This may be a question with a very obvious answer but I am wondering because yesterday I set up a farm for cows, sheep, pigs and chickens. As soon I could get two cows, two pigs and two sheep penned up I bred all of them and then I used eggs to spawn chicks rather than luring chickens. I come back today and only the lamb had grown into an adult sheep, still having a calf, a piglet and two chicks. Obviously lag will hinder the growth rate but to what degree? Perhaps it's just bad luck since the game uses a tick-based algorithm to determine if an animal should grow.