The effects of feeding lambs diets containing two levels of almond skin on meat oxidative stability were investigated. Male lambs (n = 30, 2 months old, body weight 12.7 ± 2.07 kg) Valle del Belice × Pinzirita were assigned to 3 dietary treatments and fed ad libitum for 56 days with: a concentrate-based diet (CON) or CON containing 140 (A14) or 280 (A28) g/kg of dried almond skin in replacement of maize. Vitamins and hydrophilic antioxidant capacity were assessed in fresh meat, while colour and lipid oxidation were evaluated over 7 days of refrigerated storage. Data from fresh meat were statistically analysed using one-way ANOVA, whereas shelf-life trial data were evaluated using a mixed-effects model. Almond skin inclusion affected the antioxidant capacity of meat, showing different results: Folin-Ciocalteu and ferric reducing antioxidant power (FRAP) assays showed a decreased reducing activity of the extract, while an improved radical scavenging activity was observed with the Trolox equivalent antioxidant capacity (TEAC) assay. Ferrous ion chelating activity (FICA) and DPPH (2,2-diphenyl-1-picrylhydrazyl) assays showed no differences. A reduction of the total tocopherol content was observed in A28 treatment compared to the others. Neither the colour nor the lipid oxidation was influenced by the dietary treatment, except for the TBARS (Thiobarbituric Acid Reactive Substances) values in raw meat, which tended to increase in A28 treatment. The study evidenced that 140 g/kg dietary almond skin in lambs may be a successful strategy for replacing maize without detrimental effects on meat oxidative stability.
A cross-sectional live bird market (LBM) survey was conducted to determine the prevalence and distribution of extended-spectrum β-lactamase (ESBL)-producing and carbapenem-resistant (CR) E. coli and Salmonella spp. in retail chicken meat and LBM sewage in Bangladesh. E. coli and Salmonella spp. were identified using culture-based and molecular methods. Isolates were tested for CR by a disk diffusion test; a confirmatory ESBL screening was performed by double disk synergy test. The isolates were screened for ESBL and CR genes using PCR. Prevalence of ESBL-E. coli and Salmonella spp. in retail chicken meat was 70% and 43.4%, respectively while in LBM sewage, it was 79.7% and 28.1%, respectively. Carbapenem resistance was also common, detected in 54.1% and 46.9% of E. coli and 37.2% and 12.5% of Salmonella spp. isolated from retail chicken meat and LBM sewage, respectively. Molecular analysis revealed the presence of ESBL and CR genes, including blaCTX-M-1, blaCTX-M-2, and blaNDM-1. The blaCTX-M-1 gene was detected at low frequencies among ESBL-E. coli from retail chicken meat (1.3%) and LBM sewage (3.9%), and among ESBL-Salmonella spp. from retail chicken meat (3.6%), while blaCTX-M-2 was identified in a single ESBL-E. coli isolate from LBM sewage. Notably, blaNDM-1 was detected in 5.2% of CR-E. coli and 33.6% of CR-Salmonella spp. from retail chicken meat. Multidrug resistance (MDR) was observed in 98.2% and 92.2% of ESBL-E. coli, and 97.8% and 94.4% of ESBL-Salmonella spp. from retail chicken meat and LBM sewage, respectively; while, 98.8% and 100% of CR-E. coli, and 97.5% and 87.5% of CR-Salmonella spp. from both types of samples, respectively were MDR. These results highlight the urgent need for strengthened antibiotic stewardship, regular surveillance, and improve biosecurity in live bird markets in Bangladesh.
