FAT METABOLISM IN GROWING SWINE: A REVIEW

Abstract

At birth, piglets have little body fat that can be mobilized. The influx of high-fat milk causes a rapid increase in body fat stores and a depression of lipogenic enzyme activity. Conversely, lipolytic enzyme activity increases after birth. Changing the fat intake of sucking piglets affects the amount of fat deposition. The length of the sucking period also influences body composition at weaning. Weaning produces a pronounced but temporary decrease in total body lipid, despite an increase in fat synthesis. The effect of weaning on lipolysis is not clear due to a lack of experimental data. During the growing period, fat continues to build up even though lipogenic enzyme activity tends to decline with age. The composition of the diet, the sex of the animal and genetic factors have all been shown to influence the rate of lipogenesis. Fewer reports have been published in which factors affecting lipolysis have been studied and the results are often less conclusive. However, the combined activities of lipogenic and lipolytic processes do not account for the large quantity of body fat found in growing pigs. Key words: Swine, fat, lipogenesis, lipolysis, diet, sex.