Thirty male neonatal pigs were obtained by
cesarean section and randomly allotted from littermate groups to three diets containing 2%, 17%, and 32% fat on a dry matter basis. Butterfat was used to replace
glucose in the isoenergetic liquid, semipurified diets. Each pig was placed in a sterile isolator and fed ad libitum five times daily. After 14 days, pigs were weighed, killed, and samples of liver and backfat were obtained. The carcass of each pig was ground and samples obtained for determination of total body fat and
protein. An increase in the level of
dietary fat resulted in a significant increase in 14 day
weight gain and a tendency for improved feed efficiency. These results demonstrate not only that the neonatal pig can utilize semipurified liquid diets high in butterfat content, but also that energy from butterfat appears to be used as efficiently as energy from
glucose from growth purposes. Increasing
dietary fat level decreased the activity of
fatty acid synthetase and
citrate cleavage enzyme in adipose tissue and liver, and decreased the activity of malic
enzyme in adipose tissue. The specific activities of these three
enzymes were higher in adipose tissue than in liver.