaerobic glycolysis, which is caused by pronounced hypoxic phenomena and confirmed by increased lactate dehydrogenase activity. All values confirm that Hy-Line hens with this ectoparasitosis have a disturbed homeostasis which is expressed by the depleted antioxidant system, excessively intensified lipid peroxidation processes, deficiency of high-energy compounds, and uncompensated metabolic acidosis. Thus, mixed hypoxia develops in hens in presence of the D. gallinae parasitism.