Search

Search Results

##search.searchResults.foundPlural##

A Novel Regression Approach for wind Speed Forecasting

Nguyen Hoang Huy, Hoang Thi Thanh Giang

Received: 20-07-2020 / Accepted: 08-09-2020
The paper presents a spatio-temporal data forecasting approach using Linear Regression (LR) in two steps called two-step LR. In the first step, all features were divided into subgroups and Linear Regressions was utilized to obtain a regression value for each feature subgroup. In the second step, Linear Regressions was applied again to these regression values to generate the final regression value. The approach using two-step LR had state-of-the-art performance for a wind speed forecasting problem. Wind speed forecasting would be useful for the integration of wind energy into the power grid because wind power generated by wind turbines has an intimate relationship with wind speed and unpredictability and variability of wind speed is one of the fundamental difficulties of this integration system.
Research on Technical Practicesto Build ProcedureofF1Hybrid SeedProductionfor Two-LineHybrid Rice Variety HQ21

Phan Thi Thanh Huyen, Tran Van Quang, Nguyen Thi Kim Dung, Nguyen Thi Dong, Le Van Huy, Pham Van Thuyet

Received: 11-02-2020 / Accepted: 12-08-2020
The experiments were to determine optimal technical practice for F1seed production of hybrid rice cultivars HQ21 for highest yield. They were carried out in 2018 summer season on the field of Crops Research and Development Institute of VNUA, Gialam district, Hanoi.The technical practices are sowing season, row ratio of male: female lines, transplanting density of female line, fertilizer dose and GA3spraying dose. The parental lines were sown into 8 seasons, each day separated by 07 days. Percentage of parents is arranged with 04 different formulas in the form of RCB design. Four transplanting density and 4 different fertilizer doses arranged in Split-plot design. Experiment to determine the appropriate GA3spraying dose for F1hybrid seed production field is arranged in a RCB design.The results show that, the sowing date of parental lines was recommended such that heading date of parental lines set in from 25thAugust to 10th September, female line was sown 5 days before male line, row ratio of male:female was 2:14, transplanting density of female line was 50 hills/m2, fertilizer dose was 120kg N + 60kg P2O5+ 60kg K2O/haand the amount of GA3sprayed per hectare was 160 grams of pure.
EFFECTOF TRICHODERMA sp. TC1 AND ITS EXTRACT ON GROWTH INHIBITION AND AFLATOXIN PRODUCTION OF Aspergillus flavusAND Aspergillus parasiticus

Nguyen Thi Thanh Thuy, Luu Thi Phuong Thao, Vu Quynh Huong, Nguyen Van Giang

Received: 20-04-2016 / Accepted: 10-08-2016
Aflatoxins are toxic carcinogenic secondary metabolites produced predominantly by two fungi: Aspergillus flavusand Aspergillus parasiticus. These fungi are a health risk and are responsible for losses and contamination of processed foods and feeds. It is very important to find methods to inhibit the growth of A. flavus andA. parasiticus,and degrade aflatoxin. In laboratory conditions, the Percentages of Inhibition of Radial Growth (PIRG %) of Trichodermasp. TC1 against A. flavusLA21 and A. parasiticusNG10 after 7 days’ dual culture were 63.51% and 60.22%, respectively. However, the use of Trichodermasp.TC1mycelium has restrictions in agricultural products due to the risks of consuming the substrate and degrading the products’ quality. Therefore, its extracts are more preferred in application. In the PD media, when up to 4% Trichodermasp. TC1 extract was added, the biomass rate for A. flavusLA21 and A. parasiticusNG10 reduced to 74.00% and 60.30%, respectively, after 5 days of incubation. The toxin levels of corn samples deliberately infected by aflatoxin producing fungi were negatively correlated with sprayed on Trichoderma sp. TC1 extract. Seven days after spraying the extract 4%, the aflatoxin in samples from more than 60 ppb at the initial time reduced down to 16 ppb for A. flavusLA21 and 21.33 ppb for A. parasiticus NG10.
Estimation of Breeding Values and Selection forAverage Daily Weight GainofStress Negative Piétrain Boars

