Line Breeding

 

 

 

 

 

 

Above are two of the Greatest Show Bucks to have came ouf if Ruskin at virtually the same time

Grand Champion Ruskin's MG (Ruskin's Pattrick ex Ruskin's Jane) and Supreme Champion Ruskin's Remington 

 

MG's sire was a buck called Pattrick who himself was sired by the Dutch Import EDAM

Edam was the sire of Remington

 

When I started with Miniature Lops I was not fully convinced that 'line breeding' was the way to go.  I had always managed to produce some good quality stock from my previous methods of breeding, which on retrospect was a very sporadic and hap-hazard way of working.  I spent many months talking with the TOP BREEDERS in Holland who really are true stockmen.  They instilled into me the fact that once you have got something worth working with, keep it.  Use it!

 

Too many breeders go with the latest trend or fashion, be that colour, coat, weight or overall balance.  I always thought that to keep my lines free from genetic defect or in-balance, the best way forward was to keep introducing something new into it.  Below I hope to show how this can be done with selective breeding from within.

 

All successful breeders use the system of linebreeding and inbreeding; the results can be both good and bad. A serious program is when the breeder is trying to keep and ameliorate the qualities and characteristics of its breed, for generations.

 

LINEBREEDING is mating animals which are closely related to the same ancestor but are little if at all, related to each other through any other ancestors.

 

INBREEDING is a much closer cross between the "mating pair" than is

linebreeding: son to mother, father to daughter, brother to sister, half-brother to half-sister, brother to sister...

 

Some breeders would consider inbreeding, others linebreeding when crossing a rabbit to a half-brother or a half-sister to one of the parents. It is sometimes very difficult to give the perfect definition.

 

The purpose of both linebreeding and inbreeding is to bring improvement more rapidly and narrow the pedigree to a few closely related lines of descent. This purifies the pedigree rapidly and enables a breeder to control, to some degrees, all characteristics. It reduces variability.

 

It is easier to predict the result of a breeding by linebreeding than to expect

results that have no genetic reasons. If the selection of the ancestors have been

good, it can be expected almost no surprise.

 

Judicious line breeding’s have shown, in all breeds, an important and real

improvement. The quickest and most certain way to produce superior rabbits is by careful linebreeding, especially with a breed without genetic disease.

 

However, there is a big danger in this system of breeding, if you consider only the pedigrees, without considering the physical compensation, you surely will have rabbits with notable faults. A pedigree is a guarantee of bloodlines and unfortunately many beginners will consider only pedigrees, especially if it contains winners. They will breed without considering also the respective faults and qualities of the rabbits they want to mate. Consanguinity will concentrate the qualities and the faults.

 

 

Fortunately many serious breeders will study the pedigrees very carefully; will study the family of the rabbits they want to mate (the qualities, the faults, the temperament, the results also in show, etc...) before linebreeding, to fix a type in their breeding program: the closest possible to the breed standard.

 

A fault not apparent can come out in a first or second generation whereas in non-consanguinity the fault will appear later and so, will take much longer time to be eliminated.

 

Inbreeding is linebreeding in its limits. The advantages and disadvantages of linebreeding is at the highest degree. This system of breeding is to secure at its maximum all the qualities of the sire for example (if the sire breeds his daughter).  It is again the reason why it is terribly important to study perfectly the ancestors of the sire (in this example), their qualities and faults. Those faults must not appear in the daughter or in her pedigree because the blood of her sire will be intensified in their youngsters by linebreeding the faults of the sire and the dam. It is imperative to choose a sire who has the absolute quality opposite to the fault to be eliminated.

 

Not only the conformation but also the temperament of the two rabbits being mated by linebreeding or inbreeding, must be taken in consideration very seriously with the objective to secure and preserve the qualities only...

 

When superior animals are used, inbreeding is the most powerful way to

perpetuate their qualities and to influence the future of a breeding program.

 

Inbreeding is not so much a matter of originating excellence as of holding and making the greatest use of it when it appears.

 

Line breed or inbreed only superior individuals. A line bred or inbred rabbit is a much stronger reproducer than a rabbit who has an outcross breeding.

