Bovine fasciolosis: coprological, abattoir survey and its economic impact due to liver condemnation at Soddo municipal abattoir, Southern Ethiopia

A study was carried out to determine the prevalence and the species of liver flukes in indigenous adult cattle, to compare the diagnostic efficiency of fecal and post mortem examination and to assess the economic significance of bovine fasciolosis due to liver condemnation in the abattoir. Of the 406 livers and fecal samples examined, 57 (14.0%) and 20 (4.9%) were positive for fasciolosis. The most common liver fluke species affecting the cattle was Fasciola gigantica, 9.1% of cattle were infected with F. gigantica while, Fasciola. hepatica, mixed infections and unidentified or immature forms of Fasciola spp. were present in 3.2 %, 0.7% and 1 % of cattle, respectively. A retrospective abattoir survey revealed that the prevalence of fasciolosis was 12.7%. The prevalence of fasciolosis recorded in this study was lower than that reported by other researchers in this country. There was a strong relationship between fecal examination and postmortem findings of liver lesions, (K?=?0.23) but under local conditions, postmortem examination was considered a better diagnostic tool for fasciolosis. Fasciolosis is of significant economic importance as the resultant liver condemnations caused an average loss of 4000 USD per annum. Hence, this disease deserves serious attention by the various stakeholders in order to promote the beef industry in the study area in particular and in the country in general.     

Estimation of genetic parameters for growth traits and Kleiber ratios in Boer x Central Highland goat

Tropical Animal Health and Production - Accurate performance evaluation and genetic parameters estimation are the prerequisites for any successful genetic improvement program. This study was...     

Evaluation of 20 enset (Ensete ventricosum) landraces for response to Xanthomonas vasicola pv. Musacearum infection

Xanthomonas wilt, caused by Xanthomonas vasicola pv. musacearum (Xvm), formerly X. campestris pv. musacearum, is the most threatening and economically important disease of enset (Ensete ventricosum), the multipurpose food security crop orphan in south and southwestern Ethiopia. Xvm has also had a major impact on banana and plantain production in east Africa following its detection in Uganda in 2001 and subsequent spread. The only current effective control of this disease relies on integrated disease management strategies including minimizing field pathogen inoculum and deployment of wilt-resistant enset landraces. Identifying landraces with stable and durable Xvm resistance will greatly accelerate breeding programmes. While previous reports have identified landraces with varying degrees of tolerance to Xvm, no systematic study has collectively assessed their relative resistance. Here we undertook a detailed “common garden” analysis of 20 enset landraces previously reported to exhibit lower susceptibility to Xvm using an aggressive Xvm inoculum isolated from a disease hotspot area. Detailed longitudinal and survival analyses were applied to each landrace, using a combination of area-under-disease progress stairs, disease index and apparent infection rate to capture disease metrics as well as disease progression symptoms. Considerable variation was observed among the 20 landraces; however, none exhibited full immunity to Xvm infection. Landraces Haella, Mazia and Lemat showed the lowest susceptibility to Xvm as evidenced by reduced disease units and higher survival rates compared to the susceptible control landrace Arkiya, which exhibited the highest infection level and lowest survival rate, consistent with a high degree of susceptibility to Xvm. Thus, we have in this controlled experiment identified new material suitable for incorporation into future breeding programmes to develop Xvm-resistant enset varieties.

     

Adult neurogenesis in the mammalian dentate gyrus

Earlier observations in neuroscience suggested that no new neurons form in the mature central nervous system. Evidence now indicates that new neurons do form in the adult mammalian brain. Two regions of the mature mammalian brain generate new neurons: (a) the border of the lateral ventricles of the brain (subventricular zone) and (b) the subgranular zone (SGZ) of the dentate gyrus of the hippocampus. This review focuses only on new neuron formation in the dentate gyrus of the hippocampus. During normal prenatal and early postnatal development, neural stem cells (NSCs) give rise to differentiated neurons. NSCs persist in the dentate gyrus SGZ, undergoing cell division, with some daughter cells differentiating into functional neurons that participate in learning and memory and general cognition through integration into pre-existing neural networks. Axons, which emanate from neurons in the entorhinal cortex, synapse with dendrites of the granule cells (small neurons) of the dentate gyrus. Axons from granule cells synapse with pyramidal cells in the hippocampal CA3 region, which send axons to synapse with CA1 hippocampal pyramidal cells that send their axons out of the hippocampus proper. Adult neurogenesis includes proliferation, differentiation, migration, the death of some newly formed cells and final integration of surviving cells into neural networks. We summarise these processes in adult mammalian hippocampal neurogenesis and discuss the roles of major signalling molecules that influence neurogenesis, including neurotransmitters and some hormones. The recent controversy raised concerning whether or not adult neurogenesis occurs in humans also is discussed.     

