Rabbit Pedigree Explained: How to Read One and What It Proves

A rabbit pedigree is a written record of an animal's ancestry going back three generations, listing each ancestor's name or ear number, variety and weight. It is produced by the breeder, not by a registry — the American Rabbit Breeders Association does not issue pedigrees, it requires you to bring one.

Three generations means fourteen ancestors behind the rabbit itself: two parents, four grandparents and eight great-grandparents. ARBA states the pedigree must show the name and/or ear number, weight and variety of the parents, grandparents and great-grandparents — those four items, for every animal on the sheet.

Because the breeder writes it, a pedigree is exactly as reliable as the record-keeping behind it. Nothing on the page has been checked by an outside party at the moment it changes hands with the rabbit.

A pedigreed rabbit has documented ancestry. A registered rabbit has been physically examined by an ARBA-licensed registrar, and ARBA holds a permanent file on it. Every registered rabbit is pedigreed; most pedigreed rabbits are not registered, and nothing about a pedigree implies registration.

The gap between the two is the examination. Registration is done in person, with owner and registrar both present, and the registrar checks the animal against the Standard of Perfection for general and breed disqualifications before anything is signed.

• Pedigree — written by the breeder; no external verification; no minimum age; no fee; no physical examination of the animal.
• Registration — the owner and every co-owner must hold current ARBA membership, listed as individuals rather than under a rabbitry name.
• Registration — the animal must be at least six months old and meet the senior weight requirements for its breed, in a variety recognised in the Standard of Perfection.
• Registration — a complete three-generation pedigree must be presented, with every animal in it belonging to the same breed as the rabbit being registered.
• Registration — the registrar weighs the animal on an accurate scale and inspects it for disqualifications such as ear length, eye colour and markings.
• Registration — the registrar tattoos the registration insignia in the right ear, collects USD 6, and mails the application to ARBA within 15 days.

For ARBA purposes, every animal named on the pedigree needs four things: a complete name, the ear number, the variety and the weight. Listing only the breeder's name or the rabbitry name is explicitly insufficient, and an incomplete pedigree is grounds for the registrar to decline the registration until it is fixed.

The field-level rules are stricter than most breeders expect, and they are where homemade pedigree templates usually fall short.

• Name — the animal's complete and exact name, up to 30 characters including spaces and punctuation. Left blank, ARBA uses the private ear number as the name.
• Ear number — the breeder's private tattoo from the left ear. ARBA singles this field out as the one where accuracy matters most.
• Variety — the exact recognised colour, not a group. "Solid" and "broken" are rejected; "fawn" and "broken blue" are accepted.
• Weight — pounds and ounces written as a decimal, so 10.04 means 10 lb 4 oz, roughly 4.65 kg, and not 10.4 lb.
• Registration number — include it for any ancestor that is registered; the pedigree section behind an already-registered animal does not have to be filled in by hand.
• Breed — all fourteen ancestors must be the same breed as the rabbit being registered.
• Imports — an imported ancestor still needs name, ear number, variety and weight. The word "import" on its own is not accepted.

A standard three-generation sheet reads left to right. The subject rabbit sits on the left; the next column splits into sire on top and dam below; each column after that doubles, so you get four grandparents and then eight great-grandparents. The top half of the page is always the paternal side, the bottom half the maternal side.

Read across a row to trace one line back in time. Read down a column to judge consistency: if the eight great-grandparents show four different varieties and weights spread over three pounds, you are looking at a mixed pen rather than a line.

The blank cells matter as much as the filled ones. A gap means the ancestry stops there, and for ARBA purposes a pedigree with gaps cannot support registration — the registrar checks that all three generations are complete before examining the rabbit.

