Relating long-term rainfall variability to cattle population dynamics in communal rangelands and a government ranch in southern Ethiopia

This study reconstructed 21 years of household cattle population data in key resource (tula wells) and non-key resource (pond-water) rangelands in southern Ethiopia, as well as 15 years of government cattle breed conservation ranch data, to analyze the relationship between long-term rainfall and cattle population dynamics. For the key-and-non-key resource rangelands, we assessed the reproductive life of cows and the number of calves. For both the communal and ranch systems, we analyzed impacts of multiple droughts on calving rates and herd die-offs. Relationships between pre-drought and post-drought cattle populations were used to evaluate evidence of density-dependence. Breeding females in the key resource tula well rangelands had a longer reproductive life than in the pond-water rangelands, and they produced more calves per reproductive life. Average calving rates were 55% for the communal and 52% for the ranch. Greater reductions in calving rates during droughts implied reduced herd growth potential. Breeding females and immature animals were influenced to a much greater degree by inter-annual rainfall variability than were mature males. The data showed a downward spiral for the total cattle holdings over a 21-year period, with a decline of 54%. The evidence of density-dependence was relatively important at the local land use level as compared with the regional level. Cattle population below carrying capacity under ranch management did not reduce herd die-offs, suggesting that rainfall variability, not density, had greater influence on cattle population dynamics. Long-term trends of cattle populations in the communal and ranch systems synchronized with mean deviations of rainfall. Our results indicate that rainfall variability under the different management systems strongly influenced the dynamics of cattle population, calving rates and mortality. The claim that ranching could be a superior model for range management in Borana over the communal system was not confirmed. The decline in cattle population in southern Ethiopia indicates a need for improved drought management policy. The evidence that droughts were more harmful to breeding females and immature animals than to mature males suggested that drought management needs to focus on herd recruitment potential. For the herders in southern Ethiopia, drought management involved herd mobility and accumulation of herds during periods of favourable rainfall. In the future, the importance of government ranch could be in breed conservation for the maintenance of the Borana cattle breed through distribution of bulls during the drought recovery phase.     

Euphorbia abyssinica latex promotes rooting of Boswellia cuttings

Traditional knowledge in northern Ethiopia points towards the root-stimulating properties of the latex found in Euphorbia abyssinica (EAG). Stem cuttings of EAG as well as cuttings of other species treated with EAG latex reportedly root easily in dry soil. This could be attributable to endogenous auxins contained in the latex. We screened EAG latex for auxins and precursor molecules using analytical LC-MS/MS, and tested the effect of EAG latex on the rooting of woody cuttings of Boswellia papyrifera, a threatened multipurpose tree. The EAG latex contained indole acetic acid (IAA) (0.06 μg/g latex), an auxin controlling apical dominance and lateral rooting, as well as IAA metabolites and conjugates. Boswellia cuttings treated with EAG latex rooted significantly sooner and showed higher survival ratios than untreated controls. EAG is widely available and its latex easy to obtain. Therefore it is a promising source of a natural plant growth regulator which may be used for improving low technology vegetative propagation of woody species in East and Northeast Africa, including the threatened Boswellia tree.     

Efficiency of soil and water conservation practices in different agro-ecological environments in the Upper Blue Nile Basin of Ethiopia

In developing countries such as Ethiopia, research to develop and promote soil and water conservation practices rarely addressed regional diversity. Using a water-balance approach in this study, we used runoff plots from three sites, each representing a different agro-ecological environment, e.g., high, mid and low in both elevation and rainfall, in the Upper Blue Nile Basin of Ethiopia to examine the runoff response and runoff conservation efficiency of a range of different soil and water conservation measures and their impacts on soil moisture. The plots at each site represented common land use types(cultivated vs. non-agricultural land use types) and slopes(gentle and steep). Seasonal runoff from control plots in the highlands ranged 214–560 versus 253–475 mm at midlands and 119–200 mm at lowlands. The three soil and water conservation techniques applied in cultivated land increased runoff conservation efficiency by 32% to 51%, depending on the site. At the moist subtropical site in a highland region, soil and water conservation increased soil moisture enough to potentially cause waterlogging, which was absent at the lowrainfall sites. Soil bunds combined with Vetiveria zizanioides grass in cultivated land and short trenches in grassland conserved the most runoff(51% and 55%, respectively). Runoff responses showed high spatial variation within and between land use types, causing high variation in soil and water conservation efficiency. Our results highlight the need to understand the role of the agro-ecological environment in the success of soil and water conservation measures to control runoff and hydrological dynamics. This understanding will support policy development to promote the adoption of suitable techniques that can be tested at other locations with similar soil, climatic, and topographic conditions.     