Ha Xuan Bo, Nguyen Hoang Thinh, Do Duc Luc, Dang Vu Binh

Received: 06-11-2014 / Accepted: 29-11-2014
This study was conducted to estimate breeding values (BV)of average daily weight gainBLUPs method ofstress negative Piétrain pigs raised atDong Hiep livestock farm, Hai Phong province and Animal farm of Vietnam National University of Agriculture. The dataof 373 individualswereused to estimate breeding values.In addition,BV estimates of 20 sires and average daily gain of504 stress negative Piétrain pigs (245 boars and 259 gilts) born from these 20 sires were used to estimate relationship between breeding values of sires and average daily weight gainof progenies.The results showed that there was apositive associationbetween breeding values of sires and average daily gain of progenies.Average daily gainof progeniesfrom the top 5% sires according to BV estimate was 551.20 g/day. These values decreased to 546.07, 536.94and 530.50 g/daywhenselection intensity decreased to 10%, 15% and 20%, respectively.Based on estimates ofbreeding value by BLUPfor thestress negativePiétrain boarsthe the productivity performance of progenies was improved: the selected boar proportions5, 10, 15, 20% improved13.25; 12.20; 10.32; and 9%, respectively,of the average daily gainof progenies.
Growth Performance and Meat Quality of 3/4 Dong Taoand1/4 Luong PhuongCrossbred Chickens

Nguyen Van Duy, Nguyen Dinh Tien, Vu Dinh Ton

Received: 01-06-2020 / Accepted: 25-06-2020
This study was carried to determine the growth performance, meat productivity and quality of 3/4 Dong Tao (ĐT) and 1/4 Luong Phuong (LP) crossbred chickens raising. The growth performance was determined on the 180 chicks from one day of age to 24 weeks. We first randomly divided all the chicks into 3 cocks and 3 hens to determine the meat yield and meat quality at 16, 20 and 24 weeks of age. The survival rate of 3/4ĐT and 1/4LP from one day of age to 24 weeks was 98.33%. At 24 weeks, the alive weight was 3068.33 g for cocks and 2046.67 g for hens. The average daily gain of chickens gradually increased from 1 to 12 or 13 weeks for hens and cocks, respectively and then decreased. From 19 to 20 weeks of age, the growth rate was very low with ADG/day at 12.9 g (cocks) and 8.21 g (hens). The FCR of chickens in period 20 weeks was 4.47 and in period 24 weeks was 5.15. The 3/4ĐT and 1/4LP chickens had a high meat yield and good quality of meat. In conclusion, it is possible to use the 3/4 Dong Tao and 1/4 Luong Phuong in the production of broiler chickens.
Application of Different Nonlinear Functions to Describe the Growth of Stress -Negative Piétrain Pigs

Ha Xuan Bo, Do Duc Luc, Dang Vu Binh

Received: 24-08-2020 / Accepted: 10-09-2020
This study was conducted to describe the growth and determine the best growth models to estimate body weight and average daily gain (ADG) of stress-negative Piétrain pigs raised in Dong Hiep livestock farm, Hai Phong province and animal farm of Vietnam National University of Agriculture from December 2007 to December 2015. Four functional growth Logistic, von Bertalanffy, Gompertz and Richards models were be used to estimate body weight, ADG of Piétrain pigs at birth (1198 intact male and 1141 gilts), weaning (808 intact maleand 773 gilts), 60 days (472 intact male and 483 gilts), 5.5 months (94 intact maleand 108 gilts), 7.5 months (228 intact male and 292 gilts). Richards, Gompertz functions had the highest coefficient of determination (0.968 and 0.966) and the lowest AIC (16813 and 17498), residual variance (23,6633 and 30,4267). Average daily gain from 60 days to 7.5 months of intact male (487 and 492 g per day) and gilts (493 g per day) were predicted by Richards, Gompertz similar an actual ADG. The growth of stress-negative Piétrain pigs can be well described withthe Richards and Gompertz functions.
Histopathological Characteristics of Grass Carp (Ctenopharyngodon idella)Gills Infested with Parasites

