Study on the Effects of Supplementary Ellagic Acid on Fecal Microbial Diversity of Yili Lactating Mares

Nowadays, dairy drinks, medicines, and cosmetics made from horse milk are widely used in human life. During lactation, female livestock produce excessive oxygen free radicals as their energy demands and metabolic rates increase, which can easily lead to oxidative stress in the body. Due to the special characteristics of the mares udder, frequent stimulation of the udder and thus milk secretion is required. Therefore, prolonged frequent milking and increased energy demands and metabolic rates during lactation will exacerbate oxidative stress in the organism, which will affect the health of the mares organism and reduce the yield and quality of the mares milk. Ellagic acid is a natural polyphenol with multiple antioxidant and anti inflammatory effects in humans and other animals, and it also promotes the homeostasis of intestinal microbiota. This experiment aimed to investigate the potential effects of supplemental EA on fecal microbial diversity in lactating Yili mares. The experiment was conducted from June to September 2022 at the Kudeer Ranch, Zhaosu County, Ili Kazak Autonomous Prefecture, Xinjiang (China). In this study, 18 lactating Yili mares with foals were selected from a larger group of 50 lactating Yili mares grazing at Kudeer ranch, aged 9 to 11 years, with similar parity (5 to 6 fetal), foaled in May (First foal born May 7, last foal born May 13) and had been lactating for 30 d. 18 lactating Yili mares were randomly divided into 3 groups, 6 in each group, which were the control group (CON, control group mares did not do any treatment, not supplemented with EA), EA 15 group (each mare was supplemented with EA 15 mg kg BW per day), EA 30 group (each mare was supplemented with EA 30 mg kg BW per day). The experiment began when the mares had been lactating for 30 days (i.e., day 0 of the experiment) and was a 90 day supplementary feeding trial. On day 30 of the experiment, these beneficial effects were maximized at a dose of 15 mg kg EA supplementation, and the gut microbial composition in the CON and EA15 groups was assessed. EA supplementation increased the relative abundance of Actinobacteriota, Verrucomicrobiota, Christensenellaceae, Coriobacteriales Incertae Sedis, Christensenellaceae R 7 group and Phoenicibacter in the feces of lactating mares, while simultaneously decreasing the relative abundance of Proteobacteria, Moraxellaceae, and Acinetobacter. Supplementation with EA can modify the composition of the fecal microflora in lactating Yili mares.