https://www.meatinstitute.org/index.php?ht=a/GetDocumentAction/i/55910

http://m.beefmagazine.com/eco-friendly-and-economic-benefits-conventional-beef-production-are-focus-new-industry-marketing-pro

http://www.peta.org/issues/animals-used-for-food/factory-farming/

http://firstwefeast.com/eat/bad-news-the-meat-packing-industry-is-still-the-worst/

http://www.ufcw.org/2012/01/10/is-the-meatpacking-industry-getting-safer/

Sources