Truong Dinh Hoai, Hoang Minh Tung, Nguyen Vu Son, Kim Van Van

Received: 12-08-2014 / Accepted: 29-11-2014
Histopathology provides a diagnostic method to detect the effects of irritants and pathogens in different fish organs and it can be used as an indicator for abnormal conditions in aquatic environments. The present study used histopathology to examine lesions on Grass carp (Ctenopharyngo donidella) gills associated with three common parasites. Fifty-eightGrass carp fry infectedwithmetacercaria of Centrocestus formosanus, Dactylogyrus sp. and Ichthyophthirius multifiliis r, were obtained fromfish farm nurseries. Symptoms, prevalenceand intensity were recordedandhistopathological examination was performed on sectioned gill tissuesstained with Haematoxylin-Eosin. Based on the results, the lesions in gill tissues caused by these three parasites exhibited similar characteristics as structural deformation and circulatory disturbances. However, each of them hadits own distinctive characteristics. The infection bymetacercaria of C. formosanuspresented severe lesions associated with moderate to severe hyperplasia of cartilage of the primary lamellae, epithelial hyperplasia, gill hemorrhage, congestion, and disorting andinflammation around the metacercarial cyst. Gills infected with Dactylogyrussp. mainly expressed epithelial hyperplasia, inflammation and lamellae damage due to the mechanical effects of hooks and toxic secretions. I.multifiliis causinghyperplasia and hemorrhage was noted withfurther study needed to clarify the histopathology at different stage of cyst formation.
FACTORS INFLUENCING CONSUMPTION OFIMPORTEDAPPLES IN HANOI

Tran Quang Trung, Nguyen Bao Ly

Received: 08-12-2016 / Accepted: 11-09-2016
The aims of this research were to identify the factors affecting consumption of importedapplesin Hanoi. A random sample of 80 respondentsin Hanoi was selected to collect data on their consumption of importedapples. Methodologically, a statistical analysis was used to identify the preferences of consumers in purchasing importedapplesand the two-step econometric technique was applied to measure the effects of the socio-economic and characteristics of the market on consumption of importedapples in Hanoi. The integrating results from the two models showed thattheincome of the consumerhasstrongly positive effects onthe consumer’s decisions to buy and consume imported apples in Hanoi.Atalighter level, the age of the consumerand information about importedapplesalso have positive effects on the probability of importedapple purchasing.In contrast, the price of appleshas anegative effect on the consumer’s decision to buy imported apples.Finally, several implications of this study highlighted the contribution of the research to theory by enriching the body of literature and marketing perspective by showing the worthy bases for the government to develop the market and for imported apple tradersin making their business behaviors more consistent.
Molecular Characterizations of Porcine Epidemic Diarrhea Virus (PEDV) Isolated in Hung Yen Province

Nguyen Van Giap, Dang Huu Anh, Truong Ha Thai, Huynh Thi My Le

Received: 19-05-2020 / Accepted: 02-06-2020
Since the first detection in 2009, PEDV has been circulating in the North, Centre and the South of Vietnam. The disease has caused significant damages to the pig production sector. In order to mitigate the economic damage caused by diseases, the manufacture and use of field- matching vaccines are necessary. Aimed at providing more information on the biology of pathogenic PEDV strains in Vietnam, this study analyzed the molecular biology of the gene encoding S1 domain of one PEDV isolate detected in Hung Yen in 2017. The results showed that the field isolate, PEDV_HY2017, is genogroup G2 PEDV. The virus shared nucleotide similarity with PEDV strains of Vietnam in the ranges of 90-91% and 95.7-98.2% in compared to genogroup G1 and genogroup G2, respectively. The PEDV_HY2017 strain carries two regions of insertion-deletion mutations in the gene segment encoding the S1 domain of the Spike protein. This characteristic was similar to the other Vietnamese PEDV genogroup G2 viruses.
Effects of Housing Systems on Cortisol Concentration of The Gilfs Raised in Group

