Control of bacterial contamination in boar semen doses

The increase in antibiotic-resistant bacteria is thought to have been caused, at least partly, by the high levels of antibiotics used in human and veterinary medicine around the world. Antibiotic usage in the animal breeding industry varies according to species because of differences in semen storage and handling techniques, and is stipulated by an EU Directive for intra-community trade. The species in which liquid semen is stored for several days e.g. pigs and horses, have the most problem with bacterial contamination. Any reduction in antibiotic usage could help to reduce the spread of antibiotic resistance. Possible alternatives to antibiotics in semen extenders are considered, namely to reduce bacterial contamination by strict attention to hygiene, to remove bacteria by means of Single Layer Centrifugation, or to find alternatives microbicides, for example peptides from plants or from marine organisms. The potential removal of viruses by the same processing technique is considered. Lastly, possibilities for future research are considered.