The influence of three feeding treatments of differing protein content on growth and carcass quality in bacon pigs has been investigated by the individual-feeding and group-feeding techniques. The protein supplement, which was used in conjunction with barley meal, weatings and a small allowance of lucerne meal, was composed of a mixture of ex. soya-bean meal, dried separated milk and feeding blood meal. Expressing, on the nitrogen basis, the amount of protein food in terms of its equivalent of white fish meal, the standard-protein treatment B supplied the equivalent of 9% of fish meal up to 90 lb. live weight, 7·6% from 90 to 150 lb. live weight and 3·8% from 150 to 200 lb. live weight. The corresponding figures for the low-protein treatment A were 4·5, 3·8 and 1·9%, and for the high-protein treatment C, 18, 15·2 and 7·6%.

Considering the period of feeding up to 200 lb. live weight as a whole, it was found that differences of feeding treatment gave rise to no significant differences in respect of mean rate of live-weight increase and efficiency of food conversion (see Table VI). Only in the earliest stage of the feeding period did the pigs on the low-protein treatment A show a slightly, though significantly, lower rate of live-weight increase and poorer efficiency of food conversion than the pigs on treatments B and C, but such differences had ceased to be manifested by the time the pigs had arrived at 60 lb. live weight, and the slight initial disadvantage experienced by the low-protein pigs was wiped out during the later stages of the feeding period.