Effect of seasonally changing aerial environment on testosterone in Karagouniko and Chios sheep


  • Aristidis Matsoukis Department of Crop Science, Agricultural School of Agricultural Production, Infrastructure and Environment, Agricultural University of Athens, 75 Iera Odos St., 11855, Athens, Greece
  • Aikaterini Chronopoulou-Sereli Department of Crop Science, Agricultural School of Agricultural Production, Infrastructure and Environment, Agricultural University of Athens, 75 Iera Odos St., 11855, Athens, Greece
  • George Stratakos Department of Crop Science, Agricultural School of Agricultural Production, Infrastructure and Environment, Agricultural University of Athens, 75 Iera Odos St., 11855, Athens, Greece




air temperature, photoperiod, ram reproductive physiology, repeated measures


A well-established activity in Greece and other Mediterranean countries is sheep farming. Karagouniko and Chios sheep are promising breeds and targets for the reproductive physiologist’s attention. Under this context, part of the reproductive physiology of Karagouniko and Chios was investigated, taking into account the environment. Specifically, four time periods were considered; April-June (Long days, increasing photoperiod length), July-September (Long days, decreasing photoperiod length), October-December (Short days, decreasing photoperiod length), and January-March (Short days, increasing photoperiod length). The effect of the period on the concentration of the testosterone (main male hormone) in rams of the breeds above was studied, by using repeated measures analysis of variance, also taking into account the environmental variables air temperature, relative humidity, sunshine, rainfall, and photoperiod, in the Artificial Insemination Center of Karditsa (39°21’18’’N, 21°54’19’’E), Greece. The lowering of photoperiod from April-June to July-September (long days) and afterward, even more to October-December (short days) coincided with a progressive increase of testosterone in both breeds. Photoperiod seems to have a major role in the concentration of Karagouniko and Chios breeds' testosterone compared to the other environmental variables. When considering the whole experimental period, Chios sheep had significantly higher (P < 0.05) testosterone (1.95 ng/ml) than the Karagouniko one (1.55 ng/ml). Our findings could contribute towards the more rational exploitation of the examined sheep breeds.


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Effect of season on testosterone concentration of Karagouniko and Chios sheep. In each column, the bar on it represents the standard error of the mean (n=16). Different letters above columns indicate significant differences between the respective means, separately for Karagouniko sheep (upper case letters) and Chios sheep (lower case letters) at P ≤ 0.05 after Bonferroni correction.




How to Cite

Matsoukis, A., Chronopoulou-Sereli, A., & Stratakos, G. (2022). Effect of seasonally changing aerial environment on testosterone in Karagouniko and Chios sheep. Journal of Animal Behaviour and Biometeorology, 10(1), 2105. https://doi.org/10.31893/jabb.22005



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