Zanthoxylum bungeanum seeds (ZBS) are a bioactive-rich byproduct with potential as antibiotic alternatives, yet their systemic effects on waterfowl remain unclear. This study investigated the effects of dietary ZBS supplementation on growth performance, physiological status, meat quality, and the microbiome-metabolome profile in Pekin ducks. A total of 240 ducks (14-day-old) were assigned to four treatments containing 0% (CG), 1.5% (LG), 3.0% (MG), or 4.5% (HG) ZBS for 21 days. Trend analysis revealed a significant quadratic dose-response for growth performance (P< 0.05), identifying 1.5% as the optimal inclusion level for maximizing body weight. Physiologically, ZBS supplementation enhanced antioxidant capacity and liver function by linearly upregulating serum SOD, CAT, and GSH-Px activities while significantly reducing MDA, ALT, AST, and triglyceride levels (P< 0.05). Regarding meat quality, ZBS linearly increased breast meat redness (a*) and facilitated the linear deposition of glutamic acid and alpha-linolenic acid, mirroring the ZBS nutrient profile (P < 0.05). Consequently, this deposition optimized key nutritional indices, characterized by a linear reduction in the n-6/n-3 polyunsaturated fatty acid ratio (P< 0.01) and an improved BCAA/AAA ratio. Mechanistically, 16S rRNA sequencing indicated a beneficial filtering effect where ZBS reduced alpha diversity by suppressing inflammation-associated genera (Desulfovibrio, Fusobacterium) while enriching beneficial fermenters (Faecalibacterium, Barnesiella). Metabolomics further identified upregulated antioxidant and immunomodulatory metabolites, such as orsellinic acid and purine analogs, which correlated with improved host health. Collectively, ZBS functions as an ecological modulator that promotes liver health and meat nutritional value in a linear manner, while optimizing growth performance quadratically, with 1.5% identified as the optimal dosage.
Selenium (Se) is a vital trace element affecting muscle development and quality. This study aimed to evaluate the effects of sodium selenite (SeNa), selenomethionine (SeMet), and elemental nano-selenium (SeNPs) on growth performance and meat quality and the underlying mechanisms in finishing pigs. Finishing pigs (120 pigs/group) were fed with basal diet (CON, 0.108 mg Se/kg) or CON supplemented with 0.4 mg Se/kg SeNa, SeMet, or SeNPs. At week 6, longissimus dorsi (LD) muscle was collected for meat quality, selenium, redox status, metabolomics and transcriptomics analysis. Compared with the CON, the 3 forms of Se supplementation increased (P < 0.05) body weight gain (1.84-6.07%) and reduced (P < 0.05) the feed/gain ratio (2.72-4.89%) of pigs. Feed intake (0.97%) increased (P < 0.05) in the SeNPs group but no significant changed was observed in the SeNa and SeMet groups. And SeNPs further improved (P < 0.05) these performances by 1.65-4.16% compared with SeNa. Moreover, SeNPs and SeMet enhanced (P < 0.05) Se concentration, marbling and color, but decreased (P < 0.05) drip loss in the LD muscle than those of CON and SeNa. Notably, SeNPs uniquely stabilized postmortem pH45 min and pH24 h and minimized drip loss than the other 3 groups. Additionally, SeMet and(or) SeNPs increased (P < 0.05) triglyceride (TG) contents and the activities of glutathione peroxidase (GPX) and thioredoxin reductase (TXNRD) in LD muscle. Metabolomic and transcriptomic profiling showed that SeNPs reduced lipid metabolic related pathways and associated with coordinated regulation of muscle and adipose tissue development. Multi-omics integration further identified the AMPK-mTOR signaling pathway as a central regulatory network targeted by SeNPs, thereby contributing to improvements in growth performance and meat quality in finishing pigs. Compared with SeNa or SeMet, SeNPs demonstrated a unique ability to improve growth performance, meat quality and antioxidant status in finishing pigs, associated with regulation energy metabolism by activating the AMPK-mTOR regulatory network.
