Submitted to: International Journal of Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/16/2009
Publication Date: 3/16/2009
Citation: Olanrewaju, H.A., Purswell, J.L., Collier, S.D., Branton, S.L. 2009. Age-related Effects of Varying Ammonia Concentrations on Hematophysiological Variables in Broiler Chickens. International Journal of Poultry Science. 8(2):138-144.
Interpretive Summary: The interactive effects of inhalation of ambient air with elevated ammonia concentrations and different light intensities on eyes lesions, blood physiological variables, and welfare in broiler chickens under environmentally controlled conditions were evaluated in a preceding study. The results of that study showed the positive impact on profits to modern commercial poultry facilities that are using low lighting environment to control pecking damage associated with higher illuminance activity and to reduce energy costs while promoting the need for controlling ammonia thereby improving overall poultry welfare and environment. However, it was not determined whether chickens exposed to ammonia at set concentrations but with different ages of chickens of the same genetic strain respond similarly to these ammonia concentrations i.e. do younger chickens have a more intense reaction to the ammonia than older chickens? This present study examined the age-related effects of atmospheric ammonia exposure on blood gases, electrolytes, and acid-base balance in broiler chickens under environmentally controlled conditions. Results indicated that chickens exposed to aerial ammonia at set concentrations of 0 to 75 ppm but with different aged chickens of the same genetic strain respond differently to these ammonia concentrations on some physiological blood variables, and younger chickens have a more intense reaction to the ammonia than older chickens.
Technical Abstract: This study examined the response of different aged birds of the same genetic strain exposed to ammonia (NH3) at set concentrations on blood gases, electrolytes, and acid-base balance under environmentally controlled conditions. The experiment consisted of a 4 × 4 factorial with a randomized design. The 16 treatments consisted of 4 levels (0, 25, 50 and 75 ppm) of NH3 concentrations and 4 different ages (1-d, 7-d, 14-d and 21-d) of birds. Venous blood samples were collected at the end of each 7 d of atmospheric NH3 exposure. Partial pressure of CO2 (pCO2), pH, hematocrit (Hct), and hemoglobin (Hb) increased significantly (P = 0.05), whereas partial pressure of O2 (pO2), bicarbonate (HCO3-), and K+ decreased with increasing NH3 concentration compared with 0 ppm. In addition, pO2, pCO2, HCO3-, Hct, Hb, Na+, and anion gap (Angap) increased significantly (P = 0.05), while pH, glucose, and corticosterone decreased as bird’s age increased. Ammonia × age interactions were observed for pH, anion gap, and HCO3-. Plasma corticosterone concentrations were significantly different for age and were not affected by NH3. The effect of age was more pronounced than that of NH3 on examined variables. This effect of age on examined blood physiological variables improved as the age of birds increased from 1-d to 21-d old birds. Most blood physiological variables of different aged birds of the same genetic strain respond differently to set NH3 concentrations of 0 to 75 ppm and younger birds have a more intense reaction to the NH3 than older birds.