... feed premixes, concentrates; 2 can be growth-promoting agents, combined with antibiotics; 3 associated with drug use ... of non-specific pathogenic microorganisms, including exposure to infectious agents, including Streptococcus agalactiae, Staphylococcus aureus, and mycoplasma, ... oligomeric chitosan sugar instead of antibiotics and antimicrobial agents, prevention and treatment of mastitis in dairy cows ...