So how did I get
started down this road to try and decipher the genetic makeup of the
New Zealand (NZ) rabbit? The answer is pretty simple really. Like
many people new to breeding rabbits, I thought that If I bred a New
Zealand Red (NZR) with a New Zealand White (NZW) then surely I should
see some red, white, and possibly some red and white (broken or
charlie) offspring (kits) in my litters. What I found out was that
always got chestnuts, and or dark colored steel tipped kits from
these pairings with no whites, reds, or patterned (broken or charlie)
offspring. My NZR to NZR pairings always resulted in beautiful red
offspring with no variations in color or color patterns. While my NZW
to NZW pairings almost always produce white kits, I had one female
who continued to occasionally produce a black litter when she was
bred with a white male from another breeder friend of mine which kind
of baffled me. So I decided that after three years of raising and
breeding rabbits it was time to dive into the subject of genetics and
the NZ rabbit genome.
In the second
article of this series 'Coat Color: It's In The Genes' we examined
the entire NZ rabbit genome or genotype and at the end of the article
I listed the basic genotype of each of the NZ rabbit color
combinations. Just for convenience I am going to re-list those color
gene sequences below for your reference.
Agouti (Chestnut):
A_, B_, C_, D_, E_, enen, DuDu, SiSi, VV, W_
Black: aa, B_, C_,
D_, E_, enen, DuDu, SiSi, VV, W_
Blue: aa, B_, C_,
dd, E_, enen, DuDu, SiSi, VV, W_
Red: A_, B_, C_, D_,
ee, enen, DuDu, SiSi, VV, ww +++
White: A_, B_, cc,
D_, E_, enen, DuDu, SiSi, VV, W_
The Brokens:
Black: aa, B_, C_,
D_, E_, Enen, DuDu, SiSi, VV, W_
Blue: aa, B_, C_,
dd, E_, Enen, DuDu, SiSi, VV, W_
Red: A_, B_, C_, D_,
ee, Enen, DuDu, SiSi, VV, ww +++
The Charlies:
Black: aa, B_, C_,
D_, E_, EnEn, DuDu, SiSi, VV, W_
Blue: aa, B_, C_,
dd, E_, EnEn, DuDu, SiSi, VV, W_
Red: A_, B_, C_, D_,
ee, EnEn, DuDu, SiSi, VV, ww +++
As I mentioned in
'Coat Color: It's In The Genes' all NZR's share the (DuDu), (SiSi),
and (VV) allele pairings so many breeders simply drop these when
denoting the NZR genotype. For the rest of this article I will be
doing the same, just know that if you want a complete 10 color genome
listing add the proper allele pairings to the genome. So The basic
genome of the breed would look as follows when abbreviated. NZ rabbit
basic color genome: A_, B_, C_, D_, E_, en_, W_.
Putting It All
Together
Without DNA testing,
there is only one way you can try and fill in the blank spaces in
your rabbit's genome. It's the method that breeders of livestock have
used for thousands of years and that is simply breeding your rabbits
and writing down your individual results. If you keep through
consistent records you will eventually be able to fill in most of the
blanks on your rabbits color genome based on your own out comes. The
key here is consistency and good record keeping. If you are raising
meat rabbits for just meat then you probably do not care what the
rabbit's coat color looks like as all the meat tastes the same
regardless of coat color. However, if you want to breed for a
specific color or color pattern in order to increase not only your
breeding stock, but potential sales of breeding stock, then it is
good to have an idea of the genetic makeup of your rabbits.
Eventually most breeders not only want to supply their family with
meat to eat, but rabbit sales to supplement their income or at least
pay their feed bills.
The New Zealand
Agouti “Chestnut”
Basic Genome: A_,
B_, C_, D_, E_, enen, W_
The New Zealand
Agouti (NZR) is the original color of the breed. The upper coat is a
reddish sorrel color, with the pigment running the length of the hair
shaft. The coat on the belly color tends to be the same color with a
slight lightening or cream color in the middle of the abdomen, the
underside of the tail, the front or rear food pads and around the
eyes. Their eyes are brown in color. The NZR carries the agouti (A_)
gene and when breed with self (aa) colored NZ rabbits will possibly
produce steel-tipped kits as well as a variety of different shades
depending on other genetic modifiers.
