I understand your point about reducing animal suffering, but the picture you paint in regards to "horrific factory farms" is not quite on the money. Well at least from my experience. I live on acreage and have a small farm - we have our own chooks (chickens for those not used to Australian slang) and grow goats for meat. Our neighbors (larger properties in the range of 5000 - 20000 acres) are growing beef, lamb and running dairies. Basically It is not in the farmers interest to have his animals suffer as this leads to reduced productivity eg weight gain per day, reduced milk output or reduced or weakened wool clip. Abusing your stock directly effects your businesses bottom line and the quality of your produce and therefore most farmers i know want their animals to be as happy and healthy in the paddock as possible and not have to pump them full of antibiotics or growth accelerators. Just my two cents.

Have a small goat farm myself, goats are better browsers than grazers and tend to excel at clearning properties of weeds - Blackberry and that. Wouldnt use them for mowing though - always eat the stuff you dont want them to eat. To be honest goats are bastards with the fences either jumping over or pushing under - sheep in my experience are a easier.