This is an interesting idea. but i think no mater what i do people would still do the tank holding for reset. the monthly stipend is for dairies that are not that active to always be able to afford feed and one or two items. i'll consider something like this though.
I propose that instead of the flat rate of 1000 moolah at the start of each month, dairies get a stipend based on how much milk they have at reset with a minimum of 1000 moolah. Maybe 5 moolah for each seed left over at reset even. This way, dairies are not feeling stressed about delivering all of their milk and not feeling like all the milk and seed made was a wasted effort.