Kaolin, bentonite, and zeolites as feed supplements

for animals: health advantages and risks

M. T􀑟􀑐􀑘􀑜􀑣􀑎, L. M􀑎􀑡􀑙􀑜􀑣􀑎, L. D􀑣􀑜􀑟􀑠􀑘􀑎, I. P􀑎􀑣􀑙􀑖􀑘

Veterinary Research Institute, Brno, Czech Republic

ABSTRACT: Feeding kaolin as a supplement to pigs for prevention of diarrheal diseases has been introduced into

some farms in the Czech Republic. Peat was used in the 1990s for a similar purpose; however, most farmers ceased

feeding peat as a supplement because of its frequent contamination with conditionally pathogenic mycobacteria, esp.

with Mycobacterium avium subsp. hominissuis. The aim of the present paper is to review available literature from the

standpoint of the advantages and disadvantages related to feeding kaolin as a supplement to animals. Its positive

effects exerted through the diet primarily consist in its adsorbent capability which may be useful for detoxification

of the organism and for prevention of diarrheal diseases in pigs. Because the mechanism of action of kaolin fed

as a supplement is unknown, a risk related to its potential interactions with other nutrient compounds of the diet

exists. Therefore, it is necessary to investigate the effectiveness and safety of feeding kaolin in detail with regard

to the health status and performance of each farm animal species. The disadvantage of kaolin use is its potential

toxicity, provided it has been mined from the environment with natural or anthropogenic occurrence of toxic compounds.

Another risk factor is a potential contamination of originally sterile kaolin with conditionally pathogenic

mycobacteria from surface water, dust, soil, and other constituents of the environment in the mines during kaolin

extraction, processing and storage.