Authors : V. L. Christensen , M. J. Wineland , I. Yildirum , D. T. Ort and K. M. Mann
Abstract: The plateau stage in oxygen consumption of turkey embryos occurs at 25 and 26 days of incubation and most embryonic deaths occur at that time (Rahn, 1981 and Christensen et al., 2003). At the plateau stage, vital gas diffusion through the shell is insufficient for oxygen to drive metabolism or for expelling the metabolic by products of water vapor and carbon dioxide. The objective of the experiments reported here was to determine the effect of environmental temperature and oxygen concentration during hypoxia and hypercapnia of the plateau stage on turkey embryo cardiac health. Three experiments were conducted. In Experiment 1, turkey embryos at the plateau stage were exposed to 36, 37, 38 or 39 C. In Experiment 2, embryos at the plateau stage were exposed to 17, 19, 21 or 23% oxygen concentrations, and in Experiment 3, the highest and lowest levels of temperature and oxygen treatments were combined to determine interaction effects on cardiac physiology. Temperatures greater than 37 C depressed heart weight but not BW and decreased cardiac tissue energy metabolism. Oxygen concentrations greater than 21% increased BW and improved the cardiac glycogen to lactate ratio with no effect on heart weight. When examined together, the two factors interacted to affect cardiac energy metabolism. It was concluded that the physiologic action of oxygen during the plateau stage favored BW whereas temperature affected cardiac tissue but not BW. Temperature and oxygen interact during the plateau to affect cardiac muscle energy metabolism.
V. L. Christensen , M. J. Wineland , I. Yildirum , D. T. Ort and K. M. Mann , 2004. Incubator Temperature and Oxygen Concentration at the Plateau Stage Affect Cardiac Health of Turkey Embryos1 . Journal of Animal and Veterinary Advances, 3: 52-65.