Ticks are worldwide ectoparasites to humans and animals, and are associated with numerous health ... more Ticks are worldwide ectoparasites to humans and animals, and are associated with numerous health and economic effects. Threatening over 80% of the global cattle population, tick and tick-borne diseases (TTBDs) particularly constrain livestock production in the East, Central and Southern Africa. This, therefore, makes their control critical to the sustainability of the animal industry in the region. Since ticks are developing resistance against acaricides, anti-tick vaccines (ATVs) have been proposed as an environmentally friendly control alternative. Whereas they have been used in Latin America and Australia to reduce tick populations, pathogenic infections and number of acaricide treatments, commercially registered ATVs have not been adopted in tropical Africa for tick control. This is majorly due to their limited protection against economically important tick species of Africa and lack of research. Recent advances in various omics technologies and reverse vaccinology have enabled ...
La maladie de Newcastle est toujours une maladie sévère de la volaille, en particulier dans les s... more La maladie de Newcastle est toujours une maladie sévère de la volaille, en particulier dans les systèmes de production de secteur 4 (basse-cour), et ce malgré la vaccination des volailles commerciales. La volaille apparemment saine provenant de marchés d'oiseaux vivants a été soupçonnée d'être une source majeure de la propagation de la maladie dans les élevages villageois. Cette étude avait pour but de (i) vérifier la présence de souches virulentes dans les marchés en Ouganda et (ii) comprendre leur lien moléculaire avec les souches responsables d'épizooties dans la région et dans le monde. Entre janvier et juin 2011, 1357 échantillons ont été collectés et 114 souches du virus de la maladie de Newcastle ont pu être isolées (8,7 % de prévalence par isolement) sur de la volaille apparemment saine provenant de marchés d'oiseaux vivants de tout le pays. Les isolats ont été pathotypés en utilisant trois méthodes : durée moyenne avant la mort sur oeufs embryonnés (MDT), index de pathogénicité intracérébrale (ICPI) sur poussins de 1 jour, et séquençage du motif du site de clivage de la protéine de fusion. Les gènes de la fusion (F) et de l'hémagglutinine-neuraminidase (HN) d'une partie des isolats ont également été séquencés. Les isolats, tous vélogènes, ont été classés en génotypes et sous-génotypes sur la base du système de génotypage récemment décrit par Diel et al (2012). Les virus ougandais appartiennent à un nouveau sous-génotype : Vd, au sein du génotype V. Ce sous-génotype ne comprend que des souches ougandaises et kenyanes. Les virus ougandais présentent une faible diversité génétique, notamment en comparaison avec leurs homologues vélogènes d'Afrique de l'Ouest. La présence de souches de virus de la maladie de Newcastle virulentes dans des marchés d'oiseaux vivants peut représenter un risque pour des épizooties de maladie de Newcastle dans des élevages non commerciaux.
A collaboration program was established between the group of Health and Biotechnology (SaBio) of ... more A collaboration program was established between the group of Health and Biotechnology (SaBio) of the IREC Institute of Game and Wildlife Research (CSIC-UCLM-JCCM, Spain) and the National Agricultural Research Organization of Uganda (NARO) for the development of vaccines for the control of cattle ticks in Uganda. Controlled pen trials identified a tick protective antigen, Rhipicephalus appendiculatus Subolesin, and a cross-species-effective vaccine formulation. As the next step, a controlled vaccine field trial has been approved by Ugandan state regulatory authorities, the Uganda National Council for Science and Technology (UNCST) and the National Drug Authority (NDA), to evaluate the efficacy and effectiveness of the vaccine formulation for the control of cattle tick infestations under field conditions. The results of this trial may lead to the approval of the vaccine for application in Uganda to improve cattle health and production while reducing the use of acaricides.
