Variation and association of morphological and biochemical characters in grass pea (Lathyrus sativus L.)

Fifty grass pea land race populations of Ethiopia that were selected based on administrative regions and different altitude classes were used in this study to determine variability in morphological characters, Oxalyl Diamino Propanoic acid(ODAP) – a causative agent of lathyrism, and protein contents and their associations. Highly significant differences were observed among the populations for most of the morphological characters. Populations collected from Gondar region and the higher altitude group (>2550 m) showed the highest mean and coefficient of variation indicating the presence of high genetic diversity in this region and altitude group. ODAP analysis from single plants showed significant variation both within a population and between populations. Four individual plants with low ODAP contents ranging from 0.149% to 0.182% (range within safe level) were identified in populations collected from different regions, indicating the diversity and variation of this trait with in one population and between regions. These low ODAP lines are considered important for further breeding. The association of ODAP with grain yield, biomass, plant height and seed size was negative, suggesting that the selection of tall and late maturing varieties with large seed size and high grain yield potential will enable the development of varieties with low ODAP content. This revised version was published online in August 2006 with corrections to the Cover Date.     

Genetic structure and differentiation among oregano [<Emphasis Type="Italic">Origanum vulgare</Emphasis> subsp. <Emphasis Type="Italic">glandulosum</Emphasis> (Desf.) Ietswaart] provenances from North Africa: bioinformatic approaches cause systematic bias

Thirteen simple sequence repeat (SSR) markers developed from expressed sequence tags (ESTs) of essential oil glands of Origanum vulgare were previously evaluated. These EST-SSR loci were analyzed to study the genetic diversity and differentiation of Origanum vulgare subsp. glandulosum, an endemic species of Tunisia. The study was performed on five natural populations from the Maghreb regions (North Africa) from northern Tunisia (Sejnane, Krib, Bargou, Zaghouan and Nefza). Two other subspecies of O. vulgare were used as out-group. These are O. vulgare subsp. hirtum (from USA) and O. vulgare subsp. vulgare (from Italy). A total of 60 alleles were detected in the seven populations studied. The number of alleles per locus ranged from 2 to 9. This analysis revealed that the unbiased expected heterozygosity (0.327) is higher than the observed heterozygosity (0.242), reflecting a deficit in heterozygosity in the total population. Only the Sejnane population has an excess of heterozygosity. The differentiation between Tunisian populations is highly significant and indicates the presence of a structure between these populations. However, the indexes of genetic differentiation (FST) values are low and vary between 0.048 and 0.115 which indicate the presence of a weak structure. The value of the FST between Nefza and Krib is not significant, reflecting the absence of genetic structure between them. The value of gene flow between these two populations is the most important (27.34), showing a substantial exchange of genes or genomic regions between them. The migration of genes is less important among the other Tunisian populations. Genetic structuring according to the geographical origin of Tunisian populations is low but still exists, which allows concluding the presence of a single complex gene pool.     

Cattle brucellosis in traditional livestock husbandry practice in Southern and Eastern Ethiopia,and its zoonotic implication

Background

Cattle brucellosis has significant economic and zoonotic implication for the rural communities in Ethiopia in consequence of their traditional life styles, feeding habits and disease patterns. Hence, knowledge of brucellosis occurrence in traditional livestock husbandry practice has considerable importance in reducing the economic and public health impacts of the disease.

Methods

A total of 1623 cattle sera were serially tested using the rose Bengal test as screening and complement fixation test as confirmatory tests. The Stata survey command was used to establish prevalences for the overall and individual variables, while potential risk factors for seropositivity were analyzed using a multivariable logistic regression analysis.

Results

The results showed that 3.5% (95% CI = 2.4, 4.5%) of the animals and 26.1% (95% CI = 18.6, 33.7) of the herds tested had antibodies against Brucella species. Village level seroprevalence ranged from 0% to 100%. A higher seroprevalence was observed in pastoral system than mixed farming although this variable was not significant in the final model. The final logistic regression model identified herd size; with large (odd ratio (OR) = 8.0, 95% CI = 1.9, 33.6) and medium herds (OR = 8.1, 95% CI = 1.9, 34.2) showing higher risk of Brucella infection when compared to small herds. Similarly, the odds of Brucella infection was higher in cattle aged above 4 years when compared to age groups of 1-2 (OR = 5.4, 2.1, 12.9) and 3-4 years (OR = 3.1, 95% CI = 1.0, 9.6). Herd level analysis of the risk factors revealed that large and medium herds as well as herds kept with multiple livestock species were at higher risk of acquiring Brucella infection. Brucellosis in traditional livestock husbandry practices certainly poses a zoonotic risk to the public, in consequence of raw milk consumption, close contact with animals and provision of assistance during parturition. Due to lack of diagnostic facilities and information on its occurrence, human brucellosis is most likely misdiagnosed for other febrile diseases prevailing in the areas and treated empirically.

Conclusions

The results of this study demonstrated that bovine brucellosis is widely prevalent in the study areas particularly in pastoral production system. Hence, the study suggests the need for implementing control measures and raising public awareness on prevention methods of brucellosis.     

