Seasonality in mares

Nagy, P.; Guillaume, Daniel; Daels, Peter

doi:10.1016/s0378-4320(00)00133-0

Cited by 117 publications

(95 citation statements)

References 61 publications

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“…Horse is a seasonal breeder and its reproductive efficiency varies throughout the year. In the northern hemisphere mares enter anestrus and stallions semen quality sharply declines during late fall and early winter (16,30). Information on photoperiod and the physiological reproductive season in Arabian horse is very limited.…”

Section: Discussionmentioning

confidence: 99%

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Seasonal variations in serum concentrations of melatonin, testosterone, and progesterone in Arabian horse

Çiğdem;ÜNER¹

2009

Ankara Üniversitesi Veteriner Fakültesi Dergisi

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Summary:The objective of this study was to characterize seasonal variations in serum concentrations of melatonin, testosterone, and progesterone in Arabian horses under natural photoperiodic conditions. Peripheral blood samples were collected during breeding and non-breeding seasons from mares and stallions. Serum concentrations of melatonin, testosterone, and progesterone were determined by radioimmunoassay. Serum concentrations of melatonin were greater in the non-breeding season (42.41±1.59 and 37.68±1.55 pg/ml) when compared to breeding season (23.52±1.24 and 17.22±2.10 pg/ml) in both mares and stallions, respectively. Melatonin concentrations were low but not different between the luteal and follicular phases during breeding season in cyclic mares. Mares had greater concentrations of melatonin than stallions in both breeding and non-breeding season. Mean concentrations of testosterone were greater during breeding season (6.58±0.50 ng/ml) than non-breeding season (3.64±0.48 ng/ml) in stallions. There was a negative correlation (r=-0.658, p<0.01) with melatonin and testosterone levels in both season in stallions. A negative correlation (r=-0.829, p<0.05) in luteal phase and a positive correlation (r=0.847, p<0.05) in non-breeding season were found between melatonin and progesterone concentrations in mares. We conclude that changes in day length act as a regulator and photoperiod can be used to modify the seasonal reproduction in Arabian horse.Key words: Arabian horse, melatonin, photoperiod, progesterone, testosterone. Arap atlarında serum melatonin, testosteron ve progesteron seviyelerinin mevsimsel değişimleriÖzet: Bu çalışmanın amacı, doğal fotoperiyodik koşullarda Arap atlarının serum melatonin, testosteron ve progesteron seviyelerinin mevsimsel değişimlerini belirlemektir. Kısrak ve aygırlardan üreme döneminde ve üremenin olmadığı dönemde toplanan kan örneklerinden, radioimmunoassay yöntemi ile serum melatonin, testosteron ve progesteron seviyeleri belirlenmiştir. Sırasıyla hem kısrak hem de aygırlarda melatonin seviyeleri üremenin olmadığı dönemde (42.41±1.59 ve 37.68±1.55 pg/ml) üreme dönemine göre (23.52±1.24 ve 17.22±2.10 pg/ml) daha yüksek bulunmuştur. Üreme döneminde östrus siklusu gösteren kısraklarda melatonin seviyelerinin düşük fakat luteal ve foliküler dönemler arasında fark yoktu. Kısraklar hem üreme döneminde hem de üremenin olmadığı dönemde aygırlara göre daha yüksek melatonin seviyelerine sahipti. Aygırlarda üreme dönemindeki (6.58±0.50 ng/ml) testosteron seviyeleri üremenin olmadığı dönemden (3.64±0.48 ng/ml) daha yüksekti. Aygırlarda her iki dönemde melatonin ile testosteron seviyeleri arasında negatif bir ilişki vardı (r=-0.658, p<0.01). Kısrakların melatonin ve progesteron seviyeleri arasında ise luteal dönemde negatif (r=-0.829, p<0.05), üremenin olmadığı dönemde de pozitif bir ilişki (r=0.847, p<0.05) bulundu Bu çalışma ile Arap atlarında, gün uzunluğundaki değişikliklerin mevsimsel üremede bir düzenleyici olarak görev aldığı ve fotoperiyodun bu düzenlemede değiştirici etkisi olduğu ...

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Section: Discussionmentioning

confidence: 99%

“…The horse is a seasonal polyestrous species with onset of the breeding season occurring in spring, associated with increase in daylight, temperature, and availability of food (27,30). During the fall, the duration of secretion of melatonin from the pineal gland is increased, reflecting the increased duration of darkness in horse.…”

Section: Introductionmentioning

confidence: 99%

Seasonal variations in serum concentrations of melatonin, testosterone, and progesterone in Arabian horse

Çiğdem;ÜNER¹

2009

Ankara Üniversitesi Veteriner Fakültesi Dergisi

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“…To avoid behavioural or pheromonal influences on oestrus presentation, the use of a teaser stallion was avoided (Oxender et al, 1978;McKinnon and Voss, 1993;Nagy et al, 2000). Evaluation criteria were limited to internal morphological changes on uterine oedema and follicular growth as observed through ultrasonography, and to cervical relaxation and tone judged by rectal palpations.…”

Section: Discussionmentioning

confidence: 99%

Melengestrol acetate as a tool for inducing early ovulation in transitional mares

