ESTUDIO COMPARATIVO DE LOS TESTÍCULOS, EPIDÍDIMOS, GLÁNDULAS SEXUALES ACCESORIA S Y ESPERMATOZOIDES EN TRES ESPECIES DE LA GOMORFOS (ROMEROLAGUS DIAZI, LEPUS CA LIFORNICUS Y ORYCTOLAGUS CUNICULUS).

A comparative study of the male reproductive organs and spermatozoa from three lagomorphs species, the volcano rabbit or Zacatuche (Romerolagus diazi), the black-tailed hare (Lepus californicus) and the domestic rabbit (Oryctolagus cuniculus), was conducted. The animals were euthanased and their reproductive organs excised. Testes, epididymes and accessory sexual glands were isolated, removed of any of connective and other tissues and weighed. Caudal spermatozoa were obtained from the epididymal tail, counted, fixed and measured. The testicular mass was not related to body mass, but when considered as a percentage of body mass, the values for L. californicus and R. diazi were twice as large as that determined for O. cuniculus. The epididymal mass, when expressed as a percentage of the body mass, was highest in R. diazi and smallestin O. cuniculus. Spermatozoa counts from the epididymal tail were larger in L. californicus than in R. diazi or O. cuniculus. Lengths and widths of the spermatozoa head from R. diazi were larger than from O. cuniculus and L. californicus. Total length and tail length of caudal spermatozoa from O. cuniculus and R. diazi were found to be similar but larger than those recorded from L. californicus. This is the first such quantitative and comparative study of wild lagomorphs species from North A merica.Se hizo un estudio comparativo del aparato reproductor masculino entre tres especies de lagomorfos: el conejo zacatuche (Romerolagus diazi), la liebre cola negra (Lepus californicus)y el conejo doméstico (Oryctolagus cuniculus). Se extrajo el aparato reproductor de los especímenes sacrificados y los testículos, epidídimos y glándulas sexuales accesorias fueron aislados, liberados del tejido conectivo y pesados. Los espermatozoides de la cola del epidídimo fueron obtenidos por retroperfusión, contados, fijados y medidos, utilizando técnicas fotográficas. La masa testicular no estuvo relacionada con la masa corporal y, considerada como porcentaje en relación a la masa corporal, fue más de dos veces mayor en L. californicus y R. diazi que en O. cuniculus. La masa epididimaria, expresada como porcentaje de la masa corporal, fue más grande en R. diazi que en L. californicus y en O. cuniculus. Hubo más espermatozoides, en la cola del epidídimo, de L. californicus que en R. diazi o en O. cuniculus. El largo y ancho de la cabeza espermática de R. diazi, superaron a los de O. cuniculus y L. californicus. La longitud total y el largo de la cola espermática, fueron similares en O. cuniculus y R. diazi, mientras que los espermatozoides de L. californicus fueron menores. Los datos que se presentan en este estudio, son los primeros cuantitativos de testículos, epidídimos, glándulas sexuales accesorias y espermatozoides, de especies de lagomorfos silvestres de Norteamérica

Efecto del uso de medio secuencial humano en la producción de blastocistos de hembra ovis canadensis mexicana por clonación manual

Effect of sequential human medium use in the production of blastocysts of female Ovis canadensis mexicana by interspecies handmade cloning. Faced to the notable problem that a significant number of world wild species are endangered, some biotechnologies such as the interspecific somatic cell nuclear transfer (SCNT), have been applied to raise their reproduction and conservation. This technology has been successfully applied by producing embryos and live offspring in some of these species. However, the interspecific SCNT still has to solve problems such as the low embryo production and  offspring survival rates (3-6%). These problems, among others, involve a high incidence of embryo fragmentation and in order to solve them, most studies are now aimed to determine the effect of different culture media or supplements used for in vitro embryo production. Therefore, the aim of the present study was to use a variant of the interspecific SCNT technique (Handmade cloning-HMC) for embryo production, determining the effect of human sequential media in the endangered Mexican wild sheep O. c. mexicana. Results indicate that the embryo production increased when using human sequential media, allowing the  mbryos to reach the blastocyst stage (16% vs. 0%, P < 0.05). This is the first study that reports the successful cloning of female O. c. Mexicana embryos in Mexico.RESUMEN. Efecto del uso de medio secuencial humano en la producción de blastocistos de hembra Ovis canadensis mexicana por clonación manual interespecies. Desde el evidente problema del peligro de extinción que enfrenta un número significativo de especies silvestres a nivel mundial, se han aplicado biotecnologías encaminadas a promover su conservación y reproducción. Tal es el caso de la transferencia nuclear de células somáticas (TNCS) interespecies que ha sido aplicada y ha producido exitosamente embriones y crías nacidas vivas en algunas de estas especies. Sin embargo, la TNCS interespecies aún debe lidiar con otros problemas como la baja tasa de producción de embriones y de supervivencia de las crías nacidas (3-6%). Problemas que, entre otros, involucran la alta incidencia de fragmentación embrionaria. Los estudios son ahora dirigidos a resolver estos obstáculos, determinando el efecto de diferentes medios o suplementos utilizados en la producción in vitro de embriones. El objetivo de este estudio fue aplicar una variante de la TNCS interespecies (Clonación Manual-HMC) para la producción de embriones, determinando el efecto del uso de medios secuenciales humanos, en el borrego salvaje mexicano amenazado de extinción O. c. mexicana. Los resultados muestran que la producción de embriones incrementa con el uso de medios secuenciales humanos, permitiendo al embrión desarrollarse hasta la etapa de blastocisto (16% vs. 0%, P < 0.05). Este es el primer reporte de clonación exitosa de embriones de hembra O. c. mexicana en México.

