We wanted to make a statement regarding “illegal” sheep, including ones with patterns that have not been released. The methods by which it was possible to attain these sheep have been stopped, but obviously a fair number of these are currently available, and players have been breeding them at a prodigious rate. At this point in time it would be very difficult to determine how someone received one of these sheep—and it is extremely likely that if you saw a feed post or other reference to one of these sheep, the author is someone who acquired/bred that sheep legitimately. Please bear this in mind if you think someone has “cheated.” Chances are, they haven’t been.
We also wanted to let everyone know about a change in how sheep breeding works. Previously when you got three lambs of the same gender in a row, you received a lamb of the opposite gender automatically. Currently we’ve made an alteration to this process so that the chances of getting a ram or a ewe are completely random, though the possibility of getting a ewe is higher than getting a ram.
Finally, the 100 bred sheep limit (which includes current bred lambs and sheep on your farm as well as in your sheep pen or in your Gift Box) applies for each farm. So, for instance, if you have just 75 bred sheep on your English Countryside Farm, you should still have the capability of having 100 bred sheep on your Home Farm.
source: Official FarmVille Blog