• Column 1 — the rabbit itself: name, ear number, variety, weight, date of birth.
• Column 2 — sire above, dam below.
• Column 3 — four grandparents: the paternal pair in the upper half, the maternal pair in the lower half.
• Column 4 — eight great-grandparents, the outer limit of a three-generation pedigree.
• A registration number beside an ancestor means that animal passed a registrar's examination; its absence means nothing more than that nobody registered it.
• A name that appears in more than one place is a line-bred ancestor — the closer the two appearances, the tighter the breeding.
• Blank cells mean the pedigree is incomplete and cannot be used to register the animal.

The left ear belongs to the breeder and the right ear belongs to ARBA. Show rules require every animal to be permanently and legibly earmarked in the left ear, using only the numerals 0–9 and the letters A–Z; a rabbit whose earmark the judge cannot read is disqualified from its class, leg band or no leg band.

The right ear is reserved for the registration insignia and is tattooed by the licensed registrar at the time of registration — a circled R applied with the clamp method, or the complete registration number if the pen technique is used. Leading zeros are dropped, so M0012P goes into the ear as M12P. Registrars are told this step is mandatory.

Ohio State University Extension describes tattooing as the accepted method of identifying rabbits used for breeding and showing in the United States. Most breeders encode something they can actually use — a rabbitry prefix, birth month and year, litter number, individual number — so the ear number alone locates the animal in the herd records.

• Left ear — the breeder's private ear number, required to show, legibility judged at the show table.
• Right ear — the ARBA registration insignia or number, applied only by a licensed registrar.
• Allowed characters — numerals 0–9 and letters A–Z, nothing else.
• Leading zeros — dropped when tattooed: M0012P becomes M12P, T0100X becomes T100X.
• Cavies — a registration tag is attached to the right ear instead of a tattoo.

A pedigree becomes useful the moment performance is attached to it. Litter size at birth, number weaned, weights at four, eight and twelve weeks, recorded per doe and per mating, turn a family tree into a comparison between lines. Without those numbers, ancestry is trivia.

It also matters which traits respond to selection through the pedigree and which do not. In a study of New Zealand White, Californian and Gabali rabbits, heritability for daily gain between four and twelve weeks was around 0.26 and body weight at eight weeks around 0.29, while litter size at birth and at weaning were around 0.05. A separate commercial dataset put litter size at birth at 0.01 and at weaning at 0.04, and concluded that prolificacy was driven mainly by year-to-year and seasonal environment rather than genetics.

Read practically: pick replacement bucks on growth data, because growth responds to selection within a few generations. Fix litter size mainly through feeding, housing and health, and by keeping daughters of does that have been consistently productive rather than chasing one spectacular litter. Penn State's benchmarks give you something to measure against — litters of 8 to 10 kits, weaning around 30 days, roughly five litters a year, and 25 to 50 live rabbits per doe per year yielding 57 to 113 kg (125 to 250 lb) of meat, with top production held for two to three years.

Utah State Extension's selection advice points the same way: choose animals from lines with a history of good productivity and fertility, choose rabbits that grow quickly and convert feed efficiently, and pick does with at least eight functional teats to nurse large litters. All three are things you can only know from records that follow the animal.

This only works if the performance records and the pedigree share one animal identity. RabbitBreeder keeps matings, kindlings, weights and mortality on the animal record itself, so a question like "which line weans the most kits" is a filter rather than an afternoon with a shoebox of index cards.

• Daily gain, 4–12 weeks — heritability ≈ 0.26
• Body weight at 8 weeks — ≈ 0.29
• Body weight at 12 weeks — ≈ 0.23
• Daily gain, 4–8 weeks — ≈ 0.20
• Litter size at birth — ≈ 0.05 (0.01 in a second commercial dataset)
• Litter size at weaning — ≈ 0.05 (0.04 in the same dataset)

The coefficient of inbreeding, written F, is the probability that the two copies of a gene an animal carries are copies of the same gene in a shared ancestor. Line breeding is the same arithmetic run gently — deliberately concentrating one admired ancestor while keeping F rising slowly — and there is no biological line between the two, only a difference in rate.

