Submitted to: Poultry Science Association Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/31/2004
Publication Date: 6/1/2004
Citation: Rosebrough, R.W., Poch, S.M., Russell, B.A., Richards, M.P. 2004. Dietary protein regulates short-term adaptations in lipogenic gene expression [abstract]. Poultry Science. 83(Suppl. 1):16.
Technical Abstract: The purpose of this experiment was to determine the possible relationship between certain indices of lipid metabolism and the message expression for chickens fed grade levels of dietary crude protein. Male, broiler chickens growing from 7 to 28 days of age were fed diets containing 12, 21 or 30% protein ad libitum. In addition, another group of birds was feed on a regimen consisting of a daily change in the dietary protein level (12 or 30%). This latter group was further subdivided such that one-half of the birds received each level of protein on a particular day. Birds were sampled from 28 to 30 days of age. Measurements taken included in vitro lipogenesis (IVL), hepatic enzyme activities and message expression of these enzymes and thyroid hormones. In vitro lipogenesis was determined by incubating liver explants for 2 h at 37 C in Hanks salts containing 25 mM HEPES and 10 mM [2-14C]acetate. In vitro lipogenesis and ME activity were inversely related to dietary crude protein levels (12 to 30%) and by acute changes from 12 to 30%. In contrast, ME, FAS and AcCBX message expressions were constant over a dietary protein range of 12 to 21%, but were decreased by a 30% protein diet (acute or chronic feeding). Increasing dietary crude protein increased the activities of both AAT and ICD. Results of the present study demonstrate a continued role for protein in the regulation of metabolism in the broiler chicken. It should be pointed out, however, that metabolic regulation at the gene level only occurs with very high levels of dietary protein.