Dietary Aronia melanocarpa supplementation inhibit the oxidative stress caused by aging in ovary of late laying hens from 59 to 67 weeks of age

Abstract

The ageing of laying hens’ ovaries in the late laying period leads to oxidative stress, which ultimately results in the decrease of laying performance. Thus, we investigated Aronia melanocarpa (AM) as a potent antioxidant to improve ovarian senescence in the late laying hens through antioxidant pathway, thereby improving egg production performance. A total of 480 Hy-line brown laying hens aged 59 wks (60–67 wks) were randomly divided into CON, LAM, MAM and HAM groups and fed 0, 1, 4 and 7% AM, respectively. The results showed that compared with the CON group, the MAM group could significantly improve the laying rate and reduce the feed egg ratio at 64–67 weeks of age (p < 0.05). The AM groups increased the eggshell thickness, while HAM group significantly reduced yolk colour (p < 0.05). The MAM and HAM groups significantly increased egg white weight (p < 0.05). Meanwhile, the ovarian index in MAM group was increased, and the proteins related to proliferation and anti-apoptosis of ovarian cells (PCNA and Bcl2/Bax) were enhanced in all AM groups (p < 0.05). Compared with the CON group, all AM groups could significantly reduce the malondialdehyde (MDA) content of ovary and yolk, and increase the activities of glutathione peroxidase (GSH-Px) and total superoxide dismutase (T-SOD) in yolk. LAM and MAM groups significantly increased ovarian GSH-Px activity, but only the MAM group significantly increased ovarian T-SOD activity. The expression levels of Nuclear factor E2-related factor 2 (Nrf2), haem oxygenase 1 (HO-1) and glutathione peroxidase 1 (GPX1) genes and proteins were significantly increased in all AM groups, while the expression levels of kelch ECH – associated protein 1 (Keap1) genes and proteins were decreased. The expressions of NAD(P)H: quinone oxidoreductase 1 (NQO1) and superoxide dismutase 1 (SOD1) genes were significantly increased in all AM groups, but the expression of SOD1 protein was significantly increased in MAM group and NQO1 protein was significantly increased in HAM group. Antioxidant enzyme protein expressions in the ovary showed positive associations with antioxidant enzyme activity. Furthermore, the expression of Nrf2 protein in the ovary was inversely connected with Keap1 protein expression and favourably correlated with antioxidant protein expressions. In summary, dietary AM supplementation activates the Keap1/Nrf2 antioxidant pathway to inhibit the oxidative stress caused by ageing in ovary of late laying hens. Taken together, the results of the study suggest that the inclusion of 4% AM was able to better improve the laying performance and antioxidant capacity of laying hens in the late laying period.

Keywords

• aronia melanocarpa
• late laying hens
• antioxidant pathway
• oxidative stress