AIN-93 PURIFIED DIETS FOR LABORATORY RODENTS - FINAL REPORT OF THE AMERICAN INSTITUTE OF NUTRITION AD HOC WRITING COMMITTEE ON THE REFORMULATION OF THE AIN-76A RODENT DIET

For sixteen years, the American Institute of Nutrition Rodent Diets, A IN-76 and AIN-76A, have been used extensively around the world. Becaus e of numerous nutritional and technical problems encountered with the diet during this period, it was revised. Two new formulations were der ived: AIN-93G for growth, pregnancy and lactation, and AIN-93M for adu lt maintenance. Some major differences in the new formulation of AIN-9 3G compared with AIN-76A are as follows: 7 g soybean oil/100 g diet wa s substituted for 5 g corn oil/100 g diet to increase the amount of li nolenic acid; cornstarch was substituted for sucrose; the amount of ph osphorus was reduced to help eliminate the problem of kidney calcifica tion in female rats; L-cystine was substituted for DL-methionine as th e amino acid supplement for casein, known to be deficient in the sulfu r amino acids; manganese concentration was lowered to one-fifth the am ount in the old diet; the amounts of vitamin E, vitamin K and vitamin B-12 were increased; and molybdenum, silicon, fluoride, nickel, boron, lithium and vanadium were added to the mineral mix. For the AIN-93M m aintenance diet, the amount of fat was lowered to 40 g/kg diet from 70 g/kg diet, and the amount of casein to 140 g/kg from 200 g/kg in the AIN-93G diet. Because of a better balance of essential nutrients, the AIN-93 diets may prove to be a better choice than AIN-76A for long-ter m as well as short-term studies with laboratory rodents.