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Catecholamine- cortisol-, 2.3-Diphosphoglycerate- and glucose concentrations were determined in duck embryos in the last quarter of incubation. Theses parameters were measured at standard incubation temperature (37.5 °C) as well as at increased (38.5 °C) or decreased (35.0 °C) incubation temperature. Incubation temperature was changed at D24 and the measurements were taken out between D28.5 and D33. This means the embryos of the cold group were exposed to a decreased incubation temperature from 5.5 up to 10 days. Whereas the embryos of the warm group were exposed to an increased incubation temperature from 5.5 up to 8.5 days.Change in incubation temperature as well adjustable environmental factor was chosen in order to draw conclusions from changed hormone concentrations to a reaction of the embryo.The results confirm former experiences about the influence of incubation temperature on the development of bird embryos. Increase in temperature accelerates development, whereas decrease of temperature for several days retards development. This fact was indicated by an earlier respectively later onset of ep or ip. Furthermore the well known increase in malpositions after an increase in incubation temperature could be determined. In the warm group there were 50 % more embryos in malposition than in the control group.It was assumed that not only incubation temperature effects catecholamine- and cortisol concentrations but also position of the embryo in the egg and ip. The present results hint at a possible influence. It was shown that independent of incubation temperature the embryos in malposition showed higher hormone concentrations compared to embryos in normal position. These results could not have been statistically proven because of the low sample number. Following investigations on duck embryos" catecholamines- and cortisol concentrations near hatching should consider the position of the embryo in the egg.Furthermore if embryos of a experimental group showed an earlier or later ip compared to the majority, different catecholamine concentrations were measured. Whereas cortisol concentration was not influenced by ip.In the control group ip between D31 and D31.5 especially influenced catecholamine concentrations. Before ip dopamine stayed level and increased significantly after ip. Before ip the medians of noradrenaline showed an increasing tendency and weresignificantly decreased after ip. The medians of adrenaline showed an increasing tendency before ip, too. But they stay on this level after ip.The cortisol concentration increases age-dependant during the whole investigation period.The decrease in incubation temperature retards the onset of ip about 48 h in the cold group. In order to compare the medians of the catecholamine- and cortisol concentrations of embryos in the control and cold group, the values in the cold group were attached to the new incubation age calculated according to the retardation of development. So it could have been shown that the medians of catecholamine concentrations in the cold group until D29.5 were about 40 to 60 % lower than in the control group. From D29.5 on dopamine-, noradrenaline- and adrenalineconcentration increased to an extend that on D31 there were no difference between the medians of the catecholamine concentrations in the cold and control group.Even medians of cortisol concentrations in the cold group increased from D29 on. But on D31, directly before ip of the embryos in the cold group, they were 30 % higher than in the control group. The same increase in medians of cortisol concentration could have been seen in medians of glucose concentration in the cold group.Until ip catecholamine concentration was not influenced by an increase of incubation temperature about 1 °C. After ip medians of catecholamine concentration in the warm group were higher than in the control group. Cortisol concentration was ot influenced by increase of temperature.The highest share in total catecholamines takes noradrenaline in the control as well as in the cold group. In contrast to chicken embryos in duck embryos adrenaline takes the second highest share and dopamine takes the smallest one (NA>A>DA).The established increase in 2.3-DPG under hypoxic conditions in chick embryos could have been also shown for duck embryos. 2.3-DPG in the control group was significantly increased before ip compared to the values after ip.The medians of 2.3-DPG concentration of the embryos in the cold group got to the level of the control group shortly before ip. In contrast to the embryos of the control group these values were achieved by an increase of 2.3-DPG concentrations in blood cells. In the embryos of the control group 2.3-DPG was increased because of the increasing number of blood cells.The results of the present study contribute to a characterization of the adrenal system of duck embryos shortly before hatch. With the help of the firstly determined values in duck embryos in the last quarter of incubation differences and similarities to other precocial bird embryos can be revealed.