The African continent is home to diverse populations of livestock breeds adapted to harsh environmental conditions with more than 70% under traditional systems of management. Animal productivity is less than optimal in most cases and is faced with numerous challenges including limited access to adequate nutrition and disease management, poor institutional capacities and lack of adequate government policies and funding to develop the livestock sector. Africa is home to about 1.3 billion people and with increasing demand for animal proteins by an ever growing human population, the current state of livestock productivity creates a significant yield gap for animal products. Although a greater section of the population, especially those living in rural areas depend largely on livestock for their livelihoods; the potential of the sector remains underutilized and therefore unable to contribute significantly to economic development and social wellbeing of the people. With current advances in livestock management practices, breeding technologies and health management, and with inclusion of all stakeholders, African livestock populations can be sustainably developed to close the animal protein gap that exists in the continent. In particular, advances in gene technologies, and application of genomic breeding in many Western countries has resulted in tremendous gains in traits like milk production with the potential that, implementation of genomic selection and other improved practices (nutrition, healthcare, etc.) can lead to rapid improvement in traits of economic importance in African livestock populations. The African livestock populations in the context of this review are limited to cattle, goat, pig, poultry, and sheep, which are mainly exploited for meat, milk, and eggs. This review examines the current state of livestock productivity in Africa, the main challenges faced by the sector, the role of various stakeholders and discusses in-depth strategies that can enable the application of genomic technologies for rapid improvement of livestock traits of economic importance.

The first hypervariable (HV1) region of mitochondrial DNA (mtDNA) of two popular Nigerian goat breeds: West African Dwarf (WAD) (n=35) and Red Sokoto (RS) (n=37) and one exotic breed: Kalahari Red (KR) (n=38) imported from South Africa were sequenced to investigate sequence diversity, genetic structure, origin, and demographic history of the populations. A total of 68 polymorphic sites were found in 110 sequences that grouped into 68 haplotypes. Average haplotype and nucleotide diversities for all breeds were 0.982±0.005 and 0.02350±0.00213, respectively. Phylogenetic analysis revealed two mtDNA lineages (A and B). Lineage A was predominant and included all haplotypes from WAD and RS and 5 out of 11 haplotypes of KR goats. The remaining haplotypes (6) of KR belong to lineage B. The analysis of molecular variance revealed a high-within breed genetic variance of 82.4% and a low-between breed genetic variance of 17.6%. The three breeds clustered with Capra aegagrus as their wild ancestor. Mismatch distribution analysis showed that WAD, RS and haplogroup A have experienced population expansion events. The study has revealed very high diversity within the three breeds which are not strongly separated from each other based on mtDNA analysis. The information obtained on the genetic structure of the breeds will be useful in planning improvement and conservation programs for the local populations.

Gonadotropin-releasing hormone receptor (GnRHR) gene is considered a candidate gene for litter size due to its critical role in regulating the activities of hypothalamo-pituitary-gonadal axis which synthesizes and releases gonadotropins. This study was designed to identify mutations within the caprine GnRHR gene and investigate their association with litter size at various parities. Polymorphisms scanning and genotyping of GnRHR gene in West African Dwarf (WAD) goats (n = 226) revealed three single nucleotide polymorphisms (SNPs), one mutation (g.-29T > G) was detected within 5'UTR region while two others (g.48G > A and g.209T > G) were identified in exon 1. Mutation at g.209T > G locus resulted in amino acid change from Methionine to Arginine at position 70 on the polypeptide residue. Based on heterozygosity and polymorphism information content (PIC), WAD goat population diversity at the SNP loci was moderate. Strong linkage disequilibrium (LD) (r > 0.98) existed among the detected mutations resulting in three observed haplotypes, two (T-G-T and G-A-G) had cumulative frequency of > 97%. The mutation within 5'UTR region of GnRHR gene (g.-29T > G) is novel, being reported in goats for the first time. Association analysis revealed a significant (p < 0.05) association between allele G at g.-29T > G with higher mean litter size for homozygous (GG) mutant does compared with heterozygotes (GT) or homozygotes (TT), while the relationship between SNPs at the two loci detected in exon 1 and litter size was not significant.

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