Rabbits have a well-earned reputation for, well, breeding like rabbits — except when you want them to. According to conventional wisdom, all you need to do is throw a buck and a doe together, and you’ll be swimming in rabbits in a few weeks. But often there are a few challenges in store before you can start counting your kits.
A Frenzied Fortnight
When it comes to reproduction, the words “estrous” and “estrus” look and sound annoyingly similar, but they describe very different parts of the same cycle. Estrous refers to the entire reproductive cycle, from the first day of physiological activity by the ovaries, through the sexual receptivity phase, and then to the period where all ovarian activity regresses, and back to the point where it starts again. Estrus refers solely to the period where females are receptive to mating, usually right before ovulation. This is commonly called being “in heat.” To reduce confusion, I’ll refer to the entire cycle as estrous, and the estrus period as receptivity to mating or being in heat.
The estrous cycle is a little different for rabbits than other mammals. Most livestock species have a cycle that’s composed of a longer period when they aren’t in heat, and a shorter period (usually 1 to 2 days, depending on the species) of receptivity to mating. The estrous cycle generally lasts 21 days on average, although it can vary from 18 to 24 days. Ovulation occurs at the end of the heat period, and mating is timed to make sure semen reaches the egg at the optimum time for fertilization. If the timing is off, or no breeding occurs, the follicles on the ovaries that produce both the eggs and the hormones that support pregnancy regress, and the process starts all over again.
Rabbits are pretty much the opposite. Does can have a period of up to two weeks when they’ll accept mating by the buck, and they don’t ovulate until after mating has occurred. They’re what is known in the animal kingdom as “induced ovulators.” Without the stimulation of mating, no ovulation will occur. Rabbits will remain receptive until the follicles regress. They’re also nonreceptive for a much shorter period of time, 3 to 4 days on average.
This is good news for the farmer. With cattle or sheep, if you miss the brief period of heat and don’t get your bull in or the artificial insemination done, you have to wait 21 days to try again. A rabbit will usually give you an opportunity the next day.
Sow Many Seeds
There are few absolutes when dealing with animals, but here’s one for rabbits: Always take the doe to the buck’s pen for breeding. Does can be very territorial, and bringing the buck to her cage is an invitation for her to be aggressive toward him, possibly injuring him or at least ruining the mood. A mature, experienced buck will be all business. He may take a few nudges at her to test the waters, but he’ll be focused on getting the job done. Mating should occur within a few minutes, based on the experience of your buck and doe. It might take a younger pair longer to figure things out, but they should at least be interested in one another.
Stay nearby until mating does or doesn’t occur. If mating is slow to start, it’s tempting to leave the pair together for an extended period of time, but this is inadvisable. Mating might occur while you’re gone, and you won’t know the outcome, or the doe might get tired of the buck’s advances and fight with him. When rabbits fight, they use their hind legs and claws to attempt to eviscerate one another by clawing and scratching at the underbelly, which can put a doe’s flailing claws right next to a buck’s testicles. Rabbits can effectively castrate one another, which is a dismal end to a promising breeding program.
Another reason not to leave a doe and buck together unsupervised is because an aggressive older doe can intimidate a buck to the point where he’s reluctant to even attempt to breed. A little chasing is a normal part of rabbit courtship, so don’t be alarmed if they engage in that kind of foreplay. But watch for actual fighting, and don’t hesitate to separate them and try again later. Sometimes a few hours can make all the difference.
If you have a doe that you’re positive is in heat, but she won’t hold still for the buck to mount her, you can reach into the cage to hold her still. Grip the skin on her shoulders and hold her for a few seconds until the buck mounts her. Moving around too much is more common with young, inexperienced does, and they usually get the picture pretty quickly.
When successful mating occurs, the doe will raise her hindquarters for the buck. He’ll breed quickly, with rapid thrusts, and when ejaculation occurs, he’ll lose his footing from the force of the thrusts and fall over, sometimes with a little cry. If the buck doesn’t fall over, no mating has occurred.
With other species of domestic animals, a 21-day heat check is often the first concrete sign of pregnancy. A rabbit’s gestation, however, is two-thirds complete at that point! In many rabbitries, the practice is to simply wait until the kindling (birth date) comes and goes to confirm if the doe was pregnant. However, if your goal is rabbit production, that strategy is inefficient.
Another common practice is to try a test breeding about two weeks after the initial mating. But this strategy also has its drawbacks. Some does will breed even though they’re pregnant, so you must still pay attention to the original potential due date and be prepared with a nest box, or else she could lose the litter.
A better, more accurate solution is to palpate does to confirm they’re pregnant. This is a relatively simple procedure and won’t hurt the doe, but it takes practice to be accurate. Restrain the doe by the scruff, and slide your other hand under her abdomen. Let the weight of her belly fall into your hand. Slide your fingers and thumb along either side of her abdomen, and you should feel little round objects (about the size of grapes) if she’s pregnant.
At day 11 or 12, a person experienced at palpation should be able to feel the uterus and the marble-sized kits. Until you’ve gained a lot of experience palpating, day 14 is going to be a much more realistic date to check. My husband, Eric, can palpate at day 11 and tell with a high degree of accuracy how many kits the doe is going to have. As for me, I settle for pregnant or open (not pregnant). You’ll have to palpate a lot of does to get the ability to count kits with any degree of certainty. And it’s possible to mistake kidneys for kits. This is where it’s helpful to practice regularly. Kits change and grow; kidneys don’t. Practice on a couple of does you know are open, and then as you practice with bred ones, you can at least begin to tell the difference between an empty uterus and a full one.
Most people are concerned about hurting the doe or her litter when palpating, but as long as you’re not intentionally trying to squeeze her innards into mush, a healthy doe with a healthy pregnancy won’t suffer ill effects. Palpating might also seem like an unnecessary task. However, nonproductive doe days can tank the profitability of a rabbitry. You may not plan to sell the fryers (baby rabbits) for a profit, but having fewer animals can still reduce income. Even if your goal is just to have a freezer full of meat by winter, a two-week loss in production can set things back further than necessary.
Can you guess wrong? Of course. It still pays to keep a close eye on the doe when approaching the earliest possible due date. Watch for signs of impending kindling (heavy belly, nesting behavior). If you palpate close to the due date, you should feel a heavy, full belly. Go ahead and put the nest box in; it’s always better to be safe than sorry.
Warning: Heat Advisory
Most does will not show a lot of outward behavior of being in heat, but there are a few signs to look for. Like most other livestock, a receptive doe can sometimes go off feed. (This is one reason to limit feed, and know exactly how much food she ate the day before.) She can occasionally be more vocal, and a little bit grouchier and more territorial. If you think a doe might be in heat, be careful reaching into her pen. She might be defensive.
The most reliable way to tell if she’s in heat is to look at the condition of her vulva. A receptive doe will have a vulva that’s dark-pink and moist, while a nonreceptive doe’s will look pale and dry by comparison. The only way to accurately tell the condition of her vulva is to pick her up, turn her over, and take a good look.
By day, Callene Rapp is a senior zookeeper at the Sedgwick County Zoo in Wichita, Kansas, and by night she manages The Rare Hare Barn with her husband, Eric. Between the two places, she’s learned to manage all sorts of livestock and livestock challenges.