Multi-site Pig Production
http://www.amazon.co.uk/Multi-site-Pig-Production-D-Harris/dp/0813826993/ref=sr_1_1?s=books&ie=UTF8&qid=1340004766&sr=1-1
Swine Nutrition, Second Edition
http://www.amazon.co.uk/Swine-Nutrition-Second-Edition-Austin/dp/0849306965/ref=sr_1_2?s=books&ie=UTF8&qid=1340004941&sr=1-2
The Welfare of Pigs
http://www.amazon.co.uk/The-Welfare-Pigs-Animal/dp/1402089082/ref=sr_1_1?s=books&ie=UTF8&qid=1340005041&sr=1-1