 

Inbreeding can be a disaster if practiced by a breeder beginning with the wrong stock, or not knowing perfectly its breed or not knowing what is a very good individual. In this case, anyway, he should not be a breeder...

 

It is known universally that any characteristics can be bred up or down,

strengthened or weakened by inbreeding". Severe selection is the key to a

successful linebreeding or inbreeding; never forget that "physical compensation" is the rule.

 

When a breeder, regularly, produces litters with youngsters of too much variance in type, he needs to consider linebreeding. He will have the possibility to see what are the traits (dominant and recessive) in his rabbits. It is a risk, of course, but it is the only way for him to progress and try to produce homogeneous litters.

 

Linebreeding and inbreeding are not a way to bring new things but is a way to consolidate the best traits.

 

OUTCROSSING is not a blood-related connection. After some generations of

linebreeding and inbreeding, it is time to outcross. This represents also a danger for a breeder without experience.

 

After an outcross has been made, a breeder should then breed right back into the original strain. This is the only safe procedure after the purpose of the outcross has been achieved.  A strain is a variety

within a variety of animals, obtained after successful line breeding’s and inbreeding’s in a long and serious breeding program.

 

It is almost impossible to explain when it is time to outcross. We think that after too many generations of linebreeding, it is a risk to produce smaller  or larger youngsters and also sometimes youngsters with a non-desirable temperament (too timid or too strong...).  Not all breeders agree on that but several have experienced the problem.

 

When a breeder outcrosses, he can lose the type he has worked on for a long

time. He needs to introduce a new blood, only if the rabbit used can bring something needed in his program and if he line bred and/or inbred already several times.  The breeder needs to know perfectly the ancestors of this rabbit and what they can bring to him. Phenotype is what we see and genotype is the genes the rabbit carries and will produce. In my opinion, it is just as dangerous to outcross, line breed or inbreed when used by a non-experienced breeder.

 

It is the reason why the breeder must go back, after an outcross, into his

established line, to perpetuate the "good" brought by the outcross.  Of course it is time to use an outcross blood when a breeder did not produce what he was expecting and when he can have access to a superior rabbit or a very rare and proven pedigree which is not yet in his program. This system can bring qualities he needs, or correct a fault he has not been able to eliminate. Some people say that outcross can bring vigor, but linebreeding, when very carefully planned, has the same result.  The new blood can also bring undesirable traits. The breeder will have to hold the qualities he has obtained with the new blood by returning to the linebreeding with the progeny and do the same to eliminate the bad traits brought by the outcross.

 

The general public believes that inbreeding produces bad temperament, lack of vigor and fertility, and forgets that we can see the same problems in all other systems of breeding... Of course, consanguinity is full of dangers, but it is a great tool when done by a careful breeder who knows the qualities and the faults of his rabbits and their ancestors.  He must be able to recognize what is a sound conformation and temperament and needs to be knowledgeable in the area of genetics.

 

How to Line Breed

I often get asked about my line breeding theory and how to implement it.  It’s a very good question and one which can not always be answered verbally as it’s become very complicated when trying to get someone to think back to something you have just said.  The best way to try and explain a line breeding program; how to get started and how to continue with it, is probably best shown in a diagram.  The diagram below shows line breeding in its simplest form, using LINES to show you where to go and what to do.

 

Many people will work on the theory that you need three rabbits in order to start a line to line breed to.  this is not always the case and the above diagram shows how you can work with just a pair to create a line and how to concentrate of fixing good points. It also shows that you can work to your buck line or your doe line quite easily and freely.  Obviously, in the first couple of generations inbreeding needs to take place so it is absolutely paramount that you use the best matched pair to start your line breeding program.

 

How to read the Chart

The buck line is depicted in Black and the Doe line in white.  The generations are numbered from top to bottom and the rabbit produced from mating’s is numbered in red inside the circles of colour (black and white)

 

As you can see from the top of the chart, the first litter produced from the original mating is numbered 3. This litter now contains 50% of the bloodline of the buck and 50% of the doe.

 

If we were to take a doe from this breeding and mate it back to its father - #1, a new group is formed - Group 4

 

Group 4 is 75% of the buck line and only 25% of the doe line

 

If a buck was retained from the Group 3 litter and mated back to its mother - #2, a new group yet again is formed - Group 5

 

Group 5  is the exact mirror opposite to Group 4, being 75% of the doe line but only 25% of the buck line.

