Seasonal variation in serum testosterone, T3 and andrological parameters of two Turkish sheep breeds

Gündoğan, Mustafa

doi:10.1016/j.smallrumres.2005.11.005

Cited by 30 publications

(33 citation statements)

References 9 publications

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“…According to the climatological data, the increase in plasma testosterone levels was associated with the increase in photoperiod. In a clear contrast to our results, a higher level of testosterone was found in rams during short days in comparison with long days (Gundogan, 2007). However, the influence of the photoperiod depends on sheep breeds and their location; those originating from temperate climates in mid and high latitudes are seasonal breeds, their breeding season being limited to autumn (Rhim et al, 1993); while, in tropical and subtropical climates, some breeds are almost or completely aseasonal.…”

Section: Discussioncontrasting

confidence: 99%

“…However, in the ram, testicular size and efficiency of spermatogenesis have differed between breeding and non-breeding season (Kafi et al, 2004). Moreover, seasonal changes in testosterone concentrations during a 1-year period have been used to determine that breeds such as Chios and Daglic are seasonal breeders (Gundogan, 2007). Testosterone secretion in small ruminants was driven by natural day length changes or artificial photoperiodic cycles (Langford et al, 1999).…”

Section: Introductionmentioning

confidence: 99%

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Testosterone and cortisol patterns and the effects of electro-ejaculation and copulation in Awassi rams

et al. 2016

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Abstract. The effects of month, electro-ejaculation (EE) and copulation process on testosterone and cortisol levels were investigated in Syrian Awassi rams. Jugular blood samples were collected from 10 rams at weekly intervals for 1 year. During the breeding and non-breeding season, samples were collected 60 min before EE and copulation as well as 0 (at the time of ejaculation), 20 and 60 min after EE and copulation. Low testosterone levels were detected from October to February (4.58-5.06 nmol L −1 ), while high levels were noted from May to September (8.01-11.40 nmol L −1 ) with significant differences among months (P <0.001). In contrast, cortisol levels were low from March to October (0.63-2.27 nmol L −1 ) and the highest level was recorded in December (11.30 nmol L −1 ) with a significant month effect (P <0.001). Cortisol reached its maximum concentration in the electrically stimulated rams 20 min post electro-ejaculation with no significant difference between the two seasons at this end time point. Means of testosterone levels differed between the breeding and the non-breeding season for electro-ejaculated rams. An increase in testosterone level was observed after 60 min of copulation process in the non-breeding, while no differences were noted for this hormone over the four time periods during the breeding season. Cortisol levels rose significantly in non-breeding season at 0 and 20 min after copulation (P <0.001). In conclusion, Syrian Awassi rams displayed a clear seasonality of testosterone and cortisol. Cortisol levels indicate an acute stress response to EE treatment. Females have an effect on testosterone and cortisol levels in Syrian Awassi rams only during the non-breeding season.

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Section: Discussioncontrasting

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Testosterone and cortisol patterns and the effects of electro-ejaculation and copulation in Awassi rams

et al. 2016

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“…Season and breed had no significant effect on mass motility. However, in other studies semen samples had a higher mass motility in autumn (Kafi et al, 2004;Gündoğan, 2007) and differences among breeds were reported (Boland et al, 1985). These authors observed that Dorset Horn rams produced semen which had a higher wave motion grading than Suffolk and Texel rams.…”

Section: Reproductive Characteristics Of Argentine Pampita and Corriementioning

confidence: 82%

“…The latter report indicates that the highest plasma testosterone concentration was found in summer in Karakul rams. In contrast, serum testosterone levels were recorded to be higher during the decreasing daylenght period (autumn months) in Daglic and Chios (Turkish breeds) rams (Gündoğan, 2007) and in Texel, Suffolk and Ile-de-France rams (Mandiki et al, 1998b). The latter authors found that testosterone concentration was not related to testicular mass.…”

Section: Discussionmentioning

confidence: 99%

Seasonal variation in sexual behavior, plasma testosterone and semen characteristics of Argentine Pampinta and Corriedale rams

Aller

Aguilar

Vera

et al. 2012

Span. j. agric. res.

