Rust Livestock Genetics: Cow and Sheep Genes Explained
How cow and sheep genetics work in Rust: what each of the five genes does, how calves and lambs inherit them, how inbreeding hurts, and how to breed a god clone (the "god cow" or "god sheep").
On this page
How do livestock genes work in Rust?
Every cow and sheep has five genes: Dung, Longevity, Yield, Fertility and Hardiness. Each gene has two copies, each rated Bad, OK or Good. The animal shows whichever copy is better, and each parent passes one random copy of each gene to its young.
That's the whole system. Everything below is detail: what the ratings do, how to predict the young, and how to avoid the traps. Want to skip the theory? Use the breeding calculator.
The five genes
| Gene | What it changes | Bad | OK | Good | Prioritise it when |
|---|---|---|---|---|---|
| Dung (D) | How often a tame animal drops dung | ×0.6 | ×1 | ×1.6 | You run a Biofuel Generator for Low Grade Fuel |
| Longevity (L) | Adult lifespan (48h at OK) | ×0.65 | ×1 | ×1.5 | You want breeders to last; you're building a long-term line |
| Yield (Y) | Milk (cows) or wool (sheep): amount and regrow speed | ×0.6 | ×1 | ×1.6 | Almost always: it's the output gene |
| Fertility (F) | Breeding cooldowns and twin chance | ×0.65 | ×1 | ×1.6 | You're breeding toward better genes and want more generations |
| Hardiness (H) | How low needs can fall before condition drops | ×0.7 | ×1 | ×1.5 | You're offline a lot or keep a big herd |
The genes are the same for cows and sheep; only Yield's output differs. In practice:
| Effect | OK | Good |
|---|---|---|
| Cow milk per hour | 12 | 38.4 |
| Sheep wool per hour | 120 | 307.2 |
| Adult lifespan | 48h | 72h |
| Mother's cooldown after birth | 1h 6m | 41m 15s |
| Male breeding cooldown | 10m | 6m 15s |
| Young per birth | 1 | 1–2 (60% twins) |
| Dung per hour | 6 | 9.6 |
| Need level that keeps full condition | 50% | 33% |
Full Bad/OK/Good tables for each animal are on the cow and sheep pages.
Two copies, the better one wins
An animal with one Good and one Bad copy of a gene performs exactly like a Good/Good animal. The hidden Bad copy only matters when it breeds.
This is why two animals that look identical can breed very differently. A Good/Good bull always passes on Good; a Good/Bad bull passes on Bad half the time.
How inheritance works
For each gene, the young gets one random copy from the mother and one random copy from the father. Each of a parent's two copies has a 50% chance of being the one passed on.
Each of the five genes is inherited separately, so a calf can get its mother's Yield and its father's Fertility.
Worked examples
| Mother | Father | Shows Good | Shows OK | Shows Bad | Good/Good |
|---|---|---|---|---|---|
| Good/Good | Bad/Bad | 100% | 0% | 0% | 0% |
| Good/Good | Good/Good | 100% | 0% | 0% | 100% |
| Good/Bad | Good/Bad | 75% | 0% | 25% | 25% |
| Good/OK | OK/OK | 50% | 50% | 0% | 0% |
| Good/Bad | OK/Bad | 50% | 25% | 25% | 0% |
| OK/Bad | OK/Bad | 0% | 75% | 25% | 0% |
Odds for a single gene, calculated from the inheritance rule. Multiply across genes for combined odds (assuming the young isn't inbred).
Two takeaways: one Good/Good parent guarantees the young shows Good, and if neither parent has a Good copy, the young can't either.
What genes do wild animals have?
Wild animals roll each copy on its own: Good 20%, OK 50%, Bad 30%. So a wild animal shows Good on a given gene 36% of the time, but is Good/Good only 4% of the time.
| Wild animal… | Chance |
|---|---|
| shows Good on one gene | 36% |
| is Good/Good on one gene | 4% |
| shows Bad on one gene | 9% |
| shows Good on all five genes | 0.6% |
| is a god clone (all 10 copies Good) | about 1 in 10 million |
| is born inbred (wild and vendor animals) | 1 in 16 |
That's why the community talks about "hunting" for a god clone: you'll essentially never find one in the wild. You breed toward it.
