Yes, I'm with klu - animal welfare is a stronger aspect for my objection, as 'battery farming' is so unpleasant for the animals.
From what I had heard, automated milking equipment starting to be used means cows can be milked whenever they feel the need, which is probably much better for their welfare, and if it was cheaper, could overcome some of the farming dislike of the suggestions about moving the clocks to stay in line with Europe, which has apparently some benefits in reduction of accidents to road users and pedestrians.
I appreciate there will be other issues considered higher up the scale if one lives in the area.
I can imagine the issue of slurry being a major one (though I guess there may be some anaerobic digestor scheme that could cope with the 'output' of that many cows).
When I was in California in 1997 there was a man making money from taking the slurry and using worms to 'process' it into a really clean compost (from the worm casts left on top) which was then sold on to Japan.
It meant that there was no need for landfill or other methods of disposal in California, and he was more than covering his costs (he employed staff just to deal with the worm farm, and had transport costs for shipping the bags off to Japan). I think he also had some income from the Californian farmers who had no wish to have the slurry on their farms (so not all the cost was borne by the Japanese garden centres/ gardeners).
Unfortunately I've lost contact since they moved to some bigger home, on the outskirts of San Diego, but I dare say there's still a lot of muck to process and the worms mostly bred with each other so long as they had a source of food, so he might be filling barns up with sacks of clean compost if there's been a slump in the market over in Japan