Interseryl WS is a highly effective combination of broad-spectrum antibiotics and vitamins. The product stimulates egg production, increases growth, improves feed conversion, and is used as a vitamin supplement during periods of disease and stress. It is effective against gastrointestinal, respiratory, and urinary infections caused by colistin, oxytetracycline, erythromycin, and streptomycin sensitive micro-organisms, like Bordetella, Campylobacter, Chlamydia, E. coli, Haemophilus, Klebsiella, Mycoplasma, Pasteurella, Rickettsia, Salmonella, Staphylococcus and Streptococcus spp. in calves, goats, sheep, poultry, and swine.