This study investigated the effects of the in ovo injection of luteoloside on broiler chickens. A total of 160 eggs were divided into four groups and injected on day 14 of incubation with 0, 10, 25, or 100 nmol of luteoloside, with these treatments designated as the C, L, M, and H groups, respectively. The results showed that the luteoloside injection did not significantly affect hatchability, live weight, carcass percentage, or organ indices at 1 or 7 days post-hatch. However, the chemical analysis of the serum showed that the malondialdehyde level in the H group was significantly lower than that in the C, L, and M groups at day 7. In contrast, the total superoxide dismutase activity in the M and H groups was significantly higher than that in the C and L groups. Gene expression analysis indicated that on day 1, the M and H groups showed significant upregulation of peroxisome proliferator-activated receptor gamma and downregulation of fatty acid synthase. The H group also had higher lipoprotein lipase and leptin expression. On day 7, the H group exhibited the highest lipoprotein lipase expression, while insulin-like growth factor 2 expression was significantly higher in all luteoloside-injected groups compared to the control. In conclusion, in ovo injection of luteoloside had no significant impact on growth performance but effectively alleviated oxidative stress, reduced oxidative damage, and markedly influenced the expression of key genes in the liver.

(Submitted 27 February 2026; Accepted 19 August 2026; Published 16 September 2026)