I am very glad to have this opportunity of discussing litter testing, although I imagine tliat most of you are familiar with the work which we are carrying on at Stoke Mandeville. To recapitulate the set-up as briefly as possible, we receive half-litters of three hogs and one gilt (from litters of not less than eight weaned), aged 65-70 days so that the first test weighing can be carried out at exactly ten weeks of age. Environmental conditions have been arranged so that each team of pigs receives as near standard treatment as possible. Each lot has its own 8 foot x 7 foot wooden pig hut facing south, with a 9 foot x 8 foot enclosed concrete run. The pigs are kept bedded down on a good depth of long straw litter and a Fordham automatic drinking bowl (fitted with a soft spring) is available to each house. Feeding is simplified by means of three-compartment Seaford self-feeders which are kept fully supplied with dry Sow & Weaner Meal (No. 1) until the pigs reach 110-120 lbs. liveweight (17 weeks).