"Ration analysis" or "ration balancing" programs seem to fall in this category.
You can go to the NRC Nutrient Requirements of Horses Computer Model website and determine your horse's basic (minimum) requirements for free. No fancy graphs or bells and whistles - but the information is calculated for you in a clear, readable format. You enter your horses weight, class and activity level and the protein. When you click on "Other Nutrients", protein, DE and major mineral requirements are shown on the bottom of the page, with the trace mineral and vitamin requirements listed in the center of the page.
You can then enter "dietary supply" - either by selecting from the provided database (which is somewhat limited) or by entering information from a known hay/feed analysis. This will provide information for protein, DE and major minerals only.
The downside is this does not provide any information concerning correct mineral ratios, how to correct for competing mineral excesses or deficiencies, or identify potentially troublesome excesses (such as high iron or high manganese). To do this, you need to enlist the help of an equine nutritionist, learn how to do the math yourself (it's not really that difficult) or learn how to use the spreadsheets available either in the Equine Cushings group files or you can request them from me at no charge.*
Enter Slick & Pretty
FeedXL, a program that is initially only addressing feeding conditions in Oz, works much the same as the NRC computer model. They are using an interesting subscription concept, rather than purchasing the program. This does have the advantage of allowing for ongoing updates to their forage and feed databases, along with keeping it more affordable for an average horse owner (for a "one day" one time calculation - monthly or yearly cost begins to approach program purchase costs).
They have done a nice job on this - the "results" are displayed in clear, easy to read numerical and graph formats, using correct nomenclature.
If all we were concerned with was meeting or exceeding NRC requirements (and they're quite clear that the program's recommendations are higher than NRC), I would suggest that this online model is what we've been looking for. And this could be all many horses need. But, in our experience with metabolically challenged horses, we've learned that balance is not simply meeting/exceeding requirements, but also involves paying attention to mineral ratios.
Green is Good?
The FeedXL tour example indicates iron at 506% of requirement "... is no cause for concern..." and has an iron to copper ratio of 12:1. This could be problematic for an insulin resistant horse or a horse with inflammatory issues, as excess iron is becoming well documented as a factor in IR and inflammation. "Green" (i.e. no deficiency) is NOT good if an excess of a mineral is problematic.
It becomes fairly complicated to explain mineral ratio corrections - each correction affects other minerals which then also may need adjustment. In a computer model, this becomes a multi-step process, but not difficult for a sophisticated program to handle (my spreadsheets actually do it quite easily) but does require some interpretation to ensure recommendations remain within safe limits.
I didn't see a provision for entering your own hay analysis results, and only Australian feeds are currently in the database.
So, as slick and pretty as this program is, I don't see any real advantage over what you can get from free from the NRC model, plus a little math.
*While I do charge for consultations and assistance, I have always made the spreadsheets available at no charge for individual use. I appreciate a "donation" if you find them useful, but it is not required.