Reading genes from an animal's looks
Some genes show on the animal. On cows, coat patches hint at Yield, Dung, Longevity and Fertility, and a shaggy coat means good Hardiness. On sheep, fleece colour shows Dung and fleece thickness shows Yield.
Cows
| Gene | What to look for |
|---|---|
| Yield | More patch coverage means better Yield |
| Dung | Rusty brown patches mean Good; near-black patches mean Bad |
| Longevity | Larger blotches mean better Longevity |
| Fertility | Ragged patch edges mean Good; smooth edges mean Bad |
| Hardiness | A longer, shaggier coat means better Hardiness |
Sheep
| Gene | What to look for |
|---|---|
| Dung | Black fleece means Bad, brown means OK, white means Good |
| Yield | Thick, long fleece means Good; thin, patchy fleece means Bad |
Looks show the expressed gene, not the hidden copy. To estimate the hidden copy, breed and watch the young, or use the "Only what it shows" mode in the breeding calculator.
Inbreeding
Breeding close relatives can produce an inbred young. Inbred animals show weaker genes (Good acts as OK, and OK falls halfway to Bad), but still pass on their real copies.
What we know
- Breeding close relatives can produce inbred young.
- Wild and vendor animals can also be born inbred: 1 in 16.
- Inbreeding changes what the animal shows, not what it passes on. An inbred Good/Good bull still gives every calf a Good copy.
| Copy the animal shows | Normal | If inbred |
|---|---|---|
| Good | ×1.6 (most genes) | Acts as OK (×1) |
| OK | ×1 | Halfway to Bad, e.g. ×0.8 for Yield |
| Bad | ×0.6 | ×0.6 |
What isn't published
How the game tracks family lines and how likely a related pair is to produce an inbred young. We'll update this once it's tested.
How to avoid it
- Don't let a whole herd breed freely; brothers, sisters, parents and young will pair up.
- Keep a note of which animals are related. Separate breeders into pairs.
- Bring in unrelated animals (wild or vendor) every generation or two.
- Don't throw away an inbred animal with Good copies: it's a poor producer but can still be a good parent.
What is a god clone?
A god clone is an animal with all 10 gene copies Good: Good/Good on Dung, Longevity, Yield, Fertility and Hardiness. It always breeds true, so every young gets five Good copies from it.
"God clone" comes from Rust's plant genetics, where it means a perfect plant. Facepunch reused the term for livestock: you breed animals "to hunt for a god clone". Players also talk about a "five-green" cow or sheep, meaning all five genes show Good. That's not the same thing: a five-green animal can hide Bad copies.
Plant breeding tricks don't carry over. Facepunch says livestock genes "won't behave exactly like plants". There's no crossbreeding of neighbours here: just two parents, two copies, random inheritance.
How to breed toward a god clone
- Start with numbers. Tame or buy several animals. More starting animals means more Good copies in your pool.
- Pick parents by what they can pass on. A parent that shows Good on a gene carries at least one Good copy.
- Prioritise Fertility early. Shorter cooldowns and twins mean more young per hour to choose from.
- Keep the best young, sell the rest. Each generation, keep animals that show Good on the most genes.
- Test for hidden copies. An animal whose young all show Good on a gene, across several births with a non-Good partner, is very likely Good/Good there.
- Bring in fresh blood to avoid inbreeding.
- Lock in Good/Good parents. Once one parent is Good/Good on a gene, every young shows Good on it.
Run each pairing through the breeding calculator to see the odds before you wait out a pregnancy.
Genetics FAQ
What are the genes in Rust livestock?
Dung, Longevity, Yield, Fertility and Hardiness, shown in game as D, L, Y, F and H.
What is the best gene in Rust?
Yield for production (milk or wool), Fertility for breeding speed. The best animal is Good on all of them.
Do cows and sheep have the same genes?
Yes. The same five genes and multipliers. Yield controls milk for cows and wool for sheep.
Can two OK animals have a Good young?
Only if one of them hides a Good copy, which can't happen: an animal with a Good copy shows Good. So no.
Can two Good animals have a Bad young?
Yes, if both hide a Bad copy (Good/Bad × Good/Bad gives a 25% chance of Bad/Bad).
What does inbred mean in Rust?
An inbred animal shows weaker genes: Good acts as OK and OK drops toward Bad. It still passes on its real copies.
What is a god clone?
An animal with all 10 gene copies Good. It always breeds true.