Journal of Animal Behaviour and Biometeorology
Journal of Animal Behaviour and Biometeorology
Short Communication Open Access

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

Aristidis Matsoukis, Aikaterini Chronopoulou-Sereli, George Stratakos

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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.


air temperature, photoperiod, ram reproductive physiology, repeated measures


Aguirre V, Orihuela A, Vázquez R (2007) Effect of semen collection frequency on seasonal variation in sexual behaviour, testosterone, testicular size and semen characteristics of tropical hair rams (Ovis aries). Tropical Animal Health and Production. doi: 10.1007/s11250-007-9010-8 

Belkadi S, Safsaf B, Heleili N, Tlidjane M, Belkacem L, Oucheriah Y (2017) Seasonal influence of sperm parameters, scrotal measurements, and serum testosterone in Ouled Djellal breed rams in Algeria. Veterinary World. doi: 10.14202/vetworld.2017.1486-1492

Carvajal-Serna M, Torres-Ruda F, Cardozo JA, Grajales-Lombana H, Cebrián-Pérez JA, Muiño-Blanco T, Pérez-Pé R, Casao A (2019) Changes in melatonin concentrations in seminal plasma are not correlated with testosterone or antioxidant enzyme activity when rams are located in areas with an equatorial photoperiod. Animal Reproduction Science. doi: 10.1016/j.anireprosci.2018.11.007

Chronopoulos KI, Kamoutsis AP, Matsoukis AS (2012) Thermal comfort estimation in relation to different orientation in mountainous regions in Greece by using artificial neural networks. Global NEST Journal. doi: 10.30955/gnj.000743

Feldman HA, Longcope C, Derby CA, Johannes CB, Araujo AB, Coviello AD, Bremner WJ, McKinlay JB (2002) Age trends in the level of serum testosterone and other hormones in middle-aged men: Longitudinal results from the Massachusetts male aging study. The Journal of Clinical Endocrinology & Metabolism. doi: 10.1210/jcem.87.2.8201

Gómez-Brunet A, Santiago-Moreno J, Toledano-Diaz A, López-Sebastián A (2012) Reproductive seasonality and its control in Spanish sheep and goats. Tropical and Subtropical Agroecosystems 15:47-70.

Gordon I (1997) Controlled reproduction in sheep & goats. Cabi Publishing, Wallingford, UK.

Gündoğan M, Baki D, Yeni D (2003a) Reproductive seasonality in sheep. Acta Agriculturae Scandinavica, Section A — Animal Science. doi: 10.1080/09064700310014960

Gündoǧan M, Demirci E (2003) Monthly changes in some reproductive parameters and in testosterone and thyroxine values of rams throughout one year under continental climate conditions. Deutsche Tierärztliche Wochenschrift 110:450-453.

Gündoǧan M, Uçar M,  Tekerli M (2003b) An investigation on the relationships between the morphometric measurements of testes and other spermatological features in the rams maintained in the conditions of Afyon before, during and after the breeding period. Lalahan Hayvancılık Araştırma Enstitüsü Dergisi 43:9-22.

Kamoutsis A, Chronopoulos K, Matsoukis A (2018) Altitude and canopy cover effects on air temperature in a mountainous region of Ionian islands, Greece. Current World Environment. doi: 10.12944/CWE.13.3.03

Kim TK (2015) T test as a parametric statistic. Korean Journal of Anesthesiology. doi: 10.4097/kjae.2015.68.6.540

Kozioł K, Koziorowski M (2013) Steroid hormones in peripheral blood plasma and androgen receptors in testis and epididymis of roe deer male (Capreolus capreolus) during the reproduction season. Small Ruminant Research. doi: 10.1016/j.smallrumres.2013.09.008

Matsoukis A, Stratakos G, Chronopoulou-Sereli A, Tsiros I (2019) Seasonal variation of wool fibre length in Karagouniko and Chios sheep in relation to meteorological factors. Emirates Journal of Food and Agriculture. doi: 10.9755/ejfa.2019.v31.i10.2020

Ortavant R, Bocquier F, Pelletier J, Ravault JP, Thimonier J, Volland-Nail P (1988) Seasonality of reproduction in sheep and its control by photoperiod. Australian Journal of Biological Sciences 41:69-85.

 Poulton AL, Robinson TJ (1987) The response of rams and ewes of three breeds to artificial photoperiod. Journal of Reproduction and Fertility. doi: 10.1530/jrf.0.0790609

Rekkas C, Kokolis N, Smokovitis A (1993) Breed and seasonal variation of plasminogen activator activity and plasminogen activator inhibition in spermatozoa and seminal plasma of the ram in correlation with testosterone in the blood. Andrologia. doi: 10.1111/j.1439-0272.1993.tb02690.x

Stratakos G (2015) Microclimatic conditions and reproductive physiology of sheep. Dissertation, Agricultural University of Athens, Greece.

Tzouramani I, Zelovitis J, Intxaurrandieta JM, Eguinoa P (2019) Sustainability of dairy sheep farming: Examples from Greece and Spain. In : Ruiz R, López-Francos A., López Marco L. (eds) Options Méditerranéennes, A, no. 123–Innovations for Sustainability in Sheep and Goats. CIHEAM, Zaragoza, Spain, pp 457-461.

Verma JP (2016) Repeated measures design for empirical researchers. Wiley, Hoboken, New Jersey.

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