American Rabbit Genetics
The American Blue rabbit orginally comes from Pasadena, California, developed and introduced by Lewis H. Salisbury in 1917. Like many American people, the American breed rabbit is a combination of immigrants welded together by blood to become a distinctly different and American creation. At least three different breeds of rabbit were used. The American White variety was introduced in 1925.
But, we can see the heritage of this rabbit when we look at it: we see the Flemish, the Vienna, and the Imperial in the mandolin shaped American. This unique shape is shared in the U.S. by the Beveren, English Lop, Flemish Giant and the Giant Chinchilla. Before the European War (WWI), the American Blue was known as the German Blue, but was re-named after the war, just like many immigrants who naturalized here.
Intended as a meat and fur rabbit, the American standard calls for bucks to weigh 9 – 11 lbs and does to weigh 10 – 12 lbs at senior weight. Long in body, topline starting behind the shoulder, the topline rises high over the hindquarter and down again, with a wide meaty loin.
Since the development of compact and commercial type rabbits like the New Zealand and Californians, the American breed has lost its position as a leader and is now completely ignored by the commercial market. Currently there are a small number of faithful breeders keeping this American original alive.
By the standards of the American Livestock Breeds Conservancy, this breed has been rated as “critical” for potential loss (extinction). The Blue Imperial is already extinct. The Vienna Blue is gone from the U.S. and hard to find in Germany. We encourage breeders to take on the American Blue and White as a heritage animal, to preserve this breed that is unique to our national history and culture.
Not just a historical curiosity, the American is a good meat, fur and show rabbit. They even make great pets! With some breeding care, the American can be a large and hardy animal, with large litters and fast weight gain potential. A good American is large and hard to ignore on the show table.
The reason it has survived for almost 100 years is because of the potential that was developed by Lewis H. Salisbury. The potential is in there, waiting to be tapped by the American rabbit breeder.
Understanding how genetics work can help you make informed decisions when breeding rabbits. You can get a good idea of what colors to expect from a litter and learn how to tell what genes a rabbit carries by studying a pedigree. You can learn how to correctly ID the color of your own rabbits (trust me you will sound a lot more knowledgeable if you are selling blue and white rabbits then if you are selling “gray” or “REW” rabbits). You can use genetics to lower your chances of producing a non-recognized color if you breed for show, or to learn how to tell if your rabbit IS a recognized color. You can avoid producing rabbits with “messy” genetics, and improve strength of color (for example, light blue Americans or washed out color with stray whites are far less stunning than a nice, deep, slate blue). You can learn how to manipulate genetics to produce the colors you want (this can be SUPER handy if you can’t find the color you want to BUY- MAKE it instead!). You can also learn how to use an unrecognized colored rabbit (ie, our blacks) with spectacular type and conformation to make recognized colored offspring. And all in all, just to be a more educated breeder.
Having a good understanding of color genetics will assist you in getting the colors and patterns you desire, which in my opinion is one of the best parts about it! There are over 200 possible genotypes based on the 5 main color genes (and even more adding in the broken gene and with some of the less common genes). That means LOTS of colors to play with! Don’t let the idea that genetics is daunting stop you! Especially since for Americans, we really only care about three colors – Blue, White (not necessarily in that order!), or Black. Mastering genetics takes memorization and practice. I like to remind people that genetics will become more familiar the more you use them- the more you see the results of your research (and breeding), the more that the “rules” stick with you.
If you are breeding for show, you want to be careful about mixing rabbits at random, as you can seriously set back a program and cause all sorts of grief for yourself. Mixing a “steel blue” and a “chinchilla blue,” for example, can play havoc with your “true blue” program. On the other hand, you can also use your genetics knowledge to IMPROVE your color programs and isn’t that just a bonus!
If you are more interested in pelts or meat or just breeding for pets, then you have a little more freedom in your breeding program; however, if you consider selling stock to a show breeder (ESPECIALLY 4-H kids) then it’s imperative that you disclose any odd genetic outcrosses you have done.
Genetic rules are based on science, not magic! While sometimes it seems like some rabbits “break the rules,” there is always a genetic reason why something happened. “Surprise” or “mystery” colors are usually the result of incorrect pedigrees, recording the wrong sire of a litter, the dam and/or sire being identified as the wrong color, and gene modifiers.
Off colors - aka DQs on the table!
A Sallander American, and Blue Tort American – both purebred, and pedigreed for 6+ generations – but they both had one or both parents who carried non-extension.
American Genetics: Achieving a True-Blue White in Two Easy Steps. Written by Jeremy S. Cowan
The American rabbit breed is currently recognized in two distinct varieties, the blue and white. With very limited numbers of breeding stock, breeders are often tempted to cross their blues to white, and vice-versa, to bring new lines into their varietal breeding programs. In most cases, this cross results in litters comprised of a rainbow of bunny colors. This article seeks to explain the reason behind this phenomenon and the simple, though not quick, solution to the blue to white conundrum.
