Causes of variation in xylanase research can include factors such as enzyme source,
amount of enzyme used, ingredient variety, environment under which the ingredient was grown,
stored, and processed, the age of the animal, interaction with other dietary ingredients, and health
status (Bedford and Schulze; 1998). Furthermore, while the underlying structure of most xylans
is similar, in practice the variety is enormous due to differences in xylan backbone structural size
and types and degrees of substitutions from the xylan backbone