Nguyen Thi Phuong Giang, Han Quang Hanh, Vu Tien Viet Dung, Pham Kim Dang, Vu Dinh Ton

Received: 14-11-2016 / Accepted: 05-01-2017
The study was conducted to determine the effects of two housing systems on cortisol concentration of gilts. A total of 20 gilts F1 (Landrace x Yorkshire) gilts with similar body weight and age were randomly allotted into four pens of two group-housing systems (two pens with outdoor yards and the other two without yards, 5 gilts per pen). Saliva cortisol concentration on the days 1, 3, 7, 15, 30, 50, and 80 and plasma cortisol concentration on the days 1, 3, 15, 30,and50 of the gilts after grouping wasere determined by ELISA test and ECLIA (Electrochemiluminescence Immunoassay) using COBAS system, respectively. Results showed that there were no significant differencesin saliva and plasma cortisol concentration of the gilts between the two housing systems (P > 0.05). However, in each housing system, saliva cortisol concentrations on the days of grouping were significantly different (P < 0.05). Cortisol concentration of the gilts in both two housing systems waserehighest on the 1stday after grouping (0.58 µg/ dL in the pens with yard and 0.59 µg/ dL in ones without yard),; they weregradually decreased on the 3rdday (0.48 µg/ dL and 0.46 µg/ dL)and; then theywaserelowest and stable on the following days. Similarly, in each housing system, plasma cortisol concentration taken in the days 1, 3, 15, 30 and 50 after grouping were wassignificantly different from each other (P < 0.05). Plasma cortisol concentration waserehighest in the 1stday after mixing (7.38 µg/ dL in the pens with outdoor yard and 7.17 µg/ dL in the indoor pens), followed by the 3rdday (5.35 µg/ dL and 5.19 µg/ dL), then they were gradually decreased and stable in the following days. A positive correlation between plasma and saliva cortisol concentration was found (withr = 0.73).
The Role of Salicylic Acid (SA) on Salt Tolerance of Mungbean at Seedling Stage

Vu Tien Binh, Tran Anh Tuan, Pham Tuan Anh

Received: 03-01-2020 / Accepted: 26-05-2020
Experimentswereconducted in the Summer season of 2019 at the Experimental Station of the Faculty of Agronomy, Vietnam National University of Agriculture, to determine the effect of salicylic acid (0mM, 0.25mM and 0.50mM SA) on germination, physiology and yield of two mungbean varieties (DXVN5 and DXVN7) under salinity condition (50mM NaCl). In experiment 1, seeds of mungbean varieties were immersed in SA concentrations. After that, seeds were sown on a filter paper in the petri dish and NaCl solution was added for 7 days. In experiment 2, three-leaf plants were treated with NaCl solution for 7 days. And then, foliar spray of different SA concentrations was done. The results indicated that the germination rate was not affected by SA, but increased SA levels raised shoot and root length of seedlings, fresh weight of seedling and also increased enhancedin the plant height, leaf area, leaf relative water content, dry matter, SPAD index, yield components and individual yield in both of mungbean varieties under salt stress, while the ion leakage and proline content decreased with increasing SA concentration. At the SA level of 0.50mM showed better growth and recovery in both of varieties under salinity stress. The individual yield in of DXVN5 variety increased by 110.23% and DXVN7 variety increased by 118.77%.
Effects of Tea (Camellia Sinensis O. Kuntze) Seed Oil and Some Antioxidant Substances on the Change of Quality of Linseed Oil and Walnut Oil During Storage Time

