What causes does to do this? There are many factors. At the end of the article, I will give some ideas to help your doe get "in the mood" for her next date.
When the weather becomes cooler and fall and winter begin, some does will not breed and if they do, they sometimes won't conceive. In the wild, rabbits usually don't breed in the winter because it poses a risk for the kits - since they are born in the ground, completely naked, they are exposed to the elements and die quickly if they get chilled.
~Loss of Light
Similar to the first reason above, the loss of light during fall and winter is a major reason why does will choose not to breed. They know that the chance of their kits surviving in the winter diminishes.
~She Doesn't Like the Buck
Trust me, it happens. Some does are very particular. My first doe, Gracie, had her first litter (after her first breeding) with a broken blue buck I borrowed from another breeder. Then, after her first litter was weaned, I bred her again to a chinchilla buck. She refused to let him mount her and when he did, she didn't take. Then, a month later, I bred her to the broken blue buck again. Easy peasy, a litter the next month. After that litter was weaned, I owned my own buck. It took her 3 breedings spread out over a couple months to be willing and finally conceive a litter with him. No one compared to her first love.
~She's not Ready
Really young does might not get the hint and avoid the buck if they aren't ready to breed. Usually I will get a litter from a doe for the first time around 8 months old. With my most recent breedings, if the doe was 6-7 months she didn't take or wasn't willing to be bred.
~She's not Comfortable
I usually table-breed my rabbits, but this doesn't work for all rabbits. With one of my does, I tried table breeding her but she just wasn't having it. She wasn't lifting even though I knew she was willing. That same day, just a few minutes later, I put the buck back in his cage and put her in with him. She lifted right away.
Never put a buck in a doe's cage. Does are very territorial, and super protective of their space.
~She's Overweight or Underweight
Usually the weight of the doe doesn't cause her to want to breed or not, but it can influence the receptivity of the doe. When the doe is overweight, the buck might hit the right spot, and if he does, the doe might have complications in her pregnancy or just not conceive. When a doe is underweight, the body is deprived of nutrients and the doe probably won't get pregnant because of this.
Here are some tips that are tried-and-true to increase the receptivity and willingness of your doe.
Give more light
When the days get shorter and the light dissipates, does become less receptive to a buck's advances, because she knows that winter is coming and baby bunnies born during the winter, in the wild, rarely survive. Rabbits need about 16 hours of light per day to be bred year round. If you aren't able to give your bunny extra light, you might not be able to breed year round. If there has been a long spell of dark, rainy weather, try letting the doe spend the day in the sun on the next sunny day, and breeding her early the next day or later that afternoon.
Give ACV - Apple Cider Vinegar
Apple cider vinegar has many positive uses for rabbits. It helps them stay healthy and prevents sickness. ACV also helps a doe (or buck) make the necessary changes in his or her body to want to breed and produce a litter. It smells nasty but the bunnies love the taste. Give about a tablespoon to a 32 oz water bottle.
Give wheat germ oil
I have not done this myself, but I've heard it works wonders - about the same theory as the ACV.
If she's overweight, put her on a diet
Overweight does might be receptive, but bucks can rarely hit their mark due to the excess flabbiness. Even if she does get bred, overweight does rarely conceive. When you put a rabbit on a diet, make sure you do it slowly so they aren't stressed.
Wait for the doe to get a dark pink/red vent
If a doe's vent is whitish or light pink, most likely she won't want to breed that day. The color and receptivity can change from day to day, and some does just have off days. But if the doe has a dark pink/purple vent, she will most likely breed easily that day.
Try a different buck
Some does are picky and won't breed with certain bucks. It might sound weird but it happens! It happened to me with my first breeding doe, Gracie.
Try a different setting
She could be too distracted by her surroundings and not focused on the buck. If you normally cage breed, try table breeding them. If you normally table breed, try cage breeding. You could even try letting them in your yard to breed if its a nice day.
Put her in his cage overnight (switch cages)
Sometimes, the buck's smell will get the doe in the mood. When she spends the night in his cage, the next time she sees that buck she might be more receptive to him. Don't put the buck and doe in a cage together overnight. If the doe really doesn't want to breed, she could attack him and hurt him or they could rip out nails on the wire. You can't be positive they bred if you didn't see it happen. Always watch your buck and doe when they are together.
Let her hump him
My friend suggests letting the doe mount the buck to get her in the mood. Not all does will do this however, so I don't think it would work for everyone.