Background: Avian pathogenic Escherichia coli (APEC) contributes substantially to colibacillosis outbreaks in chickens. Because APEC cells readily attach to surfaces and develop biofilms, they pose a notable hazard to poultry production and food safety. This study investigated the antibiofilm and anti-adhesion activities of deep eutectic solvent-based emulsion containing Piper betle L. extract (DEPE) and hydroxychavicol, a pure compound isolated from P. betle leaves against APEC. Methods: Antibiofilm and anti-adhesion activities of DEPE and hydroxychavicol against APEC were investigated. Molecular docking and dynamics simulation of DEPE and hydroxychavicol was conducted. In addition, anti-adhesion activity of DEPE on chicken meat during storage was evaluated. Results: DEPE and hydroxychavicol significantly inhibited biofilm formation at sub-MIC, with DEPE achieving up to 80% inhibition and hydroxychavicol up to 69%. At 8 × MIC, DEPE and hydroxychavicol diminished the viability of both early and established biofilms. Furthermore, DEPE and hydroxychavicol reduced APEC adhesion on the surface as observed by SEM. In silico analyses demonstrated the stable binding of hydroxychavicol to adhesion-related proteins, particularly EcpA and FimH, suggesting a possible mechanism for its anti-adhesion activity. At day 5, DEPE at 4 × MIC significantly reduced 63% bacterial adhesion to chicken meat surfaces during storage, while maintaining the meat's color. Conclusions: These findings indicate that DEPE and hydroxychavicol are promising candidates for limiting APEC biofilm formation and surface attachment and may serve as alternative antibacterial agents in poultry-related food safety applications.
This study aimed to investigate the effects of quercetin and rutin (the glycoside form of quercetin) on growth performance, organ indices, meat quality, serum biochemistry, intestinal morphology, and cecal microbiota of broilers under high stocking density, and compared their differential effects. A total of 480 one‑day‑old male Cobb500 broilers were randomly allocated to 6 treatment groups (6 replicates per group): a control group reared at 14 broilers/m², a high stocking density group at 20 broilers/m², and four high stocking density groups fed diets supplemented with 400 ppm or 800 ppm quercetin or rutin, respectively. The results of this study show that, compared with the control group, high stocking density, as well as supplementation with 400 ppm quercetin, 400 ppm rutin, and 800 ppm rutin, significantly reduced FI and BWG throughout the entire trial period. However, supplementation with 800 ppm quercetin showed a trend toward alleviating the reduction in FI and BWG caused by high stocking density. Supplementation with quercetin significantly increased the meat color of the pectorales at 45 min postmortem, whereas rutin supplementation significantly reduced drip loss of the pectorales at 24 h postmortem. Furthermore, quercetin and rutin supplementation significantly increased the chao1 index, enriched the beneficial intestinal bacteria Alistipes and Faecalibacterium, and reduced the relative abundance of the harmful bacterium Streptococcus at the genus level. In conclusion, quercetin and rutin differentially improved growth performance, meat quality, and cecal microbiota of broilers reared under high stocking density.
Fermentation determines the physicochemical properties and flavor characteristics of sour meat. However, research on yak sour meat fermentation remains limited, compared to pork's counterpart. This study combined physicochemical analysis, intelligent sensory techniques, gas chromatography - ion mobility spectrometry (GC-IMS), 16S rRNA sequencing and machine learning (ML) to explore bacterial dynamics and flavor development during a 45-day fermentation procedure. E-sensing distinguished stage-specific sensory profiles, with day-45 samples showing enhanced umami and sweetness. GC-IMS identified 42 volatiles, with 3-methylbutanal isomers, acetic acid and α-terpinolene increasing and 2-butoxyethanol, hexanal-D decreasing during fermentation. Bacterial diversity declined, with Staphylococcus and Lactobacillus dominating, and Lactobacillus was confirmed as the key genus for flavor formation. Fermentation caused a pH reduction, and a hardness elevation, accompanied by modifications to the color's profile. ML models demonstrated high predictive performance: Support Vector Machine (SVM) achieved 100% accuracy in classifying fermentation stages using E-nose/E-tongue data, while k-Nearest Neighbors (k-NN) optimally differentiated stages based on GC-IMS volatile profiles. This study elucidates the interplay between microbial succession and flavor evolution in yak sour meat, establishing a scientific foundation for optimizing fermentation protocols and enhancing product quality control.
