I am not having a go or criticising you - but i do have an anxiety about this stuff growing from some personal experience. I shall watch your thread on this with interest as i thought that cutting it down, presumably akin to grazing, caused an increase in vigour. Attempting to dig it up certainly has that effect. Having said that my mother has been snapping bits of what she called 'ornamental bamboo' in her garden and it has not spread very much further.
If your experience of grazing it with hens and goats works then i for one will be interested but presumably you dont want to erradicate it but actively cultivate it. If you can find a value in this plant that too would be interesting. I do know that the presence of this on land has to be disclosed if you are selling and a buyer would have real difficulties in raising finance to buy (unless, perhaps, there was a clear management to erradication proramme in place .