AbstractA protein concentrate made from wheat leaves, and dried by a commercial process, was tested as a source of supplementary protein in practical diets for newly‐weaned pigs based on a 2:1 mixture of barley meal and millers' offals. When about 7% of dried leaf protein concentrate was included in the diet the rate of growth and the efficiency of utilisation of feed by the pigs were as good as when the diet contained 8% of white fish meal, the two diets being roughly equivalent in their contents of total and supplementary protein. When the content of dried leaf protein concentrate was raised to 10%, or higher, there was no better growth but the efficiency of utilisation of feed was significantly improved. Inclusion of a small amount (4.5%) of dried leaf protein concentrate in a diet otherwise deriving its supplementary protein from groundnut meal, promoted as good growth and as high an efficiency of utilisation of feed as with high levels of leaf protein concentrat