Lifespan of encapsulated boar spermatozoa ad different temperatures in sperm controlled release device

Barium alginate controlled release capsules containing semen were developed to increase the efficiency of the artificial insemination technique. The stability of encapsulated boar semen was assessed at different storage temperatures, evaluating non-reacted acrosomes (NRA) and secondary anomalies (SA). A solution of BaCl2 was added to semen until a Baþþ concentration of 5 mM was reached; the suspension was dropped into a sodium alginate solution. Gel capsules were obtained, and suspended in an extender for swine semen. Another kind of capsules was obtained by cross-linking of G caps in a solution of protamine sulphate. NRA and SA were evaluated in semen soon after sampling and soon after the encapsulation process. Control semen was diluted in Zorlesco extender. After 24 hours of incubation at 18 C and 38 C, spermatozoa were stained for NRA and microscopically examined for SA. Semen storage in alginate or protamine alginate capsules enhances the quality of semen in terms of NRA and SA, particularly in thermal stress conditions (38 C), when cell metabolism is at physiological levels. These advantages could be related to the non-dilution of spermatozoa, simulating the in vivo testicular and epididymal conditions. Twenty-four hours 18 C storage of encapsulated spermatozoa conserves high NRA percentage and herefore supports the possibility of an in-field employment for instrumental insemination: sperm-life is guaranteed for at least 24 hours.