Among 4 distinct additives, probiotics and butyric acid were selected as top products
Last week, I conducted a quick poll on LinkedIn. It was about the most widely used additive to replace antibiotics in broiler feeds. My network there is comprised exclusively of nutrition professionals, so the outcome is rather interesting. Here, I present the rounded and easy-to-remember results below:
- 50% probiotics, bacterial origin
- 30% butyric acid, protected
- 10% yeast, dead or alive
- 10% prebiotics, inulin or fructooligosaccharides (FOS)
The majority of poultry nutrition professionals depend on probiotics to control gut health in broilers. The available probiotics, to my knowledge, fall under two broad categories: bacillales and lactobacillales strains. The first excrete a plethora of enzymes to digest indigestible fiber reaching the hindgut and, in return, they excrete short-chain volatile fatty acids, the most important being butyric acid. The lactobacteria consume the digested fiber and produce lactic acid, which in turn lowers the digesta pH; this creates an unfavorable environment for pathogens in the gut.
Butyric acid is used preferentially as an energy source for enterocytes. It is also a powerful signal compound for the regeneration of the whole gut epithelium. For that, butyric acid must be present and active at the proximal part of the large intestine, the location of signal cells.
Yeasts are marketed quite often as probiotics, but this only increases the existing confusion about this additive. First, yeasts are not of bacterial origin and, second, they have a much broader role and mode of action. Calling yeast a probiotic is an undervaluing of this superbug. The low usage of yeast in broiler feeds may present a great marketing opportunity for suppliers or the dominance of yeast-derived mannan-oligosaccharides.
Finally, the term prebiotics refers mainly to fructans such as inulin and FOS. These are similar products, differing only in the length of the fructose chains. Fructans are a rapidly digested substrate for bacteria in the gut – the equivalent of milk given to young animals. I have always advocated the concurrent use of probiotics along with a suitable prebiotic to help the first, which are often of non-animal origin, establish themselves faster in the gut.
One question that begs for an answer is whether using one of the above additives negates or diminishes the need for the rest. For example, what if we used a large enough dosage of FOS? Would this then result in the rapid growth of beneficial local bifidus and lactobacteria, negating the need for other products?