2 Alemaya University of Agriculture, PO Box 138, Dire Dawa, Ethiopia

ABSTRACT: The egg yolk pigmenting properties of increasing levels (0, 1, 2, 3, 4 and 5%) of pepper spent in the diet of White Leghorn layers was evaluated. Six months old two hundred and forty layers were divided randomly into six groups of 40 layers. Each group was further divided into two replicate groups of 20 layers and assigned to a pen with deep litter. The six treatment diets were assigned to two of the pens at random. Evaluation was based on egg yolk colour intensity measured based on Roche colour fan scores, potassium dichromate grades and consumer preference scores on raw, boiled and fried egg samples. Egg production, feed consumption, feed/dozen eggs, fertility and hatchability of eggs, albumin quality and egg weight were also measured. Significant (p<0.01) differences in Roche colour fan and potassium dichromate scores were obtained. Highest scores for the Roche colour fan (8.63) and potassium dichromate (8.09) grades were attained at the 5% level of pepper spent inclusion, while the lowest values were obtained for the control (0% inclusion). There were also significant (p<0.05) differences in consumer preference scores for boiled eggs. The highest scores (3.51) were given for eggs from birds on the 5% pepper spent diet. No differences (p>0.05) in the preference scores on the raw and fried eggs were observed with all ranging between good and very good. No significant differences (p>0.05) in egg production, feed consumption, feed conversion efficiency, feed cost per dozen eggs, fertility and hatchability of eggs, albumin quality and egg weight were noted. Based on most of the measurements used and maintaining consumer acceptability of the resulting egg products, the closest yolk colour to that of local eggs relished by local consumers was produced by inclusion of 4% pepper spent in the diet. This level of inclusion can, thus, be recommended.

Department of Animal Production and Rangeland Management

Awassa College of Agriculture, Debub University, PO Box 5

Awassa, Ethiopia, E-mail: [email protected] 

ABSTRACT: The prevalence, mean intensity, relative density of helminth species and the effects of environmental factors, sex and maturity of host on seasonal dynamics in relative density of helminthes ova in Rift Valley goats were investigated from July 1997 to June 1998. Ten nematode and three cestode species were identified. Haemonchus contortus was the most prevalent followed by Strongloides papillosus and Trichostrongylus sp. with prevalence rate of 66.5%, 36.1% and 30.4% and mean intensities and relative densities of 1139.9, 503.7, 434.8 and 344.9, 82.8, 60.1, respectively. Moniezia expansa showed 32.2% prevalence rate and 545.2 and 79.6 mean intensity and relative density, respectively. Mixed infestation was common to Rift Valley goats. About 2.8%, 6.2%, 15.8%, 21.6% and 23.7%, of the examined goats harbored multiple infestations varying from five to one species, respectively. Maturity and sex of hosts influenced seasonal variations in relative density of helminthes species. Female hosts harbored higher relative densities (p<0.005, r² = 0.91) than male hosts and young hosts harbored significantly higher (p<0.0001, r² = 0.95) than adult ones. The egg output in July was significantly different (p<0.0001) than other months except in June. The results show that mixed parasite infestation was common in goats. The highest peak of helminthes egg densities coincided with the big rainy season followed by the short rainy season. Therefore, the use of appropriate treatment before and after the rainy season could be a useful strategy to alleviate the problem. Moreover, more attention is needed for young and female goats, as they are the most affected groups.

