Effect of fasting periods on productive performance and thyroid hormones levels of Japanese quail exposed to high temperature [electronic resource].

Includes reference.

This study was designed to evaluate the effects of fasting periods on alleviating the effects of high housing temperature on productive performance and plasma thyroid hormones concentrations (T₃ & T₄) of Japanese quail. A total of 160 Japanese quails (2-wk-old) were randomly assigned to five treatment groups, with 2 replicates of 16 birds each. The 1sl group was maintained continuously in ambient temperature (24±2°C) and fed 3rd and libitum. The 2nd, , 4th and the 5th groups of quails were subjected to an acute heat exposure of 34±1°c for 7hrs/day, from 14 to 42 days of age. These groups of heat stressed birds were subjected to feed removal (fasting) for 0, 3, Sand 7hrs, respectively. The results confirmed that high housing temperature had significant negative effects on productive performance of Japanese quail. Birds Were kept at the high temperature recorded less feed intake, less weight gain, had higher mortality rate and showed lower TJ and T4 concentrations (P<0.05) compared with birds which were reared in ambient temperature. Moreover, long-term fasting period for S or 7hrs significantly (P<0.05) reduced most studied traits.

Summary in Arabic.

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