Importance of Backfat Thickness to Reproductive Performance in Female Pigs

Backfat in pigs consists of water, collagen, and lipid. Apart from age, body weight, and number of estrus expression, backfat thickness is one of the significant parameters to consider when selecting female pigs into breeding herds since it dominates a number of reproductive performances, e.g. puberty attainment, total piglets born, and farrowing rate. Besides, backfat is one of the significant sources of hormones related to puberty attainment, such as leptin, insulin-like growth factor-I, and progesterone. Evaluation of backfat thickness is majorly performed by an A-mode ultrasonography at P2 position; it provides more accurate body condition than visual scoring. High backfat gilts attain puberty earlier than low backfat gilts. Moreover, gilts with high backfat thickness at insemination deliver one more piglet than low backfat gilts. To acquire decent reproductive performance of sow in higher parity, replacement gilts should possess backfat thickness of 18.0-23.0 mm at the first insemination, and should have body weight control to protect backfat loss during gestation and lactation periods.