Effect of Diet on Milk Yield of the Ewe and Growth of her Lamb

We have already reported on the lambing of Sutherlandshire Cheviot ewes maintained during the latter half of pregnancy on either a high or a low plane of nutrition (Thomson & Thomson, 1948-9).Under the dietary conditions imposed in that experiment the low-plane ewes produced small, weakly lambs, many of which died at birth or soon after, and the high-plane ewes produced vigorous lambs amongst which there were few deaths.The present paper deals with the lactation performance of the ewes and with the food consumption and the growth of the lambs; it covers the period March to August 1947.The literature has been reviewed by Wallace (1948), who also studied milk yields from ewes maintained on different planes of nutrition.Barnicoat, Logan & Grant (1949) also have made milk-yield trials on 200 Romney ewes. EXPERIMENTAL General.Soon after parturition the ewes and lambs were arranged in four groups: (I) high-plane ewes suckling their own lambs (H.H.), (2) high-plane ewes suckling lambs born of low-plane ewes (L.H.), (3) low-plane ewes suckling their own lambs (L.L.) and (4) low-plane ewes suckling lambs born of high-plane ewes (H.L.).All twins were suckled as singles, and all lambs were weaned at 17 weeks of age.The numbers available for the various groups are shown in Table I .Table I.Numbers of animals in the four groups Ewes H.H." L.H." L.L."