Rate is what actually matters, and rate is set by effective population size rather than headcount. FAO material notes that genetic variation is lost at about 1% per generation when the effective population size is 50, and at about 5% per generation when it is 10. A commercial rabbit line followed across many generations held an effective population size of roughly 57 and kept the increase in inbreeding below 0.01 per generation, which makes that a demonstrated target rather than a textbook one.

FAO's rabbit genetics chapter is direct about the species: rabbits can support a slow and gradual increase in inbreeding, but mating programmes for small populations should minimise both its extent and its rate, and inbreeding may reduce prolificacy. A 25-year study of a selected rabbit line found inbreeding depression on kit survival at birth during the first five years, which then disappeared in the following two decades — consistent with purging of harmful alleles, but purging is what happens after the dead kits, not instead of them.

• Effective population size, not doe count, drives the rate — 40 does served by two bucks behaves like a much smaller population than the numbers suggest.
• Keep the increase in F below roughly 1% per generation; the rabbit line above achieved that with an effective size near 57.
• Rotate or replace herd bucks on a schedule, and keep several unrelated sire lines if you intend to breed closed.
• One tight mating in an otherwise wide herd is survivable. A herd where every animal traces back to the same two bucks is not, however good those bucks were.
• Utah State Extension's guidance for smallholders is simpler: do not breed closely related rabbits, and keep family-line records so you can tell which ones are.
• Line breeding is a decision to accept a known risk for a specific trait. It is not a substitute for culling.

A pedigree records who an animal descends from. It does not record whether the animal is any good, and it cannot record what its ancestors carried without ever expressing. Those are three different questions and only the first one is on the sheet.

Malocclusion is described by the MSD Veterinary Manual as the most common inherited disease in rabbits, leading to overgrown incisors; genetic malocclusion can generally be detected in rabbits three to eight weeks old, and affected animals should not be bred. A flawless four-column pedigree does not screen for it. Looking in the mouth of every kit at weaning does.

Registration is a genuinely higher bar, because the registrar inspects the animal for general and breed disqualifications and weighs it against the Standard of Perfection. But even a registration certificate is a snapshot of one individual on one date. It says nothing about how many kits that doe weans, how her daughters perform, or whether the buck settles does reliably.

The version of "quality" worth paying for is a pedigree where each ancestor carries the numbers that mattered: weight at a fixed age, kits born, kits weaned. That is a records question, not a paperwork question, and it is the reason two pedigrees printed on identical forms can be worth completely different amounts.

Every handwritten pedigree is a copy of a copy. The sheet you hand a buyer was transcribed from the sire's sheet and the dam's sheet, which were themselves transcribed. A single mis-keyed ear number does not stay put: it propagates into the pedigree of every descendant from that point forward, and nothing in a paper system ever detects it. ARBA's own instructions warn registrars to check that handwriting distinguishes 1 from I and O from 0, which tells you how routine the problem is.

ARBA also documents the structural version of the same failure. Because the registration database is not dynamic, if an offspring is registered before its ancestors, an ancestor registered later is not back-filled into the existing pedigree unless someone flags it at the time. ARBA describes each registration as a chance to catch such oversights — which is an admission that they accumulate quietly in between.

Livestock genetics has measured what this costs. Simulated dairy cattle populations with 10% incorrect paternal identification produced about 4.3% less genetic gain than correctly identified ones, and the bias in estimated breeding values grew in later generations. In Korean Hanwoo cattle, accuracy of estimated breeding values for carcass weight fell from 0.96 at a 5% pedigree error rate to 0.30 at 80%, with expected annual genetic gain falling in step. The loss is steepest for traits with low heritability — which, in rabbits, means the litter traits.

The structural fix is to stop transcribing. RabbitBreeder generates each three-generation pedigree from the mating and kindling records already in the herd book, so the sheet is a view of the data rather than a second copy of it — a sire cannot be recorded one way in the breeding log and a different way on the pedigree.

Whatever tool you use, the discipline is the same: one identity per animal, entered once, and every litter recorded against the mating that produced it.