Reproductive and seminal characteristics of Pelibuey rams infected with Mycobacterium avium subsp. paratuberculosis in the subclinical stage

Objective: To evaluate the reproductive and seminal characteristics of Pelibuey rams infected with Mycobacterium avium subsp. paratuberculosis in the subclinical phase. Design/methodology/approach: In order to determine whether paratuberculosis (PTB) affects the reproductive variables and seminal quality in Pelibuey rams naturally infected with Mycobacterium avium subsp. paratuberculosis (MAP) in the subclinical phase, weekly evaluations were conducted, over a period of two months, of the variables live weight, scrotal circumference, ejaculation latency and seminal characteristics: volume, pH, masal motility and progressive individual motility, concentration, live spermatozoids and dead spermatozoids, in five rams infected by MAP and a further five uninfected rams, of average weight and age 53.58 kg (± 3.26) and 2.91 years (± 0.59), respectively. Results: PTB was not found to affect the reproductive and seminal variables evaluated. Limitations of the study/implications: It would have been convenient to carry out the evaluation of the seminal characteristics for a longer time, however, the sampling was stopped in order to ensure the animal welfare of the rams as far as possible, since they began to show signs of PTB. Findings/Conclusions: The Pelibuey rams diagnosed with PTB in subclinical phase did not present any effect on the reproductive and seminal characteristics. Meanwhile, reproductive management can be carried out with PTB-infected Pelibuey lambs in a subclinical phase.Objective: To evaluate the reproductive and seminal characteristics of Pelibuey rams infected with Mycobacterium avium subsp. paratuberculosis in the subclinical phase. Design/methodology/approach: In order to determine whether paratuberculosis (PTB) affects the reproductive variables and seminal quality in Pelibuey rams naturally infected with Mycobacterium avium subsp. paratuberculosis (MAP) in the subclinical phase, weekly evaluations were conducted, over a period of two months, of the variables live weight, scrotal circumference, ejaculation latency and seminal characteristics: volume, pH, masal motility and progressive individual motility, concentration, live spermatozoids and dead spermatozoids, in five rams infected by MAP and a further five uninfected rams, of average weight and age 53.58 kg (± 3.26) and 2.91 years (± 0.59), respectively. Results: PTB was not found to affect the reproductive and seminal variables evaluated. Limitations of the study/implications: It would have been convenient to carry out the evaluation of the seminal characteristics for a longer time, however, the sampling was stopped in order to ensure the animal welfare of the rams as far as possible, since they began to show signs of PTB. Findings/Conclusions: The Pelibuey rams diagnosed with PTB in subclinical phase did not present any effect on the reproductive and seminal characteristics. Meanwhile, reproductive management can be carried out with PTB-infected Pelibuey lambs in a subclinical phase

Registros reprodutivos de duas fazendas de coelhos na região de Tuxtepec-Oaxaca, México

