Influence of thermal manipulations on quail embryo during embryogenesis and post hatching / Saad Nazeh Saad Abdelfatah ; Supervised Elsayed Fath Mohamed Khalifa , Hamdy Mahmoud Rizk , Karim Mohamed Khalil

Thesis (M.Sc.) - Cairo University - Faculty of Veterinary Medicine - Department of Anatomy and Embryology

Japanese quail embryo thermal manipulation was known as an effective protocol in improving post-hatch growth performance parameters and thermotolerance acquisition in association with several modifications in molecular, physiological and biochemical parameters. The aim of current study is to elucidate the onset and long-term effects of intermittent thermal manipulations during two-time window, early / late, of embryogenesis in Japanese quail (Coturnix japonica) on embryonic development, hatchability, muscle histogenesis carcass traits, internal organ weights and post hatch growth performance as well as on the expression of Myostatin & Pax7 genes during embryogenesis. The eggs of control group (Ctrl) was incubated at 37.7{u00B0}C and 55% RH.Three thermally treated groups were incubated intermittently at 41{u00B0}C and 65% RH intermittently (3 hours / day): Group (EE) during early embryogenesis (ED6 {u2013} ED8), group (LE) during late embryogenesis (ED12 {u2013} ED14), and group (EL) was thermally treated in both time window (early and late). The hatched chicks were reared under optimal managemental conditions (3 replicates per treatment). The results revealed that TM lead to significant hypertrophy of quail breast muscle in the early embryonic group (EE) without any negative effects on embryonic development, yolk consumption, hatchability, carcass traits and breast meat characteristics. Intermittent short-term (3 {u2013} 6h) thermal manipulation (39 - 40{u00B0}C) protocols during early embryogenesis (ED6 {u2013} ED8) could be recommended as a safe and effective protocol to enhance muscle mass growth and breast muscle yield in quail broilers

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