Herein we review the epidemiology of ticks and tick-borne diseases (TTBDs), their impact on lives... more Herein we review the epidemiology of ticks and tick-borne diseases (TTBDs), their impact on livestock health and on the economy, control and associated challenges in Uganda. Ticks are leading vectors of economically important pathogens and are widespread in Uganda due to suitable climatic conditions. Besides the physical injury inflicted on the animal host, ticks transmit a number of pathogens that can cause morbidity and mortality of livestock if untreated, resulting in economic losses. Uganda suffers an aggregated annual loss (direct and indirect) of over USD 1.1 billion in the TTBDs complex. East Coast fever (ECF) caused by a protozoan haemoparasite, Theileria parva, is the most prevalent and economically important tick-borne disease (TBD) in Uganda and its vector, the brown ear tick (Rhipicephalus appendiculatus) widely distributed. Other prevalent TBDs in Uganda include anaplasmosis, babesiosis and heartwater. We highlight the role of agro-ecological zones (AEZs) and livestock management system in the distribution of TTBDs, citing warm and humid lowlands as being ideal habitats for ticks and endemic for TBDs. Control of TTBDs is a matter of great importance as far as animal health is concerned in Uganda. Indigenous cattle, which make up over 90% of the national herd are known to be more tolerant to TTBDs and most farms rely on endemic stability to TBDs for control. However, exotic cattle breeds are more capital intensive than indigenous breeds, but the increasing adoption of tick-susceptible exotic cattle breeds (especially dairy) in western and central Uganda demands intensive use of acaricides for tick control and prevention of TBDs. Such acaricide pressure has unfortunately led to selection of acaricide-resistant tick populations and the consequent acaricide resistance observed in the field. Vaccination against ECF, selective breeding for tick resistance and integrated tick control approaches that limit tick exposure, could be adopted to interrupt spread of acaricide resistance. We recommend increasing monitoring and surveillance for TTBDs and for emerging acaricide resistance, improved extension services and sensitization of farmers on tick control measures, appropriate acaricide use and the development and implementation of vaccines for the control of TTBDs as more sustainable and effective interventions. A tick control policy should be developed, taking into account variations of agro-ecological zones, farm circumstances and indigenous technical knowledge, and this should be incorporated into the overall animal health program.
Uganda is a Newcastle disease (ND) endemic country where the disease is controlled by vaccination... more Uganda is a Newcastle disease (ND) endemic country where the disease is controlled by vaccination using live LaSota (genotype II) and I2 (genotype I) vaccine strains. Resurgent outbreak episodes call for an urgent need to understand the antigenic diversity of circulating wild Avian Avulavirus serotype-1 (AAvV-1) strains. High mutation rates and the continuous emergence of genetic and antigenic variants that evade immunity make non-segmented RNA viruses difficult to control. Antigenic and functional analysis of the key viral surface proteins is a crucial step in understanding the antigen diversity between vaccine lineages and the endemic wild ND viruses in Uganda and designing ND peptide vaccines. In this study, we used computational analysis, phylogenetic characterization, and structural modeling to detect evolutionary forces affecting the predicted immune-dominant fusion (F) and hemagglutinin-neuraminidase (HN) proteins of AAvV-1 isolates from waterfowl and poultry in Uganda compar...
Tree species play a significant role in sustaining the productivity of grazing lands. However, in... more Tree species play a significant role in sustaining the productivity of grazing lands. However, information on appropriate species to use in restoring degraded grazing areas is limited. This study used 120 trees to assess the effect of 8 tree species on pasture diversity, abundance and biomass. This was done in a total of 960 quadrats of 1 m 2 established under tree canopies and 5 m away from the edge of tree canopies. In each quadrat, the different pasture species and their ground cover were recorded. The pastures were harvested, weighed and their biomass recorded. Results of analysis by Shannon-Wiener's index indicated that pasture diversity was almost the same under and outside tree canopies (H = 1.8 and H = 1.78 respectively), but pasture abundance was significantly higher under tree canopies (p < 0.05). Ficus natalensis and Albizia coriaria had the highest pasture abundance under their canopies. Pasture biomass never varied significantly under and outside tree canopies but between tree species, F. natalensis had a significantly higher positive influence on pasture biomass than other species. It was discovered that F. natalensis and A. coriaria have a higher potential for restoring degraded grazing areas in Southwestern Uganda.
