Since mutated livestock are not already planned, here's my suggestion. If there are to be mutated animals, it would only make sense to have mutated livestock, such as cows, chickens, pigs, and so on. A mutated livestock will mean that they will give either a benefit or a disadvantage for what the animal originally was. Therefore, this can weaken and strengthen certain areas.
A cow with two udders would be an example of a benefit. This cow would produce more milk than a regular cow. An example of a disadvantage, a chicken with two heads. This chicken will need to be fed more than an average chicken.