Just came back from a local slaughterhouse where I was looking for some green tripe. They were kind enough to let me watch them kill the cows. It wasn't pretty.

I was standing 3 feet away from them. They had to use two 'bullets' most of the time since the first one didn't do the job (neither did the second one, if you ask me). I will refrain from giving more details since I know this kind of talk isn't welcomed on this board. Suffice to say that after 3 cows, I started sweating profusely and politely told them I had seen enough.

After that, the supervisor took me to where they clean the stomach and tripe. There was this big organ that was full of grass. He even let me touch the grass and the smell wasn't that bad (wasn't pleasant either, don't get me wrong). He then explained that the other tripe was full of shit (as opposed to undigested grass) and that it had lots of bacteria.

These pictures are too small for me to actually tell which tripe I'm looking for. Is it the one full of shit or the one with undigested grass? Should I take some of the grass as well?

The supervisor told me that they throw away these tripes and that he could give me some for free! I'll give him a bottle of something so I can go back every month or so.

http://www.thedogbowl.com/PPF/category_ID/0_84/dogbowl.asp

My understanding is that the tripe we buy and feed is from the first (flat) or second (honeycomb) of the four stomachs.

Ok Richard, the best tripe is the one that is almost out of the cows body if you will.The one that is full of bacteria is the one your dog benefits from.Those bacteria in the digested stomach content is what green tripe is.As a matter of fact , many canid eat their preys' feaces BECAUSE of the benefit it gives them.The grass that has not gone through the digested stage is of no value to the dog.You need the gastric juices which only happens through the digestion period and some stomach lining is very good too it contains enzymes.
Well lucky you to watch cows get shot not one but twice or three sad but oh well what can I say.
But hey free stuff, great! You're pup is growwwinnng...

So then the honeycomb (2nd) is not the right one?

This was what I read, but I'm not up on which does what in a ruminant.