The development of active packaging from biodegradable materials is crucial for maintaining chilled meat quality. Inspired by citrus peel, this study fabricated a multifunctional composite film combined with ultraviolet (UV) treatment. To mimic the exocarp, the film features a sodium alginate-beeswax/polylactic acid bilayer designed, where the sodium alginate-beeswax film replicates the hydrophobic cuticular wax layer and polylactic acid enhances mechanical robustness. A gelatin-based porous active layer incorporating zinc oxide nanoparticles and oregano essential oil was further constructed to simulate the sponge-like mesocarp. It exhibited enhanced barrier properties (WVP = 7.30 g·mm·m-2·d-1·kPa-1) and reduced light transmittance (T600 = 35.83%). UV irradiation further improved its thermal stability, antioxidant (DPPH scavenging rate > 86%), and antibacterial performance. This composite film combined with UV treatment extended the shelf life of chilled meat from 2-3 days to 6-7 days, demonstrating its potential in active packaging integrated with non-thermal sterilization.
While human activities are driving widespread declines in wildlife populations1,2, in Central Africa, the meat of wild animals, or wild meat, represents a major component of the diets of millions of people3. To halt faunal degradation while ensuring sustainable use of wildlife, it is crucial to understand the scale and drivers of wild meat consumption. Here, using data from over 12,000 households from 252 locations in Central Africa, we show that wild meat is a fundamental component of the diets of rural populations, accounting for 20% of the recommended daily protein intake, compared with 13% and 6% for those living in towns and cities. We estimate that the total annual biomass of wild meat consumed in Central Africa increased from 0.73 million to 1.10 million tonnes between 2000 and 2022, with increasing demand from towns and cities. To ensure that wild meat is available to rural communities, in accordance with the Sustainable Development Goals4 and the Kunming-Montreal Global Biodiversity Framework5, reducing wild meat consumption in urban metropolises is key. While our results are based on the most comprehensive dataset available, the geographical coverage is incomplete and the dataset represents a minimal fraction of the entire population of Central Africa. Targeted studies are needed to validate our model and assess critical areas of intervention.
The development of natural preservatives from agricultural by-products is essential for sustainable food systems. This study valorized burdock leaves by extracting a bioactive polysaccharide with yield of 6.422%. A burdock leaf polysaccharide (BPS) was identified as an acidic heteropolysaccharide (molecular weight 1.616 × 105 Da) with a triple-helix structure, mainly composed of galactose and arabinose. It exhibited strong antioxidant activity and notable antibacterial efficacy against Escherichia coli and Staphylococcus aureus (minimum inhibitory concentration (MIC50) = 25 mg/mL). Mechanistic analyses revealed that BPS disrupted membrane integrity, elevated reactive oxygen species (ROS) levels, and induced DNA damage. When applied as a beef coating and stored in a refrigerator at 4 °C, BPS extended shelf-life from 6 to over 12 days by preserving color, limiting weight loss and pH increase, and suppressing bacterial growth and total volatile basic nitrogen (TVB-N) accumulation. These findings highlight BPS as a promising clean-label preservative derived from agricultural waste.
The growing demand for sustainable food preservation drives interest in edible nanoemulsions encapsulating bioactive compounds. This study developed casein-lecithin-based nanoemulsions combining carvacrol (CV)-a compound with potent antimicrobial and moderate antioxidant activity-with vitamin E (VitE)-a powerful antioxidant-as multifunctional food coatings. Three formulations were prepared via homogenization: NE-CV (2% CV), NE-VitE (2% VitE), and NE-CV/VitE (1% each). Physicochemical characterization revealed monomodal size distributions (22.7-57.7 nm), with successful encapsulation confirmed by FTIR. NE-CV/VitE exhibited intermediate particle size (34.4 nm) and zeta potential (-19.8 mV). Antioxidant activity followed NE-VitE > NE-CV/VitE > NE-CV, with the co-encapsulated system preserving VitE's radical scavenging (EC50 10.76 µL/mL, DPPH). Remarkably, NE-CV/VitE demonstrated enhanced antibacterial activity against E. coli, requiring half the CV concentration (0.07 mg/mL) versus NE-CV alone (0.15 mg/mL), while maintaining CV dose-dependent activity against S. aureus (0.30 mg/mL). Nanoencapsulation significantly reduced CV cytotoxicity in human lymphocytes at concentrations up to 50 μg/mL (48.8% cytostasis vs. 58.9% for free CV), with no genotoxic effects observed within this range, while preserving full bioactivity. In fresh minced pork over 6-day refrigerated storage, NE-CV/VitE coating maintained pH stability (5.65-5.75), preserved red color (a* values 6.24 vs. 4.99 uncoated), reduced lipid oxidation (TBARS 0.74 vs. 0.82 mg MDA/kg), and achieved a 99% reduction (2-log) in total viable counts versus uncoated controls. The CV/VitE co-encapsulated nanoemulsion represents an integrated, safe, and effective multifunctional preservation technology with synergistic antimicrobial enhancement and uncompromised antioxidant protection, offering a natural alternative for comprehensive food quality preservation.
