The addition of antibiotics, either alone or in cocktail mixtures, represents today the only way to control bacterial growth during swine semen production and conservation. In general, raw ejaculates are handed at 30-34 °C while delivering and storage of AI doses occur at temperatures around 16-17 °C. However, the risk of inducing bacterial resistance represents a great challenge to overcome. During this study, we set to develop an antibiotic free semen processing technique that at the same time allows for maintenance of sperm quality and does not affect the fertility performance of swine herds. Ejaculates collected from boars of proven fertility were split in two portions and diluted in two different semen extenders. One portion was diluted in a commercial semen extender supplemented with a classical antibiotic mixture and packed in standard semen bags. The second portion was diluted in a new semen extender with no antibiotic addition and packed in bacteriostatic semen bags. Doses were cooled down up to 4°C after packing and kept in a regigerator until inseminations were performed. Computed assisted semen analysis and flow cytometry analysis were carried for evaluating motility, viability and bacterial charge. Further, sixty gilts (n=60) of the cross breed Large-White x Landrace were selected and aleatory grouped. For heat synchronization, eighteen doses of Regumate (20mg) were given daily to the experimental animals. Only gilts found in heat after the synchronization were included in the study. A total of 30 gilts were inseminated with semen doses supplemented with antibiotics and the other 30 with semen doses without antibiotics. Twenty two days after insemination, pregnancy was checked by transabdominal echography, and pregnant gilts were slaughtered for controlling embryo development and number of corpora lutea present in the ovaries at day 30 post insemination. Neither number of embryos, nor ovulation rates (controlled by the number of corpora lutea formed after ovulation) were affected by the antibiotic free AI doses. These results show that antibiotics are no longer necessary for preservation of boar ejaculates as long as minimal hygienic conditions are kept during semen processing.