I've tried to test this, only to find that it seems as if the chickens only spawn in one biome after you've killed them in other biomes, plus I think there is a limit considering the fact that everytime I have over about 7 chickens (Who have taken NO DAMAGE WHAT SO EVER!), I come back, and one is gone...but sory if this isn't enough info for you, just thought I'd let you know that I understand what you're asking.
I've tried to test this, only to find that it seems as if the chickens only spawn in one biome after you've killed them in other biomes, plus I think there is a limit considering the fact that everytime I have over about 7 chickens (Who have taken NO DAMAGE WHAT SO EVER!), I come back, and one is gone...but sory if this isn't enough info for you, just thought I'd let you know that I understand what you're asking.
I've had 13 at one time and the thrown 25 eggs with no new ones
Even tried killing g other passive mobs and throwing the eggs in different chunks
I've noticed a similar issue. I have six 3x13 pens that I had cows, pigs, yellow sheep, green sheep, red sheep, and blue sheep in, all in their own pen. The blue sheep were the last that I came around to breeding, and I noticed that I was not allowed to breed any more than three. Although I had five and more of the other colors. I even tried killing off a number of the other sheep, to see if it was a species restriction, and that didn't work. I then tried reducing my cow and pig count, and it still wouldn't let me breed more blue sheep. I even went back to make sure the pen size, and conditions were the same with each pen, and they were.
So, at first there seemed to be some sort of capacity limit. However, after reducing my overall animal numbers, I don't know what the cause was. Unfortunately, I didn't get a total number of herded animals I had, before I slaughtered them all....
And they say cracked is whack.. Pffft...
Even tried killing g other passive mobs and throwing the eggs in different chunks
So, at first there seemed to be some sort of capacity limit. However, after reducing my overall animal numbers, I don't know what the cause was. Unfortunately, I didn't get a total number of herded animals I had, before I slaughtered them all....
Sadly, yes there is a limit.