Southwestern Uganda annually experiences prolonged drought that results in dramatic drop in milk ... more Southwestern Uganda annually experiences prolonged drought that results in dramatic drop in milk production of dairy cattle. This study was conducted to assess the nutritional value and economic benefits of feeding silage and hay to dairy cattle in the sub-region. The cross-sectional study covered seven districts with 105 farmers interviewed during the wet and 45 others in the dry season. Up to 88 soil samples were collected and analyzed for soil texture, soil pH, organic matter and total Nitrogen, Phosphorus, Potassium, Calcium, Sodium and Magnesium. Likewise, 148 forage (105 fresh, 25 silage and 18 hay) tissues from 21 pasture species were collected and analyzed for nutritional values. Using a questionnaire, data on production costs and milk revenues were collected for cost-benefit analysis. Results showed that silage of Napier grass treated with molasses (10.2 MJ/kg) and hay of naturally established pastures (10.6 MJ/kg) had the highest metabolisable energy (ME) values, while the lowest (8.30 MJ/kg) was for star grass. Hay of star grass presented the highest level of crude protein (21.4%) with maize (corn) showing the lowest (9.38%). Digestibility of hay of naturally established mixed pastures was the highest (64.4%), followed by that of silage of Napier grass treated with molasses (62.0%), while star grass hay had the lowest (52.6%). With exception of silage made from maize, all the other six forms of silage had a good crude protein (CP) content. Regardless of the good CP content (≥9.9%), all silage untreated with additives was poor in quality since its ME was less than 9.9 MJ ME/kg and ration digestibility less than 67%. Nonetheless, feeding of silage and hay increased milk yield and farm productivity with a benefit-cost ratio of 5.5 and 2.7 for silage and hay respectively.
Onderstepoort Journal of Veterinary Research, 2018
Avian paramyxovirus type-1 (APMV-1) viruses of the lentogenic pathotypes are often isolated from ... more Avian paramyxovirus type-1 (APMV-1) viruses of the lentogenic pathotypes are often isolated from wild aquatic birds and may mutate to high pathogenicity when they cross into poultry and cause debilitating Newcastle disease. This study characterised AMPV-1 isolated from fresh faecal droppings from wild aquatic birds roosting sites in Uganda. Fresh faecal samples from wild aquatic birds at several waterbodies in Uganda were collected and inoculated into 9–10-day-old embryonated chicken eggs. After isolation, the viruses were confirmed as APMV-1 by APMV-1-specific polymerase chain reaction (PCR). The cleavage site of the fusion protein gene for 24 representative isolates was sequenced and phylogenetically analysed and compared with representative isolates of the different APMV-1 genotypes in the GenBank database. In total, 711 samples were collected from different regions in the country from which 72 isolates were recovered, giving a prevalence of 10.1%. Sequence analysis of 24 isolate...
Vaccine failures after Newcastle disease vaccination with the current commercial vaccines have be... more Vaccine failures after Newcastle disease vaccination with the current commercial vaccines have been reported and are associated with many factors, including genotypic and antigenic differences between vaccine and outbreak strains, although all APMV-1 members belong to one serotype. We assessed the immunoprotection ability of four thermostable, low-virulent Newcastle disease-virus isolates from Ugandan waterfowl against challenge with a virulent strain (MDT = 36.8 h, ICPI = 1.78) isolated from morbid chicken. Six-week-old commercial Leghorn layers, challenged at 21 days post immunization were used. Four isolates designated: NDV-133/UG/MU/2011, NDV-177/UG/MU/2011, NDV-178/UG/MU/2011 and NDV-173/UG/MU/2011 induced mean haemagglutinin inhibition antibody titres of log 2 9.3, 8.2, 6.3 and 2.0, respectively, at 21 days post immunization. The antibody titres correlated with the protection rates (R² = 0.86, p < 0.007) of 60%, 50%, 20% and 0% of birds, respectively, against challenge at 14 days post challenge. Further evaluation of these and more low-virulent isolates might provide an alternative to the current commercial vaccine failures.
Background: Uganda poultry production is still faced with frequent outbreaks of Newcastle disease... more Background: Uganda poultry production is still faced with frequent outbreaks of Newcastle disease (ND) in the backyard free-range systems despite the accessibility of cross protective vaccines. Live bird markets and waterfowl has long been reported as a major source of disease spread as well as potential sources of avirulent strains that may mutate to virulent strains. ND-virus has been reported enzootic in Ugandan poultry but limited studies have been conducted to ascertain thermostability phenotypes of the Ugandan ND-virus strains and to understand how these relate to vaccine strains. Methods: This study evaluated thermostability of 168 ND-virus field isolates recovered from live bird markets and waterfowls in Uganda compared to two live commercial vaccine strains (I 2 and LaSota) by standard thermostability procedures and Hemagglutinin-Neuraminidase (HN) gene domains. The known pathotypes with thermostability profiles were compared at HN amino acid sequences. Results: Field isolates displayed disparate heat stability and HN gene domains. Thermolabile isolates were inactivated within 15 min, while the most thermostable isolates were inactivated in 120 min. Four thermostable isolates had more than 2 log 2 heamaglutinin (HA) titers during heat treatment and the infectivity of 9.8 geometric mean of log 10 EID 50 % in embryonated eggs. One isolate from this study exhibited a comparable thermostability and stable infectivity titers after serial passages, to that of reference commercial vaccine was recommended for immunogenicity and protection studies. Conclusion: The occurrence of ND-virus strains in waterfowl and live bird markets with disparate thermostability and varying HN gene domains indicate circulation of different thermostable and thermolabile ND-virus pathotypes in the country.
