Influence of dietary energy on the nitrogen sparing action of methionine and arginine in chicks fed a protein-free diet.
Chicks were fed a protein-free (PF) diet or a protein-free diet with added methionine and arginine (MA) for 10 days to investigate the effect of dietary energy on the nitrogen sparing action of methionine and arginine. In experiment 1, equal amounts of a PF or MA diet were given and body weight change, N excretion, N balance and uric acid N excretion were measured to serve as criteria in determining the nitrogen sparing action. In experiment 2, a PF or MA diet was given ad libitum with the metabolizable energy content varied. In experiment 3, the energy intake of chicks was restricted for 10 days in both the PF and MA groups and carcass analysis was done. Even when equal amounts of feed providing the same amount of energy were given, the nitrogen sparing action was still observed. The nitrogen sparing action was always observed in diets with different metabolizable energy contents because the birds adjusted their energy intake voluntarily. When the energy intake was restricted by about 50%, the nitrogen sparing action was no longer apparent. The nature of the nitrogen sparing action is discussed in terms of body reserve protein stores.
D000818:Animals; D001120:Arginine / Q000378:metabolism*; D001835:Body Weight; D002645:Chickens; D004044:Dietary Proteins; D002149:Energy Intake; D004734:Energy Metabolism; D008297:Male; D008715:Methionine / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism*; D014527:Uric Acid / Q000652:urine
D004044:Dietary Proteins; D014527:Uric Acid; D001120:Arginine; D008715:Methionine; D009584:Nitrogen