Performance of eight tree species in the highland Vertisols of central Ethiopia: growth, foliage nutrient concentration and effect on soil chemical properties

The coverage of trees in the highland Vertisol areas of Ethiopia is very scarce. A tree screening trial was conducted from 1997 to 2002 in Ginchi (central Ethiopia) to select fast growing and high biomass producing tree species; evaluate foliage macronutrient concentration of different tree species; and assess effects of trees on soil chemical properties beneath their canopies. Acacia decurrens Willd, A. mearnsii De Wild and Eucalyptus globulus Labill attained the highest height growth at 64 months as compared to other indigenous and exotic species. E. globulus provided better height increment from 24 to 36 and 36 to 64 months than other tree and shrub species. Acacia mearnssi and A. saligna Labill Wendl produced high biomass at 40 and 64 months. Differences between the highest and lowest dry biomass at 12, 40 and 64 months were 1.13, 29.19 and 38.89 kg tree⁻¹, respectively. None of the tree species resulted in a foliage to stem biomass ratio of >0.98 at 40 and 64 months. Sesbania sesban (L.) Merr had high N and P concentrations in its foliages and stems at 12 and 40 months. Total N under Acacia abyssinica Hochst. Ex Benth, A.␣saligna and S. sesban was slightly greater at 40 months than 12 months.     

An investigation into human pandemic influenza virus (H1N1) 2009 on an Alberta swine farm

On May 2, 2009 the Canadian Food Inspection Agency notified the World Organization for Animal Health that an emerging novel influenza A virus (pandemic H1N1 2009) had been confirmed on a swine farm in Alberta. Over a 4-week period pigs in this farrow-to-finish operation were clinically affected by respiratory disease consistent with an influenza A virus infection and the presence of active viral infection was confirmed in all production areas by real-time polymerase chain reaction (RT-PCR). Despite clinical recovery of animals, there was reluctance by purchasers to receive animals from this operation due to concerns about the effect on both domestic and international markets. The owner decided to depopulate the entire herd due to impending welfare issues associated with overcrowding and economic concerns resulting from the inability to market these animals. Carcasses were rendered or composted and did not enter the human food or animal feed chain. The source of virus in this herd was determined to be an infected human. Zoonotic transmission to 2 individuals responding to the outbreak was suspected and recommendations to prevent occupational exposure are discussed.     

Analysis of genetic diversity and relationships of wild <Emphasis Type="Italic">Guizotia</Emphasis> species from Ethiopia using ISSR markers

Genetic relationships and diversity of 45 Guizotia populations each consisting of ten individuals and belonging to five taxa of the genus Guizotia were analyzed using Inter Simple Sequence Repeat (ISSR) markers. Five ISSR primers generated a total of 145 scorable bands across the 450 individuals used for the study. The percent polymorphic loci for the taxa ranged from 68.2 (G. arborescens) to 88% (G. scabra ssp. schimperi), with G. scabra ssp. scabra, G. zavattarii and G. villosa following G. scabra ssp. schimperi in this order with respect to the abundance of percent polymorphic loci. The Shannon-Weaver diversity indices (H′), for the five taxa also followed a similar pattern, with G. scabra ssp. schimperi exhibiting the highest H′ (0.7373) and G. arborescens the least (0.5791), while H′ for G. scabra ssp. scabra, G. villosa and G. zavattarii were 0.7313, 0.6620 and 0.6564, respectively. The least genetic distance (0.1188) was observed between G. scabra ssp. schimperi and G.villosa, revealing closer genetic relationships of the two species with each other than with the others, and the highest genetic distance (0.2740) was observed between G. scabra ssp. schimperi and G. zavattarii. The unweighted pair group method using the arithmetic average clustering of the five taxa using the standard genetic distances produced two clusters, with G. scabra ssp. schimperi and G. villosa occurring in one cluster and G. scabra ssp. scabra, G. arborescens and G. zavattarii together in the other cluster. The study reveals that G. scabra ssp. schimperi is more closely related to G. villosa than to G. scabra ssp. scabra.     

Molecular characterization of pandemic H1N1 influenza viruses isolated from turkeys and pathogenicity of a human pH1N1 isolate in turkeys

Suspected human-to-animal transmission of the 2009 pandemic H1N1 (pH1N1) virus has been reported in several animal species, including pigs, dogs, cats, ferrets, and turkeys. In this study we describe the genetic characterization of pH1N1 viruses isolated from breeder turkeys that was associated with a progressive drop in egg production. Sequence analysis of all eight gene segments from three viruses isolated from this outbreak demonstrated homology with other human and swine pH1N1 isolates. The susceptibility of turkeys to a human pH1N1 isolate was further evaluated experimentally. The 50% turkey infectious dose (TID50) for the human isolate A/Mexico/LnDRE/4487/2009 was determined by inoculating groups of 8-10-week-old turkeys with serial 10-fold dilutions of virus by oronasal and cloacal routes. We estimated the TID50 to be between 1 x 10(5) and 1 x 10(6) TCID50. The pathogenesis of pH1N1 in oronasally or cloacally inoculated juvenile turkeys was also examined. None of the turkeys exhibited clinical signs, and no significant difference in virus shedding or seroconversion was observed between the two inoculation groups. More than 50% of the turkeys in both oronasal and cloacal groups shed virus beginning at 2 days postinoculation (dpi). All birds that actively shed virus seroconverted by 14 dpi. Virus antigen was demonstrated by immunohistochemistry in the cecal tonsils and bursa of Fabricius in two of the birds that were infected by the cloacal route. Virus transmission to naive contact turkeys was at best doubtful. This report provides additional evidence that pH1N1 can cross the species barrier and cause disease outbreaks in domestic turkeys. However, it appears that the reproductive status of the host as well as environmental factors such as concurrent infections, stress, the presence or absence of litter, and stocking density may also contribute to efficient infection and transmission of this agent.     

