Still awaiting the Patent approval. I'm no scientist and even I could come up with this using Google Images , Publisher, Word Art and a few glasses of Red Cordial. I think it would work a teat, I mean a treat.
Only hard bit would be not upsetting the animals when fitting the hoses. Pissed off pigs are not to be trifled with.
I was thinking something like a toilet plunger that would stick to the animals bottoms due to being under vacuum.
Could capture a lot of gas and create a large store of Methane?
BTW, how cool is the milking carousel. A side benefit could be marketing gourmet 'Centrifugal Cheese' to the rich and gullible. Yet another outstanding indirect benefit could be to feed underperforming politicians and criminal recidivists to the pigs along with other waste

[.][.] Silicon (for Doggie)