This study aimed to determine changes and interactions of ruminal microbiota and chemical parameters in dairy cows fed FTMR. Twelve multiparous Holstein dairy cows (Body weight = 616 ± 13.4 kg; day in milk = 106 ± 7.55 d; and parity = 2.31 ± 0.49; mean ± standard deviation) were divided randomly into two treatments depending on the day in milk, milk production, and parity. The two treatments were: (1) total mixed ration (TMR) and (2) FTMR. Illumina MiSeq sequencing was used to explore the changes in the ruminal microbiota. The results revealed that the bacterial and fungal diversity of the FTMR group were significantly higher than the TMR group. The predominant microbiota phyla in the bacteria and fungi showed significant differences between TMR and FTMR, as follows: Verrucomicrobia (p = 0.03) and Tenericutes (p = 0.01), Ascomycota (p = 0.04) and Basidiomycota (p = 0.04). The dominant bacterial genera in the bacteria, fungi, protozoan, and archaea that showed significant differences between TMR and FTMR were Unclassified_Bacteroidales (p = 0.02), Unclassified_RFP12 (p = 0.03), Candida (p = 0.0005), Bullera (p = 0.002), Cryptococcus (p = 0.007), and Ostracodinium (p = 0.01). LefSe analysis was performed to reveal the biomarker genera of the rumen microbiota community (bacteria, fungi, protozoan, and archaea) in the TMR and FTMR were the genera Shuttleworthia, Ruminococcus, Cryptococcus, Mycosphaerella, Bullera, Candida, and Ostracodinium. NH₃-N concentration (p < 0.0001), total VFA concentration (p = 0.003), and molar proportion in total VFA of acetate (p = 0.01) were higher for the cows fed FTMR compared with the cows fed the TMR. Several bacterial genera showed significant correlations with rumen fermentation parameters. The genus Unclassified_Bacteroidales and Bullera were positively correlated with total volatile fatty acids (VFA) and acetate, whereas Candida and Ostracodinium showed negative correlations. Meanwhile, propionate was positively correlated with Candida and negatively correlated with Bullera. The PICRUSt functional profile prediction indicated that the xenobiotics biodegradation and metabolism, the lipid, amino acid, terpenoids, and polyketides metabolisms of the FTMR group were significantly higher than that of the TMR group. The results imply that FTMR can increase lipid and amino acid metabolism, and modulate the rumen microbiome and improve ruminal fermentation.

This study utilized multi-omics techniques to thoroughly characterize the volatile flavor compounds (VOCs) and lipids present in the breast muscle of chickens. These chickens were fed diets supplemented with 500 mg/kg curcumin (CUR) for 42 consecutive days. The findings revealed a significantly lower malondialdehyde (MDA) content in the chicken breast muscle of the CUR group compared to lower than that in the CON group (0.37 vs. 0.50; P<0.05), indicating reduced lipid oxidation. However, no significant difference in IMF content was observed between the two groups (P = 0.63). Furthermore, the flavor profiles exhibited significant variations between the groups, particularly in attributes such as green, fruity, fresh, fatty, herbal, and floral notes. Notably, VOCs like diphenyl sulfone and heptanal were identified as compounds associated with undesirable off-flavors. The lipid composition also showed significant differences between the CUR and CON groups, directly influencing the VOC profiles. The CUR group demonstrated reduced lipid oxidation and distinct volatile profiles, specifically with lower levels of the lipid oxidation-related VOCs diphenyl sulfone and heptanal. Collectively, this research establishes a theoretical foundation for modulating regulating the flavor-related volatile flavor profile of chicken meat through dietary CUR supplementation. This approach holds promise for the development of high-quality poultry products with enhanced flavor stability.