Phan Thi Phuong Thao, Tran Thi Thu Hang, Vu Hong Son

Received: 24-02-2020 / Accepted: 17-04-2020
This study was conducted to evaluate the effectiveness of tea seed oil (TSO) compared with the addition of some antioxidant substancessuch as BHA, BHT, d-α-tocopherol during storagetime(at 60C for 12 days according to the Schaal experiment, 2010) for susceptible oils such as linseed oil (LSO) and walnut oil (WNO). Peroxide (PV) and Para-anisidine (P-av) values were monitored during oxidation of the two oils at 0and 12 days of storage. The Totox value has assessed the formation of LSO first and second oxidation products after 12 days of storage in the control and formula supplemented with 0.02% BHA + BHT, 0.03% tocopherol, 3% TSO, 6% TSO respectively 176.06; 139.3; 154.38; 138.34 and 110.31. In WNO, this value was 204.56 respectively; 173.12; 177.93; 170.46 and 154.29. In this study, TSO was shown to have higher potential than BHA, BHT, tocopherol when blended with 6% TSO. Blending 3% TSO had preservation effect as good as BHA + BHT at the concentrations of 0.0 2% and D-α-tocopherol at 0.03% in inhibiting the oxidation of LSO and WNO.
Biological Age Determination for Tomato cv'Savior' Grown in Spring-Summer Season by Modeling Approach

Tran Thi Dinh, Tran Thi LanHuong

Received: 15-10-2015 / Accepted: 11-03-2016
In the curent study, the biological age of tomato cv 'Savior' grown in spring summer season was determined using modeling approach. The model was calibrated based on two input variables: mass and fruit color changes during fruit development and ripening. The model was successfully validated using a single point estimation method. The data in this study canbe combined with the quality attributes at diferent physiological stages to calibrate the model for predicting the optimal harvest timeof tomato cv Savior in further research.
Promotion of Land Accumulation for Agricultural Production Development in Nam Dinh Province

Nguyen Tuan Son, Nguyen Anh Duc, Vu Thi My Hue

Received: 25-09-2019 / Accepted: 04-11-2019
TheprocessoflandaccumulationhasoccurredinNamDinhprovinceinrecentyears, in which farm production has dominated.This study focuses on analysing the situation of land accumlation for these farms in 3 districts namely Hai Hau, Truc Ninh, and Y Yen. Usingparticipatoryapproachmethod,thisstudycollectedinformationonsituation,andfactorsaffectinglandaccumulationprocessoflarge-andsmall-scalefarmsinNamDinhprovinceinrecenttimes.Thisstudyappliedconventionalstatisticalmethodstoanalysethesituationoflandaccumulationaccordingtothedifferentlandaccumulationmodelsandstakeholders.Basedonthesurveyresults,thepaperproposessomerecommendationstopromotelandaccumulationforagriculturalandaquaculturalproductionsinNamDinhprovince.
Knowledge, Attitude and Application of Safety Measures in Pesticide Use: A Case of Tea Farmers in Binh Thuan Commune, Dai Tu District, Thai Nguyen Province

Nguyen Thi Bich Yen, Nguyen Manh Duy

Received: 15-07-2019 / Accepted: 17-10-2019
This study aimed to assess the knowledge, attitudes and levels of application of safety measures in the use of pesticides by tea farmers. Primary data were collected by interviewing 60 tea farmers using a structured-questionnaire in Binh Thuan commune, Dai Tu district, Thai Nguyen province. The survey results showed that the tea farmers still hadlimited knowledge of toxicity groups of pesticides based on information on pesticide containers and how to treat pesticide containers after use. The tea farmers hada high level of interest in the harmful effects of pesticides on human health, but only on an average level of environmental damage, especially for natural enemiesbeneficial for crops. The research results also showed that people hadapplied relatively good safety measures in pesticide use, except still regularly poured the waterfrom washingpesticide sprayer into canals or ponds and occasionally discarded pesticide containers after use right on the tea farms where the pesticideswereprepared for spraying. The gender of the household heads, participation in training, area of agricultural landand household income from agriculturewere the factors affecting the knowledge, attitudes and levels of application of safety measures in pesticide use on tea farms.These results provide necessary information to local authorities and relevant organizations in deciding suitable pesticide management measures to protect the human health and the environment.
The Current Production of Ampelopsis cantoniensis(Hook. & Arn.) Planch(Vine Tea)in the Tu Commune,Dong Giang District, Quang Nam Province

