It has been shown that a diet supplying, in addition to barley meal, weatings and 2% of lucerne meal, 5% of fish meal up to 90 lb. live weight, 2% from 90 to 150 lb. and no protein-rich food from 150 lb. to slaughter at about 200 lb. live weight, will give almost as good results, from the standpoints of mean daily live-weight increase and efficiency of food conversion over the whole period as one that provides 10% of fish meal from weaning to 150 lb. and 5% of a protein-rich food such as ex. soya bean meal from 150 to 200 lb. live weight. The small differences noted in the present trial were not statistically significant. It is true that the reduction of the fish meal supply to 5% or less retards to a significant extent the rate of growth up to 90 lb. live weight, but this initial setback, according to the results of this and the writers' previous investigations, tends to be wiped out during the later stages of feeding.

Further, a diet supplying, in addition to cereal, weatings and a small proportion of lucerne meal, as little as 2% of fish meal up to 90 lb. live weight and no protein-rich food at all thereafter has been shown to give results that are not seriously inferior, particularly when viewed against the background of wartime conditions, to those obtained on the standard diet. In this treatment, the protein required for growth beyond 90 lb. live weight was supplied by a diet of barley meal and weatings reinforced by 2% of lucerne meal.