Breeding & Genetics

You need the Herdsman profession (/mp) and points in Artificial Selection. The skill list, horse genetics, and cheese recipes are on the Herdsman page.

Starting out

Before you begin with genetics, unlock Artificial Selection in the Herdsman skill tree.

Once the skill is unlocked to the level you want, this is how to get the first custom animal:

1. Obtain the custom Barley item. With any level of the skill unlocked, harvesting wheat can randomly drop Barley.
2. Bring together two adult animals of the species you are breeding.
3. Right click each of them without sneaking. Once the love ends, they produce an offspring.
4. The offspring receives a custom breed. The parents do not change.
5. Sneak + right click the baby or the adult to open its genetics book. Hover a trait indicator to see its value.

Other parent combinations are in the table below.

How to choose a breed

For your first custom animal, the breed is chosen from the temperature at the baby’s location. Its starting trait values are random. Each starting trait is rolled within 20–50% of the breed’s potential.

The climate boundaries differ slightly by species.

Once you have a breed, use normal breeding food to continue the line without mutations. Cows and sheep use wheat. Chickens use seeds.

A custom cow can breed with an ordinary cow. Normal food keeps the custom parent’s breed and blends traits. For mutations, raise two animals of the same custom breed, then feed both Barley. Barley with ordinary parents, or with two different custom breeds, creates fresh climate-selected stock instead.

Improving your animals

Each custom breed has three traits. With two custom parents, each inherited trait starts somewhere between the parents’ values. An ordinary parent contributes hidden traits in the 20–50% range. Those hidden traits are not a copy of the custom parent, and they are not rerolled on each attempt. The ordinary parent stays an ordinary animal.

For example, an 80% custom trait paired with a hidden 30% ordinary trait produces a value between 30% and 80%. Two good custom parents are the more reliable way to keep high quality.

With normal food, traits only blend. A 30% parent and a 50% parent produce a value between 30% and 50%. Blending alone cannot push a trait past both parents.

When both parents are the same custom breed and both are fed Barley, each inherited trait then has its own 20% chance to mutate:

• A mutation is equally likely to improve or worsen the trait.
• An improvement adds 2–5 percentage points of genetic quality. A setback subtracts 2–3 percentage points, so gains are larger on average.
• Traits stay within 0–100% of that breed’s potential.
• Several traits can mutate on one baby, or none can.

For example, two parents with a 60% trait normally produce a 60% trait. A mutation can produce 62–65%, or 57–58%. This changes genetic quality, not the output by that many buckets or items.

A trait with a fixed output has nothing further to unlock. Merino’s one-bucket milk capacity is one of these. Spend mutations on that breed’s variable traits.

Breed output

These are base ranges before skill bonuses. An animal’s genes set its output inside the range. Fractional item yields can round up or down. Milk capacity rounds to a whole bucket.

Butcher, Shepherd, and Hatchery can raise drops further. Those skills are on the Herdsman page.

Cows

Sheep

Chickens

Milk storage and regeneration

To milk an animal, be a Herdsman with at least one point in Cheese Making. Right-click an adult with an empty bucket, without sneaking, and keep an empty inventory slot available. Sneaking, once that livestock species is unlocked, opens the genetics book.

Capacity is storage, not production speed. A five-bucket Holstein can hold five buckets at once. Milking takes one bucket from that stored supply. The animal refills the supply over time.

Rennet, press recipes, and the per-species regeneration times are in Getting Milk.