Haematological indices, size of erythrocytes and haemoglobin saturation in broiler chickens kept in commercial conditions

The study aimed at analysing and comparing haematological indices, blood saturation and dimensions of red blood cells of Ross 308 broiler chickens of both sexes. On day 44 of rearing, blood was withdrawn once from 60 randomly selected chickens (1:1 sex ratio). Prior to blood withdrawal the chickens were weighed and their heart rate and haemoglobin saturation were assessed. The following blood parameters were determined: number of RBC and WBC, HGB content and HCT value. In addition, MCV, MCH and MCHC indices were calculated as well as the content (%) of individual leukocyte forms. Measured was also the length, width and circumference of erythrocytes. The measured heart rate (sexes pooled) ranged from 179 to 438 beats/min. Females had significantly higher (by 26.2 beats/min.) value of this trait in comparison with males. Blood of birds of both sexes was characterized by similar haemoglobin saturation (87%). MCV value in males was found by 3.35 fl higher than that in females. Eosinophiles content of blood was by 1.77 percent units higher in females which were also characterised by smaller and more elongated red blood cells. A significant positive relationship was also found between leukocyte and erythrocyte numbers, haemoglobin content and haematocrit value. Negative values of phenotype correlation coefficient were found between MCHC and erythrocyte number, haemoglobin content and haematocrit value. A lower MCV value and higher content of eosinophils of blood were identified in females which were also characterized by smaller and more elongated erythrocytes.