As a nutritionist mission to increase energetic value of grains for animal especially in major grain importer countries, this study has focused on the micronization process and reviewed relevant literature with emphasis on operational conditions and potential benefits for ruminant. Despite simplicity of the system compartments, success in this thermal technology, requires optimization of six important sub-processes. However, because of variation in size and capacity of the different system used for micronization of various grains, no conclusive operational conditions were given which means for every micronizer-flaker machine and grain an optimization is compulsory. In livestock farms and feed plants which have access to natural gas, using micronization method for processing of the seeds has at least two nutritional benefits: it reduces ruminal starch fermentation rate that may also decrease acidosis risk and second, it increases small intestine digestion of starch and protein. Cost benefit studies and evaluation of micronization of grains on milk yield and composition still need further investigations.

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