Animal Husbandry

[Lothia]

Ave Civitas,

I have read many of the posts in the FOOD category here. I was wondering if anyone knows how the meat was gotten.

Things that I think I know.
1. There were big Bovine markets (Constantinople)
What I don't know is where did these cattle come from.
Was it large cattle ranches? - Small farmsteads that sold their oxen to middle-men who took them by the herd to market?
Would the market have a hundred owners each trying to sell their one oxen?

2. Romans ate a lot of pork
Were there Pig Markets like there were Bovine markets?
Again, where did the pigs come from?
How did they get to market?

3. Romans ate chickens.
I know that vills raised their own fowl, but the city-dweller did not have the space. Where did all those chickens come from?
Were there chicken ranches too?

Thanks.
Tom