Animal favourite food effects

[Lakursa]

For coop animals favourite food gives sparkly eggs what I understand, but what happens with barn ones? Do you get extra wool/milk?

[Errapel]

Feeding barn animals their favourite foods seems to rapidly increase their affection for you. If the animal is pregnant, feeding them their favourite food every day results in a magic baby.

[Lakursa]

Yeah I know that, but nothing else then when they are fully grown and so? Then unless it's pregnant it's quite pointless when max heart/grown.