Effects of dietary palygorskite supplementation on production performance and reproductive function of laying hens

Oxidative stress reduces the production performance of laying hens by impairing their reproductive system. Palygorskite ( Pal ), a fibrous clay mineral, exhibits antioxidant properties; however, its effects on production performance and reproductive function of laying hens remain unknown. The aim of this study was to determine the effects of dietary Pal supplementation on production performance and reproductive function of laying hens. A total of 256 laying hens were divided into two groups: the control group, which was fed a basal diet, and the Pal group, which was fed a basal diet supplemented with Pal. The production performance, gonadal development, reproductive hormone levels, antioxidant capacity, and metabolomic and transcriptome profiles of the two groups were compared. Compared to those in the control group, the average daily egg production, eggshell thickness, oviduct weight, oviduct index, and the levels of luteinizing hormone, progesterone, and follicle-stimulating hormone were significantly higher in the Pal group. Following Pal treatment, the total antioxidant capacity and total superoxide dismutase activities as well as glutathione levels in the serum increased, whereas malondialdehyde levels in the ovary and eggshell gland decreased. Moreover, upregulated expression levels of antioxidant genes, such as catalase, superoxide dismutase 1, superoxide dismutase 2, and NAD(P)H quinone dehydrogenase 1, as well as downregulated expression levels of pro-inflammatory factors, such as tumor necrosis factor-alpha were observed following Pal supplementation. Furthermore, metabolomics analysis revealed that the levels of metabolites such as ritonavir, nicotinate riboside, and inosine were upregulated in the Pal group. Similarly, transcriptome profiling revealed that the expression levels of genes involved in the anti-inflammatory response, follicular development, egg production, and eggshell quality were upregulated in the Pal group. These findings indicated that dietary Pal supplementation enhanced the production performance, antioxidant capacity, anti-inflammatory response, and reproductive function of laying hens. Therefore, these findings lay the foundation for the development of strategies and protocols for the inclusion of Pal in the diet of laying hens.