Aged male chickens experience rapid declines in spermatogenesis,
antioxidant capacity, immunity, and
hormone synthesis.
Vitamin E plays a significant role in reproduction, nervous system function, and
disease resistance in animals.
Quercetin also exerts many biological effects, such as
antioxidant ability, immunostimulation, and protection of spermatozoal plasma membranes. This study evaluated the effects of combining dietary
quercetin (Q) and
vitamin E (VE) on sperm quality,
antioxidant capacity, immunity, and expression of genes related to spermatogenesis, immunity, apoptosis, and
inflammation in aged male chickens. A total of 120 Tianfu breeder male chickens (65 wk old) were randomly allotted to 4 treatments with 3 replicates (10 birds each). The birds were fed diets containing Q (0.4g/kg), VE (0.2g/kg), Q+VE (0.4g/kg + 0.2g/kg), and a basal diet for 11 wk. At the end of the experimental period, blood, semen, liver, testes, and spleen samples were collected from 2 birds per replicate. Serum
hormones,
antioxidant parameters,
cytokines, and
immunoglobulins were evaluated; and the
mRNA expression of genes related to spermatogenesis, apoptosis, and
inflammation are determined in the testes and liver tissues. The results showed that the combination
quercetin and
vitamin E significantly promoted the sperm count and motility, as well as elevated the levels of
testosterone,
follicle-stimulating hormone, and
luteinizing hormone,
antioxidant enzymes (
Superoxide dismutase,
Glutathione, and Total
antioxidant capacity), and serum
immunoglobulins (
IgA and
IgM) in the aged male chickens; also Q+VE showed protective effects on the liver against injury. In addition, Q+VE significantly increased the expression of genes related to spermatogenesis (AR, pgk2,
Cyclin A1, and
Cyclin A2), immunity (IFN-γ and IL-2), and anti-inflammatory
cytokines (IL-10) (P < 0.05), whereas the expression of proinflammatory
cytokines (IL-1β and IL-6) was decreased (P < 0.05). Taken together, these data indicate that the combination of
quercetin and
vitamin E improved reproductive characteristics such as spermatogenesis, sperm quality, and
hormone regulation, as well as promoted
antioxidant defense, hepatoprotective capacity, and immune response in aged male chickens without any detrimental effects.