EFFECT OF AMMONIA ON THE DINAMICS OF SOME HEMATOLOGICAL INDICES IN RABBITS, EXPOSED TO PSYCHIC STRESS

M. Dyavolova, I. Yanchev, P. Moneva, D. Gudev

Abstract: Commercially farmed animals are frequently reared in conditions that impose a number of concurrent environmental stressors. For rabbits housed in closed premises, elevated levels of noise and atmospheric ammonia are common. The aim of this experiment was to assess the effect of psychic stressors, such as dog barking and introduction of a dog in the rabbits´ living premises, on some hematological indices, frequently used as indirect stress indicators. The experiment took place against the background of different levels of ammonia, naturally occurring during rabbits´ lifespan. Twenty four New Zealand male rabbits were evenly distributed into 2 groups – control, reared under low air ammonia levels (1.5-7.2 ppm) and experimental group, reared under high air ammonia levels (20-54 ppm). Forty days after the start of the experiment all rabbits were subjected to stress by playback recording of dog barking or by introduction of a dog in the room. Blood samples were collected 10 days prior to the stress episode (basal level) and 30 min and 3 h after the end of stress exposure. Hematocrit, red blood cell count (RBC), white blood cell count (WBC) and neutrophil: lymphocyte ratio were determined. Higher hematocrit and leucocyte values were found in the control rabbits at the 3rd h after exposure to dog barking (P<0.05), that was accompanied by a decline in N:L ratio (P<0.05). There was a drop in the erythrocyte count between 30 min and 3 h after stress (P<0.01). The experimental group, stressed with dog barking showed higher hematocrit levels 30 min (P<0.05) and 3 h (P<0.01) after the stress episode. Higher hematocrit and leucocyte values were found in control rabbits at 30 min (P<0.01; P<0.05) and 3 h (P<0.001; P<0.05) respectively, following exposure to dog presence. Leucocyte count was also higher 30 min and 3 h after stress (P<0.05). The experimental group had higher hematocrit levels at 3 h following exposure to stress (P<0.01). The erythrocyte count increased 30 min after stress (P<0.05) and declined on the 3rd h (P<0.05).

Keywords: AMMONIA; PSYCHIC STRESS; RABBITS

Date published: 2017-03-15