Excess backfat deposition and restricted feeding in gestating sows: An overview of mechanisms compromising their health and performance, and regulatory effects of functional dietary fibers

Statistical analysis of the relationship between pre-parturition backfat thickness and reproductive performance using a large dataset of 693 sows (gilts) revealed that both high and low backfat as detrimental to the optimal reproductive performance of sows. Further analysis indicated that the health and reproductive performance of sows are compromised by problems such as excess backfat deposition due to ad libitum feeding and reduced satiety due to restricted feeding. Despite the consensus that dietary fiber (DF) supplementation of sows during gestation improves their health and performance, there is currently disagreement about the appropriate type of DF to select. In this review, the definition of DF is revised by integrating its physicochemical properties and fermentability, and the definition of functional dietary fiber (FDF) applicable to breeding pig breeding is proposed. Additionally, the mechanisms by which FDF regulates sow constipation, satiety, lactational feed intake and reproductive performance are elaborated in detail. This review provides a theoretical basis for selecting reasonable fiber sources for sow production.