ABSTRACT
This study was performed to determine the influence of pig breed and gender on the ultimate pH and physicochemical properties of pork. The correlations between pH and pork quality traits directly related to carcass grade, and consumer's preference were also evaluated. The pH and meat grading scores for cold carcasses of 215 purebred pigs (Duroc, Landrace, and Yorkshire) from four different farms were obtained. Meat quality parameters of the pork loin were analyzed. Duroc and female animals were more affected compared to other breeds and male pigs. Duroc animals had the highest ultimate pH, carcass back fat thickness, marbling scores, yellowness, and fat content (p<0.05). Landrace pigs had the highest color lightness and cooking loss values (p<0.05). Among all trait parameters, marbling scores showed the highest significant differences when evaluating the impact of breed and gender on meat quality characteristics (p<0.001). Ultimate pH was positively correlated with carcass weight (0.20), back fat thickness (0.19), marbling score (0.17), and color score (0.16) while negatively correlated with cooking loss (-0.24) and shear force (-0.20). Therefore, pork samples with lower ultimate pH had lower cooking loss, higher lightness, and higher shear force values irrespective of breed.
ABSTRACT
In an attempt to enable comprehensive high-resolution genotyping of the swine leukocyte antigen (SLA) gene, we performed a systemic analysis of nucleotide polymorphisms at introns 1 and 2 and exon 2 from diverse alleles of SLA-DRB1 and DRB1 pseudogenes. We amplified and cloned 16 partial sequences of SLA-DRB1 and DRB2 introns 1 and 2 from different alleles, and analyzed them together with sequences of four reported SLA-DRB pseudogenes, DRB2, 3, 4, and 5. The results showed the presence of extreme nucleotide variations within introns 1 and 2 of SLA-DRB-related genes including substitutions and deletions. On the basis of these results, we developed a comprehensive genotyping method for SLA-DRB1 by genomic polymerase chain reaction (PCR) and subsequent direct sequencing. A total of 415 animals were genotyped and 67 allelic combinations from 18 DRB1 alleles were identified. Among them, two alleles, SLA-DRB1*kn04 and *kn05, were previously unreported. SLA-DRB1 genotyping results from this study combined with those of SLA-DQB1 from our previous study presented 10 SLA class II haplotypes, three of which were previously unreported. Population analysis using seven different pig breeds showed differences in the allele frequency of SLA-DRB1 among breeds. Our results should benefit biological experiments requiring sequence-level genotyping results of SLA-DRB1 and further study of the complete genetic diversity of SLA-DRB1 using field samples.
Subject(s)
HLA-DR Antigens/genetics , Histocompatibility Antigens Class II/genetics , Sequence Analysis, DNA/methods , Alleles , Animals , Base Sequence , DNA Primers , Exons , Genotype , HLA-DRB1 Chains , Haplotypes , Histocompatibility Antigens Class I , Introns , Models, Genetic , Molecular Sequence Data , Plasmids/metabolism , Polymerase Chain Reaction/methods , Polymorphism, Genetic , Reverse Transcriptase Polymerase Chain Reaction , Sequence Homology, Nucleic Acid , Species Specificity , SwineABSTRACT
Pig blood group antigens may be present on grafted tissue as 16 isoforms, including the major one, A substrance. Seoul National University (SNU) miniature pigs and domestic pigs were used in this study. Polymerase chain reaction (PCR) was performed for the erythrocyte antigen A (EAA) gene, and reverse transcriptase-PCR for pig A transferase fucosyl transferase (FUT) 1 and FUT-2. The hemagglutination test was performed with murine monoclonal anti-A and anti-B antibodies (mAb), and immunohistochemistry with anti-human blood antigen mAb. SNU miniature and domestic pigs showed blood groups A and O. Blood group A SNU miniature pigs expressed either EAA(AA) or EAA(AO) and either S(SS) or S(SO); blood group O miniature pigs expressed EAA(OO) and S(SS) or S(SO), and there was no A(weak). Additionally, blood group A could be divided into blood group A(clotting) and blood group A(not clotting) in hemagglutination tests. Pig A substance was expressed in the lung and kidney in blood group A pigs, but we could not detect pig A substance expression in the lung, kidney, and heart of blood group O pigs or the heart of blood group A pigs. In conclusion, we suggest that blood typing of SNU miniature pigs can be easily performed using immunohistochemistry, PCR, and/or RT-PCR. Molecular-based AO typing described in this study may be useful to select SNU miniature pigs bearing a specific blood group.
