Wishful Features: Animal mastery in FarmVille

As a fairly high level FarmVille player who has played the game since last summer, I have accumulated quite a few different species and varieties of animals in my time with the game. While crop mastery and even tree mastery has been added to the game since I started playing, one area of mastery has yet to be released - that being animal mastery.

While this might be an incredibly tricky procedure for Zynga to implement, considering the sheer number of different varieties of animals that are available in the game (just think of how many Horses are in the game, as an example), I don't think an animal mastery system has to be setup in such a way for each specific type of animal to receive its own mastery sign. Why not just program each horse to go to one overall Horse Mastery rating? Or, why not have all of the different colors of sheep, or all of the varieties of ducks go to one particular mastery for that basic animal type as well?

This would give users that much more incentive to purchase and care for their animals. I for one know that the only reason I tend my animals now is to remove the dozens of pink arrows that clutter my farm - not because I need the few coins each animal offers me when harvested. Mastery has already been proven to be a money maker for Zynga in the past - users have purchased limited edition crops or exclusive trees with Farm Cash just so they didn't miss out on the Mastery Sign associated with them, and I think the same thing would be said for animals.

C'mon, I know I can't be the only one that would buy more pigs if I knew I'd get a fancy sign out of the deal... Am I?

What do you think of the concept of animal mastery in FarmVille? Would you want each individual variety of animal to have its own mastery rating and sign, or would you be find if there were one mastery rating for all varieties?