Evaluation of American and British rations for growing pigs.

I. A test was carried out simultaneously in Shinfield, Reading, England, and Columbus, Ohio, USA, using typical British and American rations for growing pigs. The rations were compounded in their country of origin ; half of each consignment was used at the home station and the other half shipped to the overseas station. 2. Both restricted feeding and ad lib. feeding methods were used at each station. 3. A similar pattern of results was obtained at Shinfield and Columbus. Pigs receiving the American ration, which was higher in energy content, grew faster and required less feed per kg live-weight gain than pigs receiving the British ration. The higher energy content of the ration was probably responsible also for the poorer carcass quality of the pigs receiving the American ration, particularly the high fat content. The comparison between restricted feeding and ad lib. feeding was not affected by the type of ration. Restricted feeding resulted in slower growth rate, slightly better efficiency of feed conversion and considerably better carcass quality.