Updated estimates of HAL n and RN− effects on pork quality: Fresh and processed loin and ham

Genetic characterization of domestic pigs in the core zone of swine production of Argentina

Argentina is a small player in the global pork market, contributing only 0.7% of the total production. With increasing global demand for meat, there is an opportunity for countries with an agricultural profile to grow their pork production. However, there is a need to understand the current state of the pork production sector in all aspects to inform decision-making. The aim of this study was to genetically characterize pig herds from different production strata in the primary region for pork production in the country. For this purpose, phylogenetic and genetic variability analyses were performed using the mitochondrial control region marker (n=95 pig samples). Moreover, genotyping of ryr1 and PRKAG3 genes (n=108 pig samples) were performed to evaluate the frequency of deleterious alleles for meat quality traits in the region. The results showed high levels of genetic variability in the pig herds (Hd= 0.840 ± 0.031 and π= 0.010 ± 0.001), with a creole sow and Iberian lineage standing out in the phylogeny. The genotyping of the ryr1 marker revealed the presence of the deleterious t allele in all analyzed strata. However, the RN-allele of the PRKAG3 gene was detected only in the two lower strata. This study represents the first analysis of the phylogenetic relationships among domestic pigs from Argentina and provides an initial assessment of genetic variability in the region. Additionally, the results present, for the first time, the frequency of deleterious alleles for pig production in the productive core area, demonstrating their prevalence.

miR-152 targets pyruvate kinase to regulate the glycolytic activity of pig skeletal muscles and affects pork quality

As a type of non-coding RNA, microRNAs are widely involved in the biological processes of animals. In the present study, the expression of miR-152 in glycolytic muscle fibers (Longissimus thoracis, LT) was lower than that of oxidative muscle fibers (Psoas major, PM). Using dual luciferase assay, miR-152 was shown to target muscle pyruvate kinase (PKM) to perform biological functions. Moreover, overexpression of miR-152 in primary porcine cells inhibited PKM gene expression and reduced lactic acid production in cells, whereas inhibition of miR-152 expression promoted PKM gene expression and increased lactic acid production. Correlation analysis showed that the expression of miR-152 was significantly positively correlated with the ultimate pH of LT after slaughter, while the expression of the PKM gene was significantly negatively correlated with the final pH of LT. In vivo and in vitro experiments discussed herein suggest that miR-152 may affect muscle pH by targeting the expression of the PKM gene. Our findings enrich the understanding of the genetic regulatory network that influences pork quality.

Quality characteristics of fresh loin and cooked ham muscles as affected by genetic background of commercial pigs

This study was performed to investigate meat quality traits of loin and ham of commercial pigs as affected by genetic differences in carcass and growth traits of the parent lines. Three hybrid sow lines were crossbred with two types of Belgian Piétrain with different breeding goals (BP_growth and BP_carcass emphasizing daily growth and carcass conformation, respectively). Pig live performance and carcass quality of 270 offspring were measured, and meat quality of the loin and (cooked) ham was evaluated on 216 animals. Despite the differences in pig live performance and carcass quality for sow line, little effect on meat quality was observed. Only a lower (p < 0.05) intramuscular fat content of ham and a tendency (p < 0.1) toward lower cooking yield was observed in offspring of the sow line with the highest versus the lowest carcass lean content. Loin traits were only weakly associated with fresh and cooked ham quality traits.

Apulo-Calabrese and Crossbreed Pigs Show Different Physiological Response and Meat Quality Traits after Short Distance Transport

Simple Summary

Transport is a stressful procedure that can affect adversely the welfare of pigs and pork quality. It is well known that response to the journey is influenced by the genetic type. However, very little is known on the response of local breeds to the transport procedures despite the increasing interest in the welfare of animals during transport. The objective of this study was to investigate the effect of short distance transport on behaviour, blood parameters and meat quality traits of Apulo-Calabrese (local Italian pig breed) and crossbreed [Duroc × (Landrace × Large White)] pigs. Statistical analyses were done using univariate and multivariate approaches. Both approaches showed that glucose, albumin/globulin, urea, and aspartate aminotransferase concentrations were influenced by the genetic type. Despite at loading Apulo-Calabrese pigs were less reluctant to move and showed a lower vocalization, physiological response to the short distance transport was more intense in this breed when compared with crossbreeds. With regards to meat quality, higher a* and lower L* coordinates were found in Apulo-Calabrese which indicates darker and more reddish meat than crossbreeds. The results from this study may provide insight into the response of local breeds to the transport procedures.

