Authors : M.R. Ghorbani and J. Fayazi
Abstract: This study was conducted to determine the effects of dietary NaHCO3 supplementation on laying hens performance under heat stress. Ninety six Leghorn hens (Hy-Line), were used in a 2x4 factorial arrangement with two rearing system (cage and floor) and 4 levels of dietary NaHCO3 (0, 0.5, 1 and 1.5%) in a completely randomized design with 8 treatments and 3 replicates and 4 birds per replicate. All diet was isoenergetic and isonitrogenous. Feed Intake (FI), Egg Production (EP), Egg Weight (EW), Shell Thickness (ST), Shell Weight (SW), Shell Strength (SS), Albumen Index (AI), Yolk Index (YI) and Haugh Unit (HU) were measured weekly. In the end of experiment, 10 mL blood of hens per treatment were collected by venipuncture from the brachial vein into vacuum tubes and held on ice until all were centrifuged for plasma cations assay. The result of this experiment indicated that SW was not significantly affected by addition of dietary NaHCO3. ST was significantly decrease and EW, EP, FI and plasma potassium were increase with NaHCO3 levels in 0-1.5 percentage (p<0.05). The rearing system had no significant effect on ST (p>0.05). However, all factor in cage system is higher than floor system. SW, EP, SS and EW were significantly increased in cage system, but FI was increased in floor system (p<0.05). Haugh unit, yolk index, plasma sodium and calcium were not affected (p>0.05) by dietary NaHCO3 supplementation and system of rearing.
M.R. Ghorbani and J. Fayazi , 2009. Effects of Dietary Sodium Bicarbonate and Rearing System on Laying Hens Performance, Egg Quality and Plasma Cations Reared Under Chronic Heat Stress (42?C). Research Journal of Biological Sciences, 4: 562-565.