Ethiopian Journal of Science and Technology <p>The <em>Ethiopian Journal of Science and Technology</em> (EJST) publishes high quality original&nbsp;&nbsp; research articles, reviews, short communications, and feature articles on basic and applied aspects of science, technology, agriculture, health and other related fields.</p> <p>Other websites associated with this journal:&nbsp;<a title="" href="" target="_blank" rel="noopener"></a></p> College of Science , Bahir Dar University en-US Ethiopian Journal of Science and Technology 1816-3378 <p>The copyright belongs to the journal.</p><p>The articles in Ethiopian Journal of Science and Technology are Open Access distributed under the terms of the Creative Commons Attribution License (<a title="The articles in Ethiopian Journal of Science and Technology are Open Access distributed under the terms of the Creative Commons Attribution License ( BY4.0)." href="/index.php/ejst/manager/setup/The%20articles%20in%20Ethiopian%20Journal%20of%20Science%20and%20Technology%20are%20Open%20Access%20distributed%20under%20the%20terms%20of%20the%20Creative%20Commons%20Attribution%20License%20(http:/" target="_blank"></a>).</p> Effect of pre-slaughter beef cattle handling on welfare and beef quality in Ambo and Guder markets and abattoirs, Oromia Regional State, Ethiopia <p>Improper beef cattle handling could affect welfare and meat quality. The effect of beef cattle handling during transportation and in the lairage on the animal welfare and beef quality was studied in relation to Guder and Ambo markets and abattoirs. Data were collected from 200 respondents using a semi-structured questionnaire. For laboratory analysis, animals were randomly assigned into three groups: Group I - trekked from the nearest places (≤30 km), Group II - trekked farthest places (&gt;30 km), and Group III - transported using vehicles (&gt;50 km). One-hundred pooled beef swab samples were collected from the flank, brisket, and rump to determine aerobic bacterial load and another 100 beef samples to assess pH values. Descriptive statistics, independent t-test, and ANOVA were used for analysis. The result of the study indicated that trekking was the major means of transportation (72%). The majority of animal handlers (92%) did not allow animals to feed, water, and rest during trekking. Beef cattle were overcrowded and beaten during vehicle transport. About 47% of the beef samples were abnormal of which the majority were DFD (dark, firm and dry) beef and DFD beef with spoilage. The pH of meat was significantly affected by the distance traveled before slaughter using both trekking and vehicle transportation (t= -3.5, p=0.001). Therefore, it is concluded that there was poor handling and stressful situation of beef cattle before slaughtering, which negatively affected the welfare and beef quality. Hence, pertinent proclamations, regulations, and delivery of animal welfare awareness training for different stakeholders are urgently needed.</p> Mesfin Diro Berhane Mekete Endrias Zewdu Gebremedhin Copyright (c) 2021-06-30 2021-06-30 14 2 89 104 10.4314/ejst.v14i2.1 The effect of prey refuge on the dynamics of three species food web system <p>In this paper, a mathematical model is proposed to study the effect of prey refuge on the dynamics of three species food web system. The food web comprises of a single prey and two competing predators. The two predators predate their prey following Holling type II functional response. In this work we discussed boundedness of the system, existence condition of the equilibrium points and the Jacobean matrix is obtained by linearization techniques. The local stability of the equilibrium points was discussed by using Routh-Hurwitz criteria and the global stability of the equilibrium points by constructing suitable Lyapunov function. Numerical simulation is conducted to support the analytical result. Finally, the effect of prey refuge on the dynamics of one prey two predator was discussed based on the analytical and numerical simulation results. From the numerical simulations, it is found that the dynamical system is persistent for a small value of the refuge constant. However, an increase in the refuge constant leads to the extinction of one of the predator species.</p> Dawit Melese Abraha Hailu Copyright (c) 2021-06-30 2021-06-30 14 2 105 121 10.4314/ejst.v14i2.2 Growth, survival and egg production of exotic chicken breeds under small scale production system in Bahir Dar City Administration, Amhara Region, Ethiopia <p>Growth, survival and egg production performance and profitability of exotic chicken breeds were evaluated under small-scale chicken producers in urban and peri-urban areas of Bahir Dar City from 2018 to 2019. Data were collected using semi-structured questionnaires, monitoring and field observation. Thirty-three small-scale chicken enterprises (30 from urban and three from peri-urban areas) were included in this study. All questionnaire data were analyzed using SPSS Version 20. The monitoring data was analyzed with ANOVA using the general linear model (GLM) procedure of SAS version 9.0. The monitoring result revealed that the growth performance of chicken significantly varied with respect to breeds and production systems of producers. Sasso T44 had higher daily body weight gain (10.66 ± 0.03 g) and total body weight gain (1642 ± 5.02 g) within 22 weeks of age in the urban areas. The mean egg production for Bovans Brown at the age of six months was 124.8 ± 4.10 eggs. The annual mean egg production performance of Bovans Brown was 239.63 ± 4.32. The overall mortality rate of all exotic chicken was 6.5%. Despite many constraints, small-scale chicken production was profitable. Seasonal disease outbreaks, shortages of feed and housing problems were the major constraints of small-scale chicken producers. The growth performance and survival rate of exotic chicken was promising, but the egg production was low. Therefore, the management practices of small-scale chicken enterprises in the study area should be improved.