Study on the prevalence of cystic hydatidosis and its economic significance in cattle slaughtered at Hawassa Municipal abattoir,Ethiopia

A cross-sectional study was conducted from December 2008 to March 2009 to assess the status of cystic hydatidosis in cattle slaughtered at Hawassa Municipal abattoir. Out of the total 632 cattle examined visually and manually (palpation and incision), 333 (52.69%) were found harboring hydatid cysts. A significantly higher infection was detected in older cattle (P < 0.05, χ ² = 4.36) than young. Regarding body condition score, no significant variation (P > 0.05, χ ² = 2.148) was observed as the prevalence was 54.55% for lean cattle followed by medium (53.83%) and fat (46.88%). Of the total 333 infected, 123 (36.9%) had hydatid cysts only in the lung, 23 (6.9%) in the liver, 12 (3.6%) in the spleen, five (1.5%) in the heart, and three (0.9%) in the kidney while the rest 167 (50.2%) had multiple organ infections. Of the 530 viscera harboring hydatid cysts, the highest (52.83%) was lung followed by liver (34.15%), spleen (9.06%), heart (3.39%), and kidney (0.56%). Size assessment made on 874 cysts indicated that 308 (35.3%) were small, 251 (28.7%) medium, 89 (10.2%) large, and 226 (25.9%) were calcified. The distribution of characterized cysts in different organs based on their size was found to be statistically significant (P < 0.05). In addition, out of the total 874 cysts collected, 26.9% were fertile, 47.3% sterile, and 25.9% calcified or purulent cysts. There was a significant difference in fertility of cyst from different organs (P < 0.05, χ ² = 27.96), those of lung origin being highly fertile. Likewise, out of the 121 fertile cysts subjected for viability test, 68 (56.2%) were viable. Considering the current result, the total annual economic loss from organ condemnation and carcass weight loss due to bovine hydatidosis at Hawassa Municipal abattoir was estimated at 1,791,625.89 Ethiopian Birr (ETB; 1USD = 12.93ETB). Results in the study were discussed in light of the situation in different parts of Ethiopia and abroad, and finally, relevant recommendations were forwarded.     

Soil organic carbon and nutrients in smallholding land uses in southern Ethiopia

This study assessed the soil organic C (SOC) and soil nutrients in smallholding home garden, woodlot, grazing land, and cropland at two soil depths and two sites in Wolaita Zone, southern Ethiopia. The results showed that soil properties were significantly influenced by land use. The home garden had significantly higher (p < 0.05) SOC and soil nutrients when compared to the cropland. When the home garden was compared to the woodlot and grazing land uses, it had significantly higher (p < 0.05) values except in SOC, total N (TN), cation exchange capacity (CEC), and exchangeable Ca. Cropland, in comparison with grazing land and woodlot, had a non‐significant difference except TN. The SOC stock (0–40 cm) in the home garden, woodlot, grazing land and cropland was 79.5, 68.0, 65.0, and 58.1 Mg ha^?1, respectively. Home garden significantly differed (p ≤ 0.05) in SOC only from cropland, and this was attributed not only to the relatively higher organic input in the home garden but also to the little organic matter input and frequently tillage of the cropland. The similar SOC among the home garden, woodlot and grazing lands may imply that the balance between inputs and outputs could be nearly similar for the land uses. Soil TN and CEC had a nearly similar pattern of difference as in SOC among the land uses because of their close relationship with SOC. In general, the land use influence on soil nutrients can be in the order: home garden > wood land ≈ grazing land ≈ cropland, with home garden showing the least difference from the woodlot and the greatest from the cropland. In the agroecosystem, in general, the influence of smallholding home garden on SOC and soil nutrient was marginally different from Eucalyptus woodlot and grazing lands but evidently different from cropland.     

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.     

Causes of lamb morbidity and mortality in the Ethiopian highlands

A study was conducted to investigate causes of lamb morbidity and mortality on farms and on-station at Debre Berhan during 1989 and 1990. It showed pneumonia (bacterial and/or verminous), starvation-mismothering exposure (SME) complex, gastrointestinal parasites, enteritis, abomasal impaction and physical injuries to be important health constraints on productivity. Neonatal mortalities were 51.5% and 46.3% on farms and on-station respectively and occurred owing to management problems such as SME, abomasal impaction and physical injuries. On the farms the lamb birth weight was 2.56±0.25 kg and was significantly (p<0.05) affected by the dam's age, lambing weight, litter size, sex of lamb and year of lambing, but not by the season of lambing. Birth weight significantly (p<0.05) influenced lamb mortality. Lambs with a low birth weight tended to die from SME. Morbidities and mortalities due to infectious causes increased in older lambs, suggesting that infections were acquired with age when resistance was lowered owing to inadequate nutrition and poor management.Heavy loss of lambs could be overcome by such health management interventions as foster mothering, warming lambs during the cold season and vaccination with polyvalent vaccines against pasteurellosis, clostridial infection andDictyocaulus filaria.