Effects of dendrobium nobile polysaccharide on reproductive performance, hormone levels, antioxidant capacity, and testicular metabolism of aged roosters.

As roosters age, semen quality gradually declines, and exacerbated oxidative stress is an important contributing factor to the deterioration of their reproductive function. Dendrobium nobile Lindl. (DNL), a traditional Chinese medicine, exhibits potent antioxidant activity and plays an important role in delaying the decline of reproductive function in aging roosters; however, whether its core active component, Dendrobium nobile polysaccharide (DNP), serves as the key effective constituent remains to be verified. In this study, twenty 56-week-old male recessive white-feathered chickens (a recessive white-feathered line developed by Guizhou University) were randomly allocated to a control group (CON) and a DNP-supplemented group (DNP), with 10 birds per group, for a 60d feeding trial to investigate the effects of DNP on antioxidant capacity, hormone levels, testicular metabolism, and reproductive performance of aged roosters. The results demonstrated that, compared with the CON group, DNP supplementation improved semen quality, enhanced antioxidant capacity and serum hormone levels, and delayed testicular tissue degeneration in aged roosters. Untargeted metabolomics analysis suggested that alterations in the testicular metabolic profile of the DNP group were potentially associated with improvements in antioxidant capacity, with differential metabolites primarily enriched in amino acid biosynthesis, aminoacyl-tRNA biosynthesis, and cysteine and methionine metabolism pathways. These findings indicate that dietary DNP supplementation can effectively alleviate testicular oxidative damage and slow the decline in reproductive performance in roosters, highlighting the potential of DNP as a feed additive to enhance antioxidant capacity in breeding roosters.