Heat stress (HS) is a major challenge in poultry production due to its negative effects on growth, metabolism, and redox balance. Excessive reactive oxygen species generated during HS contribute to oxidative damage, emphasizing the need for nutritional strategies that enhance antioxidant capacity. This study evaluated the effects of dietary L-cysteine supplementation on growth performance, carcass traits, hepatic redox-related gene expression, and ileal nutrient transporters in commercial broilers. A total of 1,080 Cobb500 chickens (d 28-35) were assigned to diets containing deficient (0%), control (0.3%), or excess (0.6%) L-cysteine and exposed to thermoneutral (TN; 25°C), pair-feeding (PF; 25°C), or cyclic HS (35°C for 12 h daily). As expected, HS adversely affected (P < 0.05) BWG, feed efficiency, and carcass yields; however, L-cysteine supplementation did not improve (P > 0.05) any performance variable under HS. Hepatic cystathionine-β-synthase (CBS) expression increased under cysteine-deficient conditions, indicating enhanced endogenous cysteine synthesis via the transsulfuration pathway. In contrast, expression of glutamate-cysteine ligase catalytic subunit (GCLC), cysteine dioxygenase-1 (CDO1), and glutathione synthetase (GSS) did not differ (P > 0.05) among dietary cysteine levels, suggesting similar glutathione synthetic capacity across treatments. Ileal nutrient transporters, including SGLT1, GLUT5, FATP1, FABP2, PEPT1, and PEPT2, exhibited variable expression patterns in response to diet and temperature, reflecting differences in feed intake and intestinal physiological adaptation. Overall, dietary L-cysteine did not mitigate HS-induced declines in performance. Increased CBS expression under cysteine deficiency suggests robust endogenous regulation of cysteine supply, and further studies integrating protein abundance and enzyme activity are needed to elucidate L-cysteine's biological effects under HS.
Residual feed intake (RFI) is a key indicator for assessing feed efficiency in animals. Although olfactory cues are known to influence feeding behavior, their underlying molecular mechanisms in RFI regulation remain unclear. This study characterized the expression profiles of long non-coding RNAs (lncRNAs) and mRNAs in the olfactory tissue of Tianfu Nonghua ducks with divergent RFI phenotypes. RNA sequencing was conducted on olfactory tissue samples from low-RFI (n = 6) and high-RFI (n = 6) individuals. A total of 40 differentially expressed lncRNAs and 157 differentially expressed mRNAs were identified. Target gene prediction revealed 88 putative lncRNA target genes, primarily regulated through trans-acting mechanisms. Functional enrichment analysis highlighted significant involvement in neuroactive ligand-receptor interactions, neurotransmitter transport, and metabolic pathways. Notably, differentially expressed G protein-coupled receptors (GPCRs) were enriched in neuroactive ligand-receptor interaction pathways, suggesting their potential role in modulating olfactory signal transduction. Co-expression network analysis identified 155 lncRNA-mRNA regulatory pairs, with key interactions involving lncRNAs ENSAPLG00000024078.1 and ENSAPLG00000030384.1 and their associated target mRNAs: IQCM, LAG3, GBX2, SLC6A6, and RP1L1. These findings provide novel insights into lncRNA-mRNA regulatory networks within duck olfactory tissue and suggest a potential mechanism by which olfactory signaling may influence feed efficiency.
