Tannins in tropical browses: effects on in vitro microbial fermentation and microbial protein synthesis in media containing different amounts of nitrogen

Four species of browses (Acacia angustissima, Acacia salicina, Calliandra calothyrsus, andDichrostachys cinerea) were used to study the effect of tannins on microbial fermentation and microbial protein synthesis in incubation media containing high nitrogen (HN) and low nitrogen (LN) in the presence and absence of polyethylene glycol (PEG, MW 6000). The additional nitrogen in HN medium was supplied through ammonium bicarbonate. The use of HN medium significantly (P < 0.05) increased the in vitro gas and short-chain fatty acid (SCFA) production and microbial protein synthesis compared to the LN medium. Incubation of tannin-containing browses alone produced significantly (P < 0.05) lower gas and SCFA compared to in the presence of PEG in both HN and LN media. Inclusion of PEG in tannin-containing browses significantly (P < 0.05) reduced the molar proportion of propionate compared to in its absence. Higher N in the media resulted in 10.4 and 9.9% increases in in vitro gas and SCFA production, respectively, whereas inclusion of PEG to tannin-containing feed to remove the effect of tannins increased the in vitro gas and SCFA production by 186 and 195%, respectively, indicating that the low fermentation of tannin-containing browses could be due to the depressive effects of tannins on microbial activity and only partially accounted for by unavailability of N for rumen microbes. Incubation of browses with straw significantly (P < 0.05) decreased ammonia nitrogen concentration but increased the in vitro gas and SCFA production and microbial protein synthesis compared to straw alone.     

Effects of nitrogen,phosphorus and vermicompost on groundnut yield in Babile District,eastern Ethiopia

Groundnut is a major cash crop for smallholder farmers in several districts of eastern Ethiopia with low yield. Little or no fertilizer was applied for the crop possibly because no generic or recommended fertilizer and technology were available. Therefore, field experiments were conducted for 2 consecutive cropping seasons in Babile District, to investigate effects of applying mineral N and P fertilizer and vermicompost (VC) on seed yield and oil content of groundnut using an improved variety ‘BaHa-Gudo’. Treatments consisted of nitrogen (0,23 and 46 kg N/ha), phosphorus (0,46 and 92 kg P2O5/ha) and VC (0,2.5 and 5 t VC/ha). Results revealed that yield attributes, seed yield and seed oil content were significantly (p < 0.01) affected by fertilizers. Seed yield after combined application of 46 kg N, 46 kg P2O5 and 2.5 t VC/ha increased by about 113% compared to seed yield without any fertilizers. Enhancement in seed oil content at the aforementioned rate was 7.0%. It could, thus, be concluded that applying the aforementioned fertilizers would enable farmers to increase seed yield and oil content of groundnut for enhancing their income and livelihoods in the study area.     

Genetic diversity of the African wild rice (Oryza longistaminata Chev. et Roehr) from Ethiopia as revealed by SSR markers

Data from microsatellite markers have been extensively used for both in situ and ex situ conservation strategies by determining the level of genetic diversity of natural populations that can widen the gene pool of cultivated plants. Such conservation practices are based on understanding of the between and within population genetic variations and partitioning populations on the basis of geographic origin. Therefore, the objective of this study was to assess the genetic diversity of Oryza longistaminata Chev. et Roehr and how this variation is partitioned within and between the eight O. longistaminata populations found in the different geographic regions of Ethiopia using simple sequence repeat markers. Five microsatellite markers in 320 samples generated 64 alleles that revealed the presence of large amount of genetic variability (Ho = 0.225; He = 0.768; Na = 7.375; Ne = 6.565 and P = 0.744). The F-statistics detected by the microsatellite loci showed Fst = 0.064 and Fis = 0.743 and there was no population in Hardy–Weinberg equilibrium. The genetic diversity results obtained from this data indicated that there are high levels of genetic diversity in the populations of O. longistaminata studied and it is higher within than between populations. Among the eight populations sampled, five populations were identified as priorities for conservation strategies. Thus, national collection and conservation strategies need to consider these populations.     

Economic dependence on forest resources: A case from Dendi District, Ethiopia

This paper examines variation in dependence on forest resources among rural households in Chilimo, Ethiopia, and the income-equalizing effects of such resources. Data were collected through a systematic questionnaire survey of 102 households, randomly selected from two peasant associations in the area. Forest income contributed 39% of the average household income, roughly equal to agriculture, which contributed 40%. Forest income was more important than all other income sources combined for the poorest 40% of households and contributed more to household income than agriculture for 65% of households. While forest income represents 59% of the total household income for the poorest quintile, the contribution drops to 34% for the wealthiest quintile. On the other hand, the rich households derive a larger absolute income from forest resources than the poor households. Forest resources have an important income-equalizing potential among the rural households. Reduced access to forest resources would greatly affect the welfare of the rural population and increase wealth differentiation among rural households in the study area.     

