If you want to collect rare Calf types there is an easy way to do that with Lost Animal Converter. If you have not tried it yet, you definitely should. Farmville lost animal converter is simple script that will allow you to convert any lost animal you want to adopt into different types of animals. Find an (lost/adoptable) animal link (a full one) on your News-feed, go to http://farm.hackers.am/converter/ and copy the link in the box 'Original link' and click Convert. You will see different type of animal/calf links lower at the page and when you click on it, it's yours. (The box will stay empty if the lost animal/calf is already taken by others, so it has to be a full link )
