Selective Breeding: Manipulating Rabbit Genetics for Aesthetics

Selective breeding is when humans choose they like a particular characteristic and then breed for it by choosing rabbits with those traits and breeding them together.

Selective breeding applies to colour, size, body shape, fur quality growth rate, mothering abilities, friendliness, and any other traits that are desired.

Any rabbit’s genetic code is very complex and is tough to modify, contribute or adust it. Selective breeding gets the wanted genetic information in the kits and makes the unwanted genes disappear. The more rabbits are bred for a particular trait, the more unwanted traits disappear. But once they are gone, they are gone forever.

Rabbits were used in scientific laboratories because they are timid, non-aggressive and sociable. They also can live in cooler temperatures than most other laboratory mammals, between 16°C – 22°C. They eat continuously and drink around 120ml of water a day. Their excretions are minimal compared to the food they consume, although they can excrete up to 75ml of urine a day, this meant that the rabbit’s catch pans were cleaned twice a week.

They are very popular experimental animals because they are genetically and physiologically close to humans and other mammals, and more importantly, they are genetically and physiologically close to humans and other mammals and, therefore, a more adequate and viable model for experimental studies in several branches of science. (Online Library: Rabbits – their domestication and molecular genetics of hair coat development and quality)

Over the years, 76 breeds of rabbit were bred for laboratory use, but the New Zealand White, bred in the 1920’s has become the most popular and commonly used in research. They are used for antibody developments and are testing sentinels for a wide array of products. There are more than 160,000 rabbits in laboratories in the US each year.

Rabbit antibodies are used to target therapeutics and diagnostics. Rabbits have a gene that can also only be found in chickens, which allows scientists to use less chemicals in the testing procedures, and it still produces the desired results.

Rabbits have a low immunogenicity antigens (a weak immune system), which means if they survive the treatment, it can be safe for use on humans. Rodents like mice and rats have a tougher immune response and will not produce the results.

Testing sentinels is another way of saying an animal used for scientific testing.

Would you believe that rabbit fur is one of the world’s most economically valuable commodities?

Rabbit fur is one of the most preferred natural fibers among the textile industries. About 8500 tons of Angora wool are produced every year, which makes it the third most-produced animal fiber in the world, after sheep wool and mohair.

The economic value of rabbit hair depends on several key traits including fibre diameter, density and length, with coat colour also being an important factor. Fur quality is mostly determined genetically, through selective breeding. With rabbits bred for wool, the fur density is an especially important trait. The thickness of the fur, and how much the rabbit grows is used in quality evaluations. Although the genetic mechanisms that are used to make a rabbit have a suitable coat, is still not thoroughly researched as much as it is in sheep or alpacas. That also means that there are lots of factors that affect the quality of the fur and studies on how to get the desired characteristics are not as thorough as those on humans, sheep and mice.

Scientists have discovered that they can manipulate a rabbit’s hair at the embryonic stage, and it has those changes throughout the rabbit’s entire life. They have found the genetics that are involved with growth, density and colour. Rabbit fur is the most important natural fibre from an industrial point of view because it can replace synthetic fibres, and if scientists can change DNA to produce the types of hair that are most popular, they will produce a new type (or types) of selectively bred rabbit to accommodate these uses.

People have wanted tiny rabbits since the 1800s. Back then a normal rabbit weighed around 3-4kg. It was given the nae “Polish” to sound more posh. Each time a small rabbit appeared in a litter, it was used to breed with other small rabbits. By the 1900s Polish rabbits weighed 2-3kg, and were bred to have an arched back. Now, there are two small breeds because the dwarf gene has been promoted.

Even though it took more than a century to get small rabbits, people want them smaller, or even teacup.

Polish rabbits in the UK became so inbred that they were sickly, angry, and frightened when people approached. These traits now are permanent and cannot be undone. The only way to cease these traits is to not breed from those rabbits, and only bred from rabbits that do not have those traits.

On the flip side, if you want large bunnies, you have to start with big rabbits and breed them together with other large rabbits to get the traits that you desire.

People who are wanting meat rabbits will have to have a constant supply of rabbits. When they selectively breed meat rabbits, they want ones that have a lot of meat, can produce many kits, and have not much fat. That’s why they choose to use large rabbit breeds for meat.

China and the Mediterranean have the largest meat rabbit producers worldwide.

Some breeders breed rabbits for meat in Australia. They sell the kittens to unsuspecting buyers, and any left overs that don’t sell are slaughtered for meat. They don’t care about the genetics and health of the animal, they only care about the meat quality. But as the buyer, you have no idea that is what they do.

