EVALUATION OF BACKFAT THICKNESS IN PERFORMANCE-TESTED LANDRACE, LARGE WHITE AND THEIR F1 CROSSES IN A LOCAL SWINE BREEDING FARM

Abstract

This study evaluated backfat thickness (BFT) of 12,272 performance-tested pigs (3,351 boars and 8,921 gilts) belonging to Landrace (LDR), Large White (LRW), and their F1 crosses. Backfat thickness at the shoulder (BFT1), midback (BFT2), loin (BFT3), and their average were significantly affected (P<0.01) by breed, year, month, and weight at the end of test. Backfat thickness was highest for BFT1 (15.67 mm for boars; 15.80 mm for gilts), followed by BFT3 (14.21 mm for boars; 15.21 mm for gilts), and lowest for BFT2 (11.95 mm for boars; 12.30 mm for gilts). Average BFT was positively (P<0.01) correlated with average daily gain, body length, age, and weight at the end of test. Average BFT was significantly (P<0.05) lower in boars than in gilts. Average BFT was significantly (P<0.05) higher in Landrace than in Large White. Differences in average BFT between F1 LDR x LRW and R1 LRW x LDR crosses were not significant (P>0.05). Heterosis for average BFT in boars (–3.37% or –0.45 mm) was higher than in gilts (–1.48% or –0.21 mm). While backfat thickness can be reduced by selection within a breed, backfat thickness may also be decreased by heterosis resulting from the production of F1 crosses.