The Importance of Fiber and Microbiota in Swine Nutrition

By Pierre Lebreton, Swine and Poultry Category Manager at Lallemand Animal Nutrition

Fiber plays a crucial role in pig nutrition, aiding in digestion, participating in gut health maintenance, and contributing to overall welfare. However, the type of fiber matters significantly.

The ability of pigs to digest dietary fiber depends on their hindgut microbiota. Bacteria are essential for breaking down cellulose, as animal digestive enzymes cannot digest most complex carbohydrates and plant polysaccharides. These carbohydrates and plant polysaccharides are degraded by specific microbial populations. They are fermented into short-chain fatty acids (SCFAs), including acetate, propionate and butyrate, which are absorbed and utilized as an energy source by large intestine epithelial cells, greatly improving feed utilization rates.

Figure 1: Fiber fermentation

There are different methods to characterize dietary fiber. In pig nutrition, we primarily deal with two types of dietary fiber: soluble and insoluble, each playing a unique role in pig digestion. Soluble dietary fiber attracts water and turns to gel during digestion, slowing down the process. This helps regulate nutrient absorption and can decrease physical activity after feeding. However, the impact of soluble fiber on digesta viscosity is considered a key factor regarding the risk of post-weaning diarrhea and promoting E. coli growth ¹.

However,  excessive soluble fiber can favor pathogen development, leading to health issues and negatively impacting the growth performance of pigs.

On the other hand, insoluble dietary fiber does not dissolve in water. It adds bulk to the diet and can help reduce the risk of digestive problems such as constipation. One of the key benefits of insoluble fermentable fiber is the production of SCFAs during fermentation by specific microbiota in the hindgut. SCFAs—such as acetate, propionate, and butyrate—play an important role in gut health. They constitute slow energy release elements, improving glucose metabolism and appetite regulation in pigs.

Figure 2: Kinetics of fiber fermentation

Balancing the amount of both soluble and insoluble fiber in pig feed is crucial. One way to support this process is with LEVUCELL SB, a specific probiotic live yeast dedicated to monogastric animals. It stimulates and protects Fibrobacteres, one of the most important microbial populations responsible for fiber fermentation. Additionally, YELA PROSECURE, a specifically designed hydrolyzed yeast, provides a source of insoluble and functional fiber, offering the microbiota the ‘fuel’ they need to perform their job effectively.

By understanding and supporting the fiber fermentation process, we can support pig health and improve productivity.

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¹Canibe N, Højberg O, Kongsted H, Vodolazska D, Lauridsen C, Nielsen TS, Schönherz AA. Review on Preventive Measures to Reduce Post-Weaning Diarrhoea in Piglets. Animals (Basel). 2022 Sep 27;12(19):2585. doi: 10.3390/ani12192585. PMID: 36230326; PMCID: PMC9558551.