Nguyen Ho Lam, Tran Phuong Dong, Pham Viet Tich, Le Hoang, Nguyen Tan Tuan

Received: 08-07-2019 / Accepted: 29-08-2019
The objective of this study was to clarify the current production, natural conditions, botanical characteristics, cultivation techniques, harvesting, processing, product preservation techniques, and consumption of the vine tea, Ampelopsis cantoniensis,in Tu commune, Dong Giang District, Quang Nam Province. Primary and secondary data were collected, analyzed and evaluated. The results indicated that the vine tea was mainly planted in autumn season from August to October with a density of 20,000 plants per hactare. Six to eight months after cultivation, the vines wereharvested for the first time. The vines can be harvested once a monthwith9-10 months each year, yielding about 6.0 tons of dryvineyields per hectare per year. In order to make thisvine tea become a local major commercial plant, it is necessary to focus on improving the commercial production and processing techniques. In addition, the vine tea production cooperativesof Tu commune and the local government authorities should promote large-scale production, monitor quality, establish a brand name and advertise the product.
Development of Submergence Tolerant Rice Lines for the Northern Region of Vietnam

Pham Van Tinh, Hoang Ba Tien, Tran Van Quang

Received: 14-03-2019 / Accepted: 07-05-2019
This study was carried out to evaluate agronomical characteristics, yield and submergence tolerance of inbredrice lines thathave been selected fromcross combinations betwwen purerice line and cultivars with lines carrying submergence tolerance gene Sub1. The field experiments were conducted at Gia Loc district, Hai Duong province. Out of 24 inbred lines, 6 promising ones selected possessed good characteristics,such as short growth duration, medium plantheight, short flagleaves, slight pestinfestation, high yield as well as with the high milled rice tohead riceratio, and low to moderate amylose content. Basedon PCR amplificationusing twoSSR primers SC3 and ART5, the resultsshowed that all lines carried the submergence gene Sub1. The most promising line,U1080,selected from the cross between TL6/and Swarna-Sub1 haddesirable growth duration, slight pest infestation, high yield and good eating quality. Thus,for the improvement of submergence tolerance, therice cultivars should be crossedwith the materialscarrying submergence tolerancegeneandindividuals selectionbe practicedin the segregatingpopulationfor furtherevaluation ofagronomical characteristics in both normal and flooding conditions.
Agronomical Characteristicsand Combining Ability of New Three-Line Hybrid Rice Parental Lines

Nguyen Xuan Quang, Nguyen Tuan Anh, Tran Van Quang

Received: 18-02-2019 / Accepted: 02-04-2019
This study was carried out to evaluate agronomical characteristicsand combining ability of the new three-line hybrid rice parental lines in NamDinh province.The results showed thattheparental lines hadshort growth duration(73-84 days for the female lines and 103-114 days for the male lines). Two female lines,S201AandS202A,and four male lines,R1, R2, R3, and R4 haddesirable agronomical characteristicssuitable forthree-line hybrid rice development. The female line S202A and male line R4showed good resistance to bacterial leaf blight disease. The new three-line hybrid combinations hadshort growth durationof which eight combinations showed yieldcomparable to the check variety. Especially, the hybrid S202A/R4 hadyied higher than the check varietyand good resistance to bacterial leaf blight disease. The parental lines with high general combining ability for yield wereS201A and S202A. Tthe male lines R1 and R2 showed good combining ability for 1000 grain weight and actual yield. The hybrids withhigh specific combining abilityfor yieldwere S203A/R2 and S204A/R4.
Changes of DevelopmentalIndices, Total Polyphenol Contents and Antioxidant Activities of Soybean and Mung Bean DuringGermination