The inorganic N requirement,nodulation and yield of common bean (Phaseolus vulgaris L.) as influenced by inherent soil fertility of eastern Ethiopia

Though mineral N application impaired nodulation initiation and function, it improves the productivity of common bean. The effect of inorganic application on common bean productivity, however, is dependent on the availability of plant nutrients including nitrogen (N) in the soils. Therefore, multilocation field experiments were conducted at Babillae, Fedis, Haramaya, and Hirna to evaluate the effect of inherent soil fertility status on responsiveness of common bean to different rates of N fertilizer application and its effect on nodulation, yield, and yield components of common bean. The treatments were six levels of N fertilizer (0, 20, 40, 60, 80, and 100 kg N ha^?1) laid out in randomized completed block design with three replications. The result revealed that 20 kg N ha^?1 application significantly improved the nodule number (NN) and nodule dry weight (NDW) except Hirna site, in which reduction of NN and NDW was observed. Although the remaining investigated yield and yield components were significantly improved due to N fertilizer in all study sites, 40 kg N ha^?1 application resulted in significantly increased GY of common bean at Fedis, Haramaya, and Hirna site, while 60 kg N ha^?1 at Babillae site. The highest total biomass yield (7011.6 kg ha^?1) and GY (2475.28 kg ha^?1) of common bean were recorded at Hirna and Haramaya sites, respectively, indicating the importance of better fertile soil for good common bean production. Hence, it can be concluded that the effect of inorganic N on common bean was irrespective of soil fertility rather the total amount of N in soil would affect the need of different rate of inorganic N.     

Mass movement mapping for geomorphological understanding and sustainable development: Tigray,Ethiopia

Mass movement topography characterises the escarpments and piedmont zones of the tabular ridges in the western part of the Mekelle outlier, Tigray, Ethiopia. Several types of mass movements can be distinguished. The first type is rockfall produced by 357 km rocky escarpments and cliffs during the rainy season. In the study area, every current kilometer of Amba Aradam sandstone cliff annually produces 3.7 m³ of rock fragments. However, this is an under-estimation of the actual cliff and escarpment evolution, which is also characterised by debris slides and small rock slides.     

Determinants for adoption of physical soil and water conservation measures by smallholder farmers in Ethiopia

Adoption rates of soil and water conservation measures remain below the expected levels in Ethiopia despite the considerable investments in reducing land degradation and improving soil fertility. This constitutes one of the key research agendas in the country. This paper underscores the need for investigating the factors hindering or facilitating the adoption of soil and water conservation measures. The study results presented in this paper are based on cross-section data collected from 408 households in eastern Ethiopia, including field observations of 790 plots selected using a multi-stage sampling procedure. A multivariate probit model was employed to analyse the determinants of adoption of three soil and water conservation measures (stone bund, soil bund, and bench terracing) at the plot level. The study findings reveal that household, socioeconomic, and institution characteristics were the key factors that influenced the adoption of soil bund, stone bund, and bench terracing conservation measures. Furthermore, there was a significant correlation among the three soil and water conservation measures, indicating that the adoption of these measures is interrelated. In particular, the results show that there was a positive correlation between stone bunds and soil bunds. However, the correlations between bench terracing and stone bunds as well as bench terracing and soil bunds were negative (implying substitutability). These results imply that the Government and other relevant organizations that are responsible for reducing land degradation in order to increase agricultural production should support the establishment and strengthening of local institutions to facilitate the adoption of soil and water conservation measures.     