Genetics primer
Before we can talk breeding program, a quick primer on rabbit color genetics is necessary. The color of the two American rabbit varieties are controlled by five primary genes – A, B, C, D & E. There are two possible alleles (gene components contributed by each parent) that define the expression of each gene. In the simplest case, a dominant allele (an allele that will express when both alleles are different (heterozygous)) is notated by a capital letter and the recessive allele is notated using lower case. In order for a recessive allele to be expressed, both alleles must be the same (homozygous). When an allele is unknown it can be indicated by a question mark “?”, an underscore “_”, or other similar notation. For a more in depth look at rabbit color genetics, I encourage breeders to read Color Genetics by Bobbi Schott.
In the case of the American blue-white cross problem, we need not delve into the nuance of each individual gene. Rather, we can get there quite easily by understanding what makes a blue and what makes a white. The IDEAL blue rabbit will have a genotype (the genetic code) of “aaBBC_ddEE”. I purposely put the underscore at the second C allele, but we’ll get to that a bit later.
Whites, on the other hand, are simply albinos. The ONLY gene that dictates whether a rabbit is a red-eyed white (or REW; the appropriate white for the American breed) is the C gene. That is a double recessive, “cc”, C gene will completely mask the true color of the rabbit (the A, B, D & E genes) and leave a REW.
The true-blue white
The REW that American rabbit breeders are after would have all the genetic material to make a blue, yet have the “cc” gene that makes them appear white. This would look like “aaBBccddEE”. In this case, breeding to an ideal blue would result in nothing but blue and/or white kits. More specifically, the color of the kits would be determined by the actual allele under the blue’s “_”. If the underscore is a “C”, the entire litter will be blue (though carrier’s of the REW “c” gene). If the underscore is a ”c”, about half of the litter should be blue (carrying REW), and the other half true-blue whites.
Granted this is a gross oversimplification, but it is quite sufficient to understanding how to clean up your whites for outcrossing to blues. That is, the bottom line is to create whites that are really just blues hidden under that albino coat.
The problem with whites
The American breed is returning from the verge of complete extinction. During the time when it almost completely disappeared, outcrosses to different breeds happened in an effort to save the breed. These outcrosses resulted in a few undesirable colors entering the gene pool. If you haven’t already seen them, things like steels, torts, blacks, and agoutis are frequently hiding under the masking effect of the whites’ “cc” gene. The fact that these things are hiding has led many breeders of white Americans to strictly maintain white-to-white breeding—effectively concentrating the undesirable genes within their herds, though who could blame them. I
f the strict white-to-white breeding programs are to be replaced with programs that integrate blue-to-white crosses, then breeders of American whites need to be ready to cull, cull, cull, because here is the simple program to clean up those whites.
The true-blue two step
After you have made the decision to integrate your blue and white programs, the first step is to breed ALL of your whites to blues—every last one of them—oh, and clear out some freezer space. In all likelihood, you will see what we mean by the rainbow of bunny colors when you see these crossed litters. In the best-case scenario, you get at least one blue out of each litter, or a black, this is what you want, though I have seen this NOT happen almost as much as it has.
As a side note, I should explain the brief aside in the previous paragraph. Black is genetically identical to blue with only one exception. Where blues’ D gene is a double recessive combination “dd”, blacks have at least one “D” giving them the black coat, rather than the diluted blue coat. If at least one parent of a black is blue, since a blue only has the recessive “d” to contribute, that black must be “Dd”. This means, in theory, that half of a litter from this animal when bred to a blue will be blue while the other half is black. If you utilize black in this program, just be sure to NEVER keep or sell a black from a black-to-black breeding as you cannot guarantee that it carries the dilute “d” gene.
Back to the program.
Assuming you get any blues (or blacks) in a litter from these blue-to-white crosses, you need to prepare cage space for as many as possible, because these blues will form the basis for your true-blue program.
If at all possible you want to put together two or more pairs of these white-carrying blues (or blacks) from as many different lines as you can put together (don’t worry if you don’t have the stock to get multiple lines, you just want to avoid breeding siblings). The second step is to breed these white-carrying blues to each other. Mendelian genetics dictate that, at least in theory, one quarter of the kits in the resulting litters should be REW. The resulting whites should breed true to blue.
The what-ifs
So, what if you don’t get any blue (or black) kits from your initial blue-to-white crosses? Don’t worry, just recognize that the white parent is probably due to be removed from your rabbitry. This sounds harsh, but if you want to integrate your blue and white programs, a white that cannot produce a blue (or black) will not get you there.
What if you don’t get ANY blues (or blacks) from any of your crosses? See the previous paragraph, you’ll probably need to remove all the whites from this program. If you can’t get your hands on any new white stock you may need a personal consultation as the situation is substantially more complex now and a new program is in order. Try to find new white stock.
What if I get whites in my blue-to-white crosses? This is actually a VERY good thing. As you now know that the blue parent carries the white gene and can be used for step two of the program. If this is the same litter that had NO blues (or blacks), replace the white parent with the best looking white kit.
Jeremy Cohen runs Global Pedigree . I use Global for pedigrees, and highly recommend it; note he did not pay me to say this, and it is my own personal opinion as a breeder of American Rabbits; I make no money from mentioning the site; rather, I hope that more breeders will join so we can continue our genetics journey together to make the American Rabbit a premiere breed on the table.