Age-Related Effects of Varying Ammonia Concentrations on Hematophysiological Variables in Broiler Chickens

This study examined the response of different aged birds of the same genetic strain exposed to ammonia (NH ) at set concentrations on blood gases, electrolytes and acid-base balance under 3 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 NH concentrations and 4 different ages 3 (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 NH exposure. Partial pressure of CO (pCO ), pH, Hematocrit (Hct) and Hemoglobin (Hb) 3 2 2 increased significantly (p<0.05), whereas partial pressure of O (pO ), bicarbonate (HCO ) and K decreased 2 2 3 + with increasing NH concentration compared with 0 ppm. In addition, pO , pCO , HCO , Hct, Hb, Na and 3 2 2 3 + Anion gap (Angap) increased significantly (p<0.05), while pH, glucose and corticosterone decreased as bird’s age increased. Ammonia x age interactions were observed for pH, anion gap and HCO . Plasma 3 corticosterone concentrations were significantly different for age and were not affected by NH . The effect of 3 age was more pronounced than that of NH on examined variables. This effect of age on examined blood 3 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 NH than older birds. 3