An Improved Feeder for Mice

Abstract

In studies which require an accurate determination of food intake the spilling of food and its contamination by excreta must be kept to a minimum. Mice are notorious for their perversity in these respects. Feeders constructed along the general pattern given in the accompanying diagrams have been in use in our laboratory for over a year and have given very satisfactory service in measurements of the average caloric intakes of groups of 2 to 24 young adult mice receiving synthetic diets of widely different compositions. The feeder consists of 2 easily assembled parts. The upper piece contains compartments each of which accommodates only one mouse at a time and which are floored with 1/4 inch square wire mesh. The wire mesh extends on each side of this assembly so that it may be slipped under the ledges of the food tray from either end. Thus assembled the top piece rests freely on the food in the tray and descends into the tray as food is consumed. The upper piece is readily removed when additional diet is added to the food tray. The feeders may be constructed from No. 26 galvanized iron sheeting and the joints soldered or spot-welded; the shop on this campus employed a jig for ease of manufacture. Details of a feeder for mice weighing between 15-30 g are shown in the accompanying diagram.

The small compartments, the wire mesh, and the ledges prevent the food from being spilled or contaminated. The average daily spillage of food for 10 adult mice fed ad libitum from a 10-compartment feeder amounts to only 0.1 g or less. In feeding diets ad libitum we employ weighed amounts of food about 10% in excess of the expected consumption.