 

If we were to mate a young buck from Group 4 and a young doe from Group 5 you will see that Group 7 is formed.  This mating has produced a litter exactly the same in blood line percentages as the mating of the original pair, in that 50% is the buck line and 50% is the doe line.  This new group is the second stage in creating your own line from the original two rabbits.  100% your breeding but exactly the same blood as your first two rabbits.

 

In order to progress you need to create another group.  This is done by mating a doe from Group 4 back to the original buck - #1 - which in turn produces you Group 6.  Mirroring this mating in the doe line means taking a buck from Group 4 and mating it back to the original doe - #2, giving you your Group 8.

 

Three Clear Lines 

At this stage, if we look at the chart we can clearly see there are three clear lines from the original paring of the buck and doe.  One line that has been produced is leaning towards the buck blood and on the other side of the chart, a line which is a much higher percentage of the does.  In the middle we can see a further line with contains exactly half and half.

 

So - Where do we go from here?  Well this is now where it starts to get a little bit more complicated and where we really need to make sure that our records of mating’s etc are up to scratch and absolutely 100% correct.  Line breeding will not work if you 'forget' what you mated to what, or deviate from the outlined plan.

 

The next stage is to mate a young buck from Group 6 to a doe from Group 8 - producing you Group 10.  This litter is now exactly the same in blood percentages as Group's 3 & 7.

 

It is important to remember that whichever mating is occurring, you must always keep at least one of the parents blood at a greater percentage than that of the original sex line.

 

Using this buck from Group 6 to the doe from Group 8 has meant that you have not broken the buck line at all.  Every buck used in the mating’s beforehand have carried a much greater percentage of the original bucks blood and on the flip side this can also be seen with the does used.

 

Using this method creates pre-potent sires and prolific dams, both producing characteristics of their ancestors but generally only in the same sex line.  To create an even stronger line - where the bucks can produce the qualities of the does and vice versa you need to do further mating’s.

 

To create a buck who is of a higher percentage of the does lineage, select your best matched buck from Group 5 and mate him to a doe from Group 8.  The new group formed is called Group 11.  This group now contains the highest concentrate of the does blood so far. 81.25%  to be exact. As before, if you wanted to mirror this mating but produce a buck who carried a much higher percentage of the bucks blood, a buck from Group 6 should be selected and mated to a doe from Group 4 - producing you Group 9 and again a litter of youngsters containing 81.25% of concentrated blood - this time from the buck line.

 

Strangely enough, if we select a buck from Group 9 and a doe from Group 11 we produce Group 14 but yet again produce a litter which are half and half the blood of the original mating pair once again. This is also still keeping the three clear lines in production.

 

 

Mating a buck from Group 9 to a doe from Group 10 results in Group 12 - with the bucks blood line percentage being 65.5% and the opposite mating of this would be Groups 10 and 11 - producing Group 16.

 

Keeping the buck line going once again, a mating between Group 9 (buck) and Group 6 (doe) will culminate in Group 13 - which is 84.3% the bucks blood and a converse mating of Group 8 (buck) to Group 11 (doe) produces Group 15 with the same percentage, but back to the doe line.

 

 

Title: GROUPS 12, 13, 14, 15 & 16

These five groups are all Firth generation, even though many more mating’s have occurred to produce them, they do not go any further than 5 generations down from the original mating pair as some of the mating’s to produce them have gone back into the line, instead of forwards.

 

By this stage you should see a very tight consistency in the stock you are producing.  You should be able to plan litters with expectancy rather than hope.  You should be able to calculate ages where fitness will be at its prime (providing records of this trait have been kept also) and you should be able to almost guarantee the quality of your stock.

 

BUT, it is almost sure at this stage that you will see flaws appearing in your breeding program also.  Maybe you have fixed in traits unknowingly that were recessive and are only showing now!  Maybe you are starting to see a pattern emerge which you would like to try and fix, but can’t because the line is so tightly bred back to the original pair.

 

This is the stage you may need to very well consider and out cross.

 

Happy breeding for now.

 

 

 

 

Phil Batey

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