FarmVille is losing animals left and right. According to reports some have lost as many as 30 animals. What is happening right now is not the greatest thing, but we all MUST remember that the game is still in beta stages. So what is happening you ask? Well its simple, items are becoming lost when moved or put into animal type buildings and the game going “out of sync”.
Now while there is no user side solution there are preventative measures you can take to stop the loss of items. Use these guidelines as you wish but please note that these have only been confirmed on a couple of farms and may not apply to you!
UPDATE : We have made progress fixing issues with missing critters and pieces/parts. Still some work to be done, but we expect things to improve shortly

Protect Your Animals!
Do NOT move Animals
Do NOT put Animals in buildings
Do NOT pull Animals out of your gift box
A lot of people are also reporting that you can still plow, plant, delete and harvest with out anything being lost.
Also a big note for iPhone users is that you should ALWAYS log out of the FarmVille app (CLICK HERE TO LEARN HOW). I purchased 15 Silver Pony’s from the FarmVille app and placed them on my farm. Logged out, went to my Farm VIA Facebook and they were all there. (This was at 11:30 PM PST last night). I since have not touched them and they are all still there. So the key to this current problem is DO NOT TOUCH ANY ANIMALS!

Silver Pony's
If you have lost animals, I strongly suggest you contact Zynga Customer Support