..........If , the owner of the cow\calf operation hasn't worked to continually improve the pasture(s) then he must be feeding the animals from his own hay field and\or buying hay from an independent source, either way it is expensive ! If , the pasture rental is cheap , OR TOO CHEAP(?) , then maybe he can afford to purchase hay for his animals .
..........Maybe it's time to re examine the owner\renter agreement and let him find another property for his cows , OR motivate him to renovate the grazing , which he may or may not want to do . Sounds like he maybe a 'friend' of the family or a relative who , is taking a little too much for granted . 400 acres may or may not be an adequate sized property for a 50 c\c operation , depending upon soil conditions . , fordy