Abstract

Despite the increasing interest in the welfare of animals during transport, very little is known on the response of local pig breeds to the transport procedures. This study aims to compare the effect of short journey on behaviour, blood parameters, and meat quality traits in 51 Apulo-Calabrese and 52 crossbreed [Duroc × (Landrace × Large White)] pigs. All the animals were blood sampled five days before delivery (basal condition) and at exsanguination for the analysis of creatine kinase, cortisol, glucose, lactate, albumin, albumin/globulin, total protein, urea, creatinine, aspartate aminotransferase (AST), alanine aminotransferase, alkaline phosphate, sodium, and potassium. Post mortem pH, color, drip loss, cooking loss, and Warner-Bratzler shear force were measured at different times in longissimus thoracis samples. Univariate and multivariate analyses showed that glucose, albumin/globulin, urea, and AST at exsanguination were influenced by the genetic type. Apulo-Calabrese showed the highest increase in blood values of lactate, creatinine, sodium and potassium after the short distance transport. Behavioural occurrences were similar in both genetic types during unloading and lairage. Small differences were observed for meat quality although significantly higher a* and lower L* were found in Apulo-Calabrese pigs, showing meat with a deeper red colour than crossbreeds.

Effects of single nucleotide polymorphisms and haplotypes of the protein kinase AMP-activated non-catalytic subunit gamma 3 (PRKAG3) gene on production, meat quality and carcass traits in Italian Large White pigs

PRKAG3 is a major gene for meat quality and production in pigs. In this study, we investigated two single nucleotide polymorphisms (SNPs) of the PRKAG3 promoter region (g.-995A>G and g.-311A>G) in 381 pigs of different breeds. Association between these SNPs and three major haplotypes, constructed including other three substitutions (c.89C>A, c.154A>G and c.595G>A) and different traits (meat quality parameters: pH_2h, pH_u, glycogen and lactate content, glycolytic potential and cathepsin B activity of Semimembranosus muscle; estimated breeding values and random residuals for growth performances and carcass traits) were analysed in 271 Italian Large White performance tested pigs. A significant effect (P=0.043) of the g.-995A>G SNP on cathepsin B activity and a suggestive effect (P=0.067) of the g.-311A>G SNP on pH_u were found. The haplotype [g.-995G:g.-311G:c.89A:c.154G:c.595G] was associated with pH_u (P=0.024), glycolytic potential (P=0.040) and cathepsin B activity (P=0.086). This study on haplotypes, including promoter region SNPs, contribute to explain the effect of this gene on meat quality traits in pigs.

Evidence for three highly significant QTL for meat quality traits in the Finnish Yorkshire pig breed

Meat quality is important both to consumers and to the meat processing industry. Commonly used measures of porcine meat quality are the pH and color of the meat. The purpose of this study was to identify SNP associated with these meat quality traits in Finnish Yorkshire using the Illumina PorcineSNP60 BeadChip. The association of each SNP with the quality traits was tested with a weighted linear model. The relatedness of samples was accounted for by a random polygenic genetic effect with the accompanying full relationship matrix. The original EBV from single-trait evaluations were deregressed before analysis. The statistical significance of SNP was established using the Bonferroni correction to adjust for multiple testing. Three genomic regions were significant for the meat quality traits. The PRKAG3 region on chromosome 15 was significant for pH measured from loin and ham and for a* (redness) measured from loin. The smallest P-value in the region was obtained for pH measured from loin (ASGA0070634, P-value = 3.8 × 10(-13)). The allele substitution effect (-0.047) of the unfavorable allele A corresponds to 1 SD of the polygenic effect. The second significant region, on chromosome 2 at around 31 megabases (Mb), was associated with pH and L* (lightness) measured from loin. The most significant SNP (ASGA0009814, P-value = 3.89 × 10(-10)) had an allele substitution effect of 0.86, corresponding to 0.7 SD of the polygenic effect of L*. The third region, located on chromosome 6 at around 83 Mb, was significant for a* measured from ham. The P-value of the best SNP (ALGA0035896) was 8.71 × 10(-7) and the allele substitution effect -0.38, corresponding to 0.5 SD of the polygenic effect of a*. The significant association of PRKAG3 with pH was not due to the known AA substitutions. The candidate gene on chromosome 2 associated with color L* is RCN1, which has a high affinity Ca(2+)-binding motif, the EF hand. The significant region on chromosome 6 for color a* contains several genes, so more data are needed to identify the causative gene. Our results indicate that instead of the known AA substitutions of PRKAG3, some yet-unknown AA substitutions are causative for the pH variation in Finnish Yorkshire. Also, a new major QLT for L* was found on chromosome 2. The significant SNP identified in this study can be used in marker-assisted selection.

