The aim of this study was to measure the effect of estradiol-17b (E 2 ) injection on follicle-stimulating hormone (FSH) secretion and egg-laying performance of Japanese quail. Female Japanese quail were housed in cages and fed ad libitum. After a 7-day adaptation period, the birds were randomly assigned to three groups, that is, one control group and two test groups. The birds were weighed, before every injection. The control group was subcutaneously injected with 0.2 ml sesame oil-ethanol mixture, whereas test groups were injected, twice in a week, with 0.2 ml sesame oil-ethanol mixture containing 0.1 or 0.2 mg E 2 along the study. One day after the first injection, egg number, egg weight, eggshell strength and food conception were daily recorded. On the last day of the experiment, the birds were injected and 3 h later seven birds from each group were randomly selected for bleeding. Blood samples (2 ml/bird) were collected from the jugular vein for the measurements of serum concentrations of E 2 , FSH, calcium (Ca) and phosphorus (P). E 2 injection did not cause any significant changes in serum FSH concentrations, daily egg laid/ bird, food conception/bird, serum concentrations of the Ca and the P. Egg weight was significantly increased in the 0.1 mg E 2 -injected group as compared with the control and 0.2 mg E 2 -injected groups. Eggshell strength in the 0.2 mg E 2 -injected group was significantly high as compared with the control, whereas the difference between the 0.1 mg E 2 -and 0.2 mg E 2 -injected groups was not statistically important. These results show that serum FSH concentration was not increased even when slightly suppressed by subcutaneous injection of 0.1 or 0.2 mg E 2 . Different doses of E 2 have different functions. The increase in BWs in the 0.1 mg E 2 -injected group was a result of the dose effect, which probably increased growth hormone secretion from the pituitary or IGF-1 synthesis from the liver or both. The dose, 0.2 mg E 2 , was ineffective in increasing the BW, but it significantly increased eggshell strength probably via the increase in Ca and P utilizations.Keywords: egg, follicle, estradiol, quail ImplicationsThe Japanese quail (Coturnix japonica) belongs to the order Galliformes and the family Phasianidae. They have been used for meat and egg production since 1900. After World War II, the Japanese quail has become an important experimental animal, similar to the mouse and rat, for scientific research in universities. Recently, they have been accepted as a model animal for studying the relationship between the endocrine status and the reproductive behaviors. Not enough data are available about the relationship between serum estradiol-17b (E 2 ) concentration and egg-laying performance of the Japanese quail. A few studies were conducted to measure the effect of intramuscular E 2 benzoate injection on egglaying performance, whereas the majority of other studies mainly focused on the effect of phytoestrogen (daidzein and genistein)-containing diet on the egg-laying performance of the...

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The objective of this study was to determine the impact of different ambient temperatures on egg production and hatching parameters in Japanese quail. Sixteen weeks old male and female Japanese quail were assigned to 10 cages as 1 male and 5 females. Quails were housed in a poultry yard belonging to the Faculty of Agriculture. Quails were reared under 16 hours’ light and 8 hours’ dark photoperiod. During the study, water and food were freely available as ad-libitum. Regularly egging five layer cages were selected and their laying and hatching performances were compared for three weeks when there were highest differences in average room temperatures (22.38 ± 0.21; 23.10 ± 0.04 and 23.76 ± 0.18°C). Changes in weekly mean ambient temperatures did not affect egg weights, egg mass, weekly egg laid/hen, and weekly egg weight/hen. Fertility and hatching rates were also not significantly changed (P>0.05). Lower ambient temperature (22.38°C) caused a significant reduction in hatchability and increment in embryonic mortality as compared with the 23.10°C group. It is possible to postulate from the data presented here that the best room temperature for hatchability and lower embryonic mortality in Japanese quail, is around 23°C.