Line-breeding is a
form on inbreeding that is most often used by successful rabbitry's
in order to maintain the desired genetic traits and characteristics
of their foundation stock. Instead of mating brother and sister
(inbreeding), linebreeding is the breeding of father to daughter and
mother to son to maintain and improve the herd. The process of
selectively breeding offspring to their respective parent has been
performed for hundreds of years with cattle, goat, pigs, sheep,
poultry, and rabbits by both farmers and ranchers. The goal is to
produce enough offspring in your rabbitry that you can put meat in
the freezer and sell quality livestock while maintaining a quality
genetically stable bloodline.
So what does a
genetically stable bloodline look like? Well with linebreeding the
goal is to be able (after several generations) to produce a specific
generation that still has 50% of each of the genome of the original
parents used as your foundation stock. Sounds almost impossible
right? Actually, it is pretty easy if you keep accurate records and
are careful with your breeding program.
To be successful,
your breeding must be kept on strict lines and within limits, and may
be adopted for years without having to outcross any new rabbits into
your bloodlines. To aid you in your endeavor, you will not only need
to have a linebreeding chart, you will also need to know how to read
it, and that is the goal of this article. The process will become
clear once you understand how to use the linebreeding chart
accompanying this article.
The Linebreeding
Chart
To begin the process
we need an unrelated breeding pair of rabbits (male and female), this
pair will be known as your foundation stock or original male and
female. They are represented at the top of the chart simply as
'Female' on the left and 'Male' on the right. Each dotted line
represents a female (doe) and every solid line a male (buck). Where
the two lines meet there is a circle with a letter depicted
indicating what group the offspring of this breeding pair belong too.
In addition, there is a fraction indicating the amount of genetic
material (genes) that each parent has contributed to each offspring.
Getting Started
Once we have chosen
a breeding pair to become our foundation stock, we begin the breeding
process. All of the kits from this breeding will be labeled group A.
Looking at the chart we see that all of the kits born in this litter
will receive one-half (½ or 50%) of their genes from the original
male, and one-half (½ or 50%) of their genes from the original
female of this line.
Once the rabbits
from group A reach breeding age (about 6 months), we will breed back
one of the males from this group to our original female (mother to
son), and one of the females from this group to our original male
(father to daughter). These two breedings produce the rabbits in
groups B and C, each of which possess three-fourths (¾ or 75%) of
the genes of the parent and one-quarter (¼ or 25%) of the genes of
the other parent. In this case, Group B carries three-fourths (¾ or
75%) of the genes from our original female, one one-quarter (¼ or 25%) of the genes from our original male, while group C carries
three-fourths (¾ or 75%) of the genes from our original male and
one-fourth (¼ or 25%) of the genes from our original female.
So, how did we
arrive at these figures? Let's examine the kits produced in group C
by the breeding our original male with a female from group A. Our
original male carries 100% of his own genes and the female from group
A carries one-half (½ or 50%) of our original male genes. Adding
these two fractions together we get 1 ½. We then take 1 ½ and
divide it by 2 (because the breeding takes two rabbits) and the
result is that all the kits produced by this breeding (which will be
labeled group C) will carry three-quarters (¾ or 75%) of the genes
from our original male, and one-quarter (¼ or 25%) of the genes from
our original female (1 + ½ = 1½ / 2 = ¾ male genes). This same
principle is carried through out the chart with the number by the
circle indicating the fraction or percentage of the genetic material
that each parent has provided (left side of chart female, right side
of chart male).
For the third
generation we breed a male from group C to a female from group B.
Each of which contains three-quarters (¾ or 75%) of the genes of the
male and or female respectively. All of the kits from this breeding,
labeled group E, will contain one-half (½ or 50%) of the genes from
both our original male and female.
This is determined
by adding three-quarters (¾, or 75%) of the females genes from from
group B to the one-quarter (¼ or 25%) of the genes from the female
from group C and divide by 2 (¾ + ¼ / 2 = ½ or 50%). Likewise we
add three-quarters (¾ or 75%) the male genes from group C to
one-quarter (¼ or 25%) of the males genes from group B and divide by
2 ( ¾ + ¼ / 2 = ½ or 50%). This is the objective of linebreeding,
namely to come back to a point in which the rabbits in your herd
contain one-half (50%) of the genetic material of both your original
male and female foundation stock. As long as we do this we are not
inbreeding, rather we are linebreeding. Therefore, each time we
breed without going outside the bloodline, we are maintaining the
genetic base of our original male and female rabbits.
Next, we breed a
male from group B with our original female resulting in group D,
whose kits posses seven-eights (7/8 or 87.5%) of the original females
genes and one-eighth (1/8 or 12.5%) of our original males genes. We
also breed a female from group C, to our original male, resulting in
group F, whose kits possess seven-eights (7/8 or 87.5%) of the
original males genes and one-eighth (1/8 or 12.5%) of the original
female's genes. We will also breed a male from group F to a female
from group D, resulting in group I, and again we come back to our
genetic goal as all of the kits from this breeding contain 50% of the
genes from both our original male and female.
The next generation
will produce kits having one-half (½ or 50%) of their genes coming
from our original male and female at group N by mating a male from
group J and a female from group H. Offspring from groups G and K if
bred together will also return us to our goal of producing kits that
contain one-half (½ or 50%) of the genes of each of our original
male and female foundation stock.
