Understanding functional fibers and their distinct roles

Animal Nutrition Views

Ioannis Mavromichalis, Ph.D., gives his views on poultry, pig and dairy nutrition based on his experience as a nutrition consultant with clients around the world.

The use of functional fiber sources in pig and poultry diets is gaining momentum, and as I have already mentioned, this is a topic that I am following very closely. Surprisingly, many nutrition professionals remain unclear how to use, or rather select, the right type of fiber. As it turns out, not all fiber sources are the same as their distinct profile make them more suitable than others for specific tasks. Let’s examine these in a bit more detail.

  • Fibers that attract and hold water are required when the diet composition is causing mild secretory diarrhea (too much lactose, sucrose, salt, sulfur or ash). A fiber source with a high water binding capacity is needed here to absorb the excess luminal moisture. Care should be taken, however, not to overdo it (or select a very rapidly expanding fiber source) because this can limit feed intake in animals that are must be consuming high levels of feed.
  • Fibers that cause a laxative effect (by stimulating the gut neural system) and help against constipation. Such fibers are required in diets for animals fed on a limited scheme or are confined. Such fibers are usually high in silica, and (or) are used in very coarse form. Feeding such fibers to young animals is not recommended.
  • Fibers that promote gut health by feeding innate beneficial bacteria. Here, the type of target bacteria and the fiber source used as a substrate for growth must be matched carefully. This is perhaps the most well-marketed type of fiber, but it is not suitable for other sources. For example, pectins that belong to this group are not the preferred source to prevent constipation, where other less digestible fibers are recommended.

Understanding that not all fibers are the same can prevent disappointment when the wrong source of fiber is used for the wrong reason.