Rabbitry Setup: How Many Cages a Breeding Herd Needs, Where They Stand and What Fails First

A working rabbitry needs roughly two cages for every breeding doe, so a ten-doe herd is an eighteen-to-twenty-two-cage build, not a ten-cage one. Doe cages are half the inventory; the rest is a cage per buck, grow-out cages sized by how fast litters arrive, and one or two junior cages for replacements.

One cage per doe is biology, not comfort: adult does attack each other's young, so group housing of breeding animals fails. Bucks are cheaper, at one per ten to fifteen does commercially and one per five or fewer in a small herd.

Grow-out is where plans go wrong, because that number is not a ratio. The doe's cycle is rebreeding interval plus about 31 days of gestation, so rebreeding at day 35 gives a 66-day cycle and day 21 gives 52. Replacements get forgotten: a doe stays productive two to three years, so forty percent of the herd turns over yearly.

• Doe cages = one per doe. Adult does cannot share.
• Buck cages = one per ten does commercially, one per five or fewer in a small herd, plus a spare.
• Doe cycle in days = rebreeding interval + 31 days gestation. Litters arrive every cycle divided by does.
• Grow-out: litters on the ground at once = (market age - weaning age) x does / cycle. Convert at whatever fryers-per-cage figure you run.
• Replacement cages = does x 0.4 x (4 months / 12), rounded up.

Fix the assumptions and the pattern beats the algebra: gestation 31 days, seven kits weaned per litter, fryers leaving at about ten weeks, grow-out cages of roughly 0.7 square metres (7.5 sq ft) holding five or six rabbits.

The ratio barely moves with scale, so budget about 2.1 cages per doe at any herd size. What moves it is stocking density, since European commercial practice fits nearly eleven fatteners in that same cage and halves the grow-out block. The arithmetic is only as good as its inputs, which is why herd software such as RabbitBreeder derives the cage count from logged kindling and weaning dates.

• 5 does, relaxed (rebreed day 35, wean day 42): about 15 fryers on the ground. 5 doe + 2 buck + 3 grow-out + 1 junior = 11 cages.
• 10 does, semi-intensive (rebreed day 21, wean day 35): about 47 fryers. 10 + 2 + 8 + 2 = 22 cages, or 18 on a slower schedule.
• 20 does, semi-intensive: about 94 fryers. 20 + 3 + 16 + 3 = 42 cages.
• 50 does, semi-intensive: about 236 fryers. 50 + 6 + 40 + 7 = 103 cages.

Once the count is settled, the question is how to stack it. Wire cage systems reduce to four layouts, and the FAO description of them still reads as a straight trade of building cost against labour and air quality.

EFSA's 2020 review found it likely that does in conventional cages have lower welfare than in five other systems, and growing rabbits better off in elevated pens. Airflow modelling shows the mechanism: air above the cages was well mixed, the zone underneath practically stagnant, floor level 3 to 4 K cooler.

Ammonia makes that layer expensive. A doe unit emits 55.9 mg an hour against 10.2 mg for a fattener, and rabbits held 45 days at 16.49 ppm rather than 4.81 ppm showed shifted nasal and gut microbiota and lung gene expression consistent with inflammation. Both figures sit under the 25 ppm human workplace limit.

• Flat-deck, single level, hung or on legs: lowest density per square metre of building, best ventilation and access, highest building cost per animal.
• Californian, staggered decks one higher but not directly above: flat-deck ventilation, slightly more animals per square metre, harder access above, dearer frame.
• Inclined-slope battery, stacked with waste sliding into troughs: higher density at reasonable cost, but the waste does not slide properly and must be raked down.
• Compact battery over belts or scrapers: cheapest per animal, worst for ventilation, supervision, handling, light and wear.

Floor area per animal and interior height are the two numbers that matter, and the standards disagree by enough to change the build. Height bites hardest: the 30 cm French commercial breeding cage sits below both ARBA's 35.5 cm minimum and the 32 to 39 cm range EFSA recorded in current European cages.

