Mannose-based polymers in livestock production: the glucomannan-degrading enzymes in swine and poultry feeds

Abstract

Enzymes capable of degrading mannans belong to several families, which are distinguished by their cleavage site on the polysaccharide. The best known by far is the "β-mannanase", the only one authorized as feed additive in Europe and which is specific to β-(1,4) linkages between mannose moieties. Outside the animal feed context, mannosidases, β-glucosidases, α-galactosidases, and acetyl-mannan esterases may participate, alone or in combination, in the hydrolysis of mannose polymers. Adding β-mannanase to poultry and swine feeds largely reduces the anti-nutritional effects, especially inflammatory, of β-mannans. The nutrients sparing can then be directly valued in feed formulation by deconcentrating the diet. Beyond the cost saving made, improvements in performance (feed consumption ratio in particular) and digestive health are very often observed.