it covers everything from hogs, cattle, sugar, coffee, cotton, soybeans, corn, wheat, blah blah, blah.
These are not cyclical as a group. For instance, sugar and coffee may go up while corn and wheat prices decline. The market is built upon sector rotation (especially now with GS and god running the markets).
So DBA will likely go nowhere BUT down because of the fees. So you see Douche Bank doesn't need to do anything but set up a fund, trade a few contracts, and those that invest are guaranteed to pay the fees. They could give two shitz about putting together a fund that would be playable. If they did, they wouldn't drop everything in including the kitchen sink.
You need to find a more targeted ETF if you want ag and not DBA. You will never make any money gambling on DBA unless, by miracle, all commodities decide to turn up at the same time which does not occur except within large time cycles.