Disease diagnosis, and analysis or manipulation of both human and animal samples, expose scientis... more Disease diagnosis, and analysis or manipulation of both human and animal samples, expose scientists and practitioners to disease causing agents and toxins. In situations of poor awareness of biosecurity, the same samples can easily be accessed by persons with wrong intentions or misused by the same scientists or practitioners (dualuse). In Uganda information required to minimize the global challenges of biosafety and biosecurity has been largely lacking. The current study assessed the level of awareness and existence of procedures, regulations, laws and policies on biosafety and biosecurity among institutions in the different sectors, professions and regions across the country. Results showed that sector, profession and region were each a predictor for nine of the assessed variables. Among the most striking was that profession significantly influenced (χ 2 =49.0) the opinion that institutional measures to prevent or prohibit production, stockpiling, retention or unimpeded access to pathogenic agents and biological toxins existed. Professionals (veterinary scientists and laboratory technologists) in animal health research had reduced odds of holding this opinion (OR=0.2, 95% CI: 0.05-0.87) compared to their counterparts in public hygiene. Scientific establishments in eastern (OR=0.3, 95% CI: 0.17-0.7, p<0.01), northern (OR=0.4, 95% CI: 0.17-0.71, p<0.01) and western (OR=0.3, 95% CI: 0.16-0.51, p<0.01) regions were less associated with professionals trained in biosafety and biosecurity compared to central Uganda. Professionals in wildlife conservation, medical, human health research, public hygiene and crop extension services were 9.5, 7.0, 5.7, 5.4 and 4.0 times, respectively, more likely to consider Uganda's disease monitoring system as adequate compared to those in veterinary services sector. We conclude that there is inadequate level of awareness on laboratory biosafety and biosecurity among professionals in the country. There is need for raising awareness and training of relevant professionals and formulation of measures, policies, regulations and laws to help prevent exposure to and misuse of dangerous biological agents and toxins in Uganda.
There is an urgent need for a unified resource that integrates trans-disciplinary annotations of ... more There is an urgent need for a unified resource that integrates trans-disciplinary annotations of emerging and reemerging animal infectious and zoonotic diseases. Such data integration will provide wonderful opportunity for epidemiologists, researchers and health policy makers to make data-driven decisions designed to improve animal health. Integrating emerging and reemerging animal infectious and zoonotic disease data from a large variety of sources into a unified open-access resource provides more plausible arguments to achieve better understanding of infectious and zoonotic diseases. We have developed a model for interlinking annotations of these diseases. These diseases are of particular interest because of the threats they pose to animal health, human health and global health security. We demonstrated the application of this model using brucellosis, an infectious and zoonotic disease. Preliminary annotations were deposited into VetBioBase database (). This database is associated with user-friendly tools to facilitate searching, retrieving and downloading of disease-related information.
Infectious and non-infectious factors affecting hatchability in indigenous chickens in Eastern Uganda, 2010
Abstract Different options for improving hatchability in indigenous free-range chickens were eval... more Abstract Different options for improving hatchability in indigenous free-range chickens were evaluated. The aim was to establish alternatives that could increase mean hatchability to more than 80% as previously reported in village chickens in other countries. A total of 1,182 hens were recruited. Farmers were required to provide water and feed provision at nest, turn eggs in the nest and monitor hens for any mite infestation. Independent variables were site of egg storage, type of nest material, number of eggs provided to hen to incubate and hen-cockerel relationship. The study response variable was hatchability proportions. Data on these parameters were captured. Quantitative data were analyzed by SPSS for descriptive statistics and determination of significance of relationships done using Kruskal-Wallis Test (p=0.05). There was a significant relationship (p<0.05) between hatchability and site of egg storage; nest material used; number of eggs incubated; and the relationship bet...