Aisle width and working height are fixed by two jobs rather than by any standard. Servicing means carrying the doe to the buck, never the reverse, because a buck put in a doe's cage marks territory instead of breeding. Tier spacing is interior height plus the drop pan or sloped board plus clearance to pull it out.

• ARBA floor space per weaned rabbit: 0.14 m2 (1.5 sq ft) under 2.0 kg, 0.28 m2 (3 sq ft) at 2.0-4.0 kg, 0.37 m2 (4 sq ft) at 4.0-5.4 kg.
• ARBA minimum for a doe with litter: 0.46 m2 (5 sq ft) at 2.0-4.0 kg, 0.56 m2 (6 sq ft) at 4.0-5.4 kg, 0.70 m2 (7.5 sq ft) above.
• ARBA interior height, every class: 35.5 cm (14 in). Penn State's minimum adult cage: 76 x 76 x 51 cm (30 x 30 x 20 in).
• French commercial cages: doe with internal nest box 65-70 x 50 x 30 cm, buck 40 x 50 x 30 cm, future breeder 30 x 50 x 30 cm.
• EFSA-recorded European cages: does 38 x 87-102 x 32-39 cm; enriched 38-46 x 95-102 x 60-65 cm; growers 38 x 43.5-66 x 28-41 cm.
• Wire: 25 x 50 mm (1 x 2 in) sides and top, 13 x 25 mm (0.5 x 1 in) floors, 2.4 mm diameter, welded then galvanised.

The climate envelope decides the structure. Rabbits thermoregulate between roughly 0 and 30 C (32-86 F) and cannot above 35 C (95 F); the comfortable band is 15-20 C (59-68 F). Humidity below 55 percent is its own problem, and sore hocks rise sharply at 31-32 C or above 85 percent humidity held constantly.

Two decisions get made by default and should not be. Penn State recommends twelve hours light and twelve dark year-round, while European practice gives breeding stock sixteen hours at 30-40 lux. And straw litter must be changed at least weekly, whereas a mesh floor allows infrequent cleaning at the price of total dependence on the building's air.

• Individual roofed hutches: cheapest, workable where mean temperatures stay between 20 and 30 C (68-86 F). Overhang the sides and face the front away from prevailing wind.
• Wire cages under one common insulated roof: flat-deck outdoors, needing a wide overhang and a hedge or fence for wind and predators.
• Converted barn or stable: usually needs insulation added, almost always ventilation. Flat-deck racks fit because they need no long building.
• Purpose-built shed or indoor room: the only option that holds 15-20 C (59-68 F) and 60-65 percent humidity deliberately.

Cage wire is specified for the rabbit; predators are a different specification. Extension guidance for rabbit cages calls for 25 x 50 mm (1 x 2 in) mesh on sides and top, while extension predator guidance warns that raccoons reach through openings in mesh and wire caging to grab at the animals inside.

So the barrier that stops predators is the structure around the cages, not the cage. Dogs are the threat most likely to reach a backyard rabbitry and the answer is a perimeter; rodents are the most underestimated, since a doe does not defend her litter the way a dog or even a rat would.

• The 25 x 50 mm (1 x 2 in) mesh recommended for cage sides and tops keeps rabbits in. It does not keep a raccoon's forearm out.
• Fence the whole rabbitry against dogs and disturbance: wire netting, a thorn hedge or sturdy pickets.
• Against diggers, bury hardware cloth in a trench 30-45 cm (12-18 in) deep around the structure.
• Elevate housing off the ground, and fit tin plates or cones on legs and posts so rats cannot climb.
• Protect feeder openings too, and close gaps under 6 mm (0.25 in) where snakes are a local problem.

A doe nursing a four-to-six-week-old litter drinks 2.5 to 3.5 litres a day, and that number ends hand-filled bottles. It is roughly seven times what the same doe drinks dry, so the move to a gravity-fed nipple or cup line is a volume decision rather than a herd-size one.

