Effect of supplemental oxygen on blood plasma organic acids within embryos from selected lines of turkeys.
The hypothesis was tested that increased oxygen tensions during the plateau stage of oxygen consumption (25 and 26 d of incubation) would cause different metabolic responses from embryos selected for increased egg production or growth. Embryos were exposed to 171 or 152 mm Hg partial pressure of oxygen from 25 to 28 d of incubation, a time when the oxygen conductance properties of the eggshell are exceeded by the embryonic tissue demands for oxygen. Carbohydrate and lipid metabolism were observed by measuring plasma organic acids in embryos from selected lines and randombred controls. (E was selected for increased egg production; RBC1 is the randombred line from which it was selected. F was selected for increased BW; RBC2 is the randombred line from which it was selected.) During the plateau stage in oxygen consumption, RBC2 embryos responded to added oxygen by utilizing fat rather than carbohydrate, whereas F embryos responded by using less fat as well as less carbohydrate from the liver and kidney. The response of F embryos to added oxygen is the opposite that might be expected for aerobic metabolism. The reason that selection for growth has resulted in such a metabolism is unknown. The E embryos displayed depressed lactate and beta-hydroxybutyrate levels, but plasma urates were elevated compared with RBC1, suggesting that the selection for egg production has also resulted in a unique metabolism. The embryonic processes described in the current study suggest that selected embryos are unable to respond to elevated partial pressure of oxygen by adjusting energy metabolism, which may result in increased embryonic mortality during this stage.
Christensen
V L
VL
Department of Poultry Science, North Carolina State University, Raleigh 27695-7608, USA. vern_christensen@ncsu.edu
Donaldson
W E
WE
Nestor
K E
KE
D020155:3-Hydroxybutyric Acid / Q000097:blood*; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D050260:Carbohydrate Metabolism; D004625:Embryo, Nonmammalian / Q000098:blood supply* / Q000378:metabolism; D047108:Embryonic Development; D006128:Growth / Q000235:genetics; D019344:Lactic Acid / Q000097:blood*; D050356:Lipid Metabolism; D010100:Oxygen / Q000008:administration & dosage*; D010101:Oxygen Consumption; D013045:Species Specificity; D014422:Turkeys / Q000196:embryology* / Q000235:genetics; D014527:Uric Acid / Q000097:blood*
D001786:Blood Glucose; D014527:Uric Acid; D019344:Lactic Acid; D010100:Oxygen; D020155:3-Hydroxybutyric Acid