Prevalence, risk factors, and major bacterial causes of camel mastitis in Borana Zone, Oromia Regional State, Ethiopia

A cross-sectional study was carried out from November 2010 up to April 2011 to estimate mastitis prevalence and associated risk factors and to assess its bacterial causes in traditionally managed camels in Borana Zone, Southern Ethiopia. Thus, 348 lactating camels were examined clinically, and subclinical cases were checked with California mastitis test (CMT). The overall prevalence of mastitis was 44.8 % (156/348), comprising clinical (19, 5.4 %) and subclinical (137, 39.4 %) cases. The quarter level prevalence of mastitis was 24.0 % (334/1,392). Of the total 1,392 examined teats, 30 were blind, and hence, from the 1,362 non-blind CMT-examined teats, 22.3 % (304/1,362) were CMT positive. Of the 304 CMT-positive samples, 264 were culture positive (197 Gram-positive, 41 Gram-negative, and 26 mixed isolates), and 40 were culture negative. The prevalence of Staphylococcus aureus was found to be the highest at both the animal (12.8 %, 39/304) and quarter level (2.9 %, 39/1,362). Regression analysis revealed higher likelihood of mastitis occurrence among camels from Dharito (OR?=?3.4, 95 % confidence interval (CI)?=?1.8, 6.4), Gagna (OR?=?3.4, 95 % CI?=?1.8, 6.5), and Haro Bake (OR?=?2.6, 95 % CI?=?1.3, 5.1) than camels from Surupha. Likewise, there was higher chance of mastitis occurrence among camels at the early lactation stage (OR?=?2.3, 95 % CI?=?1.1, 4.6) and camels with udder/teat lesions (OR?=?13.7, 95 % CI?=?1.7, 109.4) than among camels at late lactation stage and camels with healthy udder/teats, respectively. In conclusion, this study reveals the current status of camel mastitis in Southern Ethiopia.     

Bovine tuberculosis is more prevalent in cattle owned by farmers with active tuberculosis in central Ethiopia

A case control study was conducted between October 2004 and April 2005 to determine the prevalence of bovine tuberculosis (BTB) in cattle in central Ethiopia relative to the tuberculosis status of their owners. A total of 174 farmers (87 with active tuberculosis and 87 with no active tuberculosis), and 1041 cattle (506 owned by farmers with active tuberculosis and 535 by farmers without active tuberculosis) were included. The comparative intradermal cervical tuberculin test was used in cattle while clinical symptoms, chest X-ray and Ziehl-Neelsen staining were used for the diagnosis of tuberculosis in the farmers. In addition, mycobacterial culture, biochemical tests, and drug susceptibility tests were performed for the identification Mycobacterium spp. from both humans and cattle. The prevalence of BTB was threefold higher (odds ratio [OR]=4.2, 95% confidence interval [CI]=2.79-6.2) in cattle owned by farmers with active tuberculosis (24.3%) than in those owned by farmers who did not have active tuberculosis (8.6%). Cattle owned by farmers with active tuberculosis were four times more likely to have tuberculosis than cattle owned by farmers with no active tuberculosis. Furthermore, cattle owners who consumed raw milk were at greater risk (chi2=14.1, P<0.001, OR=3.34) of having active tuberculosis than those who consumed boiled milk. Of the 42 human isolates, 31 (74%) were Mycobacterium tuberculosis, seven (16%) were Mycobacterium bovis while four (10%) were considered a typical mycobacteria on the basis of biochemical and drug sensitivity tests. Of the 11 cattle isolates, two (18%) were Mycobacterium tuberculosis, five (46%) Mycobacterium bovis, and four (36%) were atypical mycobacteria. The prevalence of tuberculosis was higher in cattle owned by farmers with active tuberculosis than in cattle owned by farmers who did not have active tuberculosis, which could suggest possible transmission of Mycobacterium spp. between cattle and their owners.     