The New Zealand
Black
Basic Genome: aa,
B_, C_, D_, E_, enen, W_
Broken Black Basic
Genome: aa, B_, C_, D_, E_, Enen, W_
The New Zealand
Black (NZB) has an upper coat with a uniform dark black throughout.
The undercoat may be a uniform, black color or it may be a dark
slate blue color with dark brown eyes. The NZB is a self (aa) colored
rabbit and when bred with another with self (aa) colored NZ rabbit
will possibly produce steel-tipped kits as well as a variety of
different shades depending on other genetic modifiers.
The New Zealand Blue
Basic Genome: aa,
B_, C_, dd, E_, enen, W_
Broken Blue Basic
Genome: aa, B_, C_, dd, E_, Enen, W_
The New Zealand
Black (NZBL) has an upper coat with a uniform dark black throughout.
It is the dilute (dd) allele pairing that causes the black (B_)
allele to become diluted from a black to blue coat. The undercoat
may be a uniform, blue color or it may be a dark slate blue color
with dark brown eyes. The NZBL is a self (aa) colored rabbit and when
bred with another with self (aa) colored NZ rabbit will possibly
produce steel-tipped kits as well as a variety of different shades
depending on other genetic modifiers.
The New Zealand Red
Basic Genome: A_,
B_, C_, D_, ee, enen, ww, rufus-modifier
Broken Red Basic
Genome: A_, B_, C_, D_, ee, Enen, ww, rufus-modifier
The New Zealand Red
(NZR) is the original color of the breed. The upper coat is a reddish
sorrel color, with the pigment running the length of the hair shaft.
The coat on the belly color tends to be the same color with a slight
lightening or cream color in the middle of the abdomen, the underside
of the tail, the front or rear food pads and a around the eyes. Their
eyes are brown in color. The NZR carries the agouti (A_) gene and
when breed with self (aa) colored NZ rabbits will possibly produce
steel-tipped kits as well as a variety of different shades depending
on other genetic modifiers.
The New Zealand
White or 'Ruby Eyed White' (REW)
Basic Genome: A_,
B_, cc, D_, E_, enen, W_
The New Zealand
White (NZW) is probably the rabbit that most people think of when you
mention the words “New Zealand Rabbit”. It is the most
commercially produced as well as breed for show variety of the NZ
rabbits. In fact, it is the gold standard for commercial rabbit meat
production and laboratory testing as well as a great rabbit to breed
at home for meat production. The NZW is technically and albino (lack
of melanin), because the NZW is an albino, the other genes colors
that would normally make up it's genetic code are suppressed. That
does not mean that the other color gene's are not there, rather the
albino gene (cc) blocks the color of all the pigments along the hair
shaft and eyes, producing a white rabbit with pink/red eyes known as
a 'ruby-eyed white (REW)'. It can still be a carrier for all the
other genes, it is just that you may not see their expression until
you breed a white rabbit with a rabbit of another color.
The Breeding Trials
So let's look at how
you can begin to fill in some of the blank spaces on you NZ rabbits
genome. I have listed the basic color genome for our NZR buck 'Long
Eared Red' (LER) and the our NZW doe Luna which we have breed to
several times. For whatever reason she is most responsive to this
buck so I almost always breed her to him. LER's red coloring is right
in the middle of the red color range so my best guess is that he has
three rufus-modifiers denoted as (+++) at the end of his genome, the
words 'rufus-modifier' have been replaced by this notation. As I
mentioned earlier their pairings always produce either agouti's and
or steel tipped kits. Looking at the various litters that these two
rabbits have produced, I can now begin to apply some of my knowledge
to start and flesh out their color genome's.
Our NZR
buck 'LER's' Basic Genome: A_, B_, C_, D_, ee, enen, ww, +++
Our NZW doe “Luna's' Basic Genome: A _, B_, cc, D_, E_, enen,W_,
I have bred these
two rabbits multiple times and I always get a combination of chestnut
agouti's and black cinnamon tipped steel kits, the majority of them
being steel tipped. So let's see if we can flesh out the color genome
of these two rabbits gene by gene. It is important to remember that
each parent gives one allele to it's offspring to complete the pair.