Key words/phrases: Eggs, epidemiology, mean intensity, relative density, Rift Valley goats, traditional husbandry

Arbaminch Water Technology Institute, P.O. Box 21, Arbaminch, Ethiopia

ABSTRACT: This paper examines the morphological, physical, chemical and biochemical characteristics of soils and maps the soil units of Werkaryia area, Kutaber wereda, south Welo. Moreover it examines the potential and constraints of soils for crop cultivation. The characteristics of soils were determined based on field survey and laboratory analysis. The classification of soil was based on the fao/unesco Revised Legend (1990). Eutric Vertisol, Haplic Phaeozem, Luvic Phaeozems, Mollic Gleysols, Mollic Fluvisols and Mollic, Lithic, and Eutric Leptosols are the major soil units identified in the area. Vertisols occur on the gently to strongly sloping alluvial toeslope and footslope. They are marked by high clay content, cracks, slickensides and gilgai topographic features. Cambic B and argic B of the Haplic Phaeozems and Luvic Phaeozems underlain the Mollic A of Phaeozems, respectively. Mollic Gleysols developed on alluvium deposition while Mollic Fluvisols on stratified deposition of the toeslope. Both Fluvisols and Gleysols are marked by gleyic and stagnic conditions. On the other hand, Leptosols are formed over the residuals of the trachyte of the upper slopes. They are characterized by shallow soil depth, below 30 cm. As a result of the parent materials, the soils of Werkaryia in general are characterised by high nutrient status and retention capacities. The pH of the soils is also favourable for crop cultivation. However, crop cultivation in the area is limited by low organic matter and total nitrogen of Vertisols and Phaeozems, by the poor drainage of Vertisols, the shallow depth and the high erosion rate in Leptosols, the high water table of Fluvisols and Gleysols, and the imbalance of nutrients and deficiency of some of the nutrients in almost all of the soils.

Department of Physiology, Faculty of Medicine, PO Box 9086

Addis Ababa University, Addis Ababa, Ethiopia,

ABSTRACT: Forced vital capacity (fvc, L/sec), forced expiratory volume (fev1, L/sec), fev1%, forced expiratory flow rate (fef _200—1200 ml,. L/sec), forced mid-expiratory flow rate (fmf _25—75 %, L/sec), peak expiratory flow rate (pefr, L/min), minute ventilation (ve, L/min), oxygen saturation of arterial blood (SaO₂%), working capacity (Kgm/min/m² body surface area), pulse rate (beats/min) and arterial blood pressure (mmHg) were studied in eight male sojourners descending to 1370—490 m and ascending to 2550—3300 m from their altitude of residence (2440 m). Of the lung function indices, mean fef _200—1200 ml increased from 6.54 L/sec at 2440 m to 7.18 L/sec and 8.33 L/sec, respectively, at 2550 m and 3100 m. It was not measured at 3300 m for lack of electric power supply. Mean values of fef _200—1200 ml were found to be correlated to the altitudes of investigation significantly (r=0.7316). The increase in fef _200—1200 ml probably reflects that large airways tend to open up more widely perhaps concomitant with enlargement of alveolar spaces at 2550 m and above to compensate for the reduced pao₂ and reduced O₂ uptake. Mean ve showed a 4—5-fold increase with exercise essentially at all levels of altitude. Acute altitudinal effect became quite evident at 3300 m. At rest, ve increased from 5.62 L/min at 2440 m to 7.78 L/min at 3300 m. During exercise, increase in ve with ascent apparently protects the low O₂ saturation (91.9% at rest and 86.9% in this study). Although the mean of exercise ve was markedly increased only at 3300 m, its overall correlation with altitude (r=0.6698) and mean working capacity (r=-0.6426) was quite significant (two-tailed P=0.0236). SaO₂% was found to be correlated with mean (r=0.7955) and individual measurements (r=0.7628) of working capacity. Mean working capacity was reduced by about 20% with ascent and increased by about 9% with descent. It was negatively correlated with ascent (r=-0.9101). This signifies that physical performance is quite limited by hypoxia with ascent. Mean pulse rate, which was 75 beats /min at 2440 m increased to 82 beats/min at 490 m. It decreased to 72 beats/min at 3300 m. This is probably attributable to the decrease in ambient temperature and relative humidity with ascent and to the increase with descent. Arterial blood pressure (mean systolic/diastolic) was found to be 100.1 / 62.13 mmHg at 2440 m, 93.1/59.4 mm Hg at 490 m, 99.6/59.4 at 1370 m and 101.46—102.5/62.5—63.1 mmHg at 2550–3300 m. This pattern of change seems to be attributable to changes in peripheral vascular resistance which is apparently secondary to changes in ambient temperature and relative humidity. One of the sojourners experienced only generalised fatigue. This suggests that physiological alterations occurring at 3300 m cannot apparently induce acute mountain sickness in residents of medium altitude.

