The aim of this study was to evaluate the post-thawing quality of equine semen subjected to two dimethylformamide (DMF) addition schemes during freezing. Semen of five Colombian Creole horses was obtained and diluted in modified INRA82® medium with two DMF addition treatments, T1: immediate addition of 5% DMF, and T2: fractional addition of 5% DMF (during 10 min). Semen was packed into 05. ml straws and subjected to conventional freezing. Sperm motility, vitality and morphology before and after dilution were assessed. In addition, a post-thaw analysis of sperm motility and kinetics using a computerized system and the evaluation of plasma membrane integrity by the hypoosmotic test (HOS) were performed. Before and after freezing, a lower reduction in sperm motility was observed by the immediate addition of DMF (T1), compared to the fractional addition of the cryoprotectant (T2) (p<0.05...

El objetivo del estudio fue evaluar la calidad posdescongelación de semen equino sometido a dos esquemas de adición de dimetilformamida (DMF) durante la congelación. Se obtuvo el semen de cinco caballos criollos colombianos, el cual fue sometido a dilución en medio INRA82® modificado con dos tratamientos de adición de DMF: T1, adición inmediata de 5% de DMF; T2, adición fraccionada de 5% de DMF (durante 10 min). El semen se empacó en pajillas de 0.5 ml que se sometieron a congelación convencional. La movilidad espermática, la vitalidad y la morfología de los espermatozoides se evaluaron pre- y posdilución. Adicionalmente, se realizó un análisis posdescongelación de la movilidad y de la cinética espermática mediante un sistema computarizado, y la evaluación de la integridad de la membrana plasmática por la prueba hipoosmótica (HOS). Se observó una menor reducción de...

Changes in land use and land cover are major drivers of hydrological alteration in the tropical Andes. However, quantifying their impacts is fraught with difficulties because of the extreme diversity in meteorological boundary conditions, which contrasts strongly with the lack of knowledge about local hydrological processes. Although local studies have reduced data scarcity in certain regions, the complexity of the tropical Andes poses a big challenge to regional hydrological prediction. This study analyses data generated from a participatory monitoring network of 25 headwater catchments covering three of the major Andean biomes (páramo, jalca and puna) and links their hydrological responses to main types of human interventions (cultivation, afforestation and grazing). A paired catchment setup was implemented to evaluate the impacts of change using a ‘trading space‐for‐time’ app...