The most frequent examples of CAFO’s you will hear about are hog operations. Thousands of pigs kept in pens in close quarters, inside, free fed until they are ready for market. The faster the better. To some extent I have owned and been employed by what could conceivably be called a CAFO. The difference would be in scale.
The operation we owned had about 16-20 sows in 4 pens of 4 sows each, plus the ones in pens with their piglets. These pens were inside a barn that was closed in with windows in the winter and open to the breezes in spring summer and fall. Twice a day the sows were let out of their pen whence they would run down the aisle (gleefully) to the feeding pen. Brood sows are not fattened but fed to maintain a healthy weight while they are pregnant (gestating), and then nursing their piglets. While the girls were being fed their pen would be scraped clean and new bedding laid down. Then they would wander back to their pen. This interaction would allow me to see who was in heat (ready to breed), if someone was ill or injured, etc. We had 3 smaller pens to house a boar (daddy) and to separate a sow for extra care.
We did use farrowing crates. A farrowing crate is a metal crate that does usually prevent the sow from turning around. It’s purpose is to force the sow to lie down carefully and to provide an escape route for the baby pigs so that Mama doesn’t crush them. It may be uncomfortable for the sow but it does save the lives of many baby pigs. We were fortunate to also have pens where the sow and her litter could be moved once the piglets were old enough(about 1-2 weeks) to have learned to watch out when Mama laid down.
I went to work for a facility that had about 100 sows. They were housed in groups of 10, in pens that were covered on one end and open on the other. We still used the same method of running them down to a feeding area, scraping the pens etc. These sows were usually kept in the farrowing crates until their litter was weaned. Around 4 weeks of age if I remember correctly. It was dependent on how well the piglets were eating on their own. There were 3 boars at this farm kept in their own pens near the feeding area.
On both farms I only had responsibility for the piglets until they weighed about 40 pounds. Then they went to another barn to be fed out to market size. In neither case did the pigs have access to the outside,but they were housed in pens that allowed for adequate movement, and that were kept clean.
On the larger farm where I was employed we did have sows and piglets on pasture one summer. It was amazing! I have always wanted to try this in my own small operation, but was unable to convince my husband that we wouldn’t be chasing pigs all over the neighborhood. Maybe in another life!?!