Flavor is a pivotal indicator influencing the meat quality and palatability of premium broiler chickens, shaped by multiple factors. The flavor differences among broiler chicken breeds/lines stem from the specificity of their metabolite profiles and volatile flavor compounds. This study aims to identify key metabolites and pathways that regulate flavor variations in high-quality broilers, providing data support and theoretical references for breeding superior broiler lines and developing technologies to enhance flavor quality. Breast Muscle tissue from 15-week-old roosters of the S3 and H lines (n = 6) was used as experimental material. Broad-targeted metabolomics and volatile metabolomics technologies were employed to identify key metabolites and volatile organic compounds (VOCs) influencing the flavor of breast meat in these two high-quality broiler lines. Broad-target metabolomics identified 167 differentially expressed metabolites (VIP > 1, p < 0.05) between the two strains, including 141 upregulated and 26 downregulated metabolites. These metabolites were primarily amino acids and their derivatives, and were significantly enriched in metabolic pathways such as ABC transporters (p < 0.05). Leu-Tyr, Ile-Tyr, Val-Leu, Val-Ile, and Tyr-Ala were identified as key metabolites influencing the flavor formation of breast meat from both high-quality broiler lines. Volatile metabolomics results identified 33 downregulated VOCs (VIP > 1 and p < 0.05). The flavor differences between the two strains primarily involved fatty and grassy flavor. Key flavor markers included 2-Nonanone, 2-Nonanone, 3-hydroxymethyl, 2-Methylheptanoic acid, and Hexanoic acid, butyl ester as the primary flavor markers. These significantly downregulated volatiles are formed through lipid oxidation and amino acid degradation pathways, respectively, collectively shaping the more pronounced fatty and grassy aromas in the S3 strain. Correlation analysis revealed a significant negative correlation between Met-Asn and Hexanoic acid, butyl ester, suggesting it may represent a key regulatory pathway influencing green flavor formation. In summary, this study elucidates key metabolites and pathways governing flavor differences in high-quality broiler rooster breast meat, providing a scientific foundation for poultry breeding, optimization of farming practices, and flavor regulation in meat products.

Objectives: The aim of this experiment was to explore how the addition of Schizochytrium powder to the feeding ration affected the production performance, egg quality, and antioxidant function of chickens. Schizochytrium powder is a unicellular spherical marine microalga that can be cultivated through heterotrophic fermentation, with characteristics including rapid cell growth, stable composition, and ease of large-scale production. Experimental design: Three hundred and twenty 33-week-old chickens with similar egg production rates and body weights were selected and randomly divided into four groups, with five replicates each and 16 hens in each replicate. The control group (Group I) was fed a corn–soybean meal basal diet, while the test groups were supplemented with 0.5% (Group II), 1.0% (Group III), and 2.0% (Group IV) Schizochytrium powder on top of this basal diet, respectively. The pretest period was 1 week, and the main test period was 8 weeks. The results revealed the following: (1) Compared with Group I, the average daily feed intake (ADFI) and laying rate (LR) were significantly lower (p < 0.05) in Group IV, and there was no significant difference (p > 0.05) in the ADFI and LR between Groups II and III. (2) Compared with Group I, the eggshell strength (ES) and docosahexaenoic acid (DHA) content of Groups II, III, and IV were significantly higher (p < 0.05). (3) Compared with Group I, serum triglyceride (TG) content was significantly decreased (p < 0.05), and serum low-density lipoprotein (LDL) content was significantly increased (p < 0.05) in Groups II, III, and IV. Serum total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and peroxidase (PO) activities were significantly higher (p < 0.05) and serum malondialdehyde (MDA) content was significantly lower (p < 0.05) in Groups II, III, and IV compared to Group I. In conclusion, adding Schizochytrium powder to the feeding ration could affect chickens’ production performance, increase egg DHA content, and improve the antioxidant capacity of the organism. Based on the results of this study, we recommend a ratio of 1.0% Schizochytrium powder addition.

The fat mass and obesity-associated gene (FTO) has been shown to play a critical role in fat deposition in both humans and livestock. However, its involvement in subcutaneous and intramuscular fat deposition in chickens remains underexplored. In this study, we investigated the regulatory effects and pathways of FTO on subcutaneous and intramuscular fat deposition in chickens through functional gene verification and bioinformatics analysis. Our results demonstrated that, compared to the control group, exogenous transfection of an FTO lentiviral overexpression vector significantly inhibited cell proliferation and increased lipid accumulation in both subcutaneous and intramuscular adipocytes (p < 0.05). Furthermore, transfection of FTO siRNA markedly increased cell proliferation and reduced lipid accumulation in both subcutaneous and intramuscular adipocytes. A total of 413 and 164 differentially expressed genes were regulated by FTO in subcutaneous and intramuscular adipocytes, respectively. Pathway analysis revealed that the regulation of the actin cytoskeleton was a key process involved in FTO-mediated fat deposition in both subcutaneous and intramuscular adipocytes. Additionally, NRAS and ITGAV (subcutaneous fat), as well as FGF9, PIK3R2, FGF16, and RHOA (intramuscular fat), were identified as key genes enriched in this pathway. In conclusion, FTO differentially regulates fat deposition in chicken subcutaneous and intramuscular adipocytes by targeting distinct functional genes within the actin cytoskeleton pathway.