The Rabbit-Raising Problem Solver (Storey Publishing, 2014), by Karen Patry, addresses questions and concerns about housing, feeding and breeding rabbits at every stage in their lives. From choosing productive meat and fiber breeds to preparing a proper nest box and coaxing a fussy bunny to eat, you’ll find proven answers and humane solutions to your rabbit-raising quandaries. In the following excerpt “Is the Time Right?” from Chapter 6, “The Mechanics of Mating,” Patry teaches you how to determine when to breed your rabbits.
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What will a boy and girl rabbit do if you put them together? They will mate as soon as they are physically capable of doing so, which may be a whole lot younger than you thought possible. Which is why you need to know the First Rule of Raising Rabbits:
If you house intact bucks and does together, you will wake up one morning and find kits in the cage, whether you’re ready or not.
There’s a reason for the saying “breeding like rabbits.” Rabbits mate so fast it might make you blush. Blink and you’ll miss the mounting, the mating, and the fall-off. It doesn’t take long for the buck to get to work, because reproducing is a rabbit’s main goal in life. Even the youngsters test their skills by riding each other.
Most often, of course, rabbit breedings are planned. But are the animals ready for each other? Before popping the doe into the buck’s cage (never the other way around!), always perform a full health check on both of them. This prevents the transmission of rabbit syphilis and avoids unnecessary stress on rabbits that aren’t in condition to be bred.
Is the Time Right?
Q. When do female rabbits come into heat?
A. Unlike dogs and cats, rabbits don’t go in and out of heat. Rather, they are induced ovulators, which means that the act itself causes the doe to ovulate within hours of mating. But that doesn’t mean she has no cycle. A doe will experience a hormonal cycle of approximately 18 days: 12 to 14 days of willingness and 4 days of refusing to mate.
Here’s how it works: The cycle starts with the doe having five to ten (or more) eggs that are mature and ready for fertilization. These eggs are contained in fluid-filled, cell-lined follicles that produce estrogen for up to 14 days, waiting and ready for the external stimulus of mating. If mating occurs, the follicles rupture within 10 hours, releasing the eggs, which are then fertilized and implant themselves in the uterus.
If no mating occurs, the follicles and eggs degenerate and the ovaries begin readying another set of eggs. The doe will reject any advances of a buck until the new set of eggs has matured and the follicles begin pumping out the estrogen, which takes approximately 4 days.
Q. At what age can a doe get pregnant?
A. The breeding age of domestic rabbits is correlated with size, so it varies somewhat with the breed of rabbit. Domestic rabbits can range from 2 pounds to 42 pounds. The tiny breeds mature earlier than the giant breeds, but all rabbits are considered fully adult by eight months of age, though they may be physically capable of breeding much earlier. A smallish doe can conceive a litter by 14.5 weeks (3 months and 10 days by the calendar).
That said, rabbits don’t watch the calendar for permission to breed. They will mate as soon as their individual hormones kick in. I’ve heard rare stories of small rabbits conceiving as early as 11 weeks. This doesn’t mean that any 11-week-old doe can conceive, but time flies! Neglect too long to separate littermates, and you’re guaranteed a big surprise. It is safest to separate bunnies by 10 weeks of age.
Gender can be determined as early as two weeks of age, and reliably by six weeks of age, so you should have no excuses for not separating them in plenty of time. Mistakes do happen, however, so if a rabbit in a sexed batch starts acting oddly, you should probably check it again!
Q. When are rabbits considered sexually mature?
A. Although rabbits are physically capable of becoming pregnant at about 4 months old, the general rule is not to allow small to medium breeds to mate until 6 months of age and large to giant breeds until 8 months of age. Particularly large individuals of the giant breeds might not be ready until 10 to 12 months of age.
Q. What happens if an underage rabbit becomes pregnant?
A. It depends on the rabbit. If you give her nesting materials on day 28, she may kindle a fine litter and take care of them perfectly well. The downside will be a delay, possibly permanent, in attaining her normal adult weight because she will expend that growth energy on sustaining the pregnancy.
Of rabbits that fail to mother, a significant percentage are bred too early. In this case the rabbit will kindle the litter, and may even clean up the babies, then hop away and forget she had them. You’ll lose the babies unless you foster or hand-rear them. However, the odds are good that the mother will nurture her next litter just fine when the time comes.
Q. How do bunnies start showing that they are ready to mate?
A. As they turn into teenagers, around 3 months of age, both males and females start mounting each other. Bucklings start squabbling. Some of this behavior is related to creating a dominance order, but a whole lot of it is demonstrating an increasing sexuality. It is best if the rabbits aren’t allowed to breed until they are several months older and more physically developed.
Q. Is my two-year-old doe too old to breed for the first time?
A. Rabbits are usually quite capable of breeding through 2 years of age and many times through 3 years. While many does will take a late breeding in stride, the issue with older first-time does is usually twofold:
• An unbred doe has a tendency to become overweight or even obese if her feed is not limited. With fat deposits clogging the reproductive system, she may have difficulty conceiving, and then may conceive only one or two kits. Those kits can grow to gigantic proportions in the womb and then may get stuck in the birth canal. You could lose both the doe and her kits.
• There are anecdotal reports of the pelvic bones becoming stiffened or fused in some late-bred does, making it difficult for a doe to kindle even normal-sized kits.
In either case, it may be necessary for a veterinarian to perform an expensive C-section to attempt to save the doe and perhaps her kits. If your doe is overweight, bring her down to her ideal weight (according to the breed standard) before attempting to breed her. With a normal-weight doe, you might want to seek the opinion of a rabbit-savvy vet who can assess whether her pelvic bones are fused, and if she is capable of becoming a first-time mom.
Q. Can a rabbit get pregnant if she has not had a litter in a long time?
A. Yes, depending on what you mean by “a long time.” If the doe is healthy, between 1 and 3 1/2 years old, and not excessively overweight, the chances of getting a litter from her are good even if she hasn’t been bred in a while. A few does as old as 4 or 5 can still be bred, but by that age their bodies are winding down. At best, the litter sizes will be small; at worst, the does can no longer conceive.
Q. How can you prevent rabbits from mating?
A. Keeping them in separate cages works. If you want two rabbits of opposite sex to live and play together, your only option is to spay or neuter one of them.
Q. I just saw my rabbits mating. What are the chances of the doe being pregnant?
A. The chances are very, very good if they’re adults. Go mark your calendar now while you’re thinking about it. Give the doe a nest box 28 days from today, and expect babies about 3 days after that. And by the way, your buck will need his own digs — soon.
Want to learn what to do if you suspect your rabbit of being pregnant? Read The Raising-Rabbit Problem Solver to learn how to palpate and care for your pregnant doe.
Excerpted from The Rabbit-Raising Problem Solver (c) by Karen Patry, Illustrations by (c) Elara Tanguy, used with permission from Storey Publishing. Buy this book from our store: The Rabbit-Raising Problem Solver: Your Questions Answered About Housing, Feeding, Behavior, Health Care, Breeding, and Kindling.