|De Beer, M.|
Submitted to: Poultry Science
Publication Type: Abstract Only
Publication Acceptance Date: 4/30/2006
Publication Date: 7/15/2006
Citation: DeBeer, M., Coon, C.N., Rosebrough, R.W., Russell, B.A., Poch, S.M., Richards, M.P. 2006. An examination of the role of feeding regimens in regulating metabolism during the broiler breeder grower period [abstract]. Poultry Science 85 (Suppl.) A:56. Interpretive Summary:
Technical Abstract: Skip-a-day feeding programs are commonly used in broiler breeder rearing to reduce flock variation. A trial was conducted to determine the effects of skip-a-day feeding programs on various metabolic parameters. A total of 120, 16-week old Cobb-Vantress broiler breeder pullets were used, of which, 48 had been fed using an everyday restriction program from four weeks of age, and 72 had been fed using a skip-a-day restriction program from four weeks of age. All pullets were fed to reach the same body weight at 16 weeks of age. At 112 d 48 pullets from the everyday group were fed 74 g of standard breeder grower diet and 72 pullets from the skip-a-day group were fed 148 g of the same feed. Livers from four sacrificed pullets were collected at 0, 12, and 24 (everyday) and 0, 12, 24, 36 and 48 (skip-a-day) hours after feeding. These times represented one full feeding cycle for each group. RNA was isolated from livers using Trizol ® reagent and quantitatively measured by noting the OD 260/280 ratio and qualitatively by gel electrophoresis. The expressions of certain regulatory genes in metabolism (acetyl CoA carboxylase, ACC; fatty acid synthase, FAS; malic enzyme, ME; isocitrate dehydrogenase, ICD and aspartate aminotransferase, AAT) were determined by real time PCR. ACC, FAS and ME were increased in skip-a-day birds compared to those birds fed daily. In contrast, skip-a-day decreased ICD and AAT gene expression, paralleling findings noted in fasting-refeeding experiments conducted with much younger birds. Feeding regimens practiced during the grower period may predispose the broiler breeder hen to high rates of lipogenesis during the subsequent reproductive cycle.