Ticks are worldwide ectoparasites to humans and animals, and are associated with numerous health ... more Ticks are worldwide ectoparasites to humans and animals, and are associated with numerous health and economic effects. Threatening over 80% of the global cattle population, tick and tick-borne diseases (TTBDs) particularly constrain livestock production in the East, Central and Southern Africa. This, therefore, makes their control critical to the sustainability of the animal industry in the region. Since ticks are developing resistance against acaricides, anti-tick vaccines (ATVs) have been proposed as an environmentally friendly control alternative. Whereas they have been used in Latin America and Australia to reduce tick populations, pathogenic infections and number of acaricide treatments, commercially registered ATVs have not been adopted in tropical Africa for tick control. This is majorly due to their limited protection against economically important tick species of Africa and lack of research. Recent advances in various omics technologies and reverse vaccinology have enabled ...
La maladie de Newcastle est toujours une maladie sévère de la volaille, en particulier dans les s... more La maladie de Newcastle est toujours une maladie sévère de la volaille, en particulier dans les systèmes de production de secteur 4 (basse-cour), et ce malgré la vaccination des volailles commerciales. La volaille apparemment saine provenant de marchés d'oiseaux vivants a été soupçonnée d'être une source majeure de la propagation de la maladie dans les élevages villageois. Cette étude avait pour but de (i) vérifier la présence de souches virulentes dans les marchés en Ouganda et (ii) comprendre leur lien moléculaire avec les souches responsables d'épizooties dans la région et dans le monde. Entre janvier et juin 2011, 1357 échantillons ont été collectés et 114 souches du virus de la maladie de Newcastle ont pu être isolées (8,7 % de prévalence par isolement) sur de la volaille apparemment saine provenant de marchés d'oiseaux vivants de tout le pays. Les isolats ont été pathotypés en utilisant trois méthodes : durée moyenne avant la mort sur oeufs embryonnés (MDT), index de pathogénicité intracérébrale (ICPI) sur poussins de 1 jour, et séquençage du motif du site de clivage de la protéine de fusion. Les gènes de la fusion (F) et de l'hémagglutinine-neuraminidase (HN) d'une partie des isolats ont également été séquencés. Les isolats, tous vélogènes, ont été classés en génotypes et sous-génotypes sur la base du système de génotypage récemment décrit par Diel et al (2012). Les virus ougandais appartiennent à un nouveau sous-génotype : Vd, au sein du génotype V. Ce sous-génotype ne comprend que des souches ougandaises et kenyanes. Les virus ougandais présentent une faible diversité génétique, notamment en comparaison avec leurs homologues vélogènes d'Afrique de l'Ouest. La présence de souches de virus de la maladie de Newcastle virulentes dans des marchés d'oiseaux vivants peut représenter un risque pour des épizooties de maladie de Newcastle dans des élevages non commerciaux.
A collaboration program was established between the group of Health and Biotechnology (SaBio) of ... more A collaboration program was established between the group of Health and Biotechnology (SaBio) of the IREC Institute of Game and Wildlife Research (CSIC-UCLM-JCCM, Spain) and the National Agricultural Research Organization of Uganda (NARO) for the development of vaccines for the control of cattle ticks in Uganda. Controlled pen trials identified a tick protective antigen, Rhipicephalus appendiculatus Subolesin, and a cross-species-effective vaccine formulation. As the next step, a controlled vaccine field trial has been approved by Ugandan state regulatory authorities, the Uganda National Council for Science and Technology (UNCST) and the National Drug Authority (NDA), to evaluate the efficacy and effectiveness of the vaccine formulation for the control of cattle tick infestations under field conditions. The results of this trial may lead to the approval of the vaccine for application in Uganda to improve cattle health and production while reducing the use of acaricides.
