Objective: The objective of this study was to investigate the effects of various dietary unsaturated to saturated fatty acids ratios (UFA to SFA ratios) on growth performance, carcass traits, blood lipid parameters, tissue fatty acid (FA) composition, and meat quality of finishing pigs.Methods: A total of 45 crossbred pigs ([Duroc×Landrace]×Yorkshire), with an average initial body weight of 60.3±2.4 kg, were randomly allocated to three treatment groups of 1:1, 2:1, and 3:1 dietary UFA to SFA ratios.Results: Both average daily gain and average daily feed intake of pigs were decreased linearly (p<0.05), whereas backfat thickness was decreased linearly (p<0.05) with increasing of dietary UFA to SFA ratio. Serum triglyceride and low density lipoprotein cholesterol were decreased quadratically or linearly (p<0.05) respectively, whereas high density lipoprotein cholesterol was increased quadratically (p<0.05) with increasing dietary UFA to SFA ratio. In M. longissimus thoracis, the proportion of C18:1 and monounsaturated FA was decreased linearly (p<0.05), whereas the proportion of C18:2n-6, C20:4n-6 and polyunsaturated FA (PUFA) were increased linearly (p<0.05) as dietary UFA to SFA ratio increased. In the subcutaneous adipose tissue, the proportion of SFA was decreased linearly (p<0.05), whereas the proportion of n-6 PUFA, n-3 PUFA, and the UFA to SFA ratios were increased linearly (p<0.05) with increasing of dietary UFA to SFA ratio. Meat color scores and shear force of pigs were decreased linearly (p<0.05), whereas drip loss and cooking loss were increased linearly (p<0.05) with increasing of dietary UFA to SFA ratio.Conclusion: Appropriately boosted dietary UFA to SFA ratio could be conductive to optimize blood lipid parameters and tissue FA composition. However, when the ratio is too high or too low it tends to have negative effects on growth performance and meat quality.

Objective: This study investigated the effects of dietary n-6:n-3 polyunsaturated fatty acid (PUFA) ratio on growth performance, blood indexes, tissue fatty acid composition and the gene expression in finishing pigs.Methods: Seventy-two crossbred ([Duroc×Landrace]×Yorkshire) barrows (68.5±1.8 kg) were fed one of four isoenergetic and isonitrogenous diets with n-6:n-3 PUFA ratios of 2:1, 3:1, 5:1, and 8:1.Results: Average daily gain, average daily feed intake and gain-to-feed ratio had quadratic responses but the measurements were increased and then decreased (quadratic, p<0.05). The concentrations of serum triglyceride, total cholesterol and interleukin 6 were linearly increased (p<0.05) with increasing of dietary n-6:n-3 PUFA ratio, while that of high-density lipoprotein cholesterol tended to decrease (p = 0.062), and high-density lipoprotein cholesterol:low-density lipoprotein cholesterol ratio and leptin concentration were linearly decreased (p<0.05). The concentration of serum adiponectin had a quadratic response but the measurement was decreased and then increased (quadratic, p<0.05). The proportion of C18:3n-3 was linearly decreased (p<0.05) in the longissimus thoracis (LT) and subcutaneous adipose tissue (SCAT) as dietary n-6:n-3 PUFA ratio increasing, while the proportion of C18:2n-6 and n-6:n-3 PUFA ratio were linearly increased (p<0.05). In addition, the expression levels of peroxisome proliferator-activated receptor gamma (PPARγ) and lipoprotein lipase in the LT and SCAT, and adipocyte fatty acid binding protein and hormone-sensitive lipase (HSL) in the SCAT had quadratic responses but the measurements were increased and then decreased (quadratic, p<0.05). The expression of HSL in the LT was linearly decreased (p<0.05) with increasing of dietary n-6:n-3 PUFA ratio.Conclusion: Dietary n-6:n-3 PUFA ratio could regulate lipid and fatty acid metabolism in blood and tissue. Reducing dietary n-6:n-3 PUFA ratio (3:1) could appropriately suppress expression of related genes in PPARγ signaling, and result in improved growth performance and n-3 PUFA deposition in muscle and adipose tissue in finishing pigs.