Genetic diversity and matrilineal genetic origin of fat-rumped sheep in Ethiopia

Ethiopia is home to a diverse gene pool of indigenous sheep populations. Therefore, a better understanding of genetic variation holds the key to future utilization through conservation. Three of these breeds, Afar, Blackhead Somali, and Hararghe Highland, are found in eastern Ethiopia where they contribute significantly to the livelihood of most pastoralist, agro-pastoralist, and smallholder farmers. These indigenous sheep are recognized on the basis of morphotype and their genetic distinction remains unknown. Here, to assess genetic variation, and matrilineal genetic origin and relationship of fat-rumed sheep found in eastern Ethiopia, 300 individuals from the three breeds were genotyped for 22 microsatellite markers and sequenced for the mitochondrial DNA displacement loop (mtDNA d-loop) region. The overall H_O and H_E were 0.57 and 0.75, respectively. Differentiation statistics revealed that a high proportion (97%) of the total genetic variation was explained by differences between individuals within populations. Genotype assignment independent of the population of origin showed K?=?2 to be the optimum number of genetic backgrounds present in the dataset. This result was further confirmed by mtDNA D-loop sequences comparison in which the matrilineal genetic origin of eastern Ethiopia sheep is from two haplotype groups (types A and B) among the five haplotypes globally observed. Taken together, our findings suggest that the sheep populations from three breeds originated from two ancestral genetic backgrounds that may have diverged prior to their introduction to Ethiopia. However, to obtain a complete picture of the evolutionary dynamics of Ethiopian indigenous sheep, more samples and populations from within and outside of the country will need to be analyzed.

     

Performance and limitation of two dairy production systems in the North western Ethiopian highlands

In order to characterise the dairy production systems as well as the productive and reproductive performance of dairy cows in the study area, a total of 256 and 54 dairy farms were used for survey and monitoring data collection, respectively. Based on breed, land size, feed and market accessibility, two major dairy production systems were identified: a rather specialized, urban, and a peri-urban dairy production system. Urban farmers owned larger herds but farmed less land, and sold a greater proportion of liquid milk than peri-urban farmers, who processed more milk. Purchased feed played a more important role for the feed supply of urban than peri-urban farms. Significant breed effects were found for productive and reproductive performance traits. It is concluded that improved breeding and health management, genetic improvement of local breeds and supplementation of poor quality feed resources are the key factors for enhancing productivity of dairy cows and thereby increasing family income from milk production.     

Epidemic characterization and modeling within herd transmission dynamics of an “emerging trans-boundary” camel disease epidemic in Ethiopia

A highly acute and contagious camel disease, an epidemic wave of unknown etiology, referred to here as camel sudden death syndrome, has plagued camel population in countries in the Horn of Africa. To better understand its epidemic patterns and transmission dynamics, we used epidemiologic parameters and differential equation deterministic modeling (SEIR/D-model) to predict the outcome likelihood following an exposure of susceptible camel population. Our results showed 45.7, 17.6, and 38.6 % overall morbidity, mortality, and case fatality rates of the epidemic, respectively. Pregnant camels had the highest mortality and case fatality rates, followed by breeding males, and lactating females, implying serious socioeconomic consequences. Disease dynamics appeared to be linked to livestock trade route and animal movements. The epidemic exhibited a strong basic reproductive number (R (0)) with an average of 16 camels infected by one infectious case during the entire infectious period. The epidemic curve suggested that the critical moment of the disease development is approximately between 30 and 40?days, where both infected/exposed and infectious camels are at their highest numbers. The lag between infected/infectious curves indicates a time-shift of approximately 3-5?days from when a camel is infected and until it becomes infectious. According to this predictive model, of all animals exposed to the infection, 66.8 % (n?=?868) and 33.2 % (n?=?431) had recovered and died, respectively, at the end of epidemic period. Hence, if early measures are not taken, such an epidemic could cause a much more devastative effect, within short period of time than the anticipated proportion.     

Socioeconomic characteristics of urban and peri-urban dairy production systems in the North western Ethiopian highlands

In order to evaluate the socio-economic characteristics of urban and peri-urban dairy production systems in the North western Ethiopian highlands, a field survey was conducted which included 256 farms. It is concluded that urban farmers tend to specialize on dairy production and support the family income from non-agricultural activities, while agricultural activities other than milk production forms an additional source of income in peri-urban farms. The specialization of urban dairy producers includes the more frequent use of crossbred cows with higher milk yield. Urban and peri-urban dairy production contributes to food security of the population and family income of the farmers’ families, but also provides a job opportunity for otherwise unemployed people. Access to farm land, level of education and access to certain input services such as training, veterinary and credit services were identified as the major constraints for the future development of the dairy sector.