Like with any animal, the more the genetics is refined, the more other issues arise. Blindness, tumors, deafness, organ failure, osteoarthritis, heart issues, pododermatitis (sore hocks), dental issues etc are all part and parcel of selective breeding. Some traits are obvious at birth, others develop later in life.

If you’re wanting a selectively bred bunny (from a breeder who shows their animals), make sure you ask about the health issues that are prominent with their animals.

Giant bunnies have a lot of body to carry around. Because they are so big, they are not very active, so their bones can get issues.

• Osteoarthritis – in the hips and back legs. Very painful.
• Heart issues – enlarged heart, weak vessels, insufficient blood pumping. Can happen all of a sudden and can cause immediate death.
• Eye issues – the nictitating membrane (third eyelid) protrudes, usually caused by heart issues or respiratory distress.
• Pododermatitis – sore hocks is a problem due to their size. Can get infected, cause immobility and severe pain.

Any bunny with floppy ears has been selectively bred for that trait. It is a deformity and can cause pain for the rabbit because it cannot hold it’s ears in a natural position.

• Ear issues – prone to narrow ear canals, build up of wax, ear pain caused by irritation or infection. Cannot drain debris out of their floppy ears, which can cause infections. The pressure of the ears can cause skull and jaw pressure.
• Dental issues – teeth can grow in the wrong direction and abnormally long because the lop cannot chew properly due to the weight of the ears. Shorter face means dental issues.
• Skeletal issues – mini lops are prone to spondylitis (kind of arthritis that affects the joints and ligaments of the spine) and can have trouble keeping themselves clean, and therefore are prone to flystrike.

Due to intensive breeding, Rex rabbits have no guard hairs in their coat, that’s what makes the coat so soft and thick – a Rex’s coat is actually the velvet undercoat.

• Eye issues – without guard hairs, this also means they don’t have eye lashes. This causes many eye issues.
• Pododermatitis – can get ulcers on their hocks because there isn’t a lot of hair on their back feet.

Any bunny who has a flat face, whether it is a dwarf, lop, angora, or any other breed, has a multitude of issues due to selective breeding.

• Breathing issues – the flat face causes issues with air intake. Some rabbits have very limited air that can get into their lungs, and so those bunnies are docile and love laying on the couch with you. That’s only because they aren’t getting the right amount of oxygen in their system.
• Dental Issues – the flat face is created through a skull shape change. That means the bunny’s teeth are not normal too. Their teeth can be overcrowded and the back molars can overgrow and turn into the cheeks. This causes pain and the unwillingness to eat.
• Tooth rot – dental abscesses are caused by bacteria in the tooth. Teeth can become decayed due to bacteria building up in the gums.
• Tear Duct Issues – the tear duct itself is a great place for bacteria to grow, and this can cause dental abscesses.

Bunnies who have long hair cannot clean themselves properly.

• Matting and skin issues – Rabbits need to groom themselves to keep their skin and hair healthy. If they don’t get the required grooming each day, their hair can become matted and knotty, and their skin can dry out and start flaking.
• Urine scald – this happens when a bunny can’t clean their bottom properly and their back end is stained with urine. This causes skin irritation around the back legs, tail and genitals.
• Fly strike – just like urine scald, long haired bunnies can’t clean their poop adequately, and this will make flies start hovering around their bottoms. A fly can lay hundreds of eggs that can hatch in a few hours. Maggots feed on the rabbits flesh and can be life threatening.
• Dental Issues – selective breeding has caused malocclusion in long haired and flat faced bunnies. This prevents them from eating and drinking properly.

One of the latest fads for rabbit breeders is short ears. Some rabbits have round ears like teddy bears, others have the tiniest upward ears. This is only bred for human aesthetics. It is not cute, it is a disaster. They are most likely born deaf or have bad hearing.

A medium sized rabbit (3-4kg) with a long nose and upward ears. It’s safer to get a bunny that looks like its wild relatives, because it should have less selective breeding issues.

If you’re looking at getting a rabbit, look at it’s confirmation. Is it’s back arched naturally, are it’s arms a good length, what angle are it’s hips on? How long is it’s thorax (chest)? Is it blind or deaf or both?

Make sure you do a full confirmation check on the rabbit before you purchase it.

Pick it up and feel it’s guts (gently, of course). Run your fingers over it’s belly and feel for lumps. There shouldn’t be any. If you feel any, don’t get the rabbit. Look at it’s eyes and in it’s ears, look for problems.

Do a full health check on the rabbit before you purchase it.

There is an article on checking the confirmation and health of a rabbit, please check it out.