</p> Aderaw Litigebew Fisseha Moges Damitie Kebede Copyright (c) 2021-06-30 2021-06-30 14 2 123 137 10.4314/ejst.v14i2.3 Effects of processing methods on nutritional composition of improved soybean varieties for soymilk production <p>Value addition efforts in respect of using soybean in various food applications are scarce in Ethiopia. The effect of processing methods was investigated on nutritional composition of improved soybean varieties for soymilk production. The experiment was carried out in a factorial design, improved soybean variety as the first factor (Didessa, Katta and Korme) and processing methods as a second factor of three levels (Illinois, Cornel and Traditional method), replicated three times. The Cornel processing method gave the highest ash content (0.32%) from Korme and the lowest (0.27%) from Didessa and Katta varieties. The highest (2.60%) crude protein content was recorded from Didessa and the lowest (2.13%) from Katta, using Cornel processing methods. The highest carbohydrate content (13.21%) was recorded from Didessa and the lowest (6.87%) from Korme. The highest (75.93 kcal/100 g) energy content was recorded from Didessa and the lowest (51.77 kcal/100 g) from Korme, by Cornell processing method. Generally, Cornel processing method was the best of the three processing methods for improved variety of soybean. From the three varieties of improved soybean, Didessa had higher nutritional composition and could be used in different food product development efforts and can contribute in addressing the food security problems of Ethiopia.</p> Demelash Hailu Mitiku Copyright (c) 2021-06-30 2021-06-30 14 2 139 154 10.4314/ejst.v14i2.4 Determinants of farm level market supply of tomatoes in Fogera district, South Gondar Zone of the Amhara Region, Ethiopia <p>This research attempted to analyze the determinants of market supply of tomato in Fogera district, South Gondar zone, Amhara Region of Ethiopia. Tomatoes generate income for the poor farmers of Ethiopia. Primary and secondary data were collected. The primary data was generated though a household survey (N=235), a pre-tested structured questionnaire and a key informant interview using a checklist. The data were analyzed using multiple linear regression model. The model results showed livestock ownership, size of land allocated for tomato, access to credit, income from non-farm/off-farm activities and use of improved seed significantly affected quantity of tomato supplied to the market. The findings indicated the need to encourage off/non-farm income activities, strengthen access to improved varieties of tomato, use technologies that can improve the production and productivity of tomato, and expand the access to credit.</p> Hawlet Mohammed Kassaw Zewdu Berhanie Getachew Alemayehu Copyright (c) 2021-06-30 2021-06-30 14 2 155 170 10.4314/ejst.v14i2.5 Synthesis, characterization and functional evaluation of gold nanoparticles prepared using Dovyalis abyssinica leaf extracts as reducing and surface capping agent <p>Green synthesis of nanoparticles using plants and microorganisms is biologically safe, cost effective, and environmentally friendly technology. Gold nanoparticles (Au NPs) were synthesized using aqueous extracts of leaves of <em>Dovyalis</em><em> abyssinica</em> as reducing and surface capping agent and the catalytic activity, antibacterial action and antioxidant potential of the synthesized AU NPs were evaluated. Firstly, HAuCl<sub>4 </sub>was synthesized in the laboratory from metallic gold and hydrochloric acid using a predesigned method. Secondly, Au NPs was synthesized by mixing HAuCl<sub>4 </sub>and the plant extract at 45 <sup>o</sup>C with a digestion time of 1 h. The size of the nanoparticles was modulated by varying the ratio of the plant extract and HAuCl<sub>4 </sub>with known concentrations. The synthesized Au NPs showed strong absorption around 540 nm which lies in the characteristic absorption region of Au metal nanoparticles (520–580 nm). The X-ray diffraction spectrum of the synthesized Au NPs showed characteristic crystalline structures of gold. The scanning electron spectroscopy images of the synthesized Au NPS revealed the presence of mixed shapes predominantly of irregular shapes and a particle size analyzer displayed an average size of 63.13 nm. The fourier-transform infrared spectrum of Au NPS confirmed the presence of amine, carbonyl and hydroxyl functional groups as surface capping molecules. Although the synthesized Au NPs showed poor bacterial growth inhibition activity on two selected bacteria, it demonstrated excellent free radical scavenging activity against 2, 2-Diphenyl-2-picrylhydrazyl (DPPH) radical and good catalytic activity for degrading bromothymol blue and methyl red compounds. In contrast to the hexane and ethyl acetate extracts, the aqueous fraction was identified as powerful reducing fraction for the synthesis of Au NPs in this experiment.&nbsp;</p> Abera Beyene Gebresilassie Adam Mekonnen Engida Copyright (c) 2021-06-30 2021-06-30 14 2 171 190 10.4314/ejst.v14i2.6