Following this form of
linebreeding enables the breeder to keep several different males and
females breeding that are genetically similar enough to retain and
improve on their original breeding pair without causing any genetic
anomalies or health issues.
The percentage of genes contributed from our original male and female for each group are
listed below in what I consider is a little more concise and readable format.
1st
Generation (Group A)
Group A's Genetic
Makeup: 50% original female, 50% original male.
-
Breed a male from this group, to your original female to get group B, and breed a female from this group to your original male to get group C.
2nd
Generation (Groups B and C)
Group B's Genetic
Makeup: 75% original female, 25% original male.
-
Breed a male from this group to your original female to get group D, and breed a female from this group to a male from group C to get group E. Breed a female from this group to a male from group D to get group G.
Group C's Genetic
Makeup: 25% original female, 75% original male.
-
Breed a male from this group with a female from group B to get group E. Breed a female from this group to your original male to get group F. Breed a female from this group with a male from group F to get group K.
3rd
Generation (Groups D, E, and F)
Group D's Genetic
Makeup: 87.5% original female, 12.5% original male.
-
Breed a female from this group to a male from group E to get group H. Breed a female from this group to a male from group F to get group I. Breed a male from this group to a female from group B to get group G.
Group E's Genetic
Makeup: 50% original female, 50% original male.
-
Breed a male from this group to a female from group D to get group H. Breed a female from this group to a male from group F to get group J.
Group F's Genetic
Makeup: 12.5% original female, 87.5% original male.
-
Breed a male from this group to a female from group D to get group I. Breed a male from this group to a female from group E to group J. Breed a male from this group to a female from group C to get group K.
4th
Generation (Groups G, H, I, J, and K)
Group G's Genetic
Makeup: 81.25% original female, 18.75% original male.
-
Breed a male from this group to a female from group I to get group L. Breed a female from this group to a male from group J to get group M.
Group H's Genetic
Makeup: 68.75% original female, 31.25% original male.
-
Breed a female from this group to a male from group J to get group N. Breed a female from this group to a male from group K to get group O.
Group I's Genetic
Makeup: 50% original female, 50% original male.
-
Breed a female from this group to a male from group G to get group L. Breed a female from group to a male from group K to get group P.
Group J's Genetic
Makeup: 31.25% original female, 68.75% original male.
-
Breed a male from this group to a female from group G to get group M. Breed a male from this group to a female from group H to get group N.
Group K's Genetic
Makeup: 18.75% original female, 81.25% original male.
-
Breed a male from this group to a female from group H and you get group O. Breed a male from this group to a female from group I to get group P.
5th
Generation (Groups L, M, N, O, and P)
Group L's Genetic
Makeup: 65.63% original female, 34.37% original male.
Group M's Genetic
Makeup: 56.25% original female, 43.75% original male.
Group N's Genetic
Makeup: 50% original female, 50% original male.
Group O's Genetic
Makeup: 43.75% original female, 56.25% original male.
Group P's Genetic
Makeup: 34.37% original female, 65.63% original male.
Conclusion
There are several
prominent breeders of meat rabbits throughout the United States that
have been successfully linebreeding for years. One of the more
successful pseudo-commercial type organic rabbit meat breeders is
Polyface Farms owned by the Salatin family who have a pretty
substantial herd of rabbits. They have been linebreeding meat rabbits
for more than 25 years with great success. So much so that they have
developed their own strain or bloodline of meat rabbits. Through the
process of linebreeding you can develop those traits you are looking
for in a specific breed of animal and continue to enhance those
characteristics to their full potential. This has been proven time
and again by breeders of cattle, sheep, goats, and pigs through
specific lines of livestock that have been successfully breed for 50,
to 100 years and more without any new genetic material being added to
the herd.
Now most of us will
never be breeding meat rabbits for that long, but it will probably
take you 1 to 2 years for each generation to work your way through
Fetch's chart that is listed in this article. That's 5 years in the
most optimistic view, but more likely it will take you 7 to 10 years
to produce a good quality herd while maintaining it's genetic
diversity. I say this because of the following reasons. First, in my
personal opinion you shouldn't start breeding your doe until she is 6
months old. Second, once your doe is ready to breed, you may have to
cull a few litters before you get the best male and female from each
group in order to breed for the next generation. Hey, but that's ok,
placing rabbits in the freezer is the main reason most of us are
raising meat rabbits. Finally, you have to consider that the climate
in which you live and the type of housing you use for your rabbitry
has a big impact on your breeding schedule. If you live in the south,
you will generally be unable to breed between in the months of May,
June, July, August, and most of September if you do not keep your
bucks in an air conditioned barn. In East Texas were we live, that
only leaves you with 6 to 7 months out of the year in which to breed
before the temperature starts to get above 80 degrees.
So, by the time you
get to the 3rd generation you may have five breeding pairs
with some males and females breeding to more than one generation all
producing meat for your freezer and livestock for you to sell as you
look for that next best rabbit(s) to continue your bloodline. Who
knows, with proper herd management, maybe one day you can be
successfully breeding your own bloodline for more than 20 years just
as the Salatin's on Polyface Farm. As always, if you have enjoyed
reading this article and find the information here valuable, we ask
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References:
Bennet, Bob,
Storey's Guide To Raising Rabbits, North Adams, MA: Storey
Publishing, 2009
Patry, Karen, The
Rabbit Raising Problem Solver, North Adams, MA: Storey Publishing,
2014
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