Evaluation of the efficacy of anthelmintics sold on Ethiopian markets against <Emphasis Type="Italic">Haemonchus contortus</Emphasis> in experimentally infected Sheep

A total of 54 lambs, aged between 6–8 months were experimentally infected with Haemonchus contortus to evaluate the efficacy of different anthelmintic brands sold on Ethiopian markets using the faecal egg count reduction test (FECRT) and controlled anthelmintic efficacy trial. Accordingly four different albendazole (Alzole®, Analgon-300®, Albenjung_s® and Ahshialben-300®), two tetramisole (Tetsole® and Ashitetra 600) and two tetramisole-oxyclozanide (Tetraclozan sheep® and Tetraclozash 900®) brands were evaluated at the dosage rates recommended by the manufacturers. Animals were allocated into nine groups of six animals each, and balanced for faecal egg counts (FEC), based on their pre-treatment FEC and treatments were randomized among the groups. One group was kept untreated as a control. Faecal egg count was conducted on day 30 post-infection (day of treatment) and on the 10th day post-treatment. Evaluation of anthelmintics based on FECRT revealed high efficacy (99.55–100% reduction in FEC) for all anthelmintic brands tested against H. contortus. The worm count reduction test using controlled anthelmintic efficacy trial also supported the above finding with 99–100% efficacy of the tested anthelmintics. Therefore, the suspicion on the anthelmintic products as being substandard in quality is not credible, at least, for the brands investigated in this study and it might rather be attributed to under dosing. The need for a good extension system for livestock producers with regard to good anthelmintic usage practices, in light of the inevitable development of anthelminitic resistance, is emphasized. Regular surveillance and laboratory quality evaluation of the anthelmintic products in Ethiopia is indicated.     

Efficacy of albendazole against nematode parasites isolated from a goat farm in Ethiopia: relationship between dose and efficacy in goats

A suspected case of albendazole resistance in a goat farm of Hawassa University was examined using faecal egg count reduction test (FECRT), controlled anthelmintic efficacy test and egg hatch assay (EHA) to verify the development of resistance and/or the need for higher doses of the drug in goats than in sheep. The experiment was conducted in 12 sheep (2 groups: treatment versus control) and 24 goats (4 groups: 3 treatments versus control, n = 6; per group) following artificial infection with infective larvae of Haemonchus contortus and Oesophagostomum columbianum. The first group of sheep and goats were treated orally with albendazole at the dose rate of 3.8 mg/kg body weight (i.e. manufacturer's recommended dose for sheep) while the second group of sheep and the fourth group of goats were left untreated. The second and the third group of goats were treated with albendazole at 5.7 and 7.6 mg/kg respectively. The FECRT showed an efficacy of albendazole in goats to be 65.5, 81.4 and 84.1% at the dose rate of 3.8, 5.7 and 7.6 mg/kg body weight respectively while in sheep it was 62% at the dose rate of 3.8 mg/kg. Increasing the dose to 1.5 the sheep recommended dose induced minor improvement of efficacy in goats; however the efficacy was almost the same at 1.5 and twice the dose recommended for sheep. Worm counts at day 15 post-treatment revealed that H. contortus has developed resistance to albendazole. EHA results also supported these findings. On the other hand, O. columbianum was 100% susceptible at all dose levels tested.     

Development of Chemical Index as a Measure of In-Stream Water Quality in Response to Land-Use and Land Cover Changes

Water pollution in response to accelerated land-use/land cover changes has drawn concerns because of public health and environmental impacts. The study was conducted to evaluate the impact of land use/land cover changes, seasonal, and location on water quality of streams within the Wheeler Lake Watershed basin in northern Alabama. Temporal water samples from 18 sheppard streams were randomly collected in 2000 and 2001, processed and analyzed for pH, and total nitrogen (TN), dissolved (Dp), particulate (Pp) and total phosphorus (Tp), dissolved oxygen (DO) and soluble lead (Pb) concentration, employing standard methods of analysis. The data were normalized and integrated into a simple index (WQC_Index) to evaluate stream water quality. Results showed that the urban proportion of the total watershed basin had increased from 2.9 to 14.7% with an associated loss of agricultural (8.9%) and wetland (4.8%) covers from 1992 to 2000. A change in land-use/land covers in association with seasonal and location variation significantly affected stream water quality. Total nitrogen concentration in stream water had a peak during the summer at 34% above the annual mean. While both Pp and Tp concentrations peaking during the summer at 24% above the annual mean and about 25% below the annual mean during spring, the DO concentrations were 46% above the annual mean during the fall and 18 to 26% below annual mean during summer. The WQC_Index had responded very seasonal and showed significant identical trends, with 21% degradation in water quality during the summer above the annual mean and improvement during the spring at 20% above the annual mean. Upstream water had a significantly greater Pp and Tp (21 to 28%) concentration than at down- and middle streams water. Location and seasonal variations had significant interactive effects on Pp, Tp and DO concentration of stream water. Total amount of seasonal rainfall significantly accounted 99.6% of the variations in WQC_Index. Increasing seasonal mean relative humidity, air and soil temperature, evaporation and solar radiation had positive relationship with the variations in WQC_Index. Among the water quality parameters, both Pp and Tp were correlated (r ² = 0.998^?*?) to each other, and accounted for more than 80% variability of the WQC_Index. Highly significant positive linear relationship between Pp and Tp concentration suggested that 99.8% of the P in stream water is in Pp form which probably transported with sediments in surface runoff. In other words, Pp is the main pollutant responsible for degradation of stream water quality in the Wheeler lake basin. Routine measurement of either Pp or Tp concentration could be used as sensitive and early indicator of temporal changes in stream water quality even when the other parameters changed negligibly or remain unchanged.     

