I worked on a corporate hog farm as breeder in 1994-95. Animals were moved into breeding stalls 4 across with a bore. We would manage the bores and try to get 2-3 successful stands to ensure pregnancy. Then the sals were moved to gestation in another barn. The entire process was scinetific (kinda the same process that says it takes x-number of days for an egg to hatch with chickens - also worked every aspect of chickens from the hatchery to the truck for slaughter from 1972-74). The animals were not treated poorly, and stalls were cleaned 2x daily, the animals feed 2x daily and they were rotated from pens frequently. It would not be nice to be a sal, but to be a bore would have been great;) - Of course, all the animals end up on the dinner table (unless their holves touch the ground/dirt and then they are destroyed). All these hogs live their entire life on concrete.
What is a sal and bore? Sow and boar?
How did you impregnate the sows? Did you artificially insem, or did you let the boar do the job?