Many of the feedlots are contracted with mulch companies that sell it as mulch after they mix it with other components...such as tree bark, etc.
Could be. What I know our manure is “ organically” spread by the cows themselves in the pastures that we would plant next year( or the year after) when we rotate the crops.
We do clean out the stables occasionally and let it “ sweeten” until the compost is ready to spread on our vegetable garden.
But replace fertilizer? No way.