RESUMO
The pampas deer is an endangered species, from which reproductive biology little is known. We aimed to describe and compare the reproductive seasonal patterns of adult and yearling pampas deer stags throughout the year, including morphological traits, testosterone concentration, sperm morphology and cryoresistance pattern changes. Six adult (AS) and five yearling (YS) stags were captured with anesthetic darts once in winter, spring, summer and autumn to study morphological variables, serum testosterone and semen. Adult males were heavier, their neck girth tended to be greater and their testosterone concentration was higher than in YS. Animals were heavier in summer and autumn. Neck girth and testosterone concentration were greater in autumn. Scrotal circumference, testicular volume and gonado-somatic index varied with seasons, decreasing from winter to spring, increasing in summer and remaining in greater values in autumn. Sperm quality had maximum values from summer to winter. However, the cryoresistance ratio of motility score was greater in spring. In conclusion, in the captivity conditions, pampas deer stags seems to present a light seasonal reproductive pattern, with maximum testis size, testosterone secretion and fresh semen quality in autumn. Nevertheless, sperm cryoresistance ratio seemed to remain stable along the year. Although YS were still growing, they achieved similar semen quality than AS.
Assuntos
Animais , Antílopes/embriologia , Antílopes/fisiologia , Comportamento Reprodutivo , Estações do AnoRESUMO
The pampas deer is an endangered species, from which reproductive biology little is known. We aimed to describe and compare the reproductive seasonal patterns of adult and yearling pampas deer stags throughout the year, including morphological traits, testosterone concentration, sperm morphology and cryoresistance pattern changes. Six adult (AS) and five yearling (YS) stags were captured with anesthetic darts once in winter, spring, summer and autumn to study morphological variables, serum testosterone and semen. Adult males were heavier, their neck girth tended to be greater and their testosterone concentration was higher than in YS. Animals were heavier in summer and autumn. Neck girth and testosterone concentration were greater in autumn. Scrotal circumference, testicular volume and gonado-somatic index varied with seasons, decreasing from winter to spring, increasing in summer and remaining in greater values in autumn. Sperm quality had maximum values from summer to winter. However, the cryoresistance ratio of motility score was greater in spring. In conclusion, in the captivity conditions, pampas deer stags seems to present a light seasonal reproductive pattern, with maximum testis size, testosterone secretion and fresh semen quality in autumn. Nevertheless, sperm cryoresistance ratio seemed to remain stable along the year. Although YS were still growing, they achieved similar semen quality than AS.(AU)
Assuntos
Animais , Antílopes/embriologia , Antílopes/fisiologia , Comportamento Reprodutivo , Estações do AnoRESUMO
Se colectaron 16 eyacuaciones de 4 sementales caprinos por medio de la vagina artificial y se evaluaron las siguientes características: volumen, concentración espermática, motilidad progresiva y morfología acrosomal. Cada eyaculado se dividió en dos partes y se diluyó con Tris-Yema de huevo. El semen diluido se envasó en pajillas de 0.25 y 0.5 ml, cada una conteniendo 100millones de espermatozoides mótiles. Las pajillas se congelaron en vapores de nitrógeno líquido y se descongelaron a 37ºC/15 seg. o a 55ºC/8 seg. En las muestras descongeladas se determinó la motilidad progresiva, la recuperación de espermatozoides mótiles y el daño acrosomal. La motilidad progresiva al descongelar las pajillas de 0.5 ml fue de 62.8 por ciento (37ºC/15 seg) y 58.7 por ciento (55ºC/8 seg) y en la pajilla de 0.25 ml de 59 por ciento (37ºC/15 seg) y 60 por ciento (55ºC/8 seg) (P> 0.05). El daño acrosomal fue mayor (12.3 por ciento) en las pajillas de 0.5 ml descongeladas a 55ºC/8 seg que en los demás tratamientos (P < 0.05). La descongelación del semen caprino a 37ºC/15 seg es una técnica más sencilla a nivel de campo e implica menor riesgo. La motilidad progresiva y el porcentaje de daño acrosomal del semen caprino obtenidos en este trabajo, se encuentran dentro de los criterios establecidos para su aplicación en la inseminación artificial