López-Bayghen

Zozaya

Ocampo

et al. 2008

Acta Veterinaria Hungarica

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The efficacy of melengestrol acetate (MGA) to shorten the vernal transition of mares by synchronising and accelerating the first ovulation of the year after 60 days of phototherapy was determined by ultrasonographic monitoring. Sixteen mares in late transition were fed two doses of MGA (150 mg/mare/day and 100 mg/mare/day, respectively) for 10 days. A luteolytic dose of prostaglandin was administered to each mare one day after the end of MGA treatment. The presence and duration of oestrus, follicular growth, uterine oedema and presence of ovulation were monitored by ultrasonography and the cervical tone was evaluated by rectal palpation. Ovulation was detected in 87.5% of the mares treated with 150 mg MGA/mare/day for 10 days, and in 62.5% of the mares receiving 100 mg MGA/mare/day for 10 days. This was statistically different (P = 0.03) from the untreated control mares having an ovulation rate of 20%. Mares that received 150 mg MGA/day for 10 days had a mean treatment to ovulation interval of 13.1 ± 5.97 days after the end of treatment, while mares that received 100 mg MGA/day for 10 days had a mean of 25.6 ± 10.50 days (P = 0.01) to ovulation. These results suggest that MGA can be used for synchronising and hastening the first ovulation of the year in mares.

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“…A sazonalidade reprodutiva em equinos refere-se à mudanças morfológicas e fisiológicas dos órgãos reprodutivos, primariamente devido à mudanças na relação diária de luminosidade e escuridão durante do ano (BERGFELT, 2009), que associados, estimularam a busca por conhecimentos relativos aos mecanismos da sazonalidade reprodutiva e ao desenvolvimento de métodos para uma indução antecipada da estação de monta (NAGY; GUILLAUME; DAELS, 2000;AURICH, 2011).…”

Section: Introductionunclassified

Comportamento De Éguas Após a Inserção De Dispositivo Intravaginal Impregnado Com Progesterona

Martinez

Colli

Carvalho

et al. 2017

ArqVet

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Umuarama, v. 19, n. 3, p. 143-146, jul./set. 2016.RESUMO: Considerando a escassez de estudos sobre o temperamento ou reatividade de equinos, objetivou-se com esse estudo avaliar o comportamento de éguas após a inserção do implante intravaginal de progesterona, para utilização em bovinos, por meio da observação de comportamentos individuais e coletivos. Para tanto, utilizou-se sete éguas que receberam dispositivo intravaginal impregnado com progesterona e agente luteolítico. Após a colocação dos implantes e soltura das éguas, se iniciou a observação (cinco observadores sem contato entre eles) de seus comportamentos até o tempo de 120 minutos, seguindo o modelo proposto por Heleski et al. (2002). Os resultados indicaram que durante os 120 minutos de observação todas as éguas demonstraram estar alertas, pelo menos em uma observação; que o ato de comer foi observado em todos os animais durante o período estudado e que o ato de urinar e defecar foram observados, em aproximadamente, 70 e 60%, respectivamente, dos comportamentos avaliados. Comportamentos prováveis da indicação de dor e/ou desconforto, como bater da cauda, mímica de urinar, eversão do clitóris e urinando foram observados até 65 minutos, sendo que os três primeiros cessaram aos 55 minutos. De todos os comportamentos analisados, nenhum deles foi visualizado após 65 minutos de observação. Concluiu-se que a inserção do dispositivo intravaginal impregnado com progesterona não afeta negativamente o comportamento de éguas, podendo ser utilizado sem comprometer o bem-estar desses animais. PALAVRAS-CHAVE: Equino. Temperamento. Reatividade. Sincronização de estro. BEHAVIOR OF MARES AFTER INSERTION OF INTRAVAGINAL PROGESTERONE DEVICEABSTRACT: Considering the scarcity of studies on the behavior or reactivity of horses, this study aimed to assess the behavior of mares after insertion of intravaginal progesterone implant for use in cattle, through the observation of individual and collective behavior. In order to do so, seven mares received intravaginal devices impregnated with progesterone and luteolitic agent. After the implant was placed, the mares were released, and their behavior was observed (five observers with no contact between them) for a period of 120 minutes, following the model proposed by Heleski et al. (2002). The results indicated that during the 120-minute period, all mares were alert, in at least one observation; that all animals ate during the study period, and urination and defecation were observed in approximately 70 and 60%, respectively, of the assessed behavior. Behaviors that were likely an indication of pain and/or discomfort, like hitting the tail, miming to urinate, eversion of the clitoris and urinating were observed in up to 65 minutes, with the first three symptoms ceasing after 55 minutes. None of the analyzed behaviors were viewed after 65 minutes of observation. It can be concluded that the insertion of the intravaginal device impregnated with progesterone does not adversely affect the behavior of mares, and therefore, it can be use...

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Seasonality in mares

Cited by 117 publications

References 61 publications

Seasonal variations in serum concentrations of melatonin, testosterone, and progesterone in Arabian horse

Seasonal variations in serum concentrations of melatonin, testosterone, and progesterone in Arabian horse

Melengestrol acetate as a tool for inducing early ovulation in transitional mares

Comportamento De Éguas Após a Inserção De Dispositivo Intravaginal Impregnado Com Progesterona

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