Abstract:
Besides their excellent cation exchange capability, clays have unique physical and chemical properties that make them ideal as animal feed additives. The global use of various clays and commercial derivatives as feed additives has sparked interest in using Vertisols in cattle feedlot rations. The review’s ultimate goal was to assess the potential efficacy of bentonite/smectite clays as feed additives in beef feedlot rations. This review included a mini survey on Zimbabwean feed companies use of clay based feed additives. Thematic analysis
was used to pick relevant research from a broad pool of literature. Notably, none of the research examined the Chisumbanje Vertisol, but rather its near relative, bentonite. The basis for the review was that bentonite studies could potentially forecast Chisumbanje Vertisol's potential as a feed additive. Zimbabwean livestock feed manufacturers are not using clay based feed additives. However, inclusion of clay in diets of cows result in a higher rumen pH, a scenario ideal for the rumen microflora. Smectite clay supplementation reduced rumen
ammonium-N concentrations before and three hours after feeding. Addition of 12 grams dolomite and bentonite per head/day to sheep feeds improved (p<0.05) total volatile fatty acids (TVFAs) in the rumen. Smectite clays can be used to improve rumen pH, reduce bloat, bind aflatoxins, and increase volatile fatty acid percentage. The researchers suggest characterising Chisumbanje Vertisols as binders and rumen buffers.