Department of Geology and Geophysics, Faculty of Science, Addis Ababa University

PO Box 1176, Addis Ababa, Ethiopia, E-mail: [email protected] 

ABSTRACT: Addis Ababa Observatory (aae) geomagnetic data analysed over the time-span 1958—1998 show that the annual mean values of the intensity have decreased since 1965 from 36186 nT to 35950 nT at a non-linear regression rate of 8—9 nT per year. Directional changes in the Earth’s magnetic field that could be associated with southward and westward drifts of the dip equator are observed. On plotting the secular trends of the H, Z and D components, the variation in the H-component of Addis Ababa shows a near-sinusoidal cyclicity of about 40—50 years. The residual H, Z and D curves, obtained after removing polynomial fits, have been examined. The horizontal component H has been found to show pseudo-periodicity that would be considered to have parallelism with the 11-year sunspot cycle. Comparison of the observatory data with igrf models for the period 1958—2000 show that the igrf provides an excellent estimation of the geomagnetic Z and D components for the region, while it always underestimated the value of H. The mismatch in H may be due to the fact that the representative station being a dip equatorial station, it is under the influence of the equatorial electrojet and other solar activity effects. The comparison study in particular supports the existence of a relatively small magnetic anomaly in the region as implied by the igrf data.

THE MICROBIOLOGY OF ETHIOPIAN FOODS AND BEVERAGES: A REVIEW

Institute of Pathobiology, Addis Ababa University, PO Box 1176

Addis Ababa, Ethiopia, E-mail: [email protected] 

ABSTRACT: The paper reviews the available literature on the microbiology of traditional Ethiopian foods and beverages. The topic on milk and dairy products deals with the livestock resource of the country with respect to the microbiological quality of raw and processed milk, processing and microbial status of various fermented milks ('Ergo', 'Itutu'), traditional cottage cheese ('Ayib') and microbiological safety of milk and dairy products. Under traditional fermented foods, the microbiology of 'Enjerra' fermentation, 'Kotcho' fermentation and the fermentation of various condiments are discussed. Microbiological safety issues and spoilage of these products are also addressed. Discussion on the microbiology of traditional fermented beverages deals with popular products such as 'Tella', 'Borde' and 'Shamita'. Here, the nutritional and other chemical properties of the products are also presented. Some ready-to-eat foods are discussed with respect to their level of microbial contamination, spoilage and their importance in food-borne diseases. These include different traditional sauces, street foods and weaning foods. Finally, microbial load and safety considerations were addressed with respect to other food products such as beef, fish, vegetables, fruits and fruit juices. In conclusion, the review discusses the nature of food preparation in Ethiopia, food loss due to poor traditional household processing, the extent and limitations of scientific work done so far and suggests some recommendations to curb the problem.

Key words/phrases: Traditional food, beverages, fermentation, spoilage, safety

Geological Survey of Ethiopia, PO Box 140079, Addis Ababa, Ethiopia

ABSTRACT: Water balance evaluation of Koka Reservoir was attempted by different authors, and different leakage rates were estimated. However, the water balance equation that the previous authors used does not take into account ground water inflow into the reservoir. Koka Reservoir is known to receive groundwater inflow from the north, west and south shores and from the reservoir floor, and loses water by leakage at the northeast reservoir bank and where it abuts on the Koka Dam. Hence, previous estimated leakage rates and total reservoir water loss are incorrect. An appropriate water balance equation is proposed for Koka Reservoir, and subsurface outflow (leakage rate) of 485 mm³/year and total reservoir water loss of 546 mm³/year are determined. The new determinations are recommended to be used for Awash River simulation model.