A total number of one hundred and ninety eight 32 weeks old Dandarawi laying birds (180 hens and 18 cocks) at peak production until 44 weeks of age were used to evaluate some productive and reproductive performance of Dandarawi laying hens under different ambient temperatures. The birds were randomly divided into 3 groups. Each group included sixty hens and six cocks. All birds were housed in 3 floor pens. Each group was kept in an area of 10 square meters provided with deep litter of wheat straw (10 cm). The first, second and third groups were raised under 20 to 22ºC, 24 to 26ºC, and 28 to 30ºC, respectively. The obtained results could be summarized as follows: The birds of groups 1 and 2 were achieved higher (P≤0.01) final body weight (BW) by about 4.5 and 6.0 % and also higher (P≤0.01) body weight change (BWC) by about 6.6 and 9.6 %, respectively, than those in group 3, while no significant differences (P≤0.05) were observed between groups 1 and 2 in final BW and BWC. The birds in group 2 showed significantly (P≤0.01) higher hen day egg production (HDP) by 4.4 and 6.7%, hen housed egg production (HHP) by 4.4 and 8.9%, egg number (EN) by 2.2 and 3.4 eggs, and egg mass (EM) by 4.1 and 7.7% than those in groups 1 and 3, respectively, while no significant differences were observed in HDP and EN between groups 1 and 3. However, HHP and EM in group 1 increased (P≤0.01) by about 4.8 and 3.8%, respectively than those in group 3. No deaths occurred in birds of group 2 at all age periods studied, while the mortality rate was 1.7 and 6.7 % in groups 1 and 3, respectively. The group 1 showed significantly (P≤0.05) higher feed consumption by 3.1% as compared with that in group 3, while the group 2 had an intermediate value. No significant differences in cumulative feed conversion (FCR) among the three groups were detected. However, the birds of group 2 had insignificantly (P≤0.05) better cumulative FCR by about 4.5 and 6.8 % than that of groups 1 and 3, respectively. There were no significant differences among groups in egg weight, egg shape index, and egg yolk index. However, the eggs of birds in groups 1 and 2 had significantly (P≤0.01) higher Haugh units (HU) by 5.3 and 5.3% and shell thickness (ST) by 3.1 and 3.8%, respectively than those in group 3. The yolk percentage in groups 1 and 2 was significantly (P≤0.05) higher by about 2.8 and 3.6 %, respectively than that in group 3, but the albumen percentage in group 3 was significantly (P≤0.01) higher by about 1.7 and 2.2% than that in groups 1 and 2. However, no significant differences (P≤0.05) among groups were observed in shell percentage, fertility, and hatchability of total and fertile eggs percentages. But, the chick weight at hatch in group 2 was significantly (P≤0.05) higher by about 1.8% than that of group 3, while the group 1 had an intermediate value. Economic efficiency (EE) in group 2 exceeded that of groups 1 and 3 by 17 and 29%, respectively, while the EE in group 1 exceeded that of group 3 by 12%. The group 2 recorded the best EE percentage as compared with the other two groups. The recommendation of the present study is raising Dandarawi laying hens during the period from 32 to 44 weeks of age under 24 to 26ºC to obtain higher productive and reproductive performance.

