An experiment was carried out. during the summer season. in Egypt to study the
effect of different dietary energy and protein levels on the productive performance of
laying hens under hot environments. Nine dietary treatments were designed to contain three different levels of
metabolizable energy (2600, 2800 and 3000 Kcal ME/Kg) and three different levels of
crude protein (15, 17 and 19%). A number of 135 "Bovans Brown" laying hens, 24-
weeks-old, were used in a randomized 3'3 factorial design and every dietary
treatment was fed to 5 replicate groups of 3 hens each. The experimental diet T\ was
formulated according to feed requirements of "Bevans Brown" to represent the control
treatment diet. At the end of the experiment egg production, egg weight, egg mass, feed
consumption and mortality rate were recorded. Energy intake, protein intake, feed
conversion ratio and live body weight change were calculated. The economic
efficiency of egg production for hens fed the experimental diets was calculated. The results showed that: - Mean feed consumption significantly (P<0.05) decreased with the increase of
dietary energy level. However, no Significant differences were detected for feed
consumption between treatments due to dietary protein levels (15,17 and 19%CP).
Birds fed the dietary energy level of 2800 Kcal ME/Kg and 1 S% CP recorded Ihe
highest energy and protein intake values. while those received 3000 Kcal ME/Kg
and 15% CP recorded the corresponding lowest values. Live body weight change was not affected by feeding different energy levels. While
Ihe highest protein level (19%) significantly (P<0.05) increased body weight
compared 'lith the level of 15% CPo However, highest body weight change was
attained by hens fed 2800 Kcal ME/Kg and 19% CP. The highest egg number or egg production (%) was obtained by bircs received 19%
CP and 2600 Kcal ME/Kg. White; hens fed diets contained 3000 Kcal ME/Kg and
15%CP recorded the lowest egg production. Egg weight and egg mass valves reduced as the energy level increased to 3000
Kcal ME/Kg and protein level decreased to 15% With significant diHerence
compared with the other levels of either energy or protein. The diet contained 3000 Kcal MEJKg, and 15% CP recorded significantly (P<0.05)
Ihe worst feed conversion ratio (FCR) value (2.80) while diets contained either 2600
or 2800 Kcal MElKg, each with 19% CP recorded better FCR value that did nol
significanUy diHer (P>0.05) compared to the control (2800 Kcal ME/Kg, with 17%
CP). Neither dietary energy nor protein levels affected mortality rate. The control treatment (containing 2800 Kca: MElKg and 17% CP) had recorded the
highest value of economic efficiency. which also surpassed all other treatments.