Changing animal reproduction

(Say hello to Google Translate, as I don't know English)
I would like to propose adding more baby animals when breeding (like mountain goats in the last beta) and slightly changing the overall breeding mechanics.
  I want more interaction with the animals, so why not add a gestation period to the animals? So you will need to come to your animals 2 times more often, but for the wasted time there should be more resources, right?
  Nobody breeds svens, this is the same cow, but also the skin is not Drop. For example, pigs can produce offspring in the amount of 6-12 individuals (but this is too much, so 2-5 will be enough) if pigs bring more offspring than cows, they will be used more often.
A cow can sometimes give birth to 2 calves.
And the rabbits ... no one breeds rabbits, if you increase the number of born rabbits, then perhaps this will change.
Well, I think you understand the meaning, now many animals are not used, because of the more affordable alternatives, if some animals will bring more offspring, then this may slightly improve the balance of the game.