Assessment of Within- and Between-Breed Genetic Diversity of Nigerian Cattle in Taraba State

This research examined Nigerian cattle populations in Taraba State by studying mitochondrial DNA sequence data to determine their genetic diversity within and between different breeds. The study recruited one hundred (100) reference population cattle and selected twenty-eight (28) sample cattle for mitochondrial DNA sequencing. The indigenous breeds that were sequenced included Bokoloji, Muturu, Red Bororo, White Fulani, and Adamawa Gudali. The four study locations were Iware, Wukari, Donga, and Gembu. Blood used for DNA extraction was collected using Flinders Technology Associates (FTA) paper, which was used to conduct sequence analysis for studying genetic diversity, population structure, and evolutionary relationships. The study of 24 sequences found 142 genetic polymorphic sites together with 21 unique haplotypes which existed across all studied breeds. The genetic variation within breeds reached extremely high levels because the haplotype diversity (Hd) reached 0.992 and the nucleotide diversity (π) reached 0.033. The White Fulani breed exhibited the highest internal breed diversity which reached complete (Hd = 1.000) and 41.5 percent (π = 0.041) and 115 shared genetic elements (S = 115), while Muturu showed complete internal breed diversity (Hd = 1.000) and 39 percent (π = 0.039), and Red Bororo displayed lower breed diversity which reached 93.3 percent (Hd = 0.933) and 1.5 percent (π = 0.015). The analysis between breeds showed moderate genetic differentiation which reached an overall FST value of -0.025 while the gene flow (Nm) reached 1.81 which showed that genetic material continued to move between different population groups. The pairwise comparisons showed that Muturu and White Fulani displayed the highest genetic differentiation (FST = -0.018, Gst = 0.072, Da = -0.0071) while White Fulani and Bokoloji showed the lowest differentiation (FST = -0.014, Gst = 0.072). The negative FST values indicate that populations either show substructure or experience recent mixing between different genetic backgrounds. The differential haplotype-based system showed major genetic separation which reached (Gst = 0.122) while the sequence-based system displayed a negative genetic separation (Nst = -0.212). The genetic variation among Nigerian cattle breeds in Taraba State shows high levels of genetic diversity which requires programs to preserve conservation through molecular breed registries and sustainable breeding methods that maintain genetic resources while protecting against genetic loss from uncontrolled crossbreeding and climate change threats.