Photographs: Joel Sartore/National Geographic/Getty Images (Red Wattle); Nigel Cattlin/Alamy (Duroc); Life On White/Alamy (Mangalitsa); Robert Dowling/Corbis (Tamworth, Berkshire); Dorling Kindersley/Getty Images (Gloucester); Monika Graff/Getty Images (Hampshire); Jeannette Beranger/ALBC (Ossabaw)