Usually, I'm a great fan of All Things Holstein, but I can't quite get used to either of these:

• http://www.youtube.com/watch?v=mFfIIdK2cgM (Moo Cow Song)
  
• http://www.youtube.com/watch?v=ZrPHxRqBdko (The Cow Song - for religious cows, no doubt)
  
• http://www.youtube.com/watch?v=N1U7LjRrpcE (Moo Moo Cow Song)
  
• http://www.youtube.com/watch?v=_NQGk6hgaII (Moo Cow Song - VERY strange...)
  
• http://www.youtube.com/watch?v=ljm6RU6lRuM (I'm a Cow)
  
• http://www.youtube.com/watch?v=5YH7LiU5mlw (Mad Cow Song)
  

Hey, this one is almost folk: http://www.youtube.com/watch?v=1ZOqorfPY40