Outcrossing

Ken Mclean quote  " You must first duplicate the ancestor - then breed away from it - then make sure it is reinforced again. Genetic influence from superior ancestors becomes diluted after a few generations. Yet when the same ancestors are returned to and reinforced in a pedigree it allows for the recapture of the original source of talent"

It is a common fallacy that all mares need out crossing in every mating to maintain hybrid vigor

The outcross is defined as a mating where there are no duplicated ancestors between mare and stallion within 5 generations. 

Successful long term breeding programs are far more likely if the breeder uses all three methods of breeding - linebreeding, inbreeding and outcrossing.  It is the interplay of these and knowing when to use the correct tool based on the mare's pedigree and characteristics - that bring the creativity, art and science of breeding together. 

Many breeders believe that out crossing in every generation is necessary to reduce inbreeding depression, increase genetic diversity and enhance hybrid vigor. The truth is mother nature generally takes care of genetic diversity and variation with recombination, mutations, recessive genes  and the random nature of inheritance - in almost every mating - no matter what method breeders use

It is not  difficult to find horses with no duplications in 5 generations in horses of the same breed -  but once you go out to 6 or 7 generations, the picture usually  changes dramatically 

Going out to the  7th generation may reveal a horse that is duplicated on the 3rd generation - appearing as 3 x 6 x 7 -   but you will only see this horse on the  3rd if you go out further than 5 generations to begin with  - so many of these matings are not genuine outcrosses in blood

Donnerhall is an example of this.  At 5 generations he appears to have no duplicated ancestors.

However, going to 6 generations reveals he has duplications of Dwinger and Der Lowe on the 4th generation.

Don Schufro - at 5 generations shows nothing - but extending the pedigree to 7 generations reveals many duplications beginning on the 4th generation

Ferro - shows no duplications in 5 generations but again plenty from 5-7th generations

Inbred dams and grand dams

The most effective pedigree to do an outcross mating with is one that is already dominant within itself- usually this means effective inbreeding or line breeding is present in the mare. 

There is plenty of evidence for this - a large number of successful sport and breeding horses are out of inbred dams or grand dams (with an outcross stallion mating within 5 generations)

 Some examples are For Romance I,  Sezuan, Totilas,  Bretton Woods, Total Diamond PS,  Hot Hit,  Majestic Taonga,  eventing sire Brilliant Invader, Coriander, Cassallco, Johnson, Greek Air, Negro, Viva Gold, Dream Boy,  GP horse Hot Hit ,  Quick Star,   Loredo 

The truth is that most mares do not have the pedigree dominance to carry an outcross mating.

Many mares have suffered from the effects of random matings and careless choices based on young spectacular moving flashy stallions or fashion -  or on the winning performances of their parents, rather than on the traits observed in the ancestors and the pedigrees.  

Mares  can therefore end up with pedigrees with a lot of haphazard loose bloodlines which are already effectively outcrossed, and  unlikely to reliably pass on  traits - this type of mare will not be a suitable candidate for  an outcross mating 

Still look for compatibility in the pedigrees

Bloodlines are not simply interchangeable and many, even from  top stallions  - will not work well together at all.   A pedigree can be a jumbled mish mash of incompatible discordant bloodlines that clash - they do not blend or build on each other in any way and have no genetic direction.

All matings require something different - but in warmbloods it must be remembered that we are dealing with a hybrid to begin with - a horse made up of many different breeds -  and in general most mares need duplications of superior ancestors built in to their pedigrees  to start with

 Many mares will need some  linebreeding to build up their genetic dominance in the hope of getting a filly - who will then be suitable to  attempt the outcross mating with.

 Once you have built prepotency into your mares pedigree - this will give you alot of freedom in stallion choices, because the linebreeding on the mares side will consistently set type and sport ability.

Different ways of achieving the outcross mating

It is always a good idea to use a proven stallion when looking for a suitable outcross - it will increase the probability of breeding a superior athlete

To attempt a genuine outcross - with very few common relatives up to the 7th generation -   it may be necessary to go into a different studbook altogether - like KWPN, Holstein , Trakehner, TB - or choosing a stallion with  a high percentage of different blood in his pedigree.  

 A good jumping stallion with dual purpose bloodlines is good for athleticism, or a stallion from another dressage  line altogether, such as the G line or B line. Sometimes using a much older stallion with different lines can work well too

This could be a good idea for an inbred mare who definitely needs a new influx of blood.