Two hundred and fifty two from Bovans brown (BV) and Hy-sex brown (HS) pullets at 20 weeks of age were used in this experiment. Each strain included one hundred and twenty six of hens were classified according to body weight (X); into three category groups (42 hens of each) being heavy body weight averaged (1440 and 1740 g), medium body weight (standard body weight, 1323 and 1647 g) and light body weight (1236 and 1547 g) in Bovans brown and Hy-sex brown pullets, respectively. The hens of each group divided into six replicates (7 birds each). Each replicate was kept in wire cage (7 hens per cage) for 68 weeks of age. The obtained results could be summarized as follows: The medium birds of Bovans Brown strain (MBV) showed significantly (P≤0.05) higher hen day egg production (HDP) by 4.0 and 5.4%, hen housed egg production (HHP) by 4.0 and 12.3%, eggs number (EN) by13.4 and 18.4 eggs and egg mass by 0.90 and 1.38 kg/hen and exceeded economical efficiency by 17.5 and 16.2% as compared with those of heavy and light birds of Bovans brown (HBV and LBV), respectively. The HBV showed a significantly (P≤0.05) higher egg weight (EW) by about 1.8 and 2.4% and feed consumption by 2.5 and 4.4% as compared with that of MBV and LMV, respectively. The heavy and medium birds of Hy-sex brown strain (HHS and MHS, respectively) showed significantly (P≤0.05) higher HDP by 5.0 and 5.2%, HHP by 8.6 and 8.8%, EN by 16.9 and 17.6 eggs, EW by 1.8 and 1.5%, EM by 1.26 and 1.16 Kg/hen, FC by 2.1 and 1.1% and EE by 14.9 and 18.3%, respectively as compared with that of light birds of Hy-sex brown (LHS). There were no significant differences in cumulative feed conversion (g feed/ g egg mass or g feed/ 12 eggs) among three body weight categories of both BV and HS strains. No deaths occurred of high and medium birds of both BV and HS strains at all ages, while the mortality rate was 8.0 and 4.8% for LBV and LHS, respectively. It could be concluded that, the medium birds (standard body weight) of BV and medium and heavy birds of HS recorded the best EE value as compared with the other body weight categories.

Six hundred and thirty of 8 weeks of age Dandarawi chicks were used to study the effect of type of litter and dietary molasses supplementation on the performance, carcass parts, and economic efficiency during growth period under summer season conditions of Assiut governorate. All chicks were housed in floor pens in 3 equal groups (3 replicates of 70 birds each). Each replicate was kept in a partition of 10 square meters provided with light litter (5 cm). In group 1 which served as control one, the chicks reared on wheat straw litter (WS), while the other 2 and 3 groups reared on wheat straw litter or sand with 4% molasses supplementation to the diet (WSM and SM, respectively). The photoperiod was 12 hours per day and light intensity ranged from 20 to 25 Luxes, while feed and water were available all the time. The chicks received grower diet until 20 weeks of age. The indoor temperature and humidity ranged between from 25-38°C and 40-66%, respectively. The obtained results could be summarized as follows: The birds reared on SM had significantly (P≤0.05) heavier body weight (BW) and daily weight gain (BWG) and it also observed that the overall mean of feed consumption (FC) increased (P≤0.05) than those of WS and WSM. The birds reared on SM showed improved (P≤0.05) feed conversion ration (FCR) than those of WS, while WSM group had an intermediate estimate. The birds of SM and WSM groups had significantly (P≤0.05) heaviest the percentages of carcass and liver as compared to the birds of WS group. The birds of group SM had significantly (P≤0.05) lower percentages of feet and shank, head, heart, gizzard and proventriculus than those of WS and WSM groups, it also showed significantly (P≤0.05) higher carcass weight and tibia bone length and diameter than those of WS and WSM groups. The birds reared on SM and WSM exceeded in WS control the economical efficiency by 21 and 17 %, respectively. In general, sand with 4% molasses supplementation to diet has shown good potential as alternative wheat straw with or without 4% molasses supplementation to diet for growing Dandarawi birds during high environmental temperature of summer season in Assiut governorate.

