Preantral follicle population and distribution in the horse ovary.

Abstract:Characterization of the ovarian preantral follicle population is a necessary step to improve understanding of folliculogenesis and ovarian physiology. Therefore, in the present study, the preantral follicle population in the equine ovary in young and old mares was investigated according to follicular morphology, follicular class, distance from the geometric center using ovarian maps, and follicular density within ovarian portions (lateral vs intermediary) and regions (dorsal vs ventral). Ovaries were collected from an abattoir and histologically processed for evaluation, and the follicle population was calculated. Overall, in the current detailed study, a higher preantral follicle population per mare ovary (mean: 82,206 ± 50,022; range: 1477 to 773,091) than originally reported was identified. Additionally, a mare age effect was observed in the follicle population (young: 152,664 vs old: 11,750) and the spatial distribution of morphologically normal and abnormal follicles and the density and population of follicular classes. These results demonstrate that, in addition to the preantral follicle population in the mare ovary being comparable to that of other species, the location and spatial distribution of these follicles is dynamic and varies depending on mare age and follicle status (i.e. morphology and developmental stage). The characterization of the distribution and population of preantral follicles in the mare ovary provided by this study can potentially aid in improving reproductive studies and assisted reproductive techniques and may expand the understanding of mechanisms involving ovarian plasticity and follicular migration

Perfil de registros reproductivos de ganado lechero en Uruguay.

RESUMEN:Se presenta un resumen descriptivo de cuatro encuestas llevadas a cabo en los años 2010, 2011, 2013, y 2018 en la cuenca lechera de Uruguay; con la participación de 22 técnicos en promedio/año; en hasta 7 departamentos, involucrando 312 tambos y 81.060 vacas masa. Se registró una consistencia de los índices reproductivos, con una disminución en el número de servicios por concepción y en el intervalo parto concepción en las vacas con el paso de los años. Se remarca la importancia de llevar registros para monitorear y mejorar la eficiencia reproductiva. SUMMARY: A descriptive summary of four surveys carried out in the years 2010, 2011, 2013, and 2018 in the dairy region of Uruguay is presented; with the participation of 22 technicians on average/year; in up to 7 departments, involving 312 dairy farms and 81,060 cows. A consistency of the reproductive indices over the years was observed with decreasing in the number of services per conception and in the interval calving to conception in the cows over the years. The importance of keeping records for monitoring and improving reproductive efficiency is highlighted

Pérdidas fetales en vacas Holstein asociados con el índice de temperatura-humedad en Uruguay.

El objetivo de este trabajo fue determinar el efecto de períodos climatológicos relacionados con el ITH sobre las pérdidas fetales en bovinos lecheros de la región sureste de Uruguay

Effect of β-mercaptoetanol and cysteine on post-thawing quality and oxidative activity of ram sperm and on the viability of vitrified sheep embryos

ABSTRACT The effects of β-mercaptoethanol (BME) and cysteine on the viability and oxidative activity of ram sperm after thawing and on development in vitro and viability of vitrified sheep embryos were evaluated. Ejaculates from four rams were pooled and extended, composing six treatments: no antioxidants; 2mM BME; 5mM BME; 2mM BME and 5mM cysteine; 5mM BME and 5mM cysteine; and 5mM cysteine. Sperm motility, membrane and acrosome integrity, mitochondrial functionality, production of reactive oxygen species and total antioxidant capacity were similar across treatments (P>0.05). A medium with no antioxidant presented cleavage and blastocyst development rates (60.3% and 33.6%, respectively) similar (P>0.05) to those of a medium with 50μM BME and 600μM cysteine (64.3% and 36.6%, respectively). Post-thawing viability of vitrified embryos was similar between media (P>0.05). Cysteine and BME had no influence on the post-thawing viability and oxidative activity of ram sperm and on the viability of vitrified sheep embryos