Herein we review the epidemiology of ticks and tick-borne diseases (TTBDs), their impact on lives... more Herein we review the epidemiology of ticks and tick-borne diseases (TTBDs), their impact on livestock health and on the economy, control and associated challenges in Uganda. Ticks are leading vectors of economically important pathogens and are widespread in Uganda due to suitable climatic conditions. Besides the physical injury inflicted on the animal host, ticks transmit a number of pathogens that can cause morbidity and mortality of livestock if untreated, resulting in economic losses. Uganda suffers an aggregated annual loss (direct and indirect) of over USD 1.1 billion in the TTBDs complex. East Coast fever (ECF) caused by a protozoan haemoparasite, Theileria parva, is the most prevalent and economically important tick-borne disease (TBD) in Uganda and its vector, the brown ear tick (Rhipicephalus appendiculatus) widely distributed. Other prevalent TBDs in Uganda include anaplasmosis, babesiosis and heartwater. We highlight the role of agro-ecological zones (AEZs) and livestock management system in the distribution of TTBDs, citing warm and humid lowlands as being ideal habitats for ticks and endemic for TBDs. Control of TTBDs is a matter of great importance as far as animal health is concerned in Uganda. Indigenous cattle, which make up over 90% of the national herd are known to be more tolerant to TTBDs and most farms rely on endemic stability to TBDs for control. However, exotic cattle breeds are more capital intensive than indigenous breeds, but the increasing adoption of tick-susceptible exotic cattle breeds (especially dairy) in western and central Uganda demands intensive use of acaricides for tick control and prevention of TBDs. Such acaricide pressure has unfortunately led to selection of acaricide-resistant tick populations and the consequent acaricide resistance observed in the field. Vaccination against ECF, selective breeding for tick resistance and integrated tick control approaches that limit tick exposure, could be adopted to interrupt spread of acaricide resistance. We recommend increasing monitoring and surveillance for TTBDs and for emerging acaricide resistance, improved extension services and sensitization of farmers on tick control measures, appropriate acaricide use and the development and implementation of vaccines for the control of TTBDs as more sustainable and effective interventions. A tick control policy should be developed, taking into account variations of agro-ecological zones, farm circumstances and indigenous technical knowledge, and this should be incorporated into the overall animal health program.
Uganda is a Newcastle disease (ND) endemic country where the disease is controlled by vaccination... more Uganda is a Newcastle disease (ND) endemic country where the disease is controlled by vaccination using live LaSota (genotype II) and I2 (genotype I) vaccine strains. Resurgent outbreak episodes call for an urgent need to understand the antigenic diversity of circulating wild Avian Avulavirus serotype-1 (AAvV-1) strains. High mutation rates and the continuous emergence of genetic and antigenic variants that evade immunity make non-segmented RNA viruses difficult to control. Antigenic and functional analysis of the key viral surface proteins is a crucial step in understanding the antigen diversity between vaccine lineages and the endemic wild ND viruses in Uganda and designing ND peptide vaccines. In this study, we used computational analysis, phylogenetic characterization, and structural modeling to detect evolutionary forces affecting the predicted immune-dominant fusion (F) and hemagglutinin-neuraminidase (HN) proteins of AAvV-1 isolates from waterfowl and poultry in Uganda compar...
Tree species play a significant role in sustaining the productivity of grazing lands. However, in... more Tree species play a significant role in sustaining the productivity of grazing lands. However, information on appropriate species to use in restoring degraded grazing areas is limited. This study used 120 trees to assess the effect of 8 tree species on pasture diversity, abundance and biomass. This was done in a total of 960 quadrats of 1 m 2 established under tree canopies and 5 m away from the edge of tree canopies. In each quadrat, the different pasture species and their ground cover were recorded. The pastures were harvested, weighed and their biomass recorded. Results of analysis by Shannon-Wiener's index indicated that pasture diversity was almost the same under and outside tree canopies (H = 1.8 and H = 1.78 respectively), but pasture abundance was significantly higher under tree canopies (p < 0.05). Ficus natalensis and Albizia coriaria had the highest pasture abundance under their canopies. Pasture biomass never varied significantly under and outside tree canopies but between tree species, F. natalensis had a significantly higher positive influence on pasture biomass than other species. It was discovered that F. natalensis and A. coriaria have a higher potential for restoring degraded grazing areas in Southwestern Uganda.