Bottles fail three ways and only one is visible from the aisle: the ball fails to seat and the bottle drains, the ball sticks and blocks the water path completely, or bottle and valve freeze outdoors. Nipple lines are not automatically better, because rabbits drink three to four times more slowly at a nipple and did better from open dishes whenever access was restricted.

Design the line for the failure modes. Gravity systems run off a low-pressure tank 50 to 150 cm above cage level, which doubles as the medication point; keep it shaded. Warm water improved post-weaning growth in winter, water cooled to 10-15 C reduced heat stress in summer, and dissolved salts should stay under 3 000 ppm.

• Doe with litter, days 0-14: 0.8-1.5 L a day.
• Days 14-28: 1.5-2.5 L. Milk output peaks around day 21 at about 207.6 g a day and water demand peaks with it.
• Days 28-42: 2.5-3.5 L; one figure puts a doe with an eight-week litter at 3.8 L.
• Dry adult: 0.3-0.5 L. Growing rabbit: 0.2-0.3 L. A 13-week-old New Zealand White averages 0.42 L.
• Group housing: at least two weight-valve drinkers per ten rabbits, nozzles checked daily.

A mesh floor carries 16 to 18 fatteners per square metre against about 10 on litter, because droppings and parasite pressure leave immediately. Above roughly 16 per square metre growth falls, and ARBA's per-rabbit minimums are far more generous at about seven and 3.6 rabbits per square metre, so choose your standard before counting cages.

Density and group size are separate levers, and the second gets pulled by accident. Dropping below 16 per square metre produced no measurable gain, but larger groups at the same density produced steadily more ear lesions. The removable divider that halves a pen is therefore about group size, not space.

Feeders are chosen by refill interval. A pellet hopper should hold two or three days, a forage rack one day, a mash trough a single feed, all filling from outside the cage. Open crocks are a hygiene problem rather than a saving, because rabbits soil them.

• 18.7 rabbits/m2: 2 150 g at 77 days, 32.0 g/day gain, 111 g/day feed.
• 15.6 rabbits/m2: 2 327 g, 36.1 g/day gain, 122 g/day feed.
• 12.5 rabbits/m2: 2 384 g, 36.5 g/day gain, 122 g/day feed.
• Ear lesions at 11 weeks by group size: 0 percent at 2 per cage, 7.1 percent at 8, 8.7 percent at 13, 17.4 percent at 26.
• Feed-box opening about 7-8 cm for medium breeds; rack bars 1-2 cm apart; troughs detachable for disinfection.

French rabbitry economics uses one unit for all of this: the mother-cage, meaning total investment in building, caging and equipment divided by the number of does. The benchmark was that the outlay per mother-cage came to roughly the value of the young that cage produces in twelve to eighteen months.

Buy in the order things fail. Doe cages and nest boxes first, because preweaning losses run 15 to 40 percent of liveborn kits: at least 50 x 25 x 25 cm, an entry hole about 15 cm across, a non-skid bottom and a 1 to 1.5 cm drainage gap. The watering system second, because it fails silently, and grow-out cages last.

Buy the wire once: wooden cages last no more than two years against 15 to 30 for concrete. Feed overtakes steel quickly, since a New Zealand doe and her litter eat about 45 kg (100 lb) from breeding to weaning. Keeping cage inventory, kindling dates and cull decisions in one ledger, which is what RabbitBreeder is built for, turns 'we need more cages' into a date.

• Cages: $30-200 each depending on size, materials and whether new or used.
• Feed and water containers: $3-10 per pen. Carrying cages: $10-20 per compartment.
• Breeding stock: $20-30 and up per animal.
• Pellets: $0.10-0.15 per pound, at 0.5-1.8 kg (1-4 lb) per rabbit per week; feed conversion about 3:1.
• Cage life: wood no more than two years, concrete 15-30 years.