Impacts of hybrid rye and fiber level in the diet of pregnant and early lactation sows on the reproductive performance and fecal microbiota of sows and their piglets

This study aimed to evaluate the effects of dietary fiber level and hybrid rye content on sow reproductive performance and microbiota as well as piglet growth and microbiota. A total of 245 sows were assigned to one of four diets from breeding until the first week of lactation: Control (10% neutral detergent fiber (NDF)); Fiber (20% NDF); Rye30 (30% rye, 20% NDF); Rye60 (60% rye, 20% NDF). Fecal samples were taken 7 days post-farrowing from sows and three piglets per litter. Reproductive performance was mostly unaffected ( P > 0.10), except for lower stillbirth rates in Fiber and Rye30 and reduced mortality from birth to 24 h after farrowing in Rye30 but higher in Fiber ( P < 0.05). Litter gain during lactation showed no difference between groups. Microbiota analysis revealed lower alpha diversity in Control piglets compared to other groups ( P < 0.05), but alpha diversity of sow microbiota was not affected by treatments. Sows and piglets in Fiber, Rye30, and Rye60 treatments showed higher Prevotellaceae abundance in fecal samples ( P < 0.05). In conclusion, Fiber or Rye30 treatments slightly affected reproductive performance. The Fiber, Rye30, and Rye60 treatments influenced sow microbiota and enhanced establishment in piglets, highlighting the potential of dietary fiber and hybrid rye for microbiota modulation.