Resumen de La selección espermática en el útero de la cerda está influenciada por la calidad de los espermatozoides: Análisis del reflujo

Cristina de las Mercedes Soriano Úbeda, Iván Hernández Caravaca, María José Izquierdo Rico, C. Matas, F.A. Vázquez Milanés

• The aim was to examine the way in which spermatozoa are selected by the uterus after artificial insemination. In total, 25 sows were post-cervical inseminated (1500x106 spz/25ml) using 3 different sperm doses: 1) HIGH motility: 50% of the sperm not stained and with high motility (>70%) + 50% of the sperm stained (with Hoechst 33342) with high motility (>70%); 2) MEDIUM motility: 50% of the sperm not stained with high motility (>70%) + 50% of the sperm stained with medium motility (35-70%); 3) LOW motility: 50% of the sperm not stained with high motility (>70%) + 50% of the sperm stained with low motility (<35%). Backflow was collected at different times after insemination (0-15, 16-30 and 31-60 min) and % of stained sperm was determined using fluorescence microscope (UV). The results showed that during the first moments after insemination (0-15 min) the uterus performs an indiscriminate removal (measure in the backflow) of sperm regardless of their motility (HIGH: 48.81; MEDIUM: 55.29; LOW: 55.45%). During 16-30 and 31-60 min intervals the majority of sperm in backflow were stained in MEDIUM (73.78 and 84.27%, respectively) and LOW (83.57 and 89.85%, respectively) groups but not in the HIGH one (54.47 and 59.37%). The uterus sperm selection is not specific during the first moments after insemination, but later the uterus selects those sperm with better motility, discarding those less competitive in the backflow.