Demystifying the Genetic Origins of the Mangalarga Horse Through the Influential Stallion Turbante J.O.

Pedigrees and horse written ancestry contain numerous inconsistencies and divergence between farm histories, owner accounts and registration records. In particular, the origins of the Brazilian Mangalarga, or Mangalarga Paulista horse breed is controversial, and the breed's popular history claims that one of its most famous individuals, Turbante J.O., may have been sired by an unknown Hanoverian stallion. Turbante J.O. sired over 1678 offspring and is present in about 71% of the male pedigrees. We genotyped Turbante J.O. and 29 registered Mangalarga individuals using a commercially available ancestry service and compared genomic to pedigree-based estimates . DNA was extracted for this sire from frozen semen samples. Other breed-average genomic ancestries for the Arabian, Thoroughbred, Saddlebred, and Hanoverian were utilized for comparison. Pedigree-based inbreeding coefficient (F-ped) of Turbante J.O. and the 17 other Mangalargas were analyzed, and while Turbante J.O.'s F-ped is estimated to be 18.5%, the genomicbased inbreeding coefficient is 33%. Pedigree-based co-ancestry coefficients estimate that about 3% of his ancestry should reflect Thoroughbred and Arabian heritage, however, the genomic analysis of Turbante J.O. identified 100% Iberian ancestry, and 99% in common with other Mangalarga individuals followed by other autochthonous Brazilian breeds, with no evidence of Hanoverian parentage. We demonstrate higher pedigree-estimated inbreeding coefficient errors than previously reported, perhaps a result of the pedigree depth, and the ability of genomic ancestral analysis to answer questions that pedigree analyses cannot. Due to the genomic relatedness, these results may provide more detailed guidelines in maintaining genetic diversity in this breed through selective outbreeding. (c) 2022 Elsevier Inc. All rights reserved.

Automated summary

Pedigrees and horse written ancestry often have inconsistencies, but a genomic analysis of the Brazilian Mangalarga horse breed reveals that its famous individual, Turbante J.O., has 100% Iberian ancestry instead of being sired by a Hanoverian stallion as claimed by the popular history. These results demonstrate the ability of genomic analysis to provide more accurate information about ancestry and can guide the maintenance of genetic diversity in the breed.