Evolutionary Signatures of Thermotolerance Shaped by Adaptive Admixtures in the Ghurrah Pig of India.

India's indigenous pig genetic resources are central to sustainable meat production and rural livelihoods, yet their genomic potential remains underexplored. The Ghurrah pig, a native breed from northern India, is among the most genetically distinct and adaptively resilient populations, shaped by ancestral admixture from Asian, European, and Indian wild boar lineages. This study elucidates the genetic uniqueness, population structure, and adaptive introgression of the Ghurrah pig by jointly analysing 35,777 high-quality SNPs across 270 global pig genotypes. Higher observed heterozygosity (Ho = 0.287) and lower inbreeding coefficient (FIS = 0.206) in Ghurrah indicated substantial genetic variability and minimal inbreeding, while its effective population size (Ne = 26 at 13 generations ago) revealed demographic constraint. Linkage disequilibrium (r² = 0.325) and haplotype block structure (average block size = 415.56 kb) reflected reduced recombination and hybrid ancestry. Admixture analysis at K = 5 positioned Ghurrah intermediate between Asian and European clusters, with 39.07% Asian ancestry and significant European introgression. Local ancestry inference identified adaptive admixtures from Asian ancestry on Sus scrofa chromosome (SSC) 10, SSC12, and SSC15 associated with thermotolerance, immune regulation, and stress resilience, while European ancestry on SSC11 enriched pathways for muscle growth and carcass traits. Functionally, genes such as PTPRC, CTSL, and HSPA14 contributed to environmental adaptability, whereas ATP11A influenced lean meat yield. A 1000 SNP ancestry informative marker (AIM) panel revealed 97.25% unique ancestry for Ghurrah, underscoring its genetic distinctiveness. These findings establish Ghurrah as a genomic bridge between Asian and European domestication centres, embodying hybrid vigour and adaptive potential. The study emphasizes the need for genomic-assisted conservation breeding to safeguard Ghurrah's genetic integrity and promote its sustainable use in tropical production systems.