A Yardah Spanish Warmblood is not the result of some random cross between an Andalusian or Lusitano horse with another horse. The Yardah herd is a result of careful genetic development over a period of 25 years. This genetic development was attained by line breeding using horses which showed superior characteristics of the attributes which Marji Armstrong considered the most important in a horse.
The breed has been developed in the same tradition as the great Australian Merino (among others) sheep bloodlines were developed. The dominance of the Pepppin strain of sheep in Australia is a result of careful line breeding and is a case in point. "Whenever they produced a ram with the qualities they were aiming for they inbred that line to fix the type - their outstanding sire 'Emperor', champion ram at the Hay show in 1871, was 'used on his daughters and granddaughters as long as he lived'. (ref: When Wool was King" - Alec Morrison 2009 R.M.Williams Publishing Pty. Ltd.)
Several groups of horse enthusiasts with a certain type of horse have opened registries to document the horses. These horses should not be classed as Pure Breeds and unless the gene pool is small they will not attain Pure Breed status unless their registries close. The time of developing the genetic stability depends on the number of individuals with which the programme started. In the case of the Pure Spanish Warmblood attainment of the genetic stability has been accelerated by the fact that the core herd was small.
In the case of the Pure Spanish Warmblood the time has come to increase the critical mass both to seek genetic diversity and to have more individuals available to the general public so that their attributes can become known and recognised.
The difference between line-breeding and in-breeding is simple. To quote Marji's late father: "It is line-breeding when it works and in-breeding when it doesn't." While this makes it necessary for the stud master to make decisions based on commercial reality and the long term objectives for the breed and to cull where appropriate (ie not use certain individuals as breeding stock), Yardah has been fortunate in the quality of stock produced that extensive culling has been unnecessary.
Size of herd.
As mentioned above, the size of the Yardah herd has been small but this has not prevented the development. Over the years the size of breed numbers in some endangered species has been very low, but this has not precluded their resurgence. The Whooping Crane of Canada is a classic example.
The difference between line breeding and cross breeding is the difference between "developing a breed" and "breeding a type." In the case of the Pure Spanish Warmblood it did start out as "breeding a type," but then moved on to "developing a breed." It is generally accepted that hybrid vigour (crossing of 2 breeds within a species) does not follow after the first generation. Unsystematic crossing of individuals from the same cross bred breed parentage, who are not carrying the same genetics as their close ancestors on at least one side, is not line-breeding and will not produce the genetic stability to carry into future generations