Different forms of selenium improve laying performance and ovarian antioxidant capacity: regulating gut microbiota and ovarian metabolism

Compared with the sodium selenite (SeS), nano-selenium (SeN), selenomethionine (SeM), and selenium-enriched yeasts (SeY), as novel selenium sources, are increasingly popular in laying hen production. This study was aimed to investigate the advantages and mechanism of SeN, SeM, and SeY compared with SeS on laying performance and antioxidant capacity of ovary in laying hens. A total of 288 24-week-old Jingfen No.1 laying hens were randomly divided into 4 groups: SeS group, SeN group, SeM group, SeY group. The additive dosage of Se was 0.4 mg/kg. Each group contained 6 replications and each replication contained 12 laying hens. The results showed that SeN, SeM, and SeY increased the laying rate in laying hens compared with SeS, and SeM and SeY had a higher egg selenium conversion rate. SeN, SeM, and SeY significantly increased the levels of T-AOC and SOD, and increased the relative mRNA expression levels of SOD1, SOD2, and GPX2. SeS significantly regulated PPAR signaling pathway and fatty acid elongation of ovary, and the relative abundances of Solobacterium, Monoglobus, Coprobacter, Negativibacillus, Prevotella, and Treponema of gut microbiota. SeM significantly regulated linoleic acid metabolism, glycerophospholipid metabolism, choline metabolism in cancer of ovary, and the relative abundances of Prevotella, Methanocorpusculum, Peptococcus, and Treponema of gut microbiota. SeY significantly regulated biosynthesis of unsaturated fatty acids, fatty acid biosynthesis, glycerophospholipid metabolism, and linoleic acid metabolism of ovary, and the relative abundances of Akkermansia, Olsenella, and Romboutsia of gut microbiota. Meanwhile, the gut microbiota and differential metabolites of ovary were closely related to laying performance and antioxidant capacity of ovary. Therefore, 0.4 mg/kg SeN, SeM, and SeY showed an advantage on improving laying rate, ovary function, and gut microbiota in laying hens, and they could be potential additives using in laying hen production.