Feeding various fat sources to sows: effects on immune status and performance of sows and piglets

Foetal energy demands are greatly increased during late gestation and catabolism of maternal reserves occurs if dietary energy supply is insufficient to meet requirements. Fats and oils are traditionally introduced into late gestation and lactation diets as a high-energy supply to improve neonatal survival and milk yield, and to reduce mobilization of body reserves. Furthermore, the efficiency of using metabolizable energy from lipids is very high, and they have a minimum heat increment compared with other nutrients, thereby reducing summer heat stress. Increasing the energy intake of sows during the anabolic phase of gestation is likely to increase the amount of fat available for mobilization during late pregnancy, and may result in enhanced sow performance during lactation. Besides their general importance as an energy source, fats and oils are also a source of essential fatty acids. Recent studies have shown that several fatty acids appear to improve body function and may be important in physiological processes such as neonatal immune function and sow fertility. This chapter mainly focuses on the recent advances in dietary uses of omega fatty acids (n-3 and n-6 FA) and conjugated linoleic acid (CLA) to enhance reproductive performance and immunology of sows as well as the performance and immune status of their foetuses and neonates.