Fennel seed powder in the diet of dairy buffalo affects milk volatile organic compounds profile, antioxidant activity and <i>SCD1</i> mRNA level

The aim of this study was to assess the influence of dietary fennel seed powder (FSP) supplementation on milk nutritional characteristics and gene expression in dairy buffaloes. Twenty animals were randomly assigned to two groups (CON: control and FEN: treated with fennel seeds) fed total mixed ration. Group FEN received an additional 100 g/head/day of FSP to diet. Over a four-week period, milk yield, composition, fatty acid (FA) profile, antioxidant activity and volatile organic compounds (VOCs) were analysed, along with the gene expression related to lipid metabolism and antioxidant responses. No differences were observed on milk yield or composition. The milk from FEN group exhibited significantly higher (p &lt; 0.05) mixed FA content and C18:1 isomers and lower content (p &lt; 0.05) in de novo FA. Gene expression analysis revealed lower SCD1 mRNA levels in the treated group (p &lt; 0.05). The milk cholesterol content was significantly lower (p &lt; 0.001) in the FEN group, while antioxidant parameters demonstrated higher (p &lt; 0.001) levels of SOD, CAT, TAC and DPPH observed in treated group. The analysis of VOCs revealed higher levels (p &lt; 0.001) of fennel-derived compounds, such as limonene, fenchone, estragole and anethole, and lower (p &lt; 0.001) concentrations of acid compounds in the milk of FEN group. The findings of this study indicated that FSP has the potential to enhance the nutritional and functional properties of buffalo milk by increasing its antioxidant capacity and by modulating its FA and VOCs profiles, while maintaining the yield and cheese-making potential of milk.