|Dozier Iii, William|
Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/3/2008
Publication Date: 6/23/2008
Citation: Olanrewaju, H.A., Thaxton, J.P., Dozier III, W.A., Purswell, J.L., Collier, S.D., Branton, S.L. 2008. Interactive effects of ammonia and light intensity on hematochemical variables in broiler chickens. Poultry Science. 87:1407-1414.
Interpretive Summary: Our recent study indicated that eye damages induced by the interaction of ammonia and light intensity decreased significantly beginning one week after cessation of ammonia exposure. In addition, fear along with leg health were not affected by ammonia, light-intensity or their interaction. However, the effects of ammonia exposure along with differing light-intensities on blood physiological variables in broiler chickens is not well understood. Exposure of chicks early in the growout to ammonia concentrations at 25 and 50 ppm along with differing light-intensities on blood gases, electrolytes, acid-base balance, and their involvement on welfare in broiler chicken was examined. Result indicated that the effects of ammonia were more pronounced than that of light-intensity on blood physiological variables and the conditions worsened as duration of ammonia concentration exposure increased. However, all affected variables returned to near normal at later time points in the exposed chickens so that the apparent effects were lost. In addition, plasma corticosterone and glucose concentrations that are symbols of well-being were not altered by exposure to differing levels of ammonia, light-intensity or their interaction, suggesting an absence of stress related to ammonia, light intensity or their interaction. It was concluded that exposure of broiler chickens to atmospheric ammonia concentrations in the presence of light-intensities had no direct effect on some physiological blood variables and did not induce stress in broilers. The results of this study further show 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.
Technical Abstract: This study examined the influence of atmospheric ammonia exposure, light intensity, and their interaction on blood gases, electrolytes, and acid-base balance in broiler chickens under environmentally controlled conditions. The experiment consisted of a 3 × 3 factorial arranged in a randomized complete block design. The 9 treatments consisted of 3 levels of ammonia concentrations × 3 levels of light. Venous blood samples were collected on d 6, 11, 14, and 35. Partial pressure of CO2 (pCO2), hematocrit (Hct), hemoglobin (Hb), and Na+ significantly (P less than or equal to 0.05) increased while partial pressure of O2 (pO2), pH and K+ decreased with increasing ammonia concentration. As light-intensity increased, Hct, Hb and BW significantly (P less than or equal to 0.05) increased while pO2 and K+ were reduced. Ammonia by light-intensity interactions were observed for Hb, Hct, K+ and BW. The interaction of ammonia and light-intensity for 7 d further exacerbated physiological variables. The main effect of ammonia was more pronounced than that of light-intensity. These conditions worsened as duration of ammonia concentration exposure and light-intensity increased from d 7 to 14 of exposure. However, all affected variables returned to near normal at later time points in the exposed chickens so that the apparent effects were lost. Plasma corticosterone and glucose concentrations were not significantly altered by exposure to differing levels of ammonia or light intensity, suggesting an absence of stress related to ammonia, light intensity or their interaction. It was concluded that exposure of broiler chickens to aerial ammonia concentrations from 0 to 50 ppm from d 1 to 14 post-hatch in the presence of light-intensities ranging from 0.2 to 20 lx had no direct effect on some physiological blood variables and did not induce stress in broilers.