الفهرس 
titelOnly 14 pages are availabe for public view
 |  | from | 238 |  |  |
| | | from | 238 | | |
Abstract
The present study was carried out at El-Sabahia Poultry Research Station in Alexandria, belonging to Animal Production Research Institute, throughout the period from March to May 2006. The chemical analyses were conducted at the laboratory of the same institute and the Laboratory of Animal and Fish Production Department, Faculty of Agriculture (Saba Basha), Alexandria University.
Ninety, Bandarah and Baheje layers in their 25th wks of age, were used in this study. The birds were selected on the basis of more than 50 % egg production rate after a two-week pretest period. Birds from each strain were randomly assigned to five comparable groups with nine females in each group. The present experiment was designed to evaluate the influence of supplementing laying hens’ diets with different levels of sodium bicarbonate on productive performance, egg quality and plasma blood constituents of two local strains (Bandarah and Baheje) raised in environmental controlled room under heat stress waves conditions, birds were exposed to a daily cyclic heat stress period (35º C) for 6 hours from 10 a.m to 4 p.m and then during one hour the temperature was back to the normal (25º C), and compare their response with the laying hens reared under normal conditions (thermoneutral condition, 25º C).
In each strain, the first group reared under normal ambient temperature (25º C) and received a basal corn-soybean diet. The second group received the same basal diet without supplementation and subjected to one week of normal temperature, followed by 72 daily cyclic heat stresses. The 3rd, 4th and 5th other experimental three groups were subjected to one week of normal temperature, followed by 72 daily cyclic heat stresses and given the basal diet with additional provision of 1.0, 1.5 or 2.0 % sodium bicarbonate, respectively.