To show the importance of the level at which the pregnant ewe is fed in relation to :

• (1)The birth weight of her offspring,

• (2)The volume of milk which she produces during her lactation period,

• (3)The influence of these two upon the rate of growth of the lambs,

two experiments were carried out. In the first, a group of 4-year-old Border Leicester × Cheviot ewes from the same flock were mated to the same Suffolk ram. They were then split into two uniform groups. The ewes were fed individually and after service both lots were fed just sufficient sainfoin hay to keep them at constant body weight. Then, six weeks before lambing, the members of one group were given ½ lb. of concentrate daily and as much hay as they would eat. Upon this ration these ewes gained an average of 44 lb. At the same time the amount of hay fed to the second group was reduced so that over the last six weeks these ewes lost on the average 11 lb. weight.