Submitted to: Federation of American Societies for Experimental Biology Conference
Publication Type: Abstract Only
Publication Acceptance Date: November 1, 2006
Publication Date: April 2, 2006
Citation: Rosebrough, R.W., Russell, B.A., Poch, S.M., Richards, M.P. 2006. A further examination of the role of dietary protein in regulating metabolism in the broiler [abstract]. FASEB Journal. 20:233. Technical Abstract: Experiments were conducted with broiler chickens to delineate the role of dietary protein lipid metabolism. Birds were fed 12 or 30% protein from 7 to 28 days of age. Birds were then switched to the opposite level of dietary protein. Birds were selected and killed at 12, 18 and 24 hr following the dietary reversals. Birds were sampled at 3, 6, 9, 12, 18 and 24 hr in the second experiment. In vitro lipogenesis (IVL) was determined and was indicative of acetyl CoA carboxylase activity (AcCbx). Activities of certain metabolic enzymes and genes controlling these enzymes (malic enzyme, ME; fatty acid synthase, FAS; isocitrate dehydrogenase, ICD; aspartate aminotransferase, AAT and AcCbx) were also measured. In all experiments switching dietary treatments increased and decreased lipogenesis as birds were switched from 30 to 12% protein and from 12 to 30% protein diets, respectively. The greatest rates of change elicited by either regimen occurred by the first day of each reversal (Exp 1). A further examination (Exp 2) indicated significant changes in IVL 12 hr post reversals. Changes in IVL were correlated to changes in the expression of genes for both FAS and AcCbx. Changes in gene expression always preceded changes in intermediary metabolism.