Aged Rodent Colonies Handbook

In the caloric restricted colony, mice are $6.00 per month of age. These prices apply to both caloric-restricted (CR) and ad libitum (AL) controls from this colony. Both CR and AL are individually housed. CR is initiated at 14 weeks of age at 10% restriction, increased to 25% restriction at 15 weeks, and to 40% restriction at 16 weeks where it is maintained throughout the life of the animal. CR/AL rodents are sold only by age in months, i.e. 4 months or 24 months, not by weight or age in weeks. Survival curves, food intake curves and body weights of the NIA strains have been published (Turturro et al. (1999) Growth curves and survival characteristics of the animals used in the biomarkers of aging program. J. Gerontology 54A:B492-B501).

Feeding instructions will be provided with the caloric restricted animals. If you are ordering food, please indicate how long you will maintain the animals so that the contractor can calculate how much food you will need. When food is shipped by truck, there is a flat rate freight charge of $13.00 per type of food (AL or CR). Food shipped by air freight or common carrier is subject to prevailing rates of the carrier. NIH31/NIA Fortified (for CR feeding) is available in weighed pellets at 0.5 gram intervals from 2.0 grams to 3.5 grams, at $10.00/Kg. NIH31 (for AL feeding) is only available in random weight chunk formula, at $2.00/Kg. Documentation for the diet formulations is available from the downloads page.

Feed labels are marked as follows:

NIH41: This is NIH31 formula that has been sterilized, but some of the ingredients are changed to ensure the proper levels after sterilization.

NIH31: When multiples of 10 kg are ordered, the NIH41 irradiated diet is shipped. In smaller quantities or odd quantities, the NIH 31 autoclavable diet is shipped. It is labeled NIH31 and must be autoclaved by the end user if sterilization is desired.

NIH31-Fortified: This diet is always shipped autoclaved, so the bags are labeled NIH41-fortified diet.

Starting in January 2009, animals in the caloric restricted colony will be provided nestlets to provide a minimum environmental enrichment to compensate for the lack of social enrichment that the group housed animals experience.