Long-term liquid storage and reproductive evaluation of an innovative boar semen extender (Formula12®) containing a non-reducing disaccharide and an enzymatic agent

- The boar sperm motility was investigated in a new extender formulation, containing sucrose and invertase enzyme; an average progressive motility >70% for 12 days of storage at 17 °C was reported.
- The reproductive efficiency results demonstrate a high reproductive success reported for this extender formulation.
- The long-term storage did not induce DNA fragmentation.
- This extender formulation can be used for the long-term storage of boar semen in liquid storage at 17 °C.

There are no reports of saccharolytic enzymes being used in the preparation of formulations for animal semen extenders. In the present study, the use of an innovative semen extender (Formula12®) in the long-term liquid storage of boar semen at 17 °C was evaluated. The formulation included use of a disaccharide (sucrose) as the energy source precursor coupled to an enzymatic agent (invertase). The innovative extender was evaluated and compared in vitro to a commercial extender (Vitasem LD®) for the following variables: Total Motility (TM), Forward Progressive Motility (FPM), sperm morphology, membrane integrity, acrosome integrity, and chromatin instability. Boar sperm diluted in Formula12® and stored for 12 days at 17 °C maintained a commercially acceptable FPM (>70%). Using the results from the in vitro study, an AI field trial was performed. A total of 170 females were inseminated (135 with Formula12® and 35 with Vitasem LD®). The pregnancy rates were 97.8% compared with 91.4%, and the farrowing rates were 96.3% compared with 88.6% when Formula12® and Vitasem LD® were used, respectively. The mean number of piglets born/sow were 14.92 ± 0.46 compared with 13.83 ± 0.70, and the number of piglets born alive/sow were 14.07 ± 0.46 compared with 12.12 ± 0.70 (P < 0.05). The results obtained in this study demonstrated that use of the innovative concept to provide a precursor of glucose and fructose as energy sources for an enzymatic agent in an extender allowed for meeting the metabolic requirements of boar sperm during storage at 17 °C. It is suggested that there was a beneficial effect on fertilizing capacity of boar sperm in the female reproductive tract with use of these technologies.