looking for a farm to volunteer

Hello! I´m a spanish veterinarian specializing in livestock animal welfare. Actually, I´m working as an animal welfare advisor and auditor. For the next March or April I´m looking for a dairy farm to pass around a month as a voluntary to know a little about the farms in other part of the world and improve my english. I know about this project and it likes to me very interesting and attractive. I´m looking for one farm interested in host volunteers in exchange for housing and food. I could do any work related to the farm like help feed calves, milk cows...  Thank you very much!