The Losino horse, (Pony sp.), Losino by Mason, has the name from the area where is bred, the Losa valley, in the north of Burgos (Spain). It is the only original horse from the region of Castilla Leon and is historically and geographically related to other original breeds from the Cantabrian-Pyrinean branch: "Garrano Portugués", Faco Gallego, Asturcón, Navarro Horse, Pottoca Vasco and the Merens Horse.

              The Losino horse was very important in the history, during the Middle Ages had an important participation in the Reconquest of Spain and later in the colonization of America. The Losino breed kept its population for years until 1950 but later suffered a drop to 86 heads leaving only 30 horses left. In this year due to the difficult situation, a new project to recover the Losino breed started in Pancorbo (Burgos), the first Center of  development for the Losino horse. The government recognized the importance of this situation, started a number of actions to improve the Losino situation (decree-law, April 1995) and similar action was taken by the local government by starting the first Stud Book for the Losino horse (October 1998). 

            The objective of this study is to assess the current situation of the Losino breed and the development of the different needs to put in place the right program for the conservation of the breed.

             For the ethnologic characterization of the Losino breed we took zoometric samples from a population of 75 horses out of two different nuclei (Pancorbo and Quincoces) both located in the province of Burgos. The Analysis of the zoometric measurements shows the we are facing a bigger animal than similar ponies from the north of the Iberian Peninsula, like in height, diameter, etc, with special similarity to normal riding horses.

             The inherited zoometric measures are from 0.36 for the shaft's perimeter to 0.94 for the croup height. The mayor genetic correlations are related to the body length, height and volume, showing tendency in the breed's proportion.

             For the genetic characterization of the breed, we have computerized all data from each of the animals included in the book. The GCI has a value of 2.03 and the blood correlation is 1.4 %. Since this breed is giving the first steps in their recovery, we only have 4 known generations, but we observed that the degree of completeness is suffering a decrease when we get closer to the beginning.

 The genetic markers studies have contributed to the genetic characterization (Biochemist Polymorphism and DNA microsatellites). To calculate the genetic intrapopulation variability between two different breed nuclei of the Losino horse (Pancorbo and Quincoces), we estimated the average Heterocigosity index, with a value of 0.412 for both nuclei of the 10 Loci of biochemical polymorphism, and 0.733 for the 10 microsatellites, with a Wright index of 0.025. With this result we can confirm that the Losino Horse has a medium-high genetic variability. This has been achieved due to the effort made in the Pancorbo area by the conservation program which was adjusted to the breed's standard already described and also because of the croosbreeding with PRE, Arabic and Postier-Breton horses. The contribution of the Losino horse in the colonization of America is reflected in the proximity with other breeds like the Paso Fino, Quarter mile or the Chilote horse.

 After more deep studies, we have found that there are two different nuclei in the same geographic zone, one is from the "high areas" (Pancorbo) and the other from the Rural areas (Quincoces) in the region of Castilla with genotypical and phenotypical differences. With all this information the Losino horse from the Pancorbo area has arised from a wild habitat in the mountains of Burgos and it could be one of the most ancient horses from the Spanish peninsula, differentiating from the Cantabric breeds and the breeds from the south of Spain. The Quincoces nuclei is more related to the horse breeds of the  North of Spain.