S.B. Ugbo1, J.O. Egahi1, D.S. Gwaza1, N.E.T. Tor1, I. Mallam2, D. Gambo3
1Department of Animal Breeding and Physiology, Joseph Sarwuan Tarka University, Makurdi, Benue State, Nigeria
2Department of Animal Science, Kaduna State University, Kafanchan Campus, Kaduna State, Nigeria.
3Department of Animal Science, Faculty of Agriculture, Nasarawa State University, Keffi, Shabu-Lafia Campus
(Manuscript received 17 June 2025; accepted for publication 10 December 2025)
e-mail: mallamiliya2011@gmail.com
Abstract. This study investigated the genetic diversity and gene polymorphism at the Insulin-like Growth Factor 1 (IGF-1) locus in Tiv chicken ecotype populations from Benue State, Nigeria. A total of 225 Tiv chickens were obtained from a based population and used, and growth performance was recorded from hatch to 10 weeks. Blood samples were collected for DNA extraction, PCR amplification, and sequencing of the IGF-1 gene. Genetic diversity parameters, including allele frequencies, heterozygosity, and fixation indices, were analyzed using standard molecular and statistical techniques. Results revealed 42 single nucleotide polymorphisms (SNPs) within the 5′ untranslated region of the IGF-1 gene, comprising 3 deletions, 10 substitutions, and 29 transversions. Phylogenetic analysis showed that Tiv chickens formed a distinct clade closely related to other Nigerian and Asian chicken populations. Analysis of molecular variance (AMOVA) indicated that 85% of genetic variation occurred within individuals, while 15% was among populations. Fixation indices (FIS = 0.162, FIT = -0.068, FST = 0.105) suggested moderate genetic differentiation among subpopulations. The IGF-1 locus was found to be highly polymorphic (100%) except in the Daudu population, which was monomorphic. Association analysis showed no significant effect of IGF-1 genotypes or sex on growth traits, although numerical differences were observed. These findings highlight substantial genetic diversity and polymorphism at the IGF-1 locus in Tiv chickens, supporting their potential for genetic improvement and conservation. Tiv ecotype chicken can be recommended for selection and genetic improvement for the development of an indigenous meat breed and further studies explore additional candidate genes and extend sampling to broader indigenous chicken populations to enhance genetic resource management and selective breeding programs.