So on my main file on my xbox, I have had only one sheep in my fully upgraded barn, until recently when it gave birth twice! I was under the impression that the barn animals only breed when there are two of the same animal in the barn... How did this happen???
"Similar to animal attacks, if there are no other events occurring in the night, there will be a 50% chance that the game will attempt an animal birth event. The game searches through all buildings for an upgraded Barn that isn't full. The game then makes another check where there is a 0.55% * (the number of animals inside) chance of proceeding with the event. For example, an upgraded barn with three animals inside would have a 1.65% chance of passing this check. If the building fails this check, the game will continue going through all buildings until none are left. If a barn passes all these checks, a random animal inside is chosen. If the animal is not a baby and has pregnancy enabled, that animal will give birth. " https://stardewvalleywiki.com/Animals Just need to be lucky with one animal.
