You deserve kudos...and help!
Get publicity! Contact your local TV, radio and newspapers. Get a human interest story going. Let it be known you accept donations.
Contact churches and synagogues. Ask if you can leave a container at their facility.
Ask local merchants if you can leave a change jar near their register. Pennies add up quickly.
We suggest you speak with local supermarkets about placing a barrel at the door for food donations. People are usually very good about helping.
Put a container or barrel out in front of your farm, for people to drop off donations.
Talk to the vets in your area. You may find one willing to work with you on the shots and medications.
Have a tour or OPEN HOUSE of your farm...admission - pet food donations. Who knows, you may even find a loving home for one or two of your "guests."
Check the web for free pet food and free pet food samples. Many pet food manufacturers offer free samples. For example:
http://www.talktothevet.com/FREE_PET_STUFF/
http://www.freepetmedications.com/
Let it be known in your area you are accepting donations of open pet food...sometimes when a person's pet dies or they have to change food, they have an open bag of food left. They would feel better about donating it, rather than throwing it away.
Let people know you are accepting UPC & lot codes. Some pet food manufacturers will send you a free bag of food for X number of codes.
Get creative. Get your community involved. If people know you are helping to keep these animals out of the local shelter, they may be willing to help you.
Good luck!