Effects of Carcass Weight and Back-fat Thickness on Carcass Properties of Korean Native Pigs

Association analysis of mitochondrial genome polymorphisms with backfat thickness in pigs

Mitochondrial DNA (mtDNA) variations and associated effects on economic traits have been widely reported in farm animals, as these genetic polymorphisms can affect the efficiency of energy production and cell metabolism. In studies related to metabolism, the deposition of fat was highly correlated with mitochondria. However, the effect of mtDNA polymorphisms on porcine backfat thickness (BFT) remained unclear. In this study, 243 pigs were collected to analyse the relationship between BFT and mtDNA polymorphisms. There were considerable differences in BFT, ranging from 5 mm to 18 mm. MtDNA D-loop sequencing discovered 48 polymorphic sites. Association analysis revealed that 30 variations were associated with BFT (P < 0.05). The polymorphism m.794A > G showed the maximum difference in BFT between A and G carriers, which differed at ∼2.5 mm (P < 0.001). The 48 polymorphic sites generated 22 haplotypes (H1-H22), which clustered into 4 haplogroups (HG1-HG4). HG1 had a lower BFT value than other three haplogroups (P < 0.01), whereas H4 in HG1 exhibited the lowest BFT of all haplotypes analyzed (P < 0.01). The results of this study highlight an association between mtDNA polymorphisms and BFT, and suggest the potential application of mtDNA in pig molecular breeding practices.

Effect of non-starch polysaccharide enzyme supplementation with gradually reduced energy diet on growth performance, nutrient digestibility, lean meat percentage and backfat thickness of growing pigs

This study was conducted with the objective of evaluating a way to reduce feed costs with better meat characteristics for growing pigs by supplementing non-starch polysaccharide enzyme (NSPE) in energy reduced diets. A total of 200 growing pigs [(Landrace × Yorkshire) × Duroc] weighing 22.94 ± 0.22 kg were divided into five dietary treatments, each with eight replication pens (three barrows and two gilts). The pigs were allotted in a completely randomised block design according to body weight and sex. The dietary treatments were: CON (control), basal diet (NE 2500 kcal); NSPE1, basal diet + 0.04% NSPE; NSPE2, (basal diet-20 kcal) + 0.04% NSPE; NSPE3, (basal diet-30 kcal) + 0.04% NSPE; NSPE4, (basal diet-50 kcal) + 0.04% NSPE. We have assessed growth performance, lean meat percentage (LMP) and backfat thickness at initial, Week 4 and 8. Apparent nutrient digestibility was assessed in Weeks 4 and 8. There was no significant difference (p > 0.05) among the groups on growth performance. In Week 8, gradual reduction of energy caused a linear reduction (p = 0.028) of backfat thickness and a linear increase (p < 0.05) of LMP. In addition, at Week 8, supplementation of NSPE enzyme showed improved digestibility of nitrogen (p < 0.05) and energy (p < 0.05) in the NSPE1 group than in the CON group. In short, gradual reduction of dietary energy supplemented with NSPE showed consistent growth performance through higher nutrient digestibility with positive changes in backfat thickness and LMP of growing pigs.

Blood transcriptomic differences in the immune response under stressful environmental according to stocking density in pigs

The implementation of animal welfare in the pig industry is becoming a global trend, and welfare can be improved through livestock management. In modern and intensive farming systems, it has become important to find a reasonable compromise between stocking density and productivity. The simultaneous detection of behavioral and physiological parameters is helpful when considering welfare levels for stocking density. This study aimed to confirm the effect of stocking density through transcriptome linkage. A comparison of three groups according to stocking density (low density, eight pigs and 1.0 m2 per head; normal density, eight pigs and 0.8 m2 per head; and high density, eight pigs and 0.6 m2 per head) was performed, and their transcriptomic changes were observed using the RNA-Seq method. Differentially expressed genes were identified for each comparison group (low density vs. normal density, 95 upregulated genes and 112 downregulated genes; high density vs. normal density, 133 upregulated genes and 217 downregulated genes; and high density vs. low density, 245 upregulated genes and 237 downregulated genes). Biological mechanisms according to stocking density were identified through functional annotation. T-cell differentiation and immune disease pathway enriched in the high-density group caused immune imbalance through dysregulated T-cell signaling. Moreover, oxidative stress, together with DNA damage, can lead to high susceptibility to disease. Our study confirmed the biological mechanisms through immunological expression patterns according to stocking density. The study results are expected to provide comprehensive insight into systematic operation strategies considering stocking density and biomarkers for use in welfare evaluation.

Back-fat thickness as a primary index reflecting the yield and overall acceptance of pork meat

Predicting aspects of lean meat yield and eating quality of pork based on some particular carcass traits become increasingly important from an economic profitability point of view. The present study aimed to determine the relationship between the back-fat (BF) thickness with lean meat yield and meat quality traits of crossbred pigs. A total of 220 crossbred pigs [(Landrace × Yorkshire) ♀ × Duroc ♂] reared under identical conditions and harvested at 180 days old were slaughtered and screened for BF thickness. Four BF thickness groups: 12-15, 16-20, 21-25, and 26-30 mm were classified, and longissimus dorsi (LD) muscles from these groups were used to analyze meat quality characteristics. Results showed that increasing BF thickness decreased the lean meat yield and loin lean area. Increasing BF thickness up to 26-30 mm increased intramuscular fat content and pH of LD muscles. The LD muscles of the thicker BF (21-30 mm) groups received significantly higher flavor, juiciness, and overall acceptability scores than those of the thinner back-fat (12-20 mm) groups. Overall, when all the pre-harvest factors are kept the same, BF thickness could be considered as a primary index for predicting lean meat yield, and the minimal back-fat thickness of 21-30 mm is required to improve the overall acceptability of pork meat.