Diversity,regeneration status and population structure of gum- and resin-bearing woody species in south Omo zone,southern Ethiopia

South Omo Administrative Zone in Ethiopia is home to 18 indigenous ethnic groups whose livelihood is vulnerable due to recurrent drought and degradation. Despite the preliminary observation showing the rich dry-forest resource base that, if sustainably managed could enhance livelihoods and biodiversity conservation, there is lack of empirical data on its current status. We conducted a study aiming at quantifying the population status of gum- and resin-bearing species in two randomly selected districts, Hamer and Bena-Tsemay. Seventy-five quadrats(35 at Hamer and 40 at Bena-Tsemay) each measuring 400 m2 were established along line transects to assess species diversity and equitability, density, frequency, dominance, importance value and population structure. We recorded a total of 27 woody species of 12 families and 14 genera. Fifteen species(9 at Hamer and 14 at Bena-Tsemay) of the genera Acacia, Boswellia, Commiphora and Sterculia, were identified as either major sources of commercial gums and resins or their adulterants. Gum- and resin-bearing species comprised 56% and 57% of species richness, 48% and 50% of total density per ha, 95% and 98% of basal area, and 64% and 56% of importance values at Hamer and Bena-Tsemay, respectively. Diversity of the entire woody species assemblage and of the gum- and resin-bearing species was slightly higher at Bena-Tsemay(H= 2.61, 1.4) than at Hamer(H′= 2.48, 1.28), respectively. The diversity and abundance of the resource base suggest potential for development of value-added commercialization of gum and resins to enhance livelihoods and encourage sustainable management of the forest at these study areas. We recorded, however, declining natural regeneration of most gum- and resin-bearing species, and this calls for integrated and participatory species management and landscape rehabilitation.     

Impacts of participatory forest management on forest conditions: Evidences from Gebradima Forest,southwest Ethiopia

ABSTRACT

This study examines a participatory forest management program and its impacts on forest conditions in Gebradima Forest, southwest Ethiopia. Vegetation data were collected from both participatory forest management (PFM) and nonparticipatory forest management (non-PFM) forest blocks. A total of 54 plots (27 from each forest block) measuring 20 m × 20 m were employed to collect species composition and structural data. Results indicated that a total of 51 different woody plant species (49 at PFM and 43 at non-PFM blocks), representing 31 families were recorded, with 41 species were shared for both forest sites. Species diversity and evenness were higher in the forest with PFM (H´ = 3.29, E = .85) compared to the forest without PFM (H´ = 2.97, E = .79). The overall mean values of tree/shrub and seedling density per hectare, diameter class (≤ 20 cm) were also significantly (p < .05) higher in PFM forest than non-PFM forests. However, no significant variations were observed in sapling density per hectare and basal area between the two studied forest blocks. It can be concluded that PFM had a positive effect on forest conditions compared with a similar forest without PFM. Hence, it is important to scaling up PFM in neighboring forests.     

Informal surveys to assess social forestry at Dibandiba and Aleta Wendo,Ethiopia

Two surveys were carried out at Dibandiba, a semi-arid site in central Ethiopia, and Aleta Wendo, a sub-humid site in southern Ethiopia, to assess farmers' attitudes toward and perceptions of tree planting, levels of social forestry and uses of tree products. At Dibandiba, farmers planted mostlyEucalyptus camaldulensis trees, exclusively on homesteads andAcacia albida was left on farmland. Trees were planted mainly for construction (32%), fuelwood (29%), shade (11%) and cash (11%). Major (85%) uses were fencing, fuelwood, construction and plough handles. Dung was the major source of fuel (56%). At Aleta Wendo, planting consisted ofEucalyptus globulus mostly on private woodlots and homesteads, ofMilletia ferruginea andCordia abyssinica on farms, and ofEuphorbia abyssinica on fences and boundaries. Avocado and pears were also planted. The uses were the same as at Dibandiba. Major constraints were lack of seedlings and shortage of land at both sites, plus shortage of water at Dibandiba. Also, a review of information obtained from previous surveys on household composition and income, farm holding, cropping pattern, livestock composition and the use of labour was made.     

