RESUMEN
BACKGROUND: Cryopreservation of embryos is of considerable relevance for the implementation of embryo transfer programs and the establishment of embryo banks in several mammalian species. OBJECTIVE: The present investigation compares two different vitrification systems and two different warming solutions. MATERIALS AND METHODS: Vitrification was performed using Open Pulled Straw (OPS) or CVM RingFibre plug (CVM) devices. Warming was carried out either in a warming solution containing 0.33 M sucrose or in a solution devoid of sucrose. RESULTS: Differences between vitrification systems were not significant. Warming in sucrose-containing diluent resulted in an expansion rate of 64%, as compared to 86% in a solution devoid of sucrose; reported hatching rates were 45% vs. 9%, respectively (p<0.05). Upon transfer, implantation rates for OPS- and CVM were 50% and 27%, respectively, compared with 55% for freshly collected embryos. The implantation rate after warming was 43% for sucrose-containing and 33% for sucrose-free medium. CONCLUSION: a) both vitrification systems are suitable for vitrifying mouse blastocysts; b) warming in sucrose-free diluent yields better embryo survival rates than in diluent containing 0.33 M sucrose.
Asunto(s)
Blastocisto , Criopreservación , Sacarosa , Vitrificación , Animales , Ratones , Sacarosa/farmacologíaRESUMEN
Sera of an experimentally Neospora caninum infected llama and a non-infected control llama were used to establish an immunoblot, an ELISA and an IFAT to detect antibodies against N. caninum tachyzoites. Subsequently, serum samples collected from a total of 871 South American Camelids (SAC: Lama glama, Lama pacos, Lama vicugna) of two farms in Peru and from 32 SAC of a farm in central Germany were examined for antibodies against N. caninum and Toxoplasma gondii. Based on the recognition of specific bands in the immunoblot, sera of SAC from Peru were differentiated into N. caninum-positive (n = 18) and T. gondii-positive (n = 30) samples and into samples negative or inconclusive for both parasites. Using the immunoblot results as the reference, a modified version of the p38-ELISA and the IFAT were evaluated for detecting N. caninum antibodies in SAC sera. Applying a cut-off as determined by two graph-receiver operating characteristic analysis both, the ELISA and the IFAT, exhibited a sensitivity and specificity of about 95% in the SAC sera from Peru. Serological testing confirmed that SAC may become infected with N. caninum under field conditions in Peru. In addition to alpacas and llamas also 114 wild living vicunas had been examined for antibodies against N. caninum. However, only the alpacas and llamas but no vicunas were found N. caninum-positive. In contrast, T. gondii-seropositive animals were detected in all three SAC species. The lack of N. caninum-seropositive vicunas indicates that in the study area in Peru wild canids might not serve as definitive hosts of N. caninum while for T. gondii a life cycle including wild felids is likely. On the German farm no N. caninum- but only T. gondii-seropositive SAC (n = 14) were detected. The seroprevalence of T. gondii infection was significantly higher in adult SAC (alpacas in Peru, llamas in Germany) than in crias (i.e. < 12 months old foals) indicating that the predominant route of infection is post natal. Since the present study was restricted to a few farms, the seroprevalences determined are not representative. However, our results confirm natural infections with N. caninum and T. gondii in SAC. Whether these infections are linked to any disease, e.g. reproductive losses, has to be clarified in further studies.
Asunto(s)
Camélidos del Nuevo Mundo/parasitología , Coccidiosis/veterinaria , Ensayo de Inmunoadsorción Enzimática/veterinaria , Neospora/aislamiento & purificación , Toxoplasma/aislamiento & purificación , Animales , Anticuerpos Antiprotozoarios/sangre , Especificidad de Anticuerpos , Camélidos del Nuevo Mundo/inmunología , Coccidiosis/epidemiología , Coccidiosis/inmunología , Coccidiosis/parasitología , Ensayo de Inmunoadsorción Enzimática/métodos , Femenino , Técnica del Anticuerpo Fluorescente Indirecta/veterinaria , Alemania/epidemiología , Immunoblotting/veterinaria , Masculino , Neospora/inmunología , Perú/epidemiología , Estudios Seroepidemiológicos , Estadísticas no Paramétricas , Toxoplasma/inmunologíaRESUMEN
There is a growing number of llama- and alpacabreeders in Europe. Therefore veterinarians are often asked to intervene in clinical management of different problems, especially reproductive problems. In this review the authors attempt to summarize the different possibilities of pregnancy diagnosis and to give an short overview of reproduction in female llamas and alpacas. South American Camelids are induced ovulators and ovulation will occur within 12 to 24 hours following a single breeding. Llamas and alpacas develop follicular waves. The females will usually not ovulate unless a 7 mm or larger follicle exist on one of the ovaries. Corpus luteum is needed for maintenance of pregnancy.
Asunto(s)
Camélidos del Nuevo Mundo , Estro , Pruebas de Embarazo/veterinaria , Preñez , Animales , Femenino , Ovulación , Embarazo , Pruebas de Embarazo/instrumentación , Pruebas de Embarazo/métodos , Progesterona/sangre , América del SurRESUMEN
Liamas and alpacas have gained international popularity over the last years. Therefore veterinarians are often asked to intervene in clinical management of different problems, especially reproductive problems. In this review the author attempts to summarize the material presented on the reproductive anatomy, physiology, behavior, embryo transfer and artificial insemination procedure of these animals.