Knowing this, we can look at their offspring to help us to fill in
the blanks in their genetic color code.
Their last litter basic genome:
2 - Chestnut
Agouti's Aa, B_, C_, D_, Ee, enen, Ww
5 – Black Cinnamon
Tipped Steels aa, B_, C_, D_, Ese, enen, Ww
A-Series Genes:
Agouti (A_) allele, and Self (a_) allele
Possible Allele
Pairings: Agouti Rabbits (AA, Aa), Self Colored Rabbits (aa)
The A-Series of
genes has only two possible possibilities in NZ rabbits, agouti or
self. If one dominant agouti
(A_) allele is
present you get a rabbit with agouti characteristics, if two
recessive agouti (a_) alleles are present you get a self colored
rabbit. Because the breeding of LER and Luna continue to produce some
self colored (black) rabbits with steel tips then the both must carry
the (Aa) pairing. So our first gene for these two rabbits is
complete.
Our NZR
buck 'LER's' Basic Genome: Aa, B_, C_, D_, ee, enen, ww, +++
Our NZW doe 'Luna's' Basic Genome: Aa, B_, cc, D_, E_, enen, W_,
B-Series Of Genes:
Black (B_) allele or Brown (b_) allele
Possible Allele
Pairings: Black Colored Rabbits (BB, Bb), Brown Colored Rabbits (bb)
This gene then
determines whether the rabbits base coat color is black or brown.
Because the black (B_) allele is dominant over the brown (b_) allele,
black is the most common color. The allele pairings (BB) or (Bb) will
always produce a black, while the recessive (bb) allele pairing will
always produce a brown rabbit. Because there are no brown colored NZ
rabbits, I will go out on a limb here and say that both LER and Luna
carry the (BB) allele pairing. It is possible that one of rabbits
carries the (Bb) allele pairing, but one of them is a (BB) for sure,
I just do not know which one at this time.
Our NZR
buck 'LER's' Basic Genome: Aa, BB, C_, D_, ee, enen, ww, +++
Our NZW doe 'Luna's' Basic Genome: Aa, BB, cc, D_, E_, enen, W_,
C-Series Of Genes:
Complete (C_) allele, Incomplete (c_) allele
Possible Allele
Pairings: Complete Colored Rabbits (CC, Cc), Albino Rabbits (cc)
The C-series of
genes determines whether a rabbits coat has complete color or no
color. The dominant (C_) allele allows all four of the dark and all
three of the yellow pigments to be present in the hair shaft. This
allows for full color development of the rabbits coat and works with
the E-series of genes and their alleles to produce ticking or steel
tipped colors in rabbits that carry the agouti (A_) allele. A NZ
rabbit with two recessive (c_) allele's is classified as an albino
(white rabbit with red eyes). Because multiple pairings of LER and
Luna have never produced any white kits, and you have to have a (cc)
allele pairing to produce white kits, we know that LER carries a (CC)
allele pairing. If he carried the (Cc) allele pairing, eventually
they would produce a white kit (cc), but this has never happened.
Our NZR
buck 'LER's' Basic Genome: Aa, BB, CC, D_, ee, enen, ww, +++
Our NZW doe 'Luna's' Basic Genome: Aa, BB, cc, D_, E_, enen, W_,
D-Series Of Genes:
Dense (D_) allele or Dilute (d_) allele
Possible Allele
Pairings: Dense Coat (DD, Dd), Dilute Coat (dd)
The D-series of
genes determines the depth of color of the coat of the rabbit.
Rabbits with at least one dense (D_) allele have full color shades
that are are darker (black or chestnut), and generally have brown
eyes. Rabbits with a dilute (d_) allele have a lighter more sedated
or dilute colored pigment in the hair shaft causing the coat to be
lighter in color. Unfortunately I have no definitive way to determine
the 'D' allele pairings of these two rabbits. All of their kits
appear to have a nice dark definitive coats, so I am leaning towards
(DD) for both, but because I confirm that I will leave them as
undetermined (D_).
