Browsing by Person "Houaga, Isidore"

Now showing 1 - 2 of 2

The genetic structure and diversity of smallholder dairy cattle in Rwanda
(2025) Opoola, Oluyinka; Shumbusho, Felicien; Rwamuhizi, Innocent; Houaga, Isidore; Harvey, David; Hambrook, David; Watson, Kellie; Chagunda, Mizeck G. G.; Mrode, Raphael; Djikeng, Appolinaire; Opoola, Oluyinka; Global Academy of Agriculture and Food Systems (GAAFS) and the Royal (Dick) School of Veterinary Studies (RDSVS), University of Edinburgh, Easter Bush Campus, Edinburgh, UK; Shumbusho, Felicien; Rwanda Agriculture and Animal Resources Development Board (RAB), Kigali, Rwanda; Rwamuhizi, Innocent; Rwanda Agriculture and Animal Resources Development Board (RAB), Kigali, Rwanda; Houaga, Isidore; Centre for Tropical Livestock Genetics and Health (CTLGH), The Roslin Institute, University of Edinburgh, Easter Bush Campus, Edinburgh, UK; Harvey, David; Land O’Lakes Venture37®, Arden Hills, MN, USA; Hambrook, David; Royal Jersey Agricultural & Horticultural Society (RJAHS), Trinity, Jersey Island, Jersey; Watson, Kellie; Centre for Tropical Livestock Genetics and Health (CTLGH), The Roslin Institute, University of Edinburgh, Easter Bush Campus, Edinburgh, UK; Chagunda, Mizeck G. G.; Centre for Tropical Livestock Genetics and Health (CTLGH), The Roslin Institute, University of Edinburgh, Easter Bush Campus, Edinburgh, UK; Mrode, Raphael; Scotlands’ Rural College (SRUC), Roslin Institute Building, Edinburgh, UK; Djikeng, Appolinaire; Centre for Tropical Livestock Genetics and Health (CTLGH), The Roslin Institute, University of Edinburgh, Easter Bush Campus, Edinburgh, UK
Previous genomic characterisation of Rwanda dairy cattle predominantly focused on the One Cow per Poor Family (locally called “Girinka”) programme. However, smallholder farmers in Rwanda have benefited from other livestock initiatives and development programmes. Capturing and documenting the genetic diversity, is critical in part as a key contribution to genomic resource required to support dairy development in Rwanda. A total of 2,229 crossbred animals located in all dairy-producing regions of Rwanda were sampled. For each animal, a hair sample was collected and genotyped by using the Geneseek Genomic Profiler (GGP, Neogen Geneseek ® ) Bovine 50 K ( n = 1,917) and GGP Bovine 100 K arrays ( n = 312). The combined dataset was subject to quality control, data curation for use in population genetics and genomic analyses. To assess the genetic structure and diversity of the current population, key analyses for population structure were applied: Principal Component Analysis (PCA), population structure and diversity, admixture analysis, measures of heterozygosity, runs of homozygosity (ROH) and minor allelic frequency (MAF). A dataset of global dairy population of European taurine, African indicus and African taurus ( n = 250) was used as reference. Results showed that Rwanda cattle population is highly admixed of diverse pure and crossbred animals with average MAF of 33% (standard error; se = 0.001) with proportion of foreign high yielding (taurine) dairy breeds of Jersey Island (18%); 12% non-Island Jersey and 42% Holstein-Friesian ancestries. Two African Bos taurus and five Bos indicus breeds contributed 28% of their genetics. Genetic distances were highest in Gir and N’dama (0.29); and Nelore and N’dama (0.29). There were 1,331 ROH regions and average heterozygosity were high for Rwanda cattle (0.41 se = 0.001). Asides well-established genes in cattle, we found evidence for a variety of novel and less-known genes under selection to be associated with fertility, milk production, innate immunity and environmental adaptation. This observed diversity offers opportunity to decipher the presence and/or lack of genetic variations to initiate short- and long-term breed improvement programmes for adaptation traits, disease resistance, heat tolerance, productivity and profitability of smallholder dairy systems in Rwanda.
Livestock phenomics and genetic evaluation approaches in Africa: current state and future perspectives
(2023) Houaga, Isidore; Mrode, Raphael; Opoola, Oluyinka; Chagunda, Mizeck G. G.; Mwai, Okeyo A.; Rege, John E. O.; Olori, Victor E.; Nash, Oyekanmi; Banga, Cuthbert B.; Okeno, Tobias O.; Djikeng, Appolinaire
The African livestock sector plays a key role in improving the livelihoods of people through the supply of food, improved nutrition and consequently health. However, its impact on the economy of the people and contribution to national GDP is highly variable and generally below its potential. This study was conducted to assess the current state of livestock phenomics and genetic evaluation methods being used across the continent, the main challenges, and to demonstrate the effects of various genetic models on the accuracy and rate of genetic gain that could be achieved. An online survey of livestock experts, academics, scientists, national focal points for animal genetic resources, policymakers, extension agents and animal breeding industry was conducted in 38 African countries. The results revealed 1) limited national livestock identification and data recording systems, 2) limited data on livestock production and health traits and genomic information, 3) mass selection was the common method used for genetic improvement with very limited application of genetic and genomic-based selection and evaluation, 4) limited human capacity, infrastructure, and funding for livestock genetic improvement programmes, as well as enabling animal breeding policies. A joint genetic evaluation of Holstein-Friesian using pooled data from Kenya and South Africa was piloted. The pilot analysis yielded higher accuracy of prediction of breeding values, pointing to possibility of higher genetic gains that could be achieved and demonstrating the potential power of multi-country evaluations: Kenya benefited on the 305-days milk yield and the age at first calving and South Africa on the age at first calving and the first calving interval. The findings from this study will help in developing harmonized protocols for animal identification, livestock data recording, and genetic evaluations (both national and across-countries) as well as in designing subsequent capacity building and training programmes for animal breeders and livestock farmers in Africa. National governments need to put in place enabling policies, the necessary infrastructure and funding for national and across country collaborations for a joint genetic evaluation which will revolutionize the livestock genetic improvement in Africa.