Managing cover crops profitably 3rd edition is any excellent book, that anyone serious about cover crops should at least read once. Take the time and look at this section of the book as it talks about brassicas and mustards as a whole.
Do you want to break up your current crop rotation by adding another crop species into the system? This link will provide you information on a number of row crops that historically where grown wide spread, that you may have not considered before. Each species link serves information on the history/use, key basic production/storage instruction and potential yield/result. Though this material is over 25 years old, it provides the background needed to determine the possibility of adding this crop into your operation.
Feedipedia is truly one of the best online encyclopedia's of feed values of just about any utilized species or by-products in the world! From this websites VAST range of feed products you will be provided a description/recommendation, tables of common feed values and an extensive reference sheets for further investigating. Almost all the information provided is excerpts from published research articles, adding to the creditability of the information. Many feed products will have information on the uses for large ruminates such as cattle and many times provide information on other species including monogastric or small ruminate livestock. Utilized by hundreds of thousands of individuals around the world, I would highly encourage you to be the next!
University of Georgia Extension has published an excellent article explaining the Relative Forage Quality (RFQ) test. This simple read explains how the forage score is determined, what the results mean and this forages is suitable to feed various animals. There are a number of well made charts/graphs explaining the result scores and how various forages traditionally will score.
SmartMix is the best cover crop decision making tool in the industry. Get ratings for species suitability based on goals, planting dates, geographic location C:N ratio, nitrogen fixation, grazing suitability, frost tolerance and more.