Stability of performance of tetraploid wheat landraces in the Ethiopian highland

Plant breeding has always been concerned with genotype-environment interaction. Normally high and stable performance are desirable attributes of cultivars. However, this is practically difficult to achieve where environmental variations are high and unpredictable and significant genotype-environment interactions occur. Stability of performance of 13 landraces evaluated at 4 different locations for 3 years in the highlands of Ethiopia was investigated. The testing locations have different climatic and edaphic conditions providing the conditions necessary for the assessment of stability. Stability parameters like b, s²d, s², r² and cv which are in common use were employed. Grain yield and 1000-kernel weight were the agronomic traits considered for the stability analysis. There were differences in the ranks of genotypes across the locations. Significant main environmental as well as interaction effects were observed showing the importance of genotype-environment interaction in both traits. Many of the landraces evaluated are rated as stable for these traits within the environmental conditions prevailing in these highland locations. Genotypes with specific adaptation to poor and favourable conditions were also identified. Certain genotypes showed similar manners of adaptation and stability for both of the traits. Grain yield showed low correlations with the stability parameters showing the possibility of attaining high yield and stability. Correlations between the stability parameters were mainly positive and significant for grain yield. Only a few of these correlations were found to be significant for kernel weight. The good adaptability of landraces should be exploited in the improvement of their yield potential. This revised version was published online in July 2006 with corrections to the Cover Date.     

Equine parascarosis under the tropical weather conditions of Ethiopia: a coprological and postmortem study

A cross-sectional coprological survey in the regions of Ada, Akaki, Bereh and Boset, and a retrospective postmortem investigation were conducted to study the epidemiology of Parascaris equorum in donkeys and horses in Ethiopia. Faecal samples from 803 working donkeys and 402 horses were collected, and the numbers of worms recovered from 112 donkeys examined postmortem between 1995 and 2004 were analysed. There was a high prevalence of infection and faecal egg output of P equorum in both donkeys and horses, and the severity of the infection in donkeys was increased irrespective of their age. The prevalence of the infection in the donkeys was 51.1 per cent and in the horses 16.2 per cent, and the prevalence in the donkeys examined postmortem was 55 per cent. There was no significant difference between different age groups of donkeys in either the prevalence or the intensity of the infection. The prevalence of the infection was significantly higher in the Ada and Akaki regions than in the Bereh and Boset regions.     

Hydatidosis of slaughtered animals in Bahir Dar Abattoir,Northwestern Ethiopia

The study was conducted from May 2005 to December 2006 in Bahir Dar Abattoir to assess the current status of hydatidosis in cattle and sheep. Hydatid cyst count and characterization were conducted based on routine meat inspection. Of the total 420 cattle and 340 sheep slaughtered in Bahir Dar Abattoir 143 (34.05%) and 36 (10.6%) animals were found harboring hydatid cysts respectively. Thorough meat inspection in the abattoir revealed that 202 and 54 visceral organs were found harboring one or more hydatid cysts in cattle and sheep respectively. Differences in prevalence rates between the two species of animals were highly significant (P < 0.001). The infection of the lung, liver, kidney, spleen and heart were found to be 57.9% , 36.6% , 3% , 1.5% , 1% in cattle and 50%, 48.1% and 1.9% in sheep respectively. From the total of 864 in cattle and 138 in sheep hydatid cysts counted 315 (36.4%), 268 (31.0%), 65 (7.5%), 216 (25.0%) in cattle and 92 (66.7%), 20 (14.5%), 1 (0.7%), 25 (18.1%) in sheep were found to be small, medium, large and calcified cysts respectively and 484 (56.0%), 164 (18.9%), 216 (25%) in cattle and 35 (25.4%), 78 (56.5%), 25 (18.1%) in sheep were sterile, fertile and calcified cysts respectively. Viability rates of 62.2% in cattle and 78.2% in sheep were observed. The rate of cyst calcification was higher in the liver than in the lung while fertility rate was higher among the cysts of the lung for both cattle and sheep.     

Multivariate Analysis of Diversity of Tetraploid Wheat Germplasm from Ethiopia

The variability of 2420 plants of tetraploid (2n = 4x = 28, AABB genome) wheat germplasm representing 121 accessions from Ethiopia were evaluated for 23 agro-morphological traits at Debre Zeit Agricultural Research Center area, Akaki substation, during the 2003 main season using multivariate methods. This enabled to assess the extent and pattern of variation of the germplasm with respect to regions, altitude classes and species and to identify the major traits contributing to the diversity. The first three and two principal components explained about 83 and 80% of the total variance among regions and altitudinal class, respectively. In the first principal component plant height, days to heading, the length and density of the spike, and kernel color were the most important traits contributing to variation that explained about 50% of regional variance. Cluster analysis grouped the accessions into 15 clusters, with 9 accessions remaining ungrouped. Based on the observed patterns of variation, it is concluded that there exists great variation in the germplasm, which provides opportunities to be utilized for genetic improvement.