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Five Argentine Pampinta (dairy breed) and six Corriedale (dual-purpose breed) adult rams were used to study the effect of season on sexual behavior, plasma testosterone (T) and semen characteristics for a period of 1 year. Scrotal circumference (SC) and T concentrations were determined at 2-week intervals. Each ram was exposed monthly to three ovariectomized ewes in one 20-min test and the total number of mounts and successful matings were recorded. Semen collection was attempted from each ram twice weekly for six consecutive weeks during each season. In both breeds, SC varied seasonally showing the lowest mean values during winter and spring and in the Corriedale rams (32.8 ± 0.3 cm) was smaller (p < 0.05) than in Pampinta rams (34.4 ± 0.4 cm). No difference (p > 0.05) was recorded in T concentration between breeds and both breeds reached a peak in summer and autumn. Number of matings showed the maximal values in autumn in both breeds. Season had no significant effect on mass motility, sperm concentration and percentage of live sperm. Semen volume, percentage of progressive motility and total sperm per ejaculate were higher during summer and autumn than in other seasons of the year. Pampinta rams had the highest values (p < 0.05) of sperm concentration, total sperm per ejaculate and percentage of abnormal sperm. Results of this study show that sexual behavior, SC and T concentrations exhibit seasonal variation in Pampinta and Corriedale rams and that semen of superior quantity and quality is especially collected in both breeds during the summer and autumn.Additional key words: hormone, rams; semen quality; serving capacity. Resumen Variación estacional en el comportamiento sexual, testosterona plasmática y características seminales de carneros Pampinta Argentina y CorriedaleCinco carneros adultos Pampinta Argentina (raza lechera) y seis Corriedale (raza doble propósito) fueron utilizados para estudiar el efecto de la estación del año sobre el comportamiento sexual, testosterona plasmática (T) y caracterís-ticas seminales. La circunferencia escrotal (CE) y las concentraciones de T fueron determinadas cada dos semanas. Mensualmente, cada carnero fue expuesto a tres ovejas ovariectomizadas en una prueba de 20 min y se registró el número total de montas y apareamientos. La colección del semen fue intentada dos veces por semana por seis semanas consecutivas durante cada estación. En ambas razas los menores valores de CE fueron observados en invierno y primavera (Corriedale = 32,8 ± 0,3 cm; Pampinta = 34,4 ± 0,4 cm; p < 0,05). La concentración de T alcanzó un máximo en verano y otoño y el número de apareamientos fue máximo en otoño. La estación no tuvo efecto (p > 0,05) sobre la motilidad masal, la concentración espermática y el porcentaje de espermatozoides vivos. El volumen del eyaculado, el porcentaje de motilidad progresiva y el número total de espermatozoides fueron mayores en el verano y otoño. La raza del carnero tuvo un efecto (p < 0,05) sobre la concentración espermática, el número total de espermato...

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“…The levels of plasma thyroid hormones in domestic animals are affected by many exogenous (e.g., age, gender, breed, season, ambient temperature, nutrition, climate and geographical traits of the region, method of measurement, drugs, fasting, disease, and the rearing technology) and endogenous factors (e.g., circadian and circannual rhythms, pregnancy, ovarian endocrine function, lactation, and reproduction) (Kennedy et al 1977;Almlid et al 1982;Huszenicza et al 2002;Souza et al 2002;Stockham and Scott 2002;Rasooli et al 2004;Altiner 2006;Venditti and Di Meo 2006;Gündoğan 2007;Kozat et al 2007;Todini 2007;Piccione et al 2009;Eshratkhah et al 2010a, b, d). Thyroid hormones have many target tissues; they affect the metabolism of various components and play a crucial role in regulating primary and basal metabolism (Thrall et al 2004;Chatterjea and Shinde 2005;Cassar-Malek et al 2007;Kale et al 2007;Todini 2007).…”

Section: Introductionmentioning

confidence: 99%

Relationship between plasma thyroid hormones and some biochemical parameters in Iranian Sarabi calves

et al. 2010

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The thyroid gland has some important endocrine hormones that regulate basal metabolism in various tissues of domestic animals. Thyroid hormones have a central role in animals' development and their tissue functions. In this study, the relationship between the plasma thyroxine (T 4 ), triiodothyronine (T 3 ), free thyroxine (fT 4 ), free triiodothyronine (fT 3 ), triglyceride, cholesterol, glucose, total protein, and albumin concentrations as well as albumin/globulin ratio in different ages of Iranian Sarabi calves was investigated. Blood samples were collected from the jugular vein of 47 clinically healthy calves free from internal and external parasites (grouped according to their age-1-14 days, 1-2, and 3-6 months) in early of winter. The level of thyroid hormones was determined by chemiluminescence, and other parameters were measured by spectrophotometry using commercial kits. Our data from this study indicates that there was no significant difference and correlation in all the studied parameters between age groups and sexes. But we found a significant correlation between plasma T 4 and total protein (P<0.05, r=0.600), T 4 and albumin (P<0.05, r=0.575), T 3 and fT 3 (P<0.05, r= 0.610), T 3 and total protein (P<0.01, r=0.725), T 3 and glucose (P<0.01, r=0.685), and fT 4 and fT 3 (P<0.05, r= 0.609) concentrations as well as between total protein and albumin/globulin ratio (P<0.01, r=−0.783).

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Seasonal variation in serum testosterone, T3 and andrological parameters of two Turkish sheep breeds

Cited by 30 publications

References 9 publications

Testosterone and cortisol patterns and the effects of electro-ejaculation and copulation in Awassi rams

Testosterone and cortisol patterns and the effects of electro-ejaculation and copulation in Awassi rams

Seasonal variation in sexual behavior, plasma testosterone and semen characteristics of Argentine Pampinta and Corriedale rams

Relationship between plasma thyroid hormones and some biochemical parameters in Iranian Sarabi calves

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