This study aimed to investigate the supplemental effects of fermented pine (Pinus densiflora) needle extract (FPNE) in laying hen diets on productive performance, egg quality, and serum lipid metabolites. A total of 108 40-week-old Hy-line brown laying hens were randomly assigned to one of the three dietary treatment groups: (1) basal diet + 0 mL FPNE/kg diet (CON), (2) basal diet + 2.5 mL FPNE/kg diet (T1), or (3) basal diet + 5 mL FPNE/kg diet (T2) for 6 weeks. Each group consisted of four replicates of nine hens each. Feed and water provided ad libitum. Results showed that dietary supplementation of FPNE increased egg production percentage (linear, p < 0.01 and quadratic, p < 0.05), egg mass (linear, p < 0.05), and feed intake (linear, p < 0.05) during the entire experimental period. In addition, dietary inclusion of FPNE significantly increased the eggshell color (linear, p < 0.01), egg yolk color (quadratic, p < 0.01), and eggshell breaking strength (linear, p < 0.05 and quadratic, p < 0.05) while the Haugh unit decreased (quadratic, p < 0.05). However, serum lipid profile did not differ among the dietary treatments (p > 0.05). Notably, antioxidant activity of egg yolk was improved by significantly decreasing the malondialdehyde content in egg yolks after 6 weeks of storage (linear, p < 0.001 and quadratic, p < 0.05). In summary, dietary inclusion of FPNE could improve laying performance and the antioxidant capacity of eggs.
Keywords: antioxidant capacity; egg production; laying hen; phytogenic feed additive.