Occasionally there’s just something a little… off… about a pairing.

We went to several family reunions this summer and, truth be told, our 5-year-old daughter developed a bit of a crush on one of her cousins.

I overheard the 7-year-old talking to her about this crush: “You can’t marry him! He’s our cousin! If you get married your kids will have two heads and three eyes!”

Yep. We’ve talked about the dangers of inbreeding our family. As a practice for human beings we are 100% against it.

But rabbits are a different story.

When you’re thinking about how to get the healthiest herd with the least amount of animals, there’s no doubt you have to consider how closely related you want your rabbits to be over the long haul.

We have worked pretty hard to get unrelated animals to start our herd, importing bloodlines from all over the United States. That being said, we’re planning on sticking with these animals and their offspring until we have a very solid “Mad Hatter Rabbit” stamp on any animal that comes from our barn.

The Domestic Rabbits publication by ARBA had a great article about the differences between inbreeding (breeding siblings) and line breeding (breeding father/daughter, mother/son, grandparent/grandchild, etc.). Most of the top breeders utilize line breeding regularly to “stamp in” the breed characteristics they find most desirable.  Additionally, traditional wisdom says if you get a brother/sister pair, produce one mating out of that pair (inbreed) and from that point forward switch to line breeding and you won’t run into problems.

I spoke with a friend who is a geneticist and his experience confirms this philosophy. He told me in scientific studies researchers have deliberately inbred their rabbits, trying to get the most genetically similar test subjects possible. It was only after 18+ generations the researchers began to see problems like malocclusion (wolf teeth), compromised immune systems (sickly rabbits), and other common problems associated with inbreeding.

We have personally bred a brother/sister combination of rabbits that we knew nothing of the genetic history about. The litter produced wolf teeth and poor immunity and we ended up culling it from the breeding program and vowing to never repeat that breeding. But remember – we didn’t have a pedigree on that pair and have no idea how many times their ancestors were inbred before they got to us!

This is another reason it makes sense to spring for a pedigreed rabbit when purchasing stock. In one case we found rabbits from different states but after looking over the pedigrees I discovered the rabbit was related identically to our other rabbit after two generations back! We were able to make an informed decision about whether we wanted that rabbit in our herd.

Typically line breeding makes the good stuff you’re seeing in your rabbit better and the bad stuff worse. It’s like getting a double stuff Oreo – augmenting the genetic qualities with potentially awesome or disastrous results.

Here’s a graphic that might make the idea of line breeding a bit more understandable:

line breeding / inbreeding / outcrossing chart

Ultimately every breeder must make the decision they feel is best for their herd regarding how tightly they breed their rabbits. We do practice line breeding with moderation and willingness to cull hard if a poor pairing appears. With our Astrex program we must do tight breeding to a certain extent to try to isolate and reinforce the curly gene – while always keeping the health of the rabbit in mind.

Fascinating stuff, huh?!

Tagged: brother and sister mating, can I breed littermates, inbreeding, line breeding, line breeding chart, out crossing, rabbits