20,000 is a small operation. 20+ years ago I approached Sanderson Farms, interested in raising broiler chickens for them.
Minimum operation they were looking to deal with was (let's see if I can remember the particulars) 4 houses, each 70' wide 1000' long, holding something like 70 or 80,000 birds each.
Strange as it seems I visited several broiler farms, the chickens were raised on a deep litter consisting of rice hulls. I don't remember any oppressive smell.
Funny thing about Sanderson Farms. I asked them for specifications, they required for their broiler houses. The best they could come up with was a very over copied crude drawing of a chicken house. When I asked for specifications they required on waterers and feeders, I was told to equip the house, they would send an agent out to inspect the house to see if it meet their requirements. So I then asked to speek to an agent, I was told none were available. So near as I could figure out, Sanderson Farms wanted me to invest more than $250K up front, with no commitment on their part. Didn't take me but a few calls to the La. Dept of Agriculture to find out Sanderson Farms was rumored to have decided to allow the La. chicken growers to decline. Never allowing a new one and never replacing an old one that went out of business. My understanding was that the only reason they maintained the ones that were in La is because they had just built a multi million $ processing plant in Hammond, and the La Dept of Ag commissioner told them that if the farmers in La didn't get the chickens they wanted, not one live or dead chicken would ever cross La state lines.