Phenotypic and mitochondrial DNA D-loop region characterization of Sukuma chicken (Gallus gallus domesticus) from the Lake Zone regions of Tanzania

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This study characterized the phenotypic, productive, reproductive, and molecular attributes of the Sukuma ( Horasi ) chicken ecotype, a unique indigenous population found predominantly in the Lake Zone regions of Tanzania. A total of 469 mature Sukuma chickens from the entire chicken population were purposively sampled from Mwanza and Shinyanga regions for phenotypic characterization, while 20 blood samples were collected for molecular analysis, and PCR products from 20 samples, which are representatives from five districts of the study area, were sent for sequencing. Data on historical development, productivity, adaptability, and reproductive performance were obtained through farmer interviews, visual assessments, and morphometric measurements were done following FAO guidelines for phenotypic characterization. Statistical analyses were conducted using SPSS version 27, employing chi-square, Kruskal–Wallis, and Mann–Whitney U tests. Results revealed considerable phenotypic diversity across districts and between sexes. Males consistently exhibited higher morphometric values than females, confirming sexual dimorphism. White shanks (59.1%), red earlobes (80%), single combs (55.4%), and plumage colors such as golden chestnut (23.5%) and red (20%) were predominant. Productive performance showed that hens reached sexual maturity at 5 to 6 months, producing an average of 42 eggs per year with an 83% hatchability rate and a 70% chick survival rate at weaning. The age at first mating for cocks is 5 months. Molecular analysis of mtDNA D-loop sequences identified 16 distinct haplotypes, with most clustering within haplogroup E and showing close maternal affinity to Aseel (Asil) chickens from the Indian subcontinent. High haplotype diversity (Hd = 0.963 ± 0.033) indicated substantial maternal genetic variation. Neutrality tests (Tajima’s D = 0.6793; Fu’s Fs = 3.786) indicated no significant deviation from neutrality, suggesting that the evidence does not strongly support a departure from neutral evolution. However, this lack of statistical significance in Tajima’s D and Fu’s Fs does not provide robust support for the inference of recent demographic growth. Overall, the Sukuma chicken ecotype demonstrates valuable genetic diversity, dual-purpose productivity, and adaptability, underscoring its importance for food security, rural livelihoods, and resilience. Immediate conservation and selective improvement strategies are recommended to safeguard this indigenous genetic resource.