I'm sure I'm not the first to think of this for STV, but it'd definitely be awesome to have the ability to selectively breed animals with each other. The reason behind this idea would be to increase the quality of any animal-based products based on the "invisible" stats that every farm animal would have. Here's what the (likely) stats would be based on their own quality while also based on the quality type they breed with. Whether the animal will be male or female when it's born is always 50/50: Quality Legend: N = Normal S = Silver G = Gold I = Iridium Normal: N = 90% S = 35% G = 20% I = 5% Silver: N = 50% S = 85% G = 20% I = 10% Gold: N = 15% S = 20% G = 80% I = 15% Iridium: N = 5% S = 10% G = 50% I = 75% I apologize if the stats here don't seem very clear. I know this would take some time to make possible, but this way it would make for a fun alternative to farming so your main source of income doesn't have to mostly be from crops.
I'd suggest that quality changes should be limited to at most one level, so that getting from N to I would require at least three generations of careful breeding.