It is also fine to mate an inbred mare to a stallion where there is only one common duplication 

For Romance i - out of Gesina -  she only shares one line of Donnerhall on the 4th generation with the sire Furst Romancier - he has his own dominances in other areas but it is effectively an outcross except for that one line

An interesting  example of a Trakehner / arab  outcross mating for an inbred Hanoverian or Holstein  mare would be the Trakenher stallion K-2.

Pedigree here.

He is by Stradivari who is by the AA Upan la Jarthe, and out of a Trakehner mare by Ibikus / Impuls. HIs dam is by Inschallah - Arab , and out of a Trakehner Mahogani mare with the falling dam line from the Kassette mare family - one of the strongest in the Trak studbook along with Kostolany, Karon, Kassiber, Kassio and a network of full sisters. 

An  outcross may work for one or two generations  at most - but then it is vital to correct the resulting genetic dilution in the mare by choosing a stallion that will revitalise  her gene groupings of superior ancestors - perhaps using a different branch of the same family to do so

Outcrossing can certainly create some very impressive sport horses - but their own genetic variation can make them very indifferent producers hence the reason many performance test winners disappear without trace after one or two  foal crops 

Ken Mclean " If outcrossing is maintained indefinately it will cause enormous variation to the gene pool and  be likely to lead to utter disappointment"

Different ways of outcrossing

The truly  successful outcross mating requires one parent with a genetically dominant pedigree.

Just joining two parents with unrelated bloodlines themselves can result in very average results -  and desired traits that have been selectively bred for over years can be lost.

These outcrossed foals can be very inconsistent in type temperament and performance - and nothing like the breeder was hoping for based on the quality of the parents.

 The outcomes are less predictable where the parents have no genetically similar  features - because they are less likely to transmit their own attributes. It can also bring in new genetic weaknesses and recessive genes for undesirable traits  - at the same rate  as inbreeding and linebreeding do. 

If you are attempting to outcross into the same breed,  such as  two Holstein parents or two Hanoverian parents - then you can choose parents that  have no common lines in 5 generations, but they will  share common bloodlines from the 6th generation onwards.

This does still go some way to to preserving genetic diversity  while still maintaining some predictability in traits. 

Outcrossing done properly is where the fun starts - if you are lucky enough to own or  buy a very tightly bred mare with great prepotency then you can start with this immediately.

However, you may need to take your existing mare or mares, choose genetically compatible matings to tighten them up, keep a resulting filly, and build in your own potency, and then attempt the outcross mating -  and this is also  a very rewarding path to take

One of the most reliable ways to outcross is to have two parents that are both inbred but to different bloodlines

This will preserve the desired traits in type temperament and athleticism, while at the same time bring in new blood to provide hybrid vigor.

 Both inbred parents will be far more likely to bring forward their own superior prepotent genetics, leading to more predictable desired outcomes. This is not as difficult as it sounds 

There are quite a few inbred stallions that can be used 

- Quaterhit,  Morricone,  Destano , Franklin , Gribaldi, Proud James,     there will be a more detailed  list in another section

A short list can be drawn up of tightly bred stallions with blood different to your mares' bloodlines.

Inbred and heavily linebred  mares also will give you a  much wider stallion choice.

Some experts like to see an inbred mare put to a loosely bred stallion or have only one or two duplications with a particular stallion. 

A good example is For Romance i - dam Gesina is the inbred mare and Furst Romancier is really just along for the ride - they do share a common line of Donnerhall on the  4th generation but other than that he is not that much help to her  - and she doesn't need the help.

 She has proven herself over a variety of different stallions and is a superstar producer

Another approach is to take an inbred mare to a stallion who is free of the mares own inbred duplicated relatives - but who also shares a different ancestor with the mare. The foal will be outcrossed to the inbred part of the mare's own pedigree - but will form a different inbreeding with another ancestor in the stallion's pedigree. 

Examples

If you have an inbred mare and want to keep a filly from this mare line - its important to go away  from the inbreeding for a generation and add in the  new outcrossed bloodline in the next mating   -  then you can return with that filly  to link back into a close relative of the inbreeding for the real fireworks to begin  

Example

Ken McLean - " You must first duplicate the ancestor - then breed away from it - then make sure it is reinforced again. Genetic influence from superior ancestors becomes diluted after a few generations. Yet when the same ancestors are returned to and reinforced in a pedigree it allows for the recapture of the original source of talent"