Characteristics of metabolic disorders in laying hens with dermanyssosis

Abstract

Dermanyssosis is a common ectoparasitic disease of birds. Some characteristics of metabolic disorders were identified in Hy-Line laying hens with such a disease. The disease caused by Dermanyssus gallinae, a poultry red mite, was detected during a complex parasitological survey in one of two industrial poultry buildings inspected. A high degree of mite infestation was found in the poultry building where the hens of the experimental group were kept. This condition was considered to be a stress factor for the hens, i.e. as a disturbance of their comfortable living conditions. The D. gallinae parasite infestation caused a decrease in erythrocytes and leukocytes, and in hemoglobin concentration in the laying hens. Changes in the content of some stress-associated hormones were analyzed, and they showed an increase in cortisol levels and a decrease in triiodothyronine. Multiple metabolic rate disorders in the organism of the infested hens were revealed. In dermanyssosis stimulation of gluconeogenesis occurred and an increase in the proportion of oxygen-free glycolysis in the hens. These changes were obviously due to the molecular effects of the increase in stress. The hens from the experimental group were found to have high concentrations of lipid peroxidation products as compared to the control. Increased lipid peroxidation was found, together with a decrease in the total antioxidant defense of the experimental laying hens’ organisms. The research results add to our understanding of how a high degree of infestation of a poultry building by D. gallinae impacts the organism of Hy-Line hens.