Coenurus cerebralis Infection in Ethiopian Highland Sheep: Incidence and Observations on Pathogenesis and Clinical Signs

An investigation was carried out at Debre Berhan, Ethiopia, between 1996 and 1997, into the epidemiology of coenurosis in Menz and Horro breeds of sheep. A total of 37 heads from clinically sick and 183 heads from apparently healthy sheep were examined post mortem for the presence of the cystic larvae of Taenia multiceps, of which 37 and 5 heads, respectively, contained 1 to 8 coenurus cysts (diameter 0.8 to 6.5 cm). The bladder worms were located in the cerebral hemisphere in 96% of the cases (43% and 57% for left and right, respectively), 4% being in the cerebellum. Prediction of cyst locations based on the direction of circling and head deviation had a 62% success rate. A retrospective study generated from the health record book at the ILRI Debre Berhan Station in 1992–1996 (199 Horro and 174 Menz) revealed that the incidence of coenurosis ranged from 2.3% to 4.5%. There was no significant breed difference in the incidence. The age of the affected sheep ranged from 4 to 96 months, with a mean of 19.3 months, and 72% of the cases were within the range of 6 to 24 months. In a complementary survey on necropsied stray dogs, 8 out of 17 were positive for Taenia spp. Both studies confirm the endemicity of coenurosis at the ILRI Debre Berhan Research Station. Appropriate strategies for the control of coenurosis are suggested.     

Potential demand for a mixed public-private animal health input: evaluation of a pour-on insecticide for controlling tsetse-transmitted trypanosomiasis in Ethiopia

The new pour-on insecticides that can be used to control tsetse-transmitted trypanosomiasis confer benefits to the owners of the cattle given treatments and other people keeping cattle in areas affected by the control. A study was conducted in southwest Ethiopia to assess farmers' perceptions of the public and private benefits of the pour-on and identify the household-level factors affecting its demand. Ninety-seven percent of the 166 survey respondents had received pour-on treatments when they were free and 67% paid for treatments the month before the survey. Farmers noted public and private benefits from using the pour-on, the most important of which were less trypanosomiasis, fewer problems with biting flies (including tsetse), and fewer problems with ticks. The probit model estimated to quantify the effects of different variables indicates that proportions of cows and oxen, distance to the treatment centre, and seasonal factors were significant determinants of demand.     

The estimated long-term impact of tsetse control on the size of the population of cattle in the Didessa Valley,Western Ethiopia

The long-term impact of tsetse control on cattle population size in the Didessa Valley, western Ethiopia, was analysed using an age-structured population model. A prior analytical assessment revealed that the risk of cattle dying in the tsetse-unprotected villages ranged from 4 to 9 times higher than in the tsetse-protected village. Model results show that during a period of 10 years the cattle population in the tsetse-protected village of Meti is likely to increase from 167 to 583 animals, while that in the adjacent tsetse-unprotected village of Gale remains almost constant. Model simulations also predict that improving the survival rate of calves in the tsetse-unprotected villages of Taikiltu and Temoloko (which presently have calf mortality rates of up to 35%) would bring a substantial increase in their cattle population.     

Cysticercosis of slaughtered cattle in northwestern Ethiopia

The occurrence of cysticercosis due to Taenia saginata in cattle slaughtered for meat in Amhara National Regional State, northwestern Ethiopia between September 2005 and February 2007 was investigated. Routine meat inspection of various organs of 4456 cattle in eight abattoirs of this region showed that 824 (18.49%) were infected with Cysticercus bovis. The occurrence rate did not vary significantly from abattoir to abattoir (P>0.5). The tongue, masseter muscles, heart muscles, triceps muscles and thigh muscles were the main predilection sites of the cysts. Of 4102 male cattle, examined, 768 (18.72%) had cysts of C. bovis while 56 (15.82%) of the 354 female animals investigated were infected. The animals slaughtered were all adults. No significant difference in occurrence was recorded between the sexes. Monthly occurrence of the cysts in the animals revealed a rise of infected animals during the dry season.