Haematological and histopathological findings in young broilers reared in poorly and well ventilated environments

Two strains of broilers, a modern commercial strain and a strain which has not recently been selected for economic traits, were reared in adjacent rooms which were identical except that one had good ventilation and the other poor ventilation. Mean cell volume (MCV) of erythrocytes was studied in relation to plasma viscosity and the incidence of lung nodules. Poor ventilation was associated with an increased incidence of lung nodules and increased plasma viscosity but there was no correlation between MCV and the number of nodules. Although environmental factors may influence MCV the genotype of the bird appears to be of major importance.