The objective of this experiment was to study the impact of dietary molasses supplementation on the performance of male and female Dandarawi chicks reared on two types of litter in hot climate in the summer months (June-July-August) of Upper Egypt (Assiut Goverenorate). Six hundred and thirty 8 weeks of age Dandarawi chicks were used. Chicks were randomly distributed into three groups (210 chicks/group) of three replicates each (70 chicks each, 35 male and 35 female). Birds in group 1 fed the control diet and reared on wheat straw litter (WS). Birds in group 2 fed on the experimental diet (i.e. control diet supplemented with 4 % molasses) and reared on wheat straw litter (WSM). Birds in group 3 fed on the control diet supplemented with 4 % molasses and reared on sand litter (SM). Results indicated that the males and females of chickens reared on SM and fed diets containing 4% molasses had significantly (P0.05) higher body weight than WS and WSM groups at all ages studied. Body weight at 20 weeks of age of the SM group was significantly (P0.05) higher by about 15.4 and 7.7% of males and 21.7 and 10.3% of females than those of WS and WSM groups, respectively. The males and females of the SM group significantly gained (P0.05) more than those of the WS and WSM groups at 8-12 weeks of age, respectively, while the males and females of WSM group significantly gained (P0.05) more than those of WS group. The overall mean males of SM group showed a significantly (P0.05) higher daily weight gain by about 27.3 and 8.7 % than those of WS and WSM groups, respectively, while the males of WSM group showed significantly (P0.05) higher daily weight gain by about 17.1 % than those of WS group. The average of feed consumption revealed that SM group consumed significantly (P0.05) higher feed by about 9.3 and 8.1% as compared with those of WS and WSM groups respectively. The overall mean of feed conversion in SM groups was significantly (P0.05) improved by about 24.4 and 18.3 %, respectively as compared with those of WS and WSM groups, while no significant differences in feed conversion between WS and WSM groups were observed. The males and females of SM group had significantly (P0.05) higher carcass weight, tibia bone length and tibia bone diameter than those of WS and WSM groups except tibia bone diameter of females. Males of SM group had significantly (P0.05) higher percentages of femurs and drumsticks than those of WSM group, but the males of WS group had an intermediate estimate. No significant differences in plasma concentrations of albumin, aspartate transaminase (AST), alanine transaminase (ALT) and calcium of males and albumin, AST and calcium of females were found among all groups. Males and females of WSM and SM groups recorded significantly (P0.05) lower plasma glucose than those of WS group. It is concluded that the males and females Dandarawi chicks reared on sand litter and fed dietary molasses at level of 4% had significantly (P0.05) higher body weight, body weight gain, feed consumption, carcass yield and enhanced feed conversion ratio as compared with control birds reared on wheat straw litter and fed free molasses diet under hot climate of Assiut Governorate.

The objective of this experiment was to study the impact of dietary molasses supplementation on the performance of male and female Dandarawi chicks reared on two types of litter in hot climate in the summer months (June-July-August) of Upper Egypt (Assiut Goverenorate). Six hundred and thirty 8 weeks of age Dandarawi chicks were used. Chicks were randomly distributed into three groups (210 chicks/group) of three replicates each (70 chicks each, 35 male and 35 female). Birds in group 1 fed the control diet and reared on wheat straw litter (WS). Birds in group 2 fed on the experimental diet (i.e. control diet supplemented with 4 % molasses) and reared on wheat straw litter (WSM). Birds in group 3 fed on the control diet supplemented with 4 % molasses and reared on sand litter (SM). Results indicated that the males and females of chickens reared on SM and fed diets containing 4% molasses had significantly (P0.05) higher body weight than WS and WSM groups at all ages studied. Body weight at 20 weeks of age of the SM group was significantly (P0.05) higher by about 15.4 and 7.7% of males and 21.7 and 10.3% of females than those of WS and WSM groups, respectively. The males and females of the SM group significantly gained (P0.05) more than those of the WS and WSM groups at 8-12 weeks of age, respectively, while the males and females of WSM group significantly gained (P0.05) more than those of WS group. The overall mean males of SM group showed a significantly (P0.05) higher daily weight gain by about 27.3 and 8.7 % than those of WS and WSM groups, respectively, while the males of WSM group showed significantly (P0.05) higher daily weight gain by about 17.1 % than those of WS group. The average of feed consumption revealed that SM group consumed significantly (P0.05) higher feed by about 9.3 and 8.1% as compared with those of WS and WSM groups respectively. The overall mean of feed conversion in SM groups was significantly (P0.05) improved by about 24.4 and 18.3 %, respectively as compared with those of WS and WSM groups, while no significant differences in feed conversion between WS and WSM groups were observed. The males and females of SM group had significantly (P0.05) higher carcass weight, tibia bone length and tibia bone diameter than those of WS and WSM groups except tibia bone diameter of females. Males of SM group had significantly (P0.05) higher percentages of femurs and drumsticks than those of WSM group, but the males of WS group had an intermediate estimate. No significant differences in plasma concentrations of albumin, aspartate transaminase (AST), alanine transaminase (ALT) and calcium of males and albumin, AST and calcium of females were found among all groups. Males and females of WSM and SM groups recorded significantly (P0.05) lower plasma glucose than those of WS group. It is concluded that the males and females Dandarawi chicks reared on sand litter and fed dietary molasses at level of 4% had significantly (P0.05) higher body weight, body weight gain, feed consumption, carcass yield and enhanced feed conversion ratio as compared with control birds reared on wheat straw litter and fed free molasses diet under hot climate of Assiut Governorate.

