RESUMO
The use of intravaginal sponges (IS) to synchronize estrous onset in ewes provokes vaginitis, an increase in the vaginal bacterial load, and growth of bacterial species that are not present during spontaneous estrous behavior. The objective of the study was to compare the functional sperm parameters after incubating it with mucus collected from the vagina of ewes during spontaneous estrus or estrous synchronized with IS. Pooled spermatozoa were co-incubated with: (1) vaginal mucus collected from ewes in spontaneous estrus; (2) vaginal mucus collected from ewes in estrus pretreated with progestogen-impregnated IS; (3) synthetic mucus; and (4) medium without mucus as a control group. Sperm samples were evaluated after incubating it for 30 and 90 minutes. The number of colony-forming units (CFUs/mL), pH, and osmolality were greater in the mucus collected from ewes treated with IS than from those untreated (P = 0.046; P < 0.0001, and P < 0.0001, respectively). The percentage of sperm with progressive motility was lower after incubation with vaginal mucus collected from estrous ewes treated with IS than in the other three treatments both, 30 and 90 minutes after incubation (P = 0.0009 and P < 0.0001, respectively). The sample incubated for 30 minutes with mucus from ewes treated with IS had a lower percentage of sperm with intact plasma membrane than all the other treatments (P < 0.0001). The percentage of sperm with functional membrane was significantly lower in the sample incubated for 30 minutes with vaginal mucus from ewes treated with IS than in the other three treatments (P < 0.0001). After 90 minutes, the percentage was still lower than that in the sample collected from ewes during their spontaneous estrus (P = 0.0005). The lowest percentages of sperm with acrosome damage were observed in sperm incubated with mucus collected from sheep in spontaneous estrus for 30 and 90 minutes (P < 0.0001 and P = 0.008, respectively). The percentage of apoptotic spermatozoa was greater in samples incubated during 30 minutes with vaginal mucus collected from ewes treated with IS than in the other three groups (P = 0.0005). The functionality and the viability of ram sperm is negatively affected by the cervical mucus of ewes pretreated with progestagen-impregnated IS used in estrous synchronization treatments. This may partially explain the decrease in conception rate obtained with treatments with IS.
Assuntos
Muco do Colo Uterino/efeitos dos fármacos , Dispositivos Anticoncepcionais Femininos , Congêneres da Progesterona/administração & dosagem , Análise do Sêmen , Ovinos , Espermatozoides/efeitos dos fármacos , Administração Intravaginal , Animais , Muco do Colo Uterino/química , Muco do Colo Uterino/fisiologia , Dispositivos Anticoncepcionais Femininos/veterinária , Sincronização do Estro/métodos , Feminino , Concentração de Íons de Hidrogênio , Masculino , Concentração Osmolar , Gravidez , Congêneres da Progesterona/farmacologia , Análise do Sêmen/veterinária , Espermatozoides/citologiaRESUMO
Los dispositivos intravaginales impregnados con progesterona o progestágenos son frecuentemente utilizados para la sincronización de los celos en ovejas y cabras. Sin embargo, la fertilidad de estos tratamientos es más baja que la de una ovulación espontánea, lo que parece tener un origen multicausal. La presencia de los dispositivos en la vagina (esponjas o dispositivos de silicona) provoca cambios en el ambiente vaginal caracterizados por un incremento en el número y una alteración en la composición de la biota bacteriana además de cambios histológicos y citológicos de la pared vaginal. El crecimiento bacteriano es fundamentalmente basado en un aumento en las bacterias coliformes Gram-negativas (E. coli y Klebsiella spp.). Estas vaginitis son responsables por sí mismas de una significativa reducción en las tasas de concepción. La acumulación de productos bacterianos e inflamatorios en el entorno vaginal afecta la viabilidad espermática. Recientemente, observamos que los espermatozoides en contacto con moco vaginal de ovejas en celo sincronizado con esponjas presentan alteraciones en su funcionalidad y viabilidad. El resultado del uso de dispositivos intravaginales está condicionado no solo por la respuesta ovárica, sino también por los cambios que provoca en el ambiente vaginal normal.
Intravaginal devices impregnated with progesterone or progestagens are widely used for estrous synchronization in ewes and goats. However, due to several causes, the fertility obtained with these treatments is lower than in a spontaneous estrus. The presence of these devices in the vagina induces an increase of the vaginal biota, changes in its composition, histological and cytological alterations in the vaginal wall. The main bacterial growth is based in Gram negative coliforms (E. coli y Klebsiella spp.). An important reduction in conception rates can be achieved to vaginitis. The accumulation of bacterial and inflammatory products in the vagina affects the sperm viability. Recently we have observed that the spermatozoa functionality and viability is affected after co-incubation with vaginal mucus collected from ewes pretreated with intravaginal sponges. Overall, the results of treatments with intravaginal devices are affected by the ovarian response but also by the changes induced in the normal vaginal environment.
Assuntos
Animais , Ciclo Estral/fisiologia , Ciclo Estral/sangue , Inseminação Artificial/veterinária , Administração IntravaginalRESUMO
Los dispositivos intravaginales impregnados con progesterona o progestágenos son frecuentemente utilizados para la sincronización de los celos en ovejas y cabras. Sin embargo, la fertilidad de estos tratamientos es más baja que la de una ovulación espontánea, lo que parece tener un origen multicausal. La presencia de los dispositivos en la vagina (esponjas o dispositivos de silicona) provoca cambios en el ambiente vaginal caracterizados por un incremento en el número y una alteración en la composición de la biota bacteriana además de cambios histológicos y citológicos de la pared vaginal. El crecimiento bacteriano es fundamentalmente basado en un aumento en las bacterias coliformes Gram-negativas (E. coli y Klebsiella spp.). Estas vaginitis son responsables por sí mismas de una significativa reducción en las tasas de concepción. La acumulación de productos bacterianos e inflamatorios en el entorno vaginal afecta la viabilidad espermática. Recientemente, observamos que los espermatozoides en contacto con moco vaginal de ovejas en celo sincronizado con esponjas presentan alteraciones en su funcionalidad y viabilidad. El resultado del uso de dispositivos intravaginales está condicionado no solo por la respuesta ovárica, sino también por los cambios que provoca en el ambiente vaginal normal.(AU)
Intravaginal devices impregnated with progesterone or progestagens are widely used for estrous synchronization in ewes and goats. However, due to several causes, the fertility obtained with these treatments is lower than in a spontaneous estrus. The presence of these devices in the vagina induces an increase of the vaginal biota, changes in its composition, histological and cytological alterations in the vaginal wall. The main bacterial growth is based in Gram negative coliforms (E. coli y Klebsiella spp.). An important reduction in conception rates can be achieved to vaginitis. The accumulation of bacterial and inflammatory products in the vagina affects the sperm viability. Recently we have observed that the spermatozoa functionality and viability is affected after co-incubation with vaginal mucus collected from ewes pretreated with intravaginal sponges. Overall, the results of treatments with intravaginal devices are affected by the ovarian response but also by the changes induced in the normal vaginal environment.(AU)