Our NZR
buck 'LER's' Basic Genome: Aa, BB, CC, D_, ee, enen, ww, +++
Our NZW doe 'Luna's' Basic Genome: Aa, BB, cc, D_, E_, enen, W_,
E-Series Of Genes:
Steel Extension (Es_) allele, Normal Extension (E_) allele,
Non-extension (e_)
allele
Possible Allele
Pairings: Steel Tipped Rabbits (EsEs, EsE, Ese), Black Rabbits (EE,
Ee), Red Rabbits (ee)
The (Es_) allele
works in combination with the agouti (A_) allele and is responsible
for producing the ticking or steel patterns (Gold or Cinnamon
tipped). So in order for a NZ doe to produce kits with steel
characteristics (tipped hair coloring) either the buck, doe, or both
must carry an agouti (A_) allele. If both rabbits in the breeding
pair carry the self colored (aa) allele pair, they cannot produce
kits with steel tipped fur. Because our NZR buck 'LER' carries a
non-extension (ee) gene, and NZR's also carry the dominant agouti
(A_) allele, and we get some steel tipped kits, then we know our NZW
doe Luna must carry the steel extension (Es) in her basic genome. In
addition, because all NZR rabbits are (ee), and this pairing never
produces any litters with red rabbits then her 'E' gene pairing must
be (EsE).
Our NZR
buck 'LER's' Basic Genome: Aa, BB, CC, D_, ee, enen, ww, +++
Our NZW doe 'Luna's' Basic Genome: Aa, BB, cc, D_, EsE, enen, W_,
W-Series Of Genes:
Normal Width (W_) allele, Double Width (ww) allele
Possible allele
Pairings: (WW), (Ww), and (ww)
The dominant normal
width (W_) gene produces a yellow or white agouti color band in the
hair shaft producing a normal coloring. The recessive double width
(ww) gene doubles the width of the yellow or white agouti band in the
hair shaft causing the rabbit to have the characteristic agouti
patterns typical of the new Zealand Red. Because of NZR buck LER
carries the double width (ww) agouti gene which produces the standard
agouti patterns around the eyes, triangle at the nape of the neck,
feet, legs, ear, and inside of the belly. However, none of the the
steel tipped kits exhibit these patterns, and this pairing has never
produced any litters with red rabbits Therefore Luna must carry a
(WW) allele pairing.
Our NZR
buck 'LER's' Basic Genome: Aa, BB, CC, D_, ee, enen, ww, +++
Our NZW doe 'Luna's' Basic Genome: Aa, BB, cc, D_, EsE, enen, WW,
For this particular
pairing of rabbits, fleshing out their genome was pretty
straightforward. The whole process is simply a matter of looking at
the types of offspring that this breeding produces. If Luna was bred
to a white buck, then I would have been unable to unravel both her or
LER's color genome as all the pigments in their offspring would be
suppressed by the (cc) allele which produces albinos, aka. Ruby-eyed
Whites (REW). Once we know the genome of the parents, we can then
produce an accurate genome of their offspring.
Their last litter complete genome (almost):
2 - Chestnut
Agouti's: Aa, BB, Cc, D_, Ee, enen, Ww
5 – Black Cinnamon
Tipped Steels: aa, BB, Cc, D_, Ese, enen, Ww
Conclusion
I know this may seem
like a lengthy process, but it is fairly easy, and once you have done
it a few times it goes really fast. You just have to understand that
determining the color genome of some rabbits is easier than others,
and you need to look at more than one litter to be able to accurately
determine the genetic color makeup of the rabbits in your herd. If
you have read all three of the articles in this series you may think
to yourself, I am just not interested in knowing this. That's fine,
but remember if you what to be able to produce consistent litters of
specific colors to sell as breeding stock, knowing the genetic color
makeup of your herd will help you to become more successful.
The more genetic
variables you have in your herd, the harder it is to consistently
reproduce the desired characteristics in your herd's offspring
whether it be size, shape, and or color. When adding new livestock to
your herd, a pedigree helps because it usually contains the basic
weight and color characteristics of the rabbits ancestors. Just
remember however that a pedigree does not always guarantee you
quality, that final determination must be made by you when you
examine the rabbit prior to purchase. As always, if you have found
this article interesting or informational please share it with your
friends. Don't forget to follow us on Facebook or on Google+ for the
latest articles on our blog related to raising your own meat rabbits.
Additional
References:
https://www.rabbitsforsale.com/listing-category/new-zealand/
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