Southwestern Uganda annually experiences prolonged drought that results in dramatic drop in milk ... more Southwestern Uganda annually experiences prolonged drought that results in dramatic drop in milk production of dairy cattle. This study was conducted to assess the nutritional value and economic benefits of feeding silage and hay to dairy cattle in the sub-region. The cross-sectional study covered seven districts with 105 farmers interviewed during the wet and 45 others in the dry season. Up to 88 soil samples were collected and analyzed for soil texture, soil pH, organic matter and total Nitrogen, Phosphorus, Potassium, Calcium, Sodium and Magnesium. Likewise, 148 forage (105 fresh, 25 silage and 18 hay) tissues from 21 pasture species were collected and analyzed for nutritional values. Using a questionnaire, data on production costs and milk revenues were collected for cost-benefit analysis. Results showed that silage of Napier grass treated with molasses (10.2 MJ/kg) and hay of naturally established pastures (10.6 MJ/kg) had the highest metabolisable energy (ME) values, while the lowest (8.30 MJ/kg) was for star grass. Hay of star grass presented the highest level of crude protein (21.4%) with maize (corn) showing the lowest (9.38%). Digestibility of hay of naturally established mixed pastures was the highest (64.4%), followed by that of silage of Napier grass treated with molasses (62.0%), while star grass hay had the lowest (52.6%). With exception of silage made from maize, all the other six forms of silage had a good crude protein (CP) content. Regardless of the good CP content (≥9.9%), all silage untreated with additives was poor in quality since its ME was less than 9.9 MJ ME/kg and ration digestibility less than 67%. Nonetheless, feeding of silage and hay increased milk yield and farm productivity with a benefit-cost ratio of 5.5 and 2.7 for silage and hay respectively.
Onderstepoort Journal of Veterinary Research, 2018
Avian paramyxovirus type-1 (APMV-1) viruses of the lentogenic pathotypes are often isolated from ... more Avian paramyxovirus type-1 (APMV-1) viruses of the lentogenic pathotypes are often isolated from wild aquatic birds and may mutate to high pathogenicity when they cross into poultry and cause debilitating Newcastle disease. This study characterised AMPV-1 isolated from fresh faecal droppings from wild aquatic birds roosting sites in Uganda. Fresh faecal samples from wild aquatic birds at several waterbodies in Uganda were collected and inoculated into 9–10-day-old embryonated chicken eggs. After isolation, the viruses were confirmed as APMV-1 by APMV-1-specific polymerase chain reaction (PCR). The cleavage site of the fusion protein gene for 24 representative isolates was sequenced and phylogenetically analysed and compared with representative isolates of the different APMV-1 genotypes in the GenBank database. In total, 711 samples were collected from different regions in the country from which 72 isolates were recovered, giving a prevalence of 10.1%. Sequence analysis of 24 isolate...
Vaccine failures after Newcastle disease vaccination with the current commercial vaccines have be... more Vaccine failures after Newcastle disease vaccination with the current commercial vaccines have been reported and are associated with many factors, including genotypic and antigenic differences between vaccine and outbreak strains, although all APMV-1 members belong to one serotype. We assessed the immunoprotection ability of four thermostable, low-virulent Newcastle disease-virus isolates from Ugandan waterfowl against challenge with a virulent strain (MDT = 36.8 h, ICPI = 1.78) isolated from morbid chicken. Six-week-old commercial Leghorn layers, challenged at 21 days post immunization were used. Four isolates designated: NDV-133/UG/MU/2011, NDV-177/UG/MU/2011, NDV-178/UG/MU/2011 and NDV-173/UG/MU/2011 induced mean haemagglutinin inhibition antibody titres of log 2 9.3, 8.2, 6.3 and 2.0, respectively, at 21 days post immunization. The antibody titres correlated with the protection rates (R² = 0.86, p < 0.007) of 60%, 50%, 20% and 0% of birds, respectively, against challenge at 14 days post challenge. Further evaluation of these and more low-virulent isolates might provide an alternative to the current commercial vaccine failures.
Background: Uganda poultry production is still faced with frequent outbreaks of Newcastle disease... more Background: Uganda poultry production is still faced with frequent outbreaks of Newcastle disease (ND) in the backyard free-range systems despite the accessibility of cross protective vaccines. Live bird markets and waterfowl has long been reported as a major source of disease spread as well as potential sources of avirulent strains that may mutate to virulent strains. ND-virus has been reported enzootic in Ugandan poultry but limited studies have been conducted to ascertain thermostability phenotypes of the Ugandan ND-virus strains and to understand how these relate to vaccine strains. Methods: This study evaluated thermostability of 168 ND-virus field isolates recovered from live bird markets and waterfowls in Uganda compared to two live commercial vaccine strains (I 2 and LaSota) by standard thermostability procedures and Hemagglutinin-Neuraminidase (HN) gene domains. The known pathotypes with thermostability profiles were compared at HN amino acid sequences. Results: Field isolates displayed disparate heat stability and HN gene domains. Thermolabile isolates were inactivated within 15 min, while the most thermostable isolates were inactivated in 120 min. Four thermostable isolates had more than 2 log 2 heamaglutinin (HA) titers during heat treatment and the infectivity of 9.8 geometric mean of log 10 EID 50 % in embryonated eggs. One isolate from this study exhibited a comparable thermostability and stable infectivity titers after serial passages, to that of reference commercial vaccine was recommended for immunogenicity and protection studies. Conclusion: The occurrence of ND-virus strains in waterfowl and live bird markets with disparate thermostability and varying HN gene domains indicate circulation of different thermostable and thermolabile ND-virus pathotypes in the country.
