Relationships between body composition, backfat depth and reproductive efficiency in gilts

Intensive genetic selection allowed to obtained gilts attaining just 30-40% of target mature body lean tissue mass and even further less of target mature body fatty tissue mass at the beginning of reproduction activity (Whittemore, 1996). Fat resources of actual gilts are equivalent to 14- 15 mm backfat thickness (P2) at conception (Caugant et al. 1999) and are low in comparison with old genotypes (fat mass twice than lean mass)...