[Bovine disease-related DNA mutations and their genetic control strategies in breeding for disease resistance]

Bovine genomic DNA mutations and their genetic effects on gene expression and protein function influence disease susceptibility and resistance of cattle. The genetic loci related to cattle diseases are mainly divided into two types: single-locus-disease genes and multigenic-disease loci. The single-locus-disease genes are called causal mutations; their genetic basis is simply and normally detected in the coding and non-coding regions inducing substitution of amino acid, premature termination of translation, and complete deletion of entire exon(s). In contrast, the genetic basis of disease related to multiple genes is more complex since susceptibility or resistance of these diseases is affected by the interactions among host, pathogen, and environment. This article reviewed current research and application of the major diseases of cattle con-trolled by single gene or polygenic genes. The genetic control strategies of effective identification and control of these dis-eases in bovine breeding and production were also analyzed.

Factors in pig production that impact the quality of dry-cured ham: a review

This study reviews the factors of pig production that impact the quality of dry-cured ham. When processing is standardized, the quality of the final dry-cured product is primarily determined by the quality of the meat before curing (green ham). This has been defined as the aptitude for seasoning and is determined by the green ham weight, adipose tissue quantity and quality, meat physico-chemical properties and the absence of visual defects. Various ante-mortem factors including pig age and weight, genetic type, diet, feeding strategy and slaughter conditions determine green ham properties such as the dynamics of water loss, salt intake and, as a consequence, proteolysis and lipolysis. Muscle conditions (pH, salt concentration, water content and availability, temperature) influence enzymatic activity and development of characteristic texture and flavor. Generally, hams of older and heavier pigs present better seasoning aptitude because of higher adiposity. Adiposity is also positively correlated with fat saturation, which is desired to avoid rancidity and oiliness. The fatty acid profile of tissue lipids can be manipulated by diet composition. Feeding strategy affects tissue accretion and protein turnover, thus directly impacting proteolysis. With respect to the impact of pig genotype on dry-cured ham quality, local breeds are generally considered more suitable for producing quality dry hams; however, the majority of dry-cured hams on the market today are from modern pig breeds raised in conventional systems, providing lean hams. The importance of all these factors of pig production is discussed and synthesized, with an emphasis on the main difficulties encountered in dry-cured ham production.

Joint analysis of quantitative trait loci and major-effect causative mutations affecting meat quality and carcass composition traits in pigs

Background

Detection of quantitative trait loci (QTLs) affecting meat quality traits in pigs is crucial for the design of efficient marker-assisted selection programs and to initiate efforts toward the identification of underlying polymorphisms. The RYR1 and PRKAG3 causative mutations, originally identified from major effects on meat characteristics, can be used both as controls for an overall QTL detection strategy for diversely affected traits and as a scale for detected QTL effects. We report on a microsatellite-based QTL detection scan including all autosomes for pig meat quality and carcass composition traits in an F2 population of 1,000 females and barrows resulting from an intercross between a Pietrain and a Large White-Hampshire-Duroc synthetic sire line. Our QTL detection design allowed side-by-side comparison of the RYR1 and PRKAG3 mutation effects seen as QTLs when segregating at low frequencies (0.03-0.08), with independent QTL effects detected from most of the same population, excluding any carrier of these mutations.

Results

Large QTL effects were detected in the absence of the RYR1 and PRKGA3 mutations, accounting for 12.7% of phenotypic variation in loin colour redness CIE-a* on SSC6 and 15% of phenotypic variation in glycolytic potential on SSC1. We detected 8 significant QTLs with effects on meat quality traits and 20 significant QTLs for carcass composition and growth traits under these conditions. In control analyses including mutation carriers, RYR1 and PRKAG3 mutations were detected as QTLs, from highly significant to suggestive, and explained 53% to 5% of the phenotypic variance according to the trait.

Conclusions

Our results suggest that part of muscle development and backfat thickness effects commonly attributed to the RYR1 mutation may be a consequence of linkage with independent QTLs affecting those traits. The proportion of variation explained by the most significant QTLs detected in this work is close to the influence of major-effect mutations on the least affected traits, but is one order of magnitude lower than effect on variance of traits primarily affected by these causative mutations. This suggests that uncovering physiological traits directly affected by genetic polymorphisms would be an appropriate approach for further characterization of QTLs.