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The distinctive flavor and desirable texture of Qiandongnan Xiaoxiang chicken meat make it an ideal model for studying the formation of chicken meat quality traits. This study investigated age-related changes in meat quality, gut microbiota, and the underlying molecular mechanisms in Qiandongnan Xiaoxiang chickens. By integrating multi-omics data, we systematically examined the alterations and interrelationships among serum biochemical indices, gut microbial composition, breast muscle metabolome, and transcriptome in chickens at different ages (60-180 days). The results showed that increasing age significantly affected physiological metabolism, muscle development, and meat quality formation. As age increased, breast muscle pH, shear force, and redness (a*) increased, whereas yellowness (b*) decreased. Serum lipidomic profiling revealed elevated levels of triglycerides, cholesterol, and free fatty acids, accompanied by a reduction in high-density lipoprotein cholesterol. Flavor precursors such as sucrose, arbutin, acylcarnitines, lipid-derived substrates, and bile acid-related metabolites may participate in the maillard reaction, lipid oxidation, or undergo further transformation during processing, thereby promoting aroma formation. With increasing age, lipid metabolism-related signaling pathways, including adipocytokine signaling, fatty acid biosynthesis, fatty acid metabolism, linoleic acid metabolism, glycerophospholipid metabolism, and regulation of lipolysis in adipocytes, were significantly enriched. Transcriptomic analysis identified the key lipid-related gene PLA1A, whose expression pattern was consistent with the observed metabolic changes. Multi-omics analysis identified gut microorganisms (Bifidobacterium, Lachnospiraceae NK4A136 group, and Christensenellaceae R7 group) that were negatively correlated with the PLA1A gene and flavor metabolites such as 4‑aminovaleric acid betaine, danazol, and hetisine. Collectively, these findings elucidate the microbial-metabolic-genetic network underlying meat quality development and provide new insights for optimizing poultry production.
The Liaoning Cashmere goat (LCG) is a dual-purpose breed of major economic importance in China, valued for its high cashmere yield and meat quality. Cashmere fineness (CF) remains a primary target for genetic improvement because fiber diameter directly determines textile value and market price. This study examined the sex-specific effects of single-nucleotide polymorphisms in the guanosine monophosphate synthase (GMPS) and steroid receptor coactivator (SRC) genes on CF and a broad spectrum of production traits to identify functional markers for marker-assisted selection. A total of 1,160 healthy LCGs (89 bucks and 1,071 does, 2-4 years of age) from the same nucleus herd were included. The C31799T locus in GMPS and the C34197G locus in SRC were genotyped by polymerase chain reaction (PCR) amplification followed by bidirectional Sanger sequencing. Genotype-trait associations were tested using general linear mixed models, with genotype, sex, and age as fixed effects, and pedigree information incorporated to control for relatedness. Haplotype phases were inferred separately for each sex with the SHEsis platform. Phenotypes recorded comprised cashmere production traits (fineness, length, yield), body size measurements, slaughter performance, meat quality attributes, milk composition, and lambing rate. Data normality, homoscedasticity, and multicollinearity were verified prior to analysis; statistical significance was declared at p < 0.05. The TT genotype at the GMPS C31799T locus and the CG genotype at the SRC C34197G locus were significantly associated with finer cashmere fibers (p < 0.05). Sex-stratified analyses showed that the GMPS TT genotype conferred superior CF in does (p < 0.01) and longer staple length in both sexes (p < 0.01), whereas the SRC CG genotype improved fineness specifically in does (p < 0.01). Haplotype analysis identified CCCC as the optimal combination for finer cashmere in bucks and TTGG in does. Pleiotropic effects were evident: the GMPS CC genotype favored larger body dimensions, the GMPS TT genotype enhanced carcass traits in bucks, and the SRC CG genotype improved lactation performance. CF exhibited positive correlations with cashmere yield (bucks: r = 0.412; does: r = 0.384; p < 0.01) and negative associations with several slaughter traits. Path and stepwise regression analyses clarified direct and indirect effects, underscoring sex-dependent genetic trade-offs between fiber quality and meat production. This is the first study to establish GMPS and SRC as key candidate genes influencing CF in goats. The identified superior genotypes and haplotypes provide sex-specific molecular markers that can be immediately deployed in marker-assisted selection programs to accelerate genetic gains in cashmere quality while safeguarding meat production potential in LCG breeding. Validation in independent populations will further strengthen their utility for precision breeding.
