[Analysis of the population structure of the Black Forest Draught Horse].

The research studied the genetic contributions of foreign populations, coefficients of inbreeding and relationship in 699 Black Forest Draught horses. The study found that the population’s average inbreeding coefficient is 6.5%, which was lower in new lines of stallions crossbred with different breeds. The research also found that around 70% percent of the population consisted of purebred Black Forest Draught horses, and this figure could reach 90% if horses of unknown origin were assumed to be purebred.

Understanding the Gene Contributions and Inbreeding Among Black Forest Draught Horses

• The research such a specific population of Black Forest Draught horses based on almost complete 5-generation pedigrees, which helped get to the most accurate results possible.
• Researchers found out that the average coefficient of inbreeding in the studied population was 6.5%. However, it was significantly lesser in the new lines of stallions that were established through crossbreeding with different breeds. Inbreeding refers to the reproduction from the mating of parents who are closely related genetically. A lower rate of inbreeding suggests a better genetic diversity and usually leads to healthier offsprings.
• They found high rates of inbreeding of about 1.6% in the last five generations. The researchers were able to lower this inbreeding rate by crossbreeding stallions of foreign coldblooded populations, allowing a decrease of inbreeding in the latest generation.

Relationships and Proportion of Purebred Black Forest Draught Horses

• In the whole population, the average degree of relationship was found to be 16%, meaning one horse could be related to another by 16% on average. This was, however, higher within stallion lines, ranging between 18.3% and 26.8%. Calculation of these coefficients helps in planning matings within a stud to keep the gene flow at as diverse a level as possible.
• The percentage of relationships between different lines of stallions ranged between 5.1% and 16.6%.
• Around 70% of all studied Black Forest Draught horses were found to be “purebred”, i.e., not crossbred with any other breeds. When accounting for horses of unknown origin to be purebred, this figure may reach nearly 90%.
• Foreign stallions from the Austrian Noric, Swiss Freiberg, and South German Coldblood were the most significant contributors to the Black Forest Draught horse population, meaning that these breeds had the highest influence on the genetic makeup of the studied horses.