RESUMO
A field study was carried out on two broiler farms [controlled environment,conventional ventilation] in Eastern Region of KSA to investigate the effect of indoor ambient climatic conditions [ambient temperature,Ta°C and Relative humidity, RH%] and gaseous pollutants [ammonia [NH3] and carbon dioxide [CO 2] ppm] during winter and summer on birds internal environment [body temperature,Tb and hemoglobin concentration [Hb] and heterophil / lymphocyte ratio H/L ratio].The results revealed highly significant differences between seasons for Ta [P=0.001] and less significance for RH% [P=0.063]. NH 3 gas level showed no significant difference within seasons, while CO 2 in winter was significantly higher than in summer [P=0.001]. Ta in winter did not correlate with Tb, but negatively correlated with Hb [P=0.001] while positively correlated in summer with Tb and negatively correlated with H/L ratio [P=0.001 for both]. Indoor RH% [P=0.063] and negatively with both H/L ratio [P= 0.026] and Hb [P=0.001] but in summer it was negatively correlated with Tb and Hb [P=0.001]. Ammonia gas in winter was not significantly correlated with bird measures, while in summer positively correlated with Hb and H/L ratio [P=0.001]. CO 2 gas in winter was negatively correlated with Hb [P=0.001] and H/L [P=0.003] but in summer was positively correlated with Tb [P=0.004]