|Foye, O. - NC STATE UNIVERSITY|
|Uni, Z. - HEBREW UNIV., ISRAEL|
|Ferket, P. - NC STATE UNIVERSITY|
Submitted to: International Journal of Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 6, 2006
Publication Date: August 1, 2006
Citation: Foye, O.T., Uni, Z., McMurtry, J.P., Ferket, P.R. 2006 The effects of amnionic nutrient administration, in ovo feeding of arginine and/or beta-hyroxy-beta-methybutyrate (HMB) on insulin-like growth factors, energy metabolism and growth in turkey poults. International Journal of Poultry Science. 5(4):309-317. Interpretive Summary: The avian embryo develops in a carbohydrate-free environment with a limited amount of energy and nutrients to support growth and hatching. As the embryo develops, yolk reserves are depleted, while glycogen storage becomes predominant. At hatch glycogen stores must be replenished by the neonate consuming feed. In commercial practice, access to feed is often delayed for 24-48 hours after hatch. Poor nutritional status of the avian neonate during this post-hatch period can result in mortality, stunted growth and decreased muscle development. In ovo feeding is the administration of exogenous nutrients into the amnion of the late-term embryo. Because the embryo imbibes amniotic fluid, supplementing the amnion with nutrients is similar to providing extra nutrients to the embryo prior to hatch. In this study, turkey eggs were injected on day 23 of embryogenesis with various levels of arginine and HMB, a leucine metabolite, to enhance glycogen stores prior to hatch. The results of this study showed that the administration of both arginine and HMB increased plasma levels of insulin-like growth factor-I, a hormone important for both embryonic and post-hatch growth, as well as increased liver glycogen concentrations. In ovo administration of HMB and arginine may provide the fuel needed for rapid subsequent growth during the critical post-hatch period.
Technical Abstract: In ovo feeding (IOF), injecting nutrients into the amnion, may improve growth performance by enhancing circulating IGF’s and glycogen reserves. To test this hypothesis 400 Hybrid turkey eggs were injected into the amnion with 1.5 ml saline solutions consisting of 4 IOF formulation treatments consisting of a factorial arrangement of 2 levels of arginine (ARG 0 or 0.7%) and 2 levels of HMB (0 or 0.1%) at 23 days (d) of incubation. At hatch, poults were fed ad libitum and bodyweights (BW), organ weights, total liver and pectoralis muscle (PM) glycogen were taken at hatch 3, 7, 10, and 14 d. Additionally, hepatic glucose-6-phoshatase (G6P) activity was determined at hatch and 7 d. Heparinized blood samples were taken at hatch, 3 d, 7 d and 14 d and plasma was analyzed for IGF-I and IGF-II levels using an acid-ethanol extraction method. Although arginine had no affect on BW, there were significant main effects of HMB on increased BW from hatch through 14 d. Plasma IGF-I levels were significantly enhanced at hatch, 3 and 7 d in poults in ovo fed both ARG and HMB, but not when either factor was independent. Significant ARG X HMB effects were observed on IGF-II at hatch, 3 d, and 7d: without ARG, IGF-II was decreased by HMB, but it increased when added with ARG. All in ovo treatments increased G6P at hatch, while, G6P was depressed by HMB or ARG alone at 7 d. Total hepatic glycogen was increased only at hatch by HMB or ARG, but their effects were not additive as indicated by a significant ARG X HMB effect. In ovo administration of HMB and arginine in ovo enhances hepatic liver reserves, which may provide the fuel needed for rapid subsequent growth during the critical post-hatch period.