In Mexico, rabbit production is concentrated in states with a temperate climate and an average annual temperature of 20 °C. The aim of this study was assess the productive parameters of two rabbits producing farms located in the region of Tuxtepec, Oaxaca. We analyzed 341 reproductive records (183 farms A and 158 farms B) for the years 2010 and 2011. In farm A, fertility rate was 71.3% and significantly higher than farm B (67.8%; p <0.05). In spring, the lowest incidence of births was observed, while in winter there was the highest number of births (8.7 and 41.9%) were present. The proportion of females in the offspring was significantly higher in both farms (farm A: 54.94%, farm B: 56.14%). In conclusion, despite the adverse tropical conditions for rabbit production, especially in spring, it is possible to achieve acceptable reproductive performance.En México, la producción de conejos se concentra en los Estados con clima templado y temperatura promedio anual de 20 °C. El objetivo del trabajo fue analizar los registros reproductivos en dos granjas cunicolas ubicadas en la región de Tuxtepec, Oaxaca. Se analizaron 341 registros (183 granja A y 158 granja B) de los años 2010 y 2011. En la granja A, se observo una tasa de fertilidad de 71.3% que es significativamente mayor en comparación con la granja B (p<0.05). En primavera, se presentó la menor incidencia de partos, mientras que en invierno hubo el número mayor de partos (8.7 y 41.9 %). La cantidad de hembras en las crías fue significativamente mayor en ambas granjas (granja A: 54.94 %; granja B: 56.14 %). En conclusión, a pesar de las condiciones ambientes adversas del clima tropical para el conejo, especialmente en primavera, es posible lograr producciones aceptables.No México, a produção de coelho está concentrada em Estados de clima temperado e temperatura média anual de 20 ° C. O objetivo do trabalho foi analisar os registros reprodutivos em duas coelheiras localizadas na região de Tuxtepec, Oaxaca. Foram analisados ​​341 registros (183 fazenda A e 158 fazenda B) dos anos de 2010 e 2011. Na fazenda A, foi observada uma taxa de fertilidade de 71,3%, que é significativamente maior em comparação com a fazenda B (p <0,05). Na primavera, ocorreu a menor incidência de nascimentos, enquanto no inverno ocorreu o maior número de nascimentos (8,7 e 41,9%). O número de fêmeas na prole foi significativamente maior em ambas as fazendas (fazenda A: 54,94%; fazenda B: 56,14%). Em conclusão, apesar das condições ambientais adversas do clima tropical para os coelhos, principalmente na primavera, é possível alcançar produções aceitáveis

Desarrollo embrionario temprano en el hamster Sirio Dorado, Mesocricetus auratus (Mammalia: Rodentia)

The pattern of embryonic segmentation in the golden sirian hamster (Mesocricetus auratus) was analized using two female groups: 47 nuliparous 3-4 months old females and 39 multiparous (mean 3 parturitions) 7-8 months old females. The mating time was restricted to 15 minutes and the time of ovulation was determined on the basis of secuencial studies of vaginal citology. The best moment to obtain 8-blastomeres embryos was between 62 and 63 hours postcoitus for nuliparous females. In multiparous females the time of segmentation was 2 hours longer in comparison to nuliparous. We propose that the increase in pregnancy duration, that has been correlated with age in females, occurs already during the very early embrionic development stages. In order to estimate the time of early segmentation in the golden sirian hamster, it is neccesary to restrict the mating time and to relate it accurately with the occurrence of ovulation, and to establish the age and parturition number in females. Besides, the segmentation process shows a clear asyncrony in multiparous females, making possible to recover embryos that belong to 4 distinct segmentation phases (2, 4, 6 and 8 blastomeres) between 60 to 63 hours postcoitus.Se analizó el patrón de segmentación embrionaria en el hámster sirio dorado (Mesocricetus auratus) utilizando dos grupos de hembras: 47 hembras nulíparas de 3-4 meses de edad y 39 multíparas (3 partos en promedio) de 7-8 meses de edad. El tiempo de apareamiento se restringió a 15 minutos, y el tiempo de la ovulación se determinó con base en estudios secuenciales de citología vaginal exfoliativa. El mejor momento para obtener embriones de 8 blastómeros se presentó entre las 62 y las 63 horas postcoito en las hembras nulíparas. En las hembras multíparas el tiempo de segmentación fue 2 horas mayor que en las nulíparas. Estos resultados nos permiten proponer que el aumento en la duración de la gestación, que se ha correlacionado con la edad de las hembras, ocurre ya desde las primeras etapas del desarrollo del embrión. Para precisar con exactitud el tiempo de segmentación temprana en el hámster sirio dorado, es indispensable restringir el tiempo de apareamiento y relacionarlo de una manera más precisa con la ocurrencia de la ovulación, y establecer la edad de las hembras y el número de partos. Además, el proceso de segmentación muestra una franca asincronía en las hembras multíparas, pudiéndose recuperar embriones pertenecientes a 4 fases distintas de la segmentación (2, 4, 6 y 8 blastómeros) entre las 60 y las 63 horas postcoito