Modern technologies for storing semen of domestic animals without the addi-tion of antibiotics

Abstract

Currently, there is a trend of breeding domestic animals through artificial insemination. As a result, very large amounts of sperm diluents containing antibiotics are used in animal husbandry. Antimicrobials are added to the semen diluent to control the growth of bacteria that contaminate the semen during selection. The proportion of antibiotic-resistant bacteria is steadily rising, threatening the entire health care system. That is why all fields of antibiotics application face the task of finding alternatives to this approach. The purpose of our study was to systematize modern technologies and methods of storing domestic animals’ semen which could reduce or eliminate the use of antibiotics, and would be an important step in the fight against multidrug-resistant bacteria. Due to the negative impact of antibiotics on sperm quality and their fertilizing ability, new alternative methods for sperm storage are constantly being improved and developed. The most common are low-temperature storage, physical methods to reduce bacterial stress, the use of antimicrobial peptides, nanoparticles and the use of various substances of animal, plant or other origin. The possibility of boar sperm low-temperature storage may open up completely new approaches in the future by optimizing the cooling rate. Colloidal centrifugation as one of the physical methods is a practical means of reducing the bacterial load in sperm samples and it can be effectively used applying equipment that is available at many breeding plants. Antimicrobial peptides or nanoparticles of iron oxide may be a useful alternative to the addition of antibiotics during sperm storage. Antimicrobial peptides have been shown to control the growth of aerobic and anaerobic bacteria in relatively low concentrations without adversely affecting sperm quality and fertility. However, it is substantiated that nanoparticles with the size of 40 – 60 nm have significant antimicrobial ability against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. At the same time, further studies are needed on the use of various substances of animal or plant origin (royal jelly, aloe vera, algae extracts), as well as determining adequate concentrations of these new compounds that should be effective in fighting bacteria and not affect quality characteristics of sperm.