Cowpea [Vigna unguiculata (L.) Walp.] maternal lineages,chloroplast captures,and wild cowpea evolution

Genetic Resources and Crop Evolution - Vigna unguiculata is the major grain legume in Africa and is also important in South-East Asia as a vegetable. The wild relatives, present only in Africa, are...     

Soil erosion assessment of Lake Alemaya catchment,Ethiopia

Land degradation due to soil erosion is the major problem facing Ethiopia today. In the Lake Alemaya catchment soil erosion is caused by the intense rainfall, steep topography, and poor vegetation cover coupled with cultivation of steep lands, and inadequate conservation practices. Sediment from the catchment has affected the storage capacity of Lake Alemaya. This study has integrated the Agricultural Non‐point Source Pollution Model (AGNPS) and the technique of the Gographic Information System (GIS) to quantify soil erosion in the Lake Alemaya catchment. After application of the AGNPS, it appears that 66 per cent of the catchment has a soil erosion rate of 10 to more than 80 t ha⁻¹ y⁻¹. The annual soil loss is estimated at 31 t ha⁻¹, which is more than the permissible value of 1–16 t ha⁻¹ for different agro‐ecological zones of Ethiopia. The sediment yield of the catchment is about 10 148 ton with a delivery ratio of 6·82 per cent. Therefore, an effective management plan is needed for the conservation and rehabilitation of the catchment and to maintain the storage capacity of Lake Alemaya. Copyright © 2006 John Wiley & Sons, Ltd.     

Dourine: a neglected disease of equids

Dourine is a venereal transmitted trypanosomosis causing a major health problem threatening equines worldwide. The origin and identification of Trypanosoma equiperdum within the subgenus Trypanozoon is still a subject of debate. Unlike other trypanosomal infections, dourine is transmitted almost exclusively by coitus. Diagnosis of dourine has continued to be a challenge, due to limited knowledge about the parasite and host-parasite interaction following infection. The pathological lesions caused by the diseases are poorly described and are observed mainly in the reproductive organs, in the nervous system, and on the skin. Dourine has been neglected by research and current knowledge on the disease, and the parasite is very deficient despite its considerably high burden. This paper looks in to the challenges in identification of T. equiperdum and diagnosis techniques with the aim to update our current knowledge of the disease.     

Equine colic: clinical epidemiology and associated risk factors in and around Debre Zeit

A prospective study was conducted to describe clinical epidemiology of equine colic in the Society for Protection of Animal Abroad and Donkey Sanctuary Project Clinic, at Debre Zeit, Ethiopia, from November 2014 to April 2015. The objectives were to describe clinical epidemiology of equine colic, to characterize the main types of equine colic, and to determine the major risk factors associated with equine colic. The method which was used in the study was attending clinical case of equine and assessing physiological parameters, fecal egg count, abdominal sounds, and rectal examination as well as questioner interviewing of the owners. The data were collected and analyzed using Statistical Package for Social Science. The incidence of colic was 10.3% in the study period. Colicky were typed as unknown, flatulent, impaction, spasmodic, and enterolithiasis. The proportion of case incidence were 63.1 (41/65), 33.8 (22/65), and 3.1% (2/65), in donkey, horse, and mule, respectively. The total mean (±SD) of temperature 37.80 ± 1.003, heart rate 57.54 ± 10.098, fecal egg count 236.922 ± 67.990, respiratory rate 30.92 ± 7.315, and packed cell volume 41.40 ± 10.221 were recorded. The case fatality rate of equine colic was 15.38% (10/65). There were statistically highly significant (p < 0.01) differences in impaction colic in relation to species. Interview with 183 equine owners revealed incidence of equine colic as the sixth major disease condition affecting equine. A long-term epidemiological study of the true representative population should be carried out to determine the incidence rate and associated risk factors of equine colic in the study area.     

Late Miocene teeth from Middle Awash, Ethiopia, and early hominid dental evolution

Late Miocene fossil hominid teeth recovered from Ethiopia's Middle Awash are assigned to Ardipithecus kadabba. Their primitive morphology and wear pattern demonstrate that A. kadabba is distinct from Ardipithecus ramidus. These fossils suggest that the last common ancestor of apes and humans had a functionally honing canine-third premolar complex. Comparison with teeth of Sahelanthropus and Orrorin, the two other named late Miocene hominid genera, implies that these putative taxa are very similar to A. kadabba. It is therefore premature to posit extensive late Miocene hominid diversity on the basis of currently available samples.