High Weeds and Goats

We have about 3 acres of land besides the 3/4 acre that our home and lawns sit on.
Unfortunately, we do not have water rights to our land and we only have a well big enough to water our yard and supply our home with the water that we need.
The result of this is that we can sprinkle small areas of our field that are close to the yard and the rest grows on it's own. We have planted pasture grass seed, a disaster filled experience on the back of a 4 wheeler that I do not want to try again. Anyway, some of the grass has come up but mostly weeds have filled the field.
Waist high weeds have filled the field. Lots of weeds have filled the field.
We are boarding 2 beautiful horses who eat the grass. But not the weeds that fill the field.
So, we are going to borrow about 15 goats. We have done this in the past and it was very successful until we realized that the goats poop what they eat.......including the seeds of the weeds that fill the field!!
Anyway the weeds are high and the goats will come and eat the weeds and then they will poop the seeds and next spring the weeds will fill the field again.
Ah, the circle of life goes on.