Antibiotics in Dairy Cattle Nutrition. IV. Comparative Effects of Different Levels of Crystalline Aureomycin and a Crude Aureomycin Fermentation Product (Aurofac 2A) on the Growth and Well-Being of Young Dairy Calves

Several investigators have shown that feeding aureomycin to young calves exerts a favorable influence on growth and well-being (reviewed by Bartley et al. 1, In those experiments the source of the antibiotic has been either a pure crystalline aureomycin salt or aureomycin contained in fermentation residues. The crude aureomycin fermentation residues or products probably contain, in addition to known amounts of aureomycin and vitamin B12, other substances that could influence calf growth. The experiment reported herein was initiated to compare the effects of pure crystalline aureomycin HC1 on the growth and well-being of young dairy calves with an equivalent intake of aureomycin in the form of a crude aureomycin fermentation product (Aurofac 2A).