While both human and animal trypanosomiasis continue to present as major human and animal public health constraints globally, detailed analyses of trypanosome wildlife reservoir hosts remain sparse. African animal trypanosomiasis (AAT) affects both livestock and wildlife carrying a significant risk of spillover and cross-transmission of species and strains between populations. Increased human activity together with pressure on land resources is increasing wildlife–livestock–human infections. Increasing proximity between human settlements and grazing lands to wildlife reserves and game parks only serves to exacerbate zoonotic risk. Communities living and maintaining livestock on the fringes of wildlife-rich ecosystems require to have in place methods of vector control for prevention of AAT transmission and for the treatment of their livestock. Major Trypanosoma spp. include Trypanosoma brucei rhodesiense, Trypanosoma brucei gambiense, and Trypanosoma cruzi, pathogenic for humans, and Trypanosoma vivax, Trypanosoma congolense, Trypanosoma evansi, Trypanosoma brucei brucei, Trypanosoma dionisii, Trypanosoma thomasbancrofti, Trypanosma elephantis, Trypanosoma vegrandis, Trypanosoma copemani, Trypanosoma irwini, Trypanosoma copemani, Trypanosoma gilletti, Trypanosoma theileri, Trypanosoma godfreyi, Trypansoma simiae, and Trypanosoma (Megatrypanum) pestanai. Wildlife hosts for the trypansomatidae include subfamilies of Bovinae, Suidae, Pantherinae, Equidae, Alcephinae, Cercopithecinae, Crocodilinae, Pteropodidae, Peramelidae, Sigmodontidae, and Meliphagidae. Wildlife species are generally considered tolerant to trypanosome infection following centuries of coexistence of vectors and wildlife hosts. Tolerance is influenced by age, sex, species, and physiological condition and parasite challenge. Cyclic transmission through Glossina species occurs for T. congolense, T. simiae, T. vivax, T. brucei, and T. b. rhodesiense, T. b. gambiense, and within Reduviid bugs for T. cruzi. T. evansi is mechanically transmitted, and T. vixax is also commonly transmitted by biting flies including tsetse. Wildlife animal species serve as long-term reservoirs of infection, but the delicate acquired balance between trypanotolerance and trypanosome challenge can be disrupted by an increase in challenge and/or the introduction of new more virulent species into the ecosystem. There is a need to protect wildlife, animal, and human populations from the infectious consequences of encroachment to preserve and protect these populations. In this review, we explore the ecology and epidemiology of Trypanosoma spp. in wildlife.
Genetic characterization of African goats is one of the current priorities in the improvement of goats in the continent. This study contributes to the characterization effort by determining the levels and number of generations to common ancestors (“age”) associated with inbreeding in African goat breeds and identifies regions that contain copy number variation mistyped as being homozygous. Illumina 50k single nucleotide polymorphism genotype data for 608 goats from 31 breeds were used to compute the level and age of inbreeding at both local (marker) and global levels (F G ) using a model-based approach based on a hidden Markov model. Runs of homozygosity (ROH) segments detected using the Viterbi algorithm led to ROH-based inbreeding coefficients for all ROH (F ROH ) and for ROH longer than 2 Mb (F ROH > 2Mb ). Some of the genomic regions identified as having ROH are likely to be hemizygous regions (copy number deletions) mistyped as homozygous regions. Although the proportion of these miscalled ROH is small and does not substantially affect estimates of levels of inbreeding for individual animals, the inbreeding metrics were adjusted by removing these regions from the ROH. All the inbreeding metrics varied widely across breeds, with overall means of 0.0408, 0.0370, and 0.0691 and medians of 0.0125, 0.0098, and 0.0366 for F ROH , F ROH > 2Mb , and F G , respectively. Several breeds (including Menabe and Sofia from Madagascar) had high proportions of recent inbreeding, while Small East African, Ethiopian, and most of the West African breeds (including West African Dwarf) had more ancient inbreeding.
Maintaining diversity of small ruminant genetic resources is instrumental for sustainable agricultural production. Community-based livestock breeding programs (CBBPs) have emerged as a potential approach to implement breeding programs in smallholder farms. This study assesses the viability of CBBPs as a potential approach for conservation and improvement of indigenous small ruminants, using case studies of goat CBBPs in Malawi and Uganda. Data were collected using focus group discussions, personal interviews, and direct observations. The program promotes and empowers smallholders to have access to small ruminant feed resources through protection of existing communal pasturelands, capacity building in pasture production, and conservation of crop residues and crop by-products. Implementation of the CBBP enhances the contributions through improved animal growth performance, kids’ survival, and twinning rates leading to increased offtake rates and better prices. The existence of permanently established supporting organizations and other stakeholders provides sustainable institutional support instrumental for the establishment and growth of CBBPs. However, establishment of functional community-based institutions (producer cooperatives) and investments in institutional/policy reforms to safeguard fair trading, access to common resources by small ruminant keepers, and adoption of the CBBP model into national livestock development programs are some of the key milestones that can guarantee sustainability.
SummaryCharacteristics of lactation performance, based on AM milk offtake and conformation, of Ankole cattle were studied during one year in 37 herds with 606 recorded cows in Mbarara district in southwestern Uganda. Recording of AM milk offtake was undertaken in eight areas of Mbarara district which represent different production systems and vegetation types.The 467 cows with complete lactation cows yielded, on average, a total AM offtake of 252 and 325 kg over first and second or higher lactations, respectively. These offtakes were higher than other African indigenous populations in pastoral systems. Mean body weight was 292 and 341 kg for first and second or higher parities, respectively. Average body measurements for all parities were 161 cm for heart girth, 129 cm for height at withers and 193 cm for body length.The daily AM milk offtake varied from 1.1 kg in the Ruhengere area characterized by thorny Acacia thickets to 1.9 kg in the bush-cleared Kanyanya area with improved pastures. Although the Ankole cows performed best on the improved pastures, their future may relatively be more favourable in the original non-cleared bush areas because of the gradually increasing competition from exotic dairy breeds and their crosses.
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