On how montmorillonite as an ingredient in animal feed functions

Abstract Mycotoxins, bacteria, heavy metals and other toxic contaminants in feed have adverse effects on the health of animal. The decontamination of feed to reduce the content of harmful substances before feeding is inevitably needed. Clay minerals are a promising effective feed additive due to their cost-effectiveness and nearly without side effects. Montmorillonite (Mt) has high adsorption for mycotoxins, bacteria, heavy metals in animal feed and body. This review made a comprehensive and critical review of how Mt as an ingredient in animal feed functions. It covers the recent understanding of removing mycotoxins, bacteria and heavy metals onto Mt and the relevant influences of Mt on animal intestinal health, growth performance and product quality. Mt as feed additive can remove mycotoxins and bacteria in feed and gastrointestinal tract of the animal by surface adsorption, electrostatic adsorption and intermolecular force. In addition, Mt can adsorb heavy metals effectively in feed by the exchangeability of interlayer cations and by the swellability due to cation hydration. Modification of Mt by metal ions, metal oxides, and organic cations can improve the adsorption efficiency of mycotoxins, bacteria, heavy metals in vitro and in vivo. Mt and its modified products as feed additive can remarkably enhance the intestinal health and growth performance of livestock, aquatic and poultry. Utilization of Mt as feed additive can effectively improve the quality of milk, egg and meat.