الفهرس 
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Abstract
The present study was carried out in the Department of Physiology, Faculty of Veterinary Medicine, (Moshtohor), Benha University, from March, 2004 to March, 2005.
The aim of the present work was to investigate the effect of in ovo administration of amino acids mixture and estradiol benzoate into fertilized Japanese quail eggs on the following parameters: (1) hatchability %, (2) embryonic mortality %, (3) ratio of male to female hatched (sex ratio), (4) hatching weights, (5) post-hatch growth, (6) Age of puberty and sexual maturity, (7) free amino acid contents of plasma, (8) levels of some circulating hormones (T3, T4 and testosterone) (8) histological changes of the reproductive organs, (9) cytology and chromosomal aberrations.
This study included 1800 fertilized eggs of Japanese quail artificially incubated at 37.5 °C and more than 50-70 % relative humidity. On the 5th day of incubation, eggs were randomly divided into six equal groups:
Group 1: eggs were kept without treatment as a control group. Group 2: eggs injected with 50.0 vl distilled water (solvent of amino acids).
Group 3: eggs injected with 50.0 ill of the amino acids mixture. Group 4: eggs injected with 50.0 ml of olive oil only (solvent of estradiol benzoate).
Group 5: eggs injected with 50.0 μl olive oil containing 20.0 .tg estradiol benzoate
Group 6: eggs treated with 50.0 ill olive oil containing 40.0 .t.g estradiol benzoate.
After hatching, birds were housed in separate cages, received ad libitum feed and water and a commercial balanced broiler ration containing 24.8 % crude protein for grower and 20.2 % crude protein for adults.
Summary The obtained results revealed that:
1-Hatchability of the control group was 81.33 %, in ovo administration of amino acids mixture resulted in no significant change in hatchability percentage (79.33 %). While in ovo administration of estradiol benzoate significantly decreased hatchability % in a dose-dependent manner (52.00 % after 20 pg and 36.00 % after 40pg estradiol banzoate treatment).
2-Embryonic mortality of the control group was 18.67 %, in ovo administration of amino acids mixture resulted no significant change in embryonic mortality percentage (18.67 %). While in ovo administration of estradiol benzoate significantly increased embryonic mortality % in a dose-dependent manner (48.00 % after 20 p,g and 64.00 % after 40gg estradiol banzoate treatment).
3-In ovo administration of both amino acids mixture and estradiol benzoate had no significant effect on sex ratio percentage.
4-The hatching weight of the control group was 7.12 g. In ovo administration of amino acids mixture significantly increased the weight of hatch (8.16 g). In ovo treatment with estradiol benzoate increased the hatching weight than that of the control group in a dose-dependent manner (7.73g after 20 p,g and 8.02g after 40 μg estradiol banzoate treatment).
5- Body weights of amino acids administered males were heavier than the control during all experimental periods. While, the difference was significant during the 5th, 6th, 7th and 9th
weeks of age.
• Males hatched from 20 1,1g, estradiol banzoate treated eggs was heavier than those of the control group during the whole experimental periods. While, the difference was significant during the 7th, 8th and 9th weeks only.
•Males hatched from 40 lig estradiol banzoate treated eggs exhibited heavier body weights than those of the control group and oil treated group in all ages. But the difference was significant only from the 7th week till the end of the experiment.
6- In ovo administration of amino acids mixture significantly increased the body weights of females than those of the control in all ages except during the 1st and the 9th weeks of life.
•In ovo administration of 20 lig estradiol benzoate resulted in no significant change in body weights of females when compared to control.
•In ovo administration of 40 lig estradiol benzoate caused no significant change in body weights of females except during the 6th, 9th and 10th weeks of life when this treatment significantly (P < 0.05) increased females body weights than those of the control.
7- In ovo administration of amino acids accelerated the ages of puberty (44 days) and sexual maturity (50 days) in females, as compared to control (45 and 53, respectively). While, in ovo administration of 20 and 40 jig estradiol benzoate delayed both the puberty (55 and 64 days, respectively) and sexual maturity (59 and 66 days, respectively) ages.
•In ovo administration of amino acid mixture resulted in earlier puberty (sex call at day 31) in males than control males (34 days). While, the age of maturity was similar to that of control (42 days).
•In ovo administration of estradiol benzoate delayed the age of puberty indicated by delaying the characteristic sex call (39 days after 20 pg and 41 days after 40 pig estradiol treatment). In addition, a later age of sexual maturity (49 days) was observed as compared to control (42 days).
8- The testicular weights of amino acids treated group were significantly heavier than that of the control on the 3rd, 4th,and
S’uttunary
7th weeks. While, the differences were not significant during the rest of the experimental periods.
•Males of estradiol benzoate treated groups had lighter testes than the control. While, the differences were significant of
the 3rd, 5th, 6th and ,111
9 weeks after 20 gg estradiol treatment
and from the 3rd till the end of the experiment after 40 tig estradiol treatment.