title: Effects of the porcine IGF2 intron 3-G3072A mutation on carcass cutability, meat quality, and bacon processing.
abstract: A SNP in a regulatory region of intron 3 within the porcine IGF2 gene (IGF2-G3072A) is associated with increased lean deposition and decreased fat deposition in pigs with paternal A alleles (APat) compared with pigs with paternal G alleles (GPat). However, data regarding fresh and processed meat quality characteristics of pigs with different alleles for this polymorphism are limited. A single heterozygote (AG) boar was bred to homozygous (AA) commercial Yorkshire-cross sows producing F1 barrows and gilts with either GPat or APat. Two farrowing groups of barrows and gilts were group housed, provided ad libitum access to a diet that met or exceeded NRC nutrient recommendations throughout production, and slaughtered at 176 d (±4 d) of age. Fresh LM quality and estimated percent fat-free lean measurements were taken on the left side of carcasses, while carcass cutouts were completed with right sides. Fresh belly and bacon processing traits were characterized for only block 1 pigs. Pig was treated as the experimental unit for all analyses. Ending live weight and HCW were not affected by IGF2 allele; however, 10th rib backfat thickness was 0.41 cm less (P=0.01), loin eye area was 4.0 cm2 greater (P=0.01), and predicted fat-free lean was over 2 percentage units greater (P<0.01) in APat pigs compared with GPat pigs. Furthermore, boneless lean cuts from the shoulder, loin, and ham were heavier (P<0.05) in APat pigs compared with GPat pigs. Minolta L* value was 2.36 units greater (P=0.03) but cooking loss was 1.82 percentage units greater (P<0.01) in APat pigs compared with GPat pigs. Additionally, despite reductions in subcutaneous fat, extractable intramuscular lipid from the LM was 0.64 percentage units greater (P=0.02) in APat pigs compared with GPat pigs. Bellies were 7.17 mm thinner (P=0.01), had 7.27 cm less flop distance (P=0.05), and tended to have 1.34 units greater iodine value (P=0.09) in APat pigs compared with GPat pigs. While not statistically different (P=0.30), the magnitude of difference in slicing yield as a percentage of green weight was 1.57 percentage units between bellies from APat pigs (85.83%) and bellies from GPat pigs (87.40%). Pigs with GPat had superior belly quality that may positively impact commercial bacon production. However, pigs with APat yielded a greater amount of lean product at the expense of producing lighter LM color and increased cooking loss.
authors.affiliation: Department of Animal Sciences, University of Illinois, Urbana 61801.
authors.forename: D L
authors.initials: DL
authors.lastname: Clark
authors.affiliation: Department of Animal Sciences, University of Illinois, Urbana 61801.
authors.forename: B M
authors.initials: BM
authors.lastname: Bohrer
authors.affiliation: Department of Animal Sciences, University of Illinois, Urbana 61801.
authors.forename: M A
authors.initials: MA
authors.lastname: Tavárez
authors.affiliation: Department of Animal Sciences, University of Illinois, Urbana 61801.
authors.forename: D D
authors.initials: DD
authors.lastname: Boler
authors.affiliation: Department of Animal Sciences, University of Illinois, Urbana 61801.
authors.forename: J E
authors.initials: JE
authors.lastname: Beever
authors.affiliation: Department of Animal Sciences, University of Illinois, Urbana 61801 adilger2@illinois.edu.
authors.forename: A C
authors.initials: AC
authors.lastname: Dilger
mesh_terms: D000483:Alleles; D000818:Animals; D001823:Body Composition / Q000235:genetics* / Q000502:physiology; D001835:Body Weight / Q000235:genetics / Q000502:physiology; D001947:Breeding; D005260:Female; D019649:Food Industry; D007335:Insulin-Like Growth Factor II / Q000235:genetics*; D007438:Introns / Q000235:genetics*; D008297:Male; D008460:Meat / Q000592:standards*; D008461:Meat Products / Q000592:standards*; D018482:Muscle, Skeletal / Q000502:physiology; D009154:Mutation / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D013552:Swine / Q000235:genetics* / Q000502:physiology
chemical_list: D007335:Insulin-Like Growth Factor II
keywords: IGF2-G3072A; belly quality; carcass cutout; insulin-like growth factor; pig; single nucleotide polymorphism