Fewer farmers are needed today because they are able to produce more food from their land. Hay is no longer the main source of winter feed for livestock and has largely been replaced by silage, particularly baled silage wrapped in film that can be handled mechanically. This has reduced the manpower needed on farms, and there has been an increase of use by farmers of specialised contractors who provide services in silage making, harvesting and fencing.[20] Another problem facing Welsh farmers is their distance from the main distribution centres used by supermarkets which are mostly located near centres of population in England.[3]