M. Azizian - Department of Animal Science, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Islamic Republic of Iran.
A. A. Saki - Department of Animal Science, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Islamic Republic of Iran.

The current study was conducted to determine the effect of the feed form (mash, pellet, and extrude) on Hypoxia-Inducible Factor ۱α (HIF-۱α mRNA) and heart index in broiler chickens. The relative weight of hearts and lungs, the ratio of Right Ventricle heart weight to the Total Ventricle weight (RV/TV, heart index), Hematocrit value (HCT) and gene expression (HIF-۱α mRNA) in the hearts and lungs tissues of the broiler chickens were determined at ۳۵ days of age. Also, mortality and performance parameters were recorded throughout the experiment. The results showed that Average Daily Weight Gain (ADWG), Average Daily Feed Intake (ADFI) (P< ۰.۰۱), Right Ventricle weight (RV), Ventricles Total weight (TV), hematocrit value and expression of HIF-۱α mRNA in the lungs tissues were higher in the pellet and extrude diet form compared to the mash diet form (P< ۰.۰۵). Also, a higher Feed Conversion Ratio (FCR) (P< ۰.۰۱) was observed in the mash diet form. The hematocrit value and expression of the HIF-۱α mRNA gene in the lung tissues of the broiler chickens were increased by feeding pellet and extruded diets, which was associated with increase in mortality from ascites. Our findings, therefore, revealed that the HIF-۱αmRNA gene might be concerned with the increase of pulmonary and ascites syndrome in the broiler chickens.

Feed form, Hypoxia-Inducible Factor ۱α (HIF-۱α), Pulmonary pressure.