A total number of one hundred and fifty of one-day old brown shaver broilers chicks were used to study the effect of daily feeding time restriction on broiler chicken performance and mortality rate under summer season condition of Upper Egypt. The chicks were randomly divided into 5 experimental groups, (control and 4 treatments). Each group included three replicates of 10 chicks. Group 1 (FFC) was used as control in which the birds were fed ad libitum from 1 to 49 days of age. In groups 2 (EFR6) and 3 (EFR9), the feed was removed for 6 or 9 hours per day from 2 to 4 weeks of age, respectively. In groups 4 (LFR6) and 5 (LFR9), the feed was removed for 6 or 9 hours per day from 5 to 7 weeks of age, respectively. The birds were subjected to heat stress during the experiment since the temperature ranged between 26 and 38 °C. The obtained results could be summarized as follows: At 7 weeks of age, broilers of EFR6 group had significantly (P≤0.05) higher body weight (BW) than those of FFC, EFR9 and LFR9 groups, while the broilers of LFR6 group had an intermediate BW. Also, the broilers of EFR6 group showed a significantly higher (P≤0.05) daily weight gain than those of FFC, EFR9 and LFR9 groups, but not than those of LFR6 group. Time of feed restriction had no effect on the overall mean of feed consumption (FC) and in cumulative feed conversion ratio (FCR) among all groups, however birds in LFR-6H, EFR6 and EFR9 groups had better cumulative FCR by about 5.4, 3.6 and 2.3 %, respectively than that of FFC group. The broilers of all restricted fed groups had fewer deaths than their controls, while the mortality rate was 13.3, 0.00, 6.70, 0.00 and 6.70% for FFC, EFR6, EFR9, LFR6 and LFR9 groups, respectively. Broilers of EFR6 and EFR9 groups had significantly heavier (P≤0.05) carcass weight compared to those of FFC, LFR6 and LFR9 groups. It was found that the birds of EFR9 had significantly heavier breast (P≤0.05) percentage than those of LFR6 and LFR9, while FFC and EFR6 groups had an intermediate percentages. The broilers of EFR6 had significantly lower (P≤0.05) percentage of liver than those of FFC and LFR9; gizzard and giblets than those of FFC, LFR6 and LFR9, but there are significant (P≤0.05) differences in the fat percentages of abdominal, subcutaneous, neck and total of those groups. The EFR6 and EFR9 groups had insignificantly lower percentage of total fat by about 21.1 and 19.9%, respectively than that of FFC group. Time of feed restriction at different ages had no significant effect on the percentage of other carcass (yield and parts) and body organs weight. All restricted fed groups (EFR6, EFR9, LFR6 and LFR9) showed increased economical efficiency by 70, 36, 85 and 28%, respectively as compared with FFC one. It could be concluded that, the most suitable and economically efficient feeding program during high environmental temperature was feed restriction for 6 hours per day (from 9 a.m. to 3 p.m.) from 5 to 7 weeks of age.

