Table 2 Effect of backfat thickness (BF) at insemination on litter size at birth, age at first farrowing of
the first parity sows, farrowing rate and backfat gain (BFG) of the gilts. (Least-squares mean±
standard error of the mean).
Variable Backfat thickness
Low Moderate High
(≤13.5 mm) (14.0-16.5 mm) (≥17.0 mm)
Total number of piglets born/ litter 12.1±0.6ab 12.0±0.4a 13.1±0.4b
Number of piglets born alive/ litter 10.6±0.6a 10.8±0.4a 10.8±0.4a
Mummified fetuses/litter (%) 4.3±1.3a 3.5±0.9a 3.9±1.0a
Stillborn piglets/litter (%) 8.0±2.8a 7.2±1.8a 14.5±2.2b
Age at first farrowing (d) 387.4±3.0a 388.0±2.0a 390.2±2.5a
Farrowing rate (%) 82.0a 82.6a 86.7a
Backfat gain (mm) 6.3±0.5a 4.8±0.3b 3.3±0.4c
a,b,c Different superscripts within a row are significantly different (P < 0.05).