If you are interested in compiling data on farms in your city or state, here are a variety of resources that may help in your endeavor. We also provided some of the information we utilized in finding information on farms in the state of California.
Yahoo Yellow Pages: In some instances, farms are listed in directories, like yahoo. You need to input the city and state you are interested in searching. Keywords: hog farm, pig farm, turkey ranch, hatchery, feedlot, slaughterhouse, rendering, chicken farm, chicken ranch, dairy, processing plants, sheep, duck farm, beef ranch, auction yard, etc. Obviously, not all farms are listed in the directories.
California Department of Food and Agriculture is an excellent source of information on agriculture in the state of California, including regulations and laws on various issues surrounding animal transport, maintenance and slaughter. You can request detailed information on inspected facilities by utilizing the Public Records Act (pdf) Most states have similar laws regarding the dissemination of information (like farm locations). You can contact the agency responsible for agriculture & ask about public records laws, acts or statutes.
Freedom of Information Act: APHIS would be the contact for requesting information regarding farms that are federally inspected.
Who's Who in the Egg and Poultry Industry USA/Canada is a magazine containing key information on the major (and minor) players in the poultry industry. It isn't cheap ($120/year), but it does contain excellent information on the chicken industry - university or public libraries might be a good spot to check for a copy.
Confined Animal Facilities in California Senate Office of Research Report (Acrobat reader required) is an excellent free report on the multitude of problems associated with factory farms. The research paper contains information on stereotypical and unnatural behaviors animals on factory farms exhibit as well as the environmental hazards associated with confined animal facilities. Though it may be focused on California, its conclusions apply to all standard factory farming operations.
California Agricultural Statistics 2003 is a free publication put out by the California Department of Food and Agriculture. It contains statistical data on all crops and livestock farmers in California produce.
Livestock's Long Shadow is an excellent publication created by the Food and Agriculture Organization of the United Nations. Though it is over 400-pages long, the Executive Summary is a succinct representation of the data.
USDA National Agricultural Statistics Service is a superb source of statistical information on agriculture. It contains up-to-date data on number of animals, species, age, gender, etc who are raised for food or fiber in the country. Statistics can be separated by state