Growth of Pigs given Skim Milk Soured with Nisin-producing Streptococci

Stokstad and Jukes 1 reported that diets supplemented with aureomycin hydro chloride have a growth-stimulating effect. Since then, many reports have confirmed that a number of antibiotics may act as growth stimulants in pigs and poultry. It was of interest to see if nisim 2 , the antibiotic produced by Str. lactis , had a similar effect. The nisin used was not concentrated or purified, but was obtained by growing the cultures of Str. lactis in skim milk, when 100–200 units/ml. ( c . 50 units = 1 µgm.) is always produced.