Published online by Cambridge University Press: 14 July 2025

The aim of the study was to evaluate calcium anacardate (CAn), associated or not with citric acid (CAc) in laying hen diets on performance, egg quality, serum biochemical profile, serum lipid peroxidation (TBARS) and catalase (CAT) in reproductive tissue. A total of 432 laying hens from 63 to 74 weeks of age, were distributed in nine diets: Control; 0.25% CAn; 0.25% of CAn associated with 0.25% CAc; 0.50% CAn; 0.50% CAn associated with 0.25% CAc; 0.50% CAn associated with 0.50% CAc; 0.75% of CAn; 0.75% CAn associated with 0.25% CAc; 0.75% CAn associated with 0.50% CAc. There was no effect of CAn or CAc on laying hen performance. Yolk colour showed greater pigmentation for 0.75% CAn and its associations with CAc (0.25% and 0.50%). Lower egg yolk oxidation was observed for an isolated dose of 0.75% CAn. Higher values of TBARs were observed in eggs from birds fed control diet; 0.25% CAn; 0.50% CAn associated with 25% CAc and 0.75% CAn associated with 0.25 and 0.50% CAc. Dietary inclusion of CAn (0.75%) and its association with CAc (0.50% CAn with 0.50 CAc) for late-phase laying hens reduce serum peroxidation. CAn from 0.50% associated with CAc increases catalase in magnum. The addition of 0.75% CAn increases yolk pigmentation, reduces lipid oxidation in the yolk and blood plasma and increases CAT activity in the magnum in late-stage laying hens. These benefits can also be obtained with the combination of 0.50% CAn and 0.50% CAc.