Following is an experiment on rice mill feed in the Journal of Animal Science, J. Animal Sci. 2004, pages 2193-2199.
Mill feed is a combination of hulls and bran in approximately two-thirds, one-third ratio. There is little work that from the United States on this mixture. There is a considerable amount of work on rice straw.
There appears to be a large amount of work from Louisiana and the southeast United States from the 1960s and 1970s. There is also a large amount of research from Asia.
Milled rice appears to work okay at up to 5 percent in finishing diets, and perhaps much greater concentrations in growing diets. The application will depend on your specific scenario and what you want to replace.
Most of the nutritional value appears to be in the bran based on this work. Get this feed source analyzed for -- fiber (NDF and ADF), fat content, protein, and ash or mineral content -- would be useful to help with decision-making. Of course, cost is also an issue to compare to what you want to replace.
