Restated for those that can not understand. Why Farms are broken
Right now there are 2 different main reasons that farms are not loading.
1) This is affecting people that do not even have a sheep pen: AWS (Amazon Web Services) Is having issues, and a number of companies including Zynga are having issues.
2) You were Breeding your Red and Blue Polka Dotted Sheep and now you can not load your farm. This is because that sheep is broken at the moment due to a coding mistake.
Source: I just tested this on My farm, and received word from about 100 other people that did the same and now their farms do not load.
Speculation: Both problems may be connected in a way, because with the AWS Issues maybe Zynga Can not Update the game to repair it? This may not be true, but seems possible.