Cow & Sheep Genetics

The short version

• Only cows and sheep have genes: five of them, D L Y F H (Dung, Longevity, Yield, Fertility, Hardiness). Chickens and horses have none.
• Each gene has two copies, each Bad, Ok or Good. The better copy shows on the panel and does the work. The other copy is hidden, but it still passes to calves.
• A calf gets one random copy of each gene from its mother and one from its father.
• Five green discs, not inbred, is as good as it gets for milk, wool and price. A "god" animal (all ten copies Good) adds only one thing: all its calves show five greens too.
• Inbreeding halves every gene. Never pen a bull with his own daughters.

Reading the gene panel

Look at a cow or sheep up close. Under GENETICS the panel shows five discs, then a number.

What the panel never shows on a normal server: the hidden copy of each gene, the second marker, and the parents. Green does tell you exactly who carries Good: a Good copy always shows.

Do you need a god cow?

For milk, wool and price, no. The game uses only the copy that shows, for performance and for the sale price. A five-green animal that isn't inbred works and sells exactly like a god genome.

A god genome (all ten copies Good) matters only for breeding: every calf it has shows five greens, whoever the other parent is. In a best-case simulation with 12 ranch animals, the first clean five-green calf came after about 4 hours of play, and the first god calf after about 11 hours with the plan below. One player reported about 8 hours to a five-green calf.

A breeding plan that works

• Start with about 12 animals(say 3 bulls and 9 cows). Then there's a 98% chance your herd holds a Good copy of every gene; with 6 animals, only 70%. At the ranch, calves cost 300 scrap and lambs 150. Breeding can never create a Good copy your herd doesn't have.
• One bull with up to 6 cows per pen, and move calves out. A pen left alone stalls after about five births, because it gets crowded.
• Breed forward: each time a calf grows up, breed your newest five-green animals.
• Never sell or kill one of the last two animals with a green disc on a gene. Lose them and that Good copy is gone for good. Without this rule, a fifth to a quarter of simulated herds lost a gene.
• You choose pairs by distance. A ready bull goes to the nearest ready female of his species within 30 m. To breed a pair, keep everyone else further away or lead them apart.

Inbreeding

Every animal carries two lineage markers, numbers from 0 to 15, one from each parent. It's inbred when the two are the same. Inbreeding halves every gene: Good works like Ok, Ok falls halfway to Bad. An inbred animal still passes its copies on normally, but it sells for less.

The panel shows only one of each animal's two markers, so different numbers don't make related animals safe: a bull and his daughter usually show different numbers, and 30% of their calves are inbred. Rotate bulls, bring in an unrelated animal every few generations, and never pen a bull with his daughters.

Proving a god bull

The panel can't tell a god bull from any other five-green bull. A test cross can: mate him with cows that show no green at all (about 1 in 9 fresh animals). A god bull gives every calf five greens. Each five-green calf makes it likelier: for a bull bought fresh, 10 in a row make it 96% sure, and a bull bred from good parents needs fewer. One calf missing a green proves he isn't a god. The Herd Planner keeps the count for you.

Cheaper, one gene at a time: to test his Fertility, use a cow showing gray or red on F. If he's Good/Good on F, every calf shows green F.

What each gene does

How calves inherit genes

For every gene, the calf gets one copy from its mother and one from its father, each picked at random. On vanilla servers nothing mutates, so a calf can only get Good copies its parents carry. Genes are inherited separately, so for the whole calf, multiply the five genes.

A calf's chance of Good/Good on a gene = the mother's Good copies ÷ 2 × the father's Good copies ÷ 2. Two five-green animals bought fresh give a five-green calf only about 1 time in 3, because most green discs hide a worse copy. If you know their hidden copies, the answer can be quite different: in one worked example it's 56%.

How lucky is your animal?

A fresh wild or ranch animal rolls each of its ten copies: Good 20%, Ok 50%, Bad 30%. So:

• A green disc hides Good 11%, Ok 56% or Bad 33%. A gray disc hides Ok 45% or Bad 55%.
• Five greens: 1 in 165. Four or more greens: 6%.
• A five-green wild animal is a true god 1 time in 59,049.
• Born inbred: 1 in 16.
• About 1 in 200 wild animals is a named special with fixed genes, like the ram Shadowfleece (Good/Good on L, Y, F and H, Bad on D). Only one of each name lives at a time.

Why breeding stops

Both animals must be:

• Tame: 300 seconds of you being within 20 m. Animals bought at the ranch start tame, and so do calves of a tame mother.
• Happy: food, water and personal space all above 50%.
• In condition: breeding pauses at 60% condition or less, and starts again at 70%.
• Free: grown up, not on a lead rope, not on cooldown, and the female not already pregnant.
• Not crowded: 12 of a species within 20 m (calves count), or more than about 4 adults packed within 2.5 m, stops breeding.

Timings: a calf grows up in 54-66 minutes, pregnancy takes 10 minutes, so one generation takes about 71 minutes. The timers run day and night. A Facepunch fix merged on 2 Oct (not live yet) will need a 15-minute bond before animals can breed.

Selling

The ranch vendor's offer depends on the shown genes, the animal's condition (full price at 80% or more) and its age, and it's 20% lower for wild or bought animals than for ones you bred. A five-green animal that isn't inbred already gets the top price. You get up to three offers, then a 15-minute wait.

Servers can change this

Server owners can change the gene odds (livestock.geneGoodChance, geneBadChance), turn on mutation (geneMutationChance), change how much inbreeding costs (inbredScale) and each gene's effect, and show the hidden copies (panelAlleles). This guide uses the vanilla values.

Questions

What do D, L, Y, F and H mean?

Dung, Longevity, Yield, Fertility and Hardiness. See What each gene does.

Is 4 green and 1 gray good?

Yes: only 6% of fresh animals have four or more greens. A bred cow like that sells at about 96-97% of the top price.

Do chickens or horses have genes?

No. Only cows and sheep.

Can a cow breed with a sheep?

No. Mates must be the same species.

Why did my cows stop breeding?

Usually crowding, a need below 50%, or condition below 60%. See Why breeding stops.

Is reading genes with a tool allowed?

Our tools only read what's on your screen. They never touch the game.