Frontiers in Veterinary Science · 16 authors, 5 centres
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Adding 1.25 or 2.50 g/kg of Litsea cubeba fruit extract to broiler feed did not significantly affect growth or slaughter performance but improved breast meat color and increased levels of certain unsaturated fatty acids (e.g., arachidonate, docosapentaenoate) and homocysteine. These changes were associated with shifts in cecal microbiota, suggesting the extract may enhance meat sensory and nutritional quality as a natural feed additive.
**Background:** White-feather broilers dominate global poultry meat production due to rapid growth and high feed efficiency. Antibiotic use in feed raises concerns about residues and resistance, prompting interest in natural alternatives. Litsea cubeba (Lour.) Pers., a traditional Chinese medicinal plant, contains bioactive compounds with antioxidant and anti-inflammatory properties, but its potential as a broiler feed additive had not been studied. This research aimed to evaluate the effects of L. cubeba fruit extract on growth performance, meat quality, and gut microbiota in white-feather broilers.
**Methods:** Forty-eight 3-day-old AA+ hybrid white-feather broilers (initial weight ~37 g) were randomly assigned to three groups (n=16 each): control (CON, basal diet), low-dose (L, basal diet + 1.25 g/kg L. cubeba extract), and high-dose (H, basal diet + 2.50 g/kg extract). The extract was prepared by aqueous extraction of pulverized fruit (1:10 ratio, 90°C, 30 min), filtered, and spray-dried (yield 6.04%). The experiment lasted 35 days (7–42 days of age). Growth performance (ADG, ADFI, F/G) was recorded weekly. At day 42, five broilers per group were slaughtered; breast muscle was analyzed for slaughter performance (dressing, semi-eviscerated, eviscerated percentages), meat quality (pH at 45 min and 24 h, color L*a*b*, shear force, cooking loss, drip loss, moisture, ash, crude protein, crude fat), amino acids (UPLC-MS), and fatty acids (GC-MS). Cecal contents were collected for 16S rRNA gene sequencing (V3–V4 region) to assess microbiota composition. Statistical analyses included one-way ANOVA with Tukey's post-hoc test, Kruskal-Wallis test, and correlation analyses.
**Key Results:** Growth performance: No significant differences in final body weight, ADG, ADFI, or F/G among groups during early (7–21 d) or late (22–42 d) stages (all p>0.05). Slaughter performance: Dressing, semi-eviscerated, and eviscerated percentages did not differ significantly (p>0.05). Meat quality: At 45 min post-mortem, L* and b* values differed significantly (p<0.01) but without clear dose trends; at 24 h, a*, b*, and L* values all showed significant differences (p<0.01), with dose-dependent decreases in a* and b*. pH at 45 min was significantly lower in the high-dose group vs. control (p=0.009); pH at 24 h, drip loss, shear force, cooking loss, moisture, ash, crude protein, and crude fat showed no significant differences. Amino acids: Homocysteine (Hcy) was significantly higher in the high-dose group vs. control (p=0.04) and low-dose (p=0.01). Proline (Pro) was lower in high-dose vs. control (p=0.007) and low-dose (p=0.002). Asparagine (Asn) was lower in both high-dose (p=0.004) and low-dose (p<0.001) vs. control. Ornithine (Orn) decreased in high-dose (p=0.003) and low-dose (p<0.001) vs. control. Fatty acids: Significant increases in arachidonate (C20:4n6; p<0.001), docosatetraenoate (C22:4; p=0.001), docosapentaenoate (C22:5n6; p<0.001), and docosapentaenoate (C22:5n3; p<0.001) in extract groups vs. control. Laurate (C12:0) showed the smallest absolute increase (p<0.001). Gut microbiota: Alpha diversity (Chao1, Shannon, Goods coverage) did not differ significantly. Beta diversity (PCoA) showed separation among groups (axis 1: 13.9%, axis 2: 11% variance). LDA identified differential taxa: Parabacteroides (LDA=3.72) and GCA_900066575 (LDA=3.66) enriched in control; Ruminococcus__torques_group (LDA=4.26) and Peptococcus (LDA=3.71) in low-dose; Coprobacter (LDA=3.85) and Tyzzerella (LDA=3.74) in high-dose. Correlation analysis revealed positive associations between Alistipes, Desulfovibrio, Faecalibacterium, Colidextribacter and laurate (C12:0), and between laurate and arachidonate (C20:4n6; r=0.849, p<0.001) and docosatetraenoate (C22:4; r=0.862, p<0.001).
**Clinical Implications:** This exploratory study provides preliminary evidence that L. cubeba fruit extract can be used as a natural feed additive to improve the sensory and nutritional quality of broiler meat without compromising growth performance. The enhanced meat color and increased levels of beneficial unsaturated fatty acids (e.g., arachidonic acid, docosapentaenoic acids) may improve consumer appeal and health value. The modulation of gut microbiota, particularly genera associated with fatty acid metabolism, suggests a potential mechanism. However, the small sample size (n=16 per group, only 5 slaughtered per group) limits statistical power and generalizability. Future studies with larger sample sizes and longer durations are needed to confirm these findings and explore dose-response relationships. The study did not assess antibiotic resistance or environmental impacts, which are important for sustainability claims. Overall, L. cubeba extract shows promise as a green alternative to antibiotics in poultry feed, but further research is required before commercial application.