JPH0136810B

PURPOSE:To provide a carrier containing a mycinamicin antibiotic substance as an active component, and capable of remarkably increasing the growth rate, improving the feed efficiency and exhibiting excellent live weight gain when added to a feed or drinking water of cattle, poultry or fish. CONSTITUTION:The objective carrier contains 0.5-500ppm of the mycinamicin antibiotic substance of formula I [X is epoxy or a bond; R1 is H or OH; R2 is H or group of formula II (R3 and R4 are H or lower alkyl)] or its derivative or salt. The amount of the antibiotic substance is preferably 5-40ppm for cattle including experimental animal, 0.5-20ppm for poultry, and 5-200ppm for fish. The antibiotic substance not only exhibits excellent gain of live weight but also improves the egg production rate and fertilization rate. It is also effective to the diseases of digestive organs and respiratry system of cattle, the diseases of the respiratory system of poultry and various bacterial diseases of fish, and is extremely excellent feed additive for animal.