A large-scale test of the effects of food restriction on the performance of fattening pigs

1. A co-ordinated trial has been carried out at twenty-six centres to study the effects of feeding different quantities of food to fattening pigs. The treatments studied were ad lib. feeding throughout, ad lib. feeding to 120 lb. live weight after which the amount of food given was restricted to 6·5 lb./pig/day and two scales of feeding according to live weight, one moderate and one severe (Table 1). 2. Food conversion was best for the pigs on the most restricted feeding scale, being 8% better than that for the pigs fed ad lib. 3. The slower growing pigs were less fat, slightly longer and their depths of eye muscle were greater. 4. The ad lib. fed pigs had higher killing-out percentages and higher weights into cure. 5. The bacon sides from pigs fed on restricted diets yielded a higher proportion of gammon and fore-end and had thicker streaks. 6. Restriction of feeds led to softer fats. 7. An economic appraisal has been made which shows that, on the basis of certain assumptions, the medium feeding scale would have led to a smaller profit per year than the ad lib. or the ad lib. restricted treatments under the price structure and system of grading prevailing during the period of the experiment.