Unlocking the value of citrus waste: a sustainable feeding strategy for slow-growing chickens enhancing performance, meat traits, and profitability.

The objective of this study was to evaluate the effects of Tahiti lemon residue (TLR) as partial feed replacement in the diet on the performance, meat quality and economic viability of slow-growing chickens. A total of 250 Mesclado-lineage chickens were used across two experimental phases: a starter phase (1–28 days) and a grower-finisher phase (29–70 days). Five TLR inclusion levels (0, 1.5, 3.0, 4.5, and 6.0%) were tested with five replications of each dietary treatment. During the starter phase, body weight, weight gain, and feed conversion were significantly influenced in a linear manner (p < 0.05) as the feed was progressively replaced with increasing levels of lemon residue, with these variables deteriorating accordingly. In the grower-finisher phase, inclusion levels up to 6% did not impair performance, carcass yield, or organ development (p > 0.05), indicating a high physiological adaptability to the altered diet. Notably, higher inclusion levels (4.5–6%) enhanced (p < 0.05) meat color and aroma, likely due to the bioactive citrus compounds present in the residue. From an economic perspective, 4.5% TLR significantly reduced feed costs and maximized operating profit and profitability index for chickens sold per unit. Conversely, for birds sold by live weight, the most favorable economic outcomes were achieved with 1.5% TLR. In conclusion, Tahiti lemon residue represents a cost-effective, sustainable, and functionally active feed additive for slow-growing poultry systems. Strategic inclusion at 2% during the starter phase and 1.5% or 4.5% during the grower-finisher phase, depending on the marketing model, can enhance animal performance, product quality, and economic return without compromising bird health.