Technogenic pollution from industrial activities and legacy nuclear testing remains a major environmental concern in several regions of Kazakhstan. Contaminants such as heavy metals and radionuclides can migrate through environmental matrixes into the food chain, potentially compromising the safety of livestock- and fish-derived food products. This study aimed to assess contamination levels of toxic elements and radionuclides in meat, poultry, milk, dairy products, and freshwater fish from technogenically hazardous regions of Eastern, Northern, and Central Kazakhstan and to evaluate their compliance with established safety standards. A cross-sectional monitoring study was conducted from August 2024 to September 2025 in the Abai, Akmola, and Karaganda regions. A total of 383 samples of meat, milk, and dairy products and 143 freshwater fish samples were collected from farms, retail markets, and local water bodies. Concentrations of lead (Pb), cadmium (Cd), copper (Cu), and zinc (Zn) were determined using inductively coupled plasma optical emission spectrometry. Radionuclides cesium-137 and strontium-90 were analyzed using a multichannel gamma spectrometer with radiochemical methods where applicable. Descriptive statistics and analysis of variance were performed using IBM SPSS Statistics version 25, with p < 0.05 considered statistically significant. Elevated concentrations of toxic elements were detected in several livestock products. The Karaganda region showed the highest contamination, including exceedances of Pb, Cd, Cu, and Zn in horse meat and elevated Cu in beef. In the Akmola region, exceedances were mainly observed for Cu and occasionally Cd, whereas in the Abai region Cd exceedances predominated. Poultry meat generally met safety standards, except for Cd exceedance in chicken from the Akmola region. In dairy products, Cd and Cu exceeded permissible levels in cottage cheese and milk in selected districts, while Pb exceeded limits in whole milk samples from the Abai region. Freshwater fish contained detectable heavy metals, but concentrations remained below maximum permissible limits. Radionuclide levels in all tested products were substantially below regulatory thresholds, and no statistically significant regional differences were observed. The findings demonstrate localized accumulation of toxic elements in livestock-derived foods in industrially impacted regions of Kazakhstan, while radionuclide contamination remains within safe limits. Continuous environmental monitoring and strengthened food safety surveillance are required to minimize health risks and ensure the safety of animal-derived food products in technogenically affected areas.
This study conducted a comprehensive comparison of the metabolomic and proteomic profiles of pigeon breast muscles from 12-month-old (M12) and 28-day-old (D28) birds to investigate the influence of age on meat quality. The M12 samples showed lower L*, a*, and b* values but higher ΔpH, shear force, cooking loss, hardness, cohesiveness, and gumminess compared to the D28 samples. Metabolomic analysis identified five down-regulated metabolites, L-histidine (fold change, FC = 0.216), L-arginine (FC = 0.560), 4-hydroxyproline (FC = 0.149), D-sedoheptulose 7-phosphate (FC = 0.465), and L-glutamic acid 5-phosphate (FC = 0.120), that were primarily involved in amino acid and related metabolic pathways, differentiating the two groups. Proteomic profiling revealed a reduced abundance of several proteins, importantly A306_00011918, A306_00011919, ENPP1, TKT, and ALDH18A1, which are involved in amino acid biosynthesis in M12. Integrative analysis of metabolomic and proteomic data highlighted amino acid biosynthesis, mediated by specific metabolites and proteins, as the major differentiating pathway between M12 and D28. In conclusion, these findings provide mechanistic insights into the molecular basis underlying age-dependent variations in pigeon meat quality, offering valuable guidance for poultry producers in determining the optimal slaughter age to achieve desirable meat characteristics.