Rice Bran Part 2: Extruded Rice Bran Can Help Replace Antibiotics in Animal Diets
I recently discussed the results of a study on our blog, and I reported the following:
- Extruded rice bran can be used to help improve performance in antibiotic-free nursery pig diets.
- Using my price estimations, 10% extruded rice bran, when substituted for some corn and solvent-extracted soybean meal, nursery pig diets were less expensive.
So, all of this begs the question – how does extruded rice bran work when included in the diet?
We typically speak of improved digestibility with properly-done extrusion, especially with extruded soy meals versus other ingredients (see here, here, and here).
However, in this study, digestibility of dry matter (basically everything except moisture) was measured, and the data below was reported:
The use of antibiotics and/or extruded rice bran in nursery pig diets did not affect digestibility. So, what was the mode of action? The researchers reported data from tests on various gut samples to characterize what was happening in the intestine. And, the data led them in one main direction – changes in bacterial populations within the intestine:
This is most of the data on gut bacteria reported in the study. You can clearly see that the use of antibiotics reduced populations of beneficial bacteria, while extruded rice bran increased these populations. Antibiotics, after all, are used to kill bacteria, so these findings are not surprising. What is surprising is that extruded rice bran seems to function as a prebiotic fiber.
The role that gut bacteria play in overall health is complex and only beginning to be understood, but any ingredient that can increase bacterial populations shown to do good things (see here and here) should be used – especially as alternatives to antibiotics are being sought for animal production. And, especially if they can be shown to improve feed efficiency and reduce feed costs, as I discussed in the first part of this blog.
