According to this source, cows have a pregnancy period of 21 days, followed by another 20 days until adolescence. While the source is somewhat incomplete, I would hazard a guess that sheep and alpaca have the same pre-adolescent period since they share the same pregnancy period of 21 days.

Chickens, on the other hand, have an incubation period of 7 days (since you put eggs in the hatcher, rather then get them pregnant), followed by 8 days until adolescence.

Note that this source is incomplete for higher quality breeds such as Jersey cows and Silkie chickens, but from my experience with previous games in the series (such as Tale of Two Towns), they should share the same pregnancy/incubation/adolescence period as the base livestock.

How long does it take for a calf to be full grown in Harvest Moon A New Beginning?
At least twice in LoTR:FotR, ringwraiths cower away from bodies of water. The second time (the ford of Bruinen) can be explained away by their fear of some Elvish magical trap through the enchantment of the water; but what about the first time, at the ferry? One of the Nazgul could have easily made the jump onto the barge and quickly dispatched those pesky Hobitsses.
