Most farmers think the cheapest feed is what's the cheapest price or what their dad and grandpa fed to their livestock which is incorrect. You need to figure all your nutrients on a dm basis. Use of a DM basis is critical because removing moisture allows producers to compare nutrient concentrations of feeds with varying moisture content. The ones I like to look at are Protein, Fat, TDN (Total Digestible Nutrients, which is one measure of energy concentration in feed). Below are some comparisons with rough prices for 2022. Prices will be different depending where you are located so if you need help determining the cheapest commodities I can help you figure that out.
As you can see in this comparison the cheapest CP is WDG being only .14/Ib of protein. Soyhull Pellets was the highest source of protein being 1.15/Ib of Protein. The Cheapest Fat was Wet Germ at .11/Ib of Fat and the highest was Soyhull Pellets at $4.71/Ib of protein.
Here's another comparison of corn and hominy. With the prices today it seems hominy is the better buy.
Here is a comparison of roughage feeds. As you can see in this comparison for 2022 prices Gin Trash and Rye Haylage seem to be the cheapest sources of CP. With hay being hard to find and $70-$80 a bale gin trash is a good option to help save a little money.
Liquid Feed Comparison
Here is a comparison between liquid feeds. QLF and Mix 30 are excellent feeds when you can't take a 25 ton load but as you can see corn syrup is extremely cheaper then both of them.
Saving Money on Commodities
I hope this helps show how to compare feeds when determining which are the cheapest commodities accordingly. With the commodity prices in 2022 you need to price all commodities as frequently as possible.