Dietary broccoli stem-and-leaf meal in laying hens: Effects on production performance, egg quality, antioxidant...

This study examined the potential of broccoli stems and leaves meal (BSLM) as a functional feed ingredient for aged laying hens, focusing on its effects on production performance, egg quality, antioxidant status, gut immunity, and cecal microbiota during the late-laying phase. A 12-week trial involved 270 Hy-Line Brown hens (66 weeks old), divided into three dietary groups: control (basal diet), 0.5 % BSLM, and 1 % BSLM, with six replicates of 15 hens each. Production and egg quality parameters were presented across three age-defined phases: 66-69 weeks (Weeks 1-4), 70-73 weeks (Weeks 5-8), and 74-77 weeks (Weeks 9-12), as well as over the entire 12-week experimental period. Results showed that dietary BSLM increased egg production rates (P < 0.05) at all time points, with the 1 % BSLM group showing the highest values, while egg weight remained significantly higher in the control group during weeks 9-12 (P < 0.05). Feed intake remained unchanged, whereas the overall effect showed that both BSLM inclusion levels improved the feed-to-egg ratio compared to the control (P < 0.05). Eggshell thickness was greater in the 0.5 % BSLM group, while the 1 % BSLM group demonstrated superior albumen height, Haugh unit, and yolk colour (P < 0.05). Serum analysis indicated significant dietary effects (P < 0.05); 0.5 % BSLM reduced glucose and alkaline phosphatase levels, whereas 1 % BSLM lowered malondialdehyde levels, a marker of oxidative stress. Jejunal mucosal cytokines suggested a shift towards anti-inflammatory profiles in BSLM-fed hens, with the 1 % BSLM group exhibiting increased IL-2 and decreased IL-1β, IL-6, and IL-10 compared to the control (P < 0.05). Cecal microbiota analysis via 16S rRNA sequencing revealed that BSLM selectively enriched short-chain fatty acid-producing genera (Ruminococcaceae, Lachnospiraceae) and Parabacteroides, which correlated with increased IL-10 levels, indicating microbiota-driven anti-inflammatory effects. Overall, BSLM supplementation at 1 % inclusion level significantly improved production performance, egg quality, antioxidant capacity, and gut immune function, while positively modulating the cecal microbiota in aged laying hens. These findings suggest BSLM as a promising dietary strategy to enhance sustainability and productivity in poultry systems.