Association of the Insulin-like Growth Factor II Gene (IGF-II) with Growth and Body Conformation Traits in a Commercial Swine Population

Abstract

Data on growth, body length (BL), shoulder width (SW), hip width (HW), backfat depth (BF), loin dept (LD), and percent lean (PL) of gilts and castrated males from Pietrain (P; 19 pigs), Yorkshire (Y; 16 pigs), crossbred between Y and P (YP; 17 pigs), crossbred between Landrace (L) and P (LP; 18 pigs), and crossbred between Y and LP (YLP; 23 pigs) were considered with genotype (GG, GC, and CC) of IGF-II (Insulin-like growth factor-II), which was from DNA restricted by a specific restriction endonuclease enzyme BcnI, in order to study the difference at gene level related to growth and body conformation. All pigs were negative halothane gene and they were raised under an open-house system from 84 to 178 days of age. The statistical model composed of interaction between sex and breed group, age, and genotype as fixed effects, and had residual as the random effect. The results revealed that IGF-II genotype had influenced on BL (P < 0.01), BF (P < 0.05), and PL (P < 0.05). Pigs with GG genotype had highest least square means (LSM) for BL (76.20 + 1.37 cm; P < 0.05) and BF (12.25 + 0.75 mm; P < 0.05). Pigs with GC genotype had highest LSM for PL (60.13 + 0.21%; P < 0.05). Substitution G with C at position of 162 in intron 7 of the IGF-II resulted in reducing BL and BF, but increasing PL. Additive effect of allele C decreased BL and FAT2 (P < 0.05). Dominance effect was found in increasing PL (P < 0.05) of the studied population. Thus, variation of IGF-II gene at the position would be used to classify the difference in growth and body conformation among pigs in order to genetic selection.