Since they've been in the news lately, here's a link to the (in)famous Granjas Carroll. They have a nice, feel-good webpage which says, among other thing that Granjas Carroll is a "socially responsible business:
Granjas Carroll de Mexico is a Mexican business owned by two companies: Agroinustrias Unidas de Mexico, which has produced and marketed cotton, food oils, coffee and cocoa. The North American associate, Smithfield, is a world leader in pork production and has factories in France, Spain, Romania, the US and Mexico.
In 1994 we opened our first specialized pig "farm" in the Valley of Perote. Since then we have built and are operating 16 "farms" with a total of 566,000 [vientres?] on the border between the states of Veracruz and Puebla.
In a sustainable manner, we have consolidated our presence in the domestic market as the principal producer of pigs in Mexico, contributing annually 10% of national pork producton, equal to a million heads.
Makng use of scientific research, available technology, our experience, andinnovation, GCM continually improves its animal husbandry practices resulting in excellent quality meat produced susainably and competitively.