Incubazione in liquido follicolare preovulatorio di spermatozoi di stallone freschi e crioconservati

Recently, several studies were conducted to develop new artificial insemination techniques in horses based on reduced spermatozoa dose. Few data are available on intrafollicular insemination in mare. We analyzed morfological and functional changes of fresh and cryopreserved stallion spermatozoa incubated for six hours in preovulatory follicular fluid at 1:2 and 1:50 concentrations. Fresh sperm viability decreased from 78% to 57% at the dilution 1:2, whereas no changes were recorded for frozen spermatozoa (38% to 39%). At diluition 1:50 sperm viability showed a similar trend and there were no statistical differences with dilution 1:2. Either fresh and cryopreserved sperm showed a slight increase in acrosomal reactions during incubation at 1:2 dilution. At 1:50 dilution acrosome reactions in thawed sperm didn’t change significantly (25.86% to 18.42%), while for fresh sperm the variation from 22.58% to 51.28% risulted to be significant (P<0,05).