Disease diagnosis, and analysis or manipulation of both human and animal samples, expose scientis... more Disease diagnosis, and analysis or manipulation of both human and animal samples, expose scientists and practitioners to disease causing agents and toxins. In situations of poor awareness of biosecurity, the same samples can easily be accessed by persons with wrong intentions or misused by the same scientists or practitioners (dualuse). In Uganda information required to minimize the global challenges of biosafety and biosecurity has been largely lacking. The current study assessed the level of awareness and existence of procedures, regulations, laws and policies on biosafety and biosecurity among institutions in the different sectors, professions and regions across the country. Results showed that sector, profession and region were each a predictor for nine of the assessed variables. Among the most striking was that profession significantly influenced (χ 2 =49.0) the opinion that institutional measures to prevent or prohibit production, stockpiling, retention or unimpeded access to pathogenic agents and biological toxins existed. Professionals (veterinary scientists and laboratory technologists) in animal health research had reduced odds of holding this opinion (OR=0.2, 95% CI: 0.05-0.87) compared to their counterparts in public hygiene. Scientific establishments in eastern (OR=0.3, 95% CI: 0.17-0.7, p<0.01), northern (OR=0.4, 95% CI: 0.17-0.71, p<0.01) and western (OR=0.3, 95% CI: 0.16-0.51, p<0.01) regions were less associated with professionals trained in biosafety and biosecurity compared to central Uganda. Professionals in wildlife conservation, medical, human health research, public hygiene and crop extension services were 9.5, 7.0, 5.7, 5.4 and 4.0 times, respectively, more likely to consider Uganda's disease monitoring system as adequate compared to those in veterinary services sector. We conclude that there is inadequate level of awareness on laboratory biosafety and biosecurity among professionals in the country. There is need for raising awareness and training of relevant professionals and formulation of measures, policies, regulations and laws to help prevent exposure to and misuse of dangerous biological agents and toxins in Uganda.
There is an urgent need for a unified resource that integrates trans-disciplinary annotations of ... more There is an urgent need for a unified resource that integrates trans-disciplinary annotations of emerging and reemerging animal infectious and zoonotic diseases. Such data integration will provide wonderful opportunity for epidemiologists, researchers and health policy makers to make data-driven decisions designed to improve animal health. Integrating emerging and reemerging animal infectious and zoonotic disease data from a large variety of sources into a unified open-access resource provides more plausible arguments to achieve better understanding of infectious and zoonotic diseases. We have developed a model for interlinking annotations of these diseases. These diseases are of particular interest because of the threats they pose to animal health, human health and global health security. We demonstrated the application of this model using brucellosis, an infectious and zoonotic disease. Preliminary annotations were deposited into VetBioBase database (). This database is associated with user-friendly tools to facilitate searching, retrieving and downloading of disease-related information.
Infectious and non-infectious factors affecting hatchability in indigenous chickens in Eastern Uganda, 2010
Abstract Different options for improving hatchability in indigenous free-range chickens were eval... more Abstract Different options for improving hatchability in indigenous free-range chickens were evaluated. The aim was to establish alternatives that could increase mean hatchability to more than 80% as previously reported in village chickens in other countries. A total of 1,182 hens were recruited. Farmers were required to provide water and feed provision at nest, turn eggs in the nest and monitor hens for any mite infestation. Independent variables were site of egg storage, type of nest material, number of eggs provided to hen to incubate and hen-cockerel relationship. The study response variable was hatchability proportions. Data on these parameters were captured. Quantitative data were analyzed by SPSS for descriptive statistics and determination of significance of relationships done using Kruskal-Wallis Test (p=0.05). There was a significant relationship (p<0.05) between hatchability and site of egg storage; nest material used; number of eggs incubated; and the relationship bet...
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Papers by Halid Kirunda