Performance Evaluation of Malt Barley: from Malting Quality and Breeding Perspective

Lack of suitable malt barley varieties that exhibit high yielding, stable performance, and good malting quality is the major factor among several production constraints contributing to low productivity of malt barley in the North Gondar Zone. The present study was done to evaluate and recommend the best performing varieties in the major potential areas of North Gondar. The experiment was conducted at three locations for two consecutive years (2015 and 2016) during the main cropping season using twelve improved varieties. The design was randomized complete block design with three replications. Analysis of variance and GGE [genotype main effect (G) and genotype-by-environment interaction (GE)] biplot analysis were conducted following their respective procedures. Combined analysis of variance revealed a highly significant difference (P < 0.01) among genotypes, environments, and genotype-by-environment interaction for grain yield, most agronomic and malt quality traits. All the varieties had acceptable malt quality traits. The variety IBON-174/03 was found to be the highest yielding and the most stable variety across environments. According to the polygon view of biplot analysis, the varieties were spread across four sections and the test environments spread across two sections. Among the six test environments, D and C were more discriminating and F and B were less discriminating. Test environments F, E, and A were found to be more representative of the mega-environment than D. Considering early maturity, malt quality, grain yield, and stability performance; it is recommended to use the variety IBON-174/03 for production in the study areas and in similar areas.     

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.     

Relationship of seedling and adult plant resistance and evaluation of wheat germplasm against tan spot (<Emphasis Type="Italic">Pyrenophora tritici</Emphasis>-<Emphasis Type="Italic">repentis</Emphasis>)

Genetic resistance is the most effective, economical and environment friendly method of managing tan spot of wheat caused by the ascomycete Pyrenophora tritici-repentis (Died.) Drechs. (anamorph Drechslera tritici-repentis, Died.). This study was carried out to determine the association between seedling and adult plant resistance in winter wheat cultivars, study the inheritance of tan spot resistance and evaluate wheat germplasm for resistance. A significant positive correlation was noted between seedling resistance evaluated in greenhouse and adult plant resistance estimated in field conditions. The absence of segregation into resistant plants in the F₁ disomic crosses of the resistant spring and winter wheat cultivars with the susceptible cultivars, and the segregation of the corresponding F₂ crosses into 1 resistant: 3 susceptible ratio indicated that tan spot resistance is controlled by a single recessive gene which inherits qualitatively. The winter wheat cultivars: Ibis, Heines VII, Albrecht, Solitar, Ohio, Toronto, Yindos, Zenith and Kronjuwel, and the spelt wheat cultivars: Ceralion, Hercule, and Schwabenkorn showed highly resistant response to both race 1 and race 5 isolates. We recommend these genotypes to be used for gene deployment in wheat breeding programs.     

Perceptions of households on purpose of keeping,trait preference,and production constraints for selected goat types in Ethiopia

A study was carried out to understand the needs and perception of goat keepers in selected areas of Ethiopia in order to identify the breeding objectives, traits of preference, and production constraints that may be required in designing improvement programs. The study was conducted in three districts (Bati, Meta, and Kebri-Beyah) representing the lowland crop–livestock (LLCL), highland cereal–livestock (HLCL), and pastoral/agropastoral (P/AP) systems, respectively. The study targeted the three goat types (Bati, Hararghe Highland, and Short-eared Somali) found in Ethiopia. Households in all systems considered meat production, milk production, and income generation as major purpose of keeping goats. However, those in the low rainfall and arid environments of P/AP systems gave high ranking to adaptability to harsh environments and also to building social and religious values. In LLCL and HLCL systems, goat skin and manure were more valued than in P/AP systems. Principally, in P/AP systems, the awareness of households to skin utilization and marketing was very low. Despite diverse multiple breeding objectives identified, household breeding practices were affected by constraints related to disease prevalence, feed shortage and water scarcity, and lack of awareness on skin management, utilization, and marketing. Thus, designing and implementing of sustainable goat improvement programs is an overriding priority and should take into account the breeding objectives and knowledge of goat keepers in all production systems. Along with the breed improvement, a strategy should also be devised to enhance the utilization and marketing of goat skin at all levels of production.