This experiment was conducted to investigate the effect of duration of feed withdrawal and full-feeding during high environmental temperature condition on broiler chicken performance and mortality rate. One hundred and twenty one-day old brown Shaver broilers were used in this study. The experiment consisted of four groups, each group included three replicates of 10 chicks each. The broilers were full-fed ad libitum in the control group 1 (FFC) while feeders were removed for three (at 9.00 a.m. and return it at 12.00 p.m.), six (at 9.00 a.m. and return it at 3.00 p.m.) or nine (at 9.00 a.m. and return it at 6.00 p.m.) hours per day in groups 2, 3 and 4, (FW3, FW6, and FW9) respectively from 2 to 7 weeks of age. The average indoor temperature was 26-38 °C. The obtained results could be summarized as follows: No significant differences in the final body weight, feed consumption and cumulative feed conversion ratio were observed between full-fed and all restricted broilers. The broilers of all restricted-fed groups had fewer deaths than that of the control group. The mortality rate was 13.3, 10.0, 0.0 and 10.0% for groups 1, 2, 3, and 4, respectively. No significant differences in carcass weight, its percentage, as well as the percentage of femurs, breast, wings, blood, feet & shank, heart, liver, gizzard, giblets, intestine, drumsticks & femurs fat, and total fat weight were found among all groups. However, significant (P≤0.05) differences were detected in the percentage of head, back, skin, proventriculus, spleen, gallbladder, abdominal fat, subcutaneous fat and breast fat of the groups. The broilers of all restricted-fed groups had significantly lower (P≤0.05) percentage of drumsticks & femurs as compared with that of FFC. It could be observed that, the FFC group had significantly higher (P≤0.05) neck fat as compared with all restricted groups, while it had significantly lower (P≤0.05) heart fat. The FW6 birds had insignificantly lower total fat than that of FFC birds. All restricted fed broilers (groups 2, 3 and 4) increased economical efficiency by 13, 99 and 2%, respectively as compared with FFC broilers. The FW6 group had the best economic efficiency (EE) value. It could be concluded that, the most suitable feeding regime during high environmental temperature is the withdrawal of feed for 6 hours per day at 9.00 a.m. and return it at 3.00 p.m. from 2 to 7 weeks of age because it was best economically efficient than other feed restriction regimes. Also, using this regime was associated with a reduction in fat deposition and with no mortalities.

In the present study, two hundred and forty chicken hens (70 weeks of age) were divided into five equal groups (genotypes): namely New Hampshire (NH), White Selected Lohman (LW), Naked neck strain (NA), Cross of Naked neck X New Hampshire (NANH) and Cross of Naked neck X White Selected Lohman (NALW)) were used in this study. Birds genotype were classified into two subgroups; the first was kept at 32 ºC (high temperature, HT), while the second (control) was kept at 20 ºC (normal temperature, NT, control). Birds were force molted by feed restriction for 21 days. The achieved results could be summarized as follow: Inducing molt under HT caused a significant decrease in egg production (HDP and HHP) in the tested genotypes except NA. The LW was the most affected genotype followed by NALW and finally by NANH and NH. HT increased mortality rate (MR) in LW, NH and NANH. The highest MR was in LW followed by NH and finally by NANH, while it was not affected in both NA and NALW. HT significantly decreased daily feed consumption in all tested genotypes as compared with NT. The decrease reached the maximum in LW and NA followed by NANH and NH and finally by NALW. The feed conversion ratio (FCR) affected by HT was relatively better in NANH, NA, NALW and NH than that of NT, while it declined in LW. The highest improvement in FCR due to HT was obtained in NANH followed by NA and finally by NALW and NH as compared with NT. Therefore, it could be concluded that, force-molt induction under HT in NA and NALW had no adverse effects on egg production, FCR and MR, while the negative effect was pronounced in LW, NH, and NANH in egg production, feed consumption and livability.