Influence of Dietary Fiber on Gut Microbiota and Health in Ruminants
Year: 2026
Type: article
Abstract: Dietary fiber is a key nutritional factor influencing rumen fermentation, microbial diversity, digestive stability, and growth performance in ruminants. Inadequate fiber intake may disturb ruminal pH, impair microbial balance, and increase gastrointestinal health problems. To evaluate the influence of different dietary fiber levels on growth performance, rumen fermentation, gut microbiota composition, Objective: and health-related outcomes in growing ruminants. Methods: A controlled-feeding parallel-group experimental trial was conducted at the University of Agriculture, Faisalabad, Punjab, Pakistan, from August 2025 to February 2026. Thirty clinically healthy growing lambs were randomly allocated into three dietary groups: low-fiber (LF), moderate-fiber (MF), and high-fiber (HF), with 10 animals in each group. Animals were maintained under similar housing and management conditions and received isoenergetic and isonitrogenous diets differing mainly in fiber content. The trial lasted eight weeks after acclimatization. Growth outcomes included initial body weight, final body weight, average daily gain, and feed intake. Rumen pH, Shannon diversity index, relative abundance of Lactobacillus, Bacteroidetes, and Firmicutes, fecal score, health score, and diarrhea incidence were also assessed. Data were analyzed using SPSS, with p < 0.05 considered statistically significant. Results: Initial body weight was comparable among groups (p = 0.988). Final body weight, average daily gain, and feed intake were significantly higher in the MF and HF groups compared with the LF group (p < 0.001). Rumen pH increased progressively from LF to HF groups, indicating improved fermentation stability. Microbial diversity was also higher in the MF and HF groups, with increased Lactobacillus and Bacteroidetes abundance and reduced Firmicutes abundance (p < 0.001). Health outcomes improved with increasing fiber levels, as fecal score decreased, health score increased, and diarrhea occurred only in the LF group (60%) compared with 0% in both MF and HF groups (p = 0.001). Conclusion: Moderate to high dietary fiber inclusion improved growth performance, rumen pH stability, microbial diversity, fecal consistency, and overall health in growing ruminants. These findings suggest that balanced dietary fiber supplementation may support better rumen function and reduce gastrointestinal disturbances under controlled feeding conditions.
Language: English
Subfield: Agronomy and Crop Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: diamond
OpenAlex ID: W7160900534