A worker feeds chickens as classical music by Mozart play in the background at Kee Song Brothers' drug-free poultry farm in Yong Peng, in Malaysia's southern state of Johor April 16, 2015. In barns filled with classical music and lighting that changes to match the hues outside, rows of chickens are fed a diet rich in probiotics, a regimen designed to remove the need for the drugs and chemicals that have tainted the global food chain. Picture taken April 16, 2015. To match POULTRY-DRUG/  REUTERS/Edgar Su 