A wide survey of the distributions of polycyclic aromatic hydrocarbons (PAHs) in vegetable oils (n = 86) for human consumption from manufacturers and retail shops in China were conducted by GC-MS following extraction with acetonitrile and purification using silica gel solid phase. Levels of BaP and PAH4 in 37 and 34 samples, respectively, were not in line with maximum permitted limit set by EU regulations. The three-ring and four-ring PAH compounds were predominant in vegetable oils, followed by 2 rings, which may be attribute to the truth that low molecular weight PAHs are prone assimilated by plant roots than high-ring PAHs, and are mainly produced under low temperature (<200 °C) processing conditions. The level of PAHs contamination found in this study in oil products should prompt a suitable intervention strategy to meet the health needs of consumers. Considering the vegetable oil categories, the levels of 16 PAHs in peanut and sesame oil were higher than other oils. This may be related to the two oils mostly extracted from roasted seeds for the development of flavor or aromatic in China. To hold the flavor of the crude oils, they were not refined. The health risk assessment of PAHs showed that there was a potential carcinogenic risk for the vegetable oil intake in China, but it has not yet reached the priority risk level.

This study evaluated dietary quercetin supplementation to investigate the effects of increasing inclusion levels on growth performance, diarrhea, serum health-related indicators, and whole-blood gene expression in weaned piglets. In a 28-day feeding trial, 128 piglets received diets formulated to contain 0, 100, 200, or 300 mg/kg quercetin (four pens of eight piglets per treatment; pen as the experimental unit). Final body weight and average daily gain were higher in the 200 and 300 mg/kg groups than in the control, and the 300 mg/kg group had the highest gain-to-feed ratio (G:F) (p < 0.05). Diarrhea rate declined linearly (p < 0.001); the rate in the 300 mg/kg group was lower than in the control and 100 mg/kg groups but did not differ from the 200 mg/kg group. Quercetin reduced serum malondialdehyde, pro-inflammatory cytokines, urea nitrogen, and aspartate aminotransferase, while increasing total protein, albumin, total antioxidant capacity, several antioxidant enzyme activities, and interleukin-10 (p < 0.05). Serum diamine oxidase activity and D-lactate concentration also declined linearly (p < 0.001). Whole-blood expression of PTGS2 decreased; HMOX1, NFE2L2, and NQO1 increased; and SOD1 was unchanged. Overall, within the tested range, increasing dietary quercetin improved growth and feed efficiency, reduced diarrhea, and was accompanied by coordinated changes in serum health-related indicators and whole-blood transcripts.

Pig growth is an economically important trait regulated by multiple genes and signaling pathways. To explore the molecular mechanisms underlying muscle growth, RNA sequencing was conducted to compare the transcriptomic profiles of the longissimus dorsi muscle between indigenous Liaoning Black pigs (CH) and commercial Duroc pigs (HD). Muscle samples from six CH (three males and three females) and six HD (three males and three females) pigs were analyzed. Functional annotation, Gene Ontology (GO) and KEGG enrichment, and protein–protein interaction (PPI) analyses were performed. Sequencing yielded 12 high-quality datasets (Q20 > 97%, Q30 > 93%). Comparative analysis identified 5051 DEGs in females (CHF vs. HDF; 2310 upregulated and 2681 downregulated) and 9972 DEGs in males (CHM vs. HDM; 4984 upregulated and 4988 downregulated). GO terms were mainly enriched in organonitrogen compound and protein metabolic processes, while KEGG pathways were enriched in focal adhesion and insulin signaling. PPI analysis highlighted hub genes ITGB1, SRC, MYL2, PRKACA, and MAPK3. qPCR validation showed strong agreement with RNA-seq data. These findings provide valuable insights into the molecular basis of divergent muscle growth between pig breeds.

Relative phenotypic positioning among pig populations may differ across production, carcass, and pork-quality domains. We tested whether source-defined Liaodan Black (LDB) pigs occupied a uniformly intermediate position between Liaoning Black (LB) and Duroc (DR) references at a common target body weight. Sixty pigs (20 per source population; 10 barrows and 10 gilts) entered at 70 d and were slaughtered at 106–114 kg. Population effects were evaluated using a Population × Sex model with false-discovery-rate control for individual fatty acids and amino acids. Sensitivity analyses addressed final body weight, slaughter batch, a shared 50–80 kg interval, intramuscular fat (IMF), fatty-acid compositionality, and principal component analysis (PCA) variable selection. Over 50–80 kg, average daily gain increased and feed-to-gain ratio decreased from LB through LDB to DR (both p < 0.001). LDB had the lowest C18:1n-9c and monounsaturated fatty-acid proportion, while its polyunsaturated fatty-acid profile was closer to DR than LB; these lipid differences persisted after IMF adjustment and centered-log-ratio analysis. Exploratory PCA retained the LB–LDB–DR production/carcass ordering under alternative specifications. Thus, production/carcass ordering did not extend uniformly to intramuscular lipid composition within these sampled source populations.