Nguyen Van Lam, Nguyen Thi Thanh

Received: 01-01-2019 / Accepted: 05-03-2019
This study aimed to investigatethe effect of soaking temperature on germination and the effect of light exposure conditions and time on the polyphenol content and antioxidant activity of germinated soybean and mungbean seeds. Five soaking temperatures,viz. 25, 30, 35, 40,and 45C,were tested andseeds were germinated under dark and light conditions. Results showed that 30C was optimal for soaking as evidenced bythe highest germination rateandsprout length and weight. Polyphenol contents and antioxidant activities measured by Folin-ciocalteu and DPPH methods, respectively, showed thatpolyphenol content increased over time under both dark and light conditions, in which mung beans increased more significantly. Indark condition, the polyphenol of mung bean rised from 0.5 mg GAE/g DW in the original seeds to 4.9 mg GAE/g DW at 5thday, while this value of soybean increased from 1.0 mg GAE/g DW in the original seeds to 3.4 mg GAE/g DW at 5thday. The antioxidant activity also increased during germiation. The antioxidant activities of mung beans and soybeans were 0.12 and 1.3 mol TE/g DW, respectively, and these increased to 4.8 và 3.2 µmol TE/g DW at 5thdayunder dark condition.Germination resulted in an increase in polyphenol contents and antioxidant activities of the two beans.
Bacilluswith Potential Probiotic Properties from Chicken Intestine

Nguyen Thi Lam Doan, Nguyen Hoang Anh

Received: 18-07-2018 / Accepted: 30-08-2018
The aim of this study was to evaluate the probiotic potential of 60 Bacillus strains isolated from chichken intestine to produce probiotic preparation for use in the poultry industry. Three strains, RGB6.11, RGB7.1, and RGB8.8, were selected with good probiotic characteristics such as tolerance to low pH (pH 1.0; 2.0; 3.0) after 3 hrs culture, tolerance to 0.3% bile salt after 4 hrs culturing OD620nm >0.44, production of extracellular enzymes with ring diameter of substrate resolution from 13-21 mm, resistance to gastrointestinal pathogens Salmonella Typhimurium and Escherichia coli with zone of inhibition diameter 9-14mm, and good adhesion ability on chicken intestinal epithelium. Moreover, suitable cultural temperatures (30-40oC) and pH (6.5-7.0) for these strains were identified. The three Bacillus spp. strains were suggested for species identification and production of probiotics for the poultry industry.
Building Land Price Zone in Rural Areas: A Case Study of Duong Quang Commune, Gia Lam District, Hanoi City

Pham Sy Liem, Tran Van Tuan

Received: 29-06-2018 / Accepted: 30-10-2018
Land price zone in rural areas was built for two main types of land: agricultural land and rural residential land. The study used mass-appraisal method from the land price regression model combined with spatial interpolation analysis to calculate the continuous values for the whole study area. Land price data were collected through survey using current market price, while the impact factor data were measured from spatial data analysis. Rural residential land price model consisted of 9 variables with type of contiguous road, the distance to contiguous road and the distance to market as the main factors. Agricultural land price model consisted of 6 variables with the main factors of land use type, the distance to main road, and the distance to water source. Based on the above two models, land price zone was established for 10 different sub-areas of the study area.
Establishment ofthe Machine Model and BuildingaReasonable Working Mode for Windrow Straw Harvester

Nguyen Trong Minh, Bui Viet Duc

Received: 26-01-2018 / Accepted: 10-08-2018
Rice straw after harvest need to cut and dry before collection and storage. Large volume of rice straw to be handled in a short time requires mechanical operation. At present, the collection system was established, but the number, types and features remain limited and mainly used to collect straw after harvest. The article introduces the basis for the establishment and construction of a rational working mode of the windrow straw harvester. The machine system was designed on the basis of combining two-wheeled tractor power and rice harvesting device widely used today. With this solution, a windrow straw harvester can be quickly constructed with a reasonable working mode, meeting the practical requirements and raising the efficiency of agricultural production.
Changes in Total Phenolic, Carotenoid Contentsand Antoxidant Activity during Tomato Ripening

Nguyen Van Lam, Dao Thi Ngoc Mai

Received: 07-06-2018 / Accepted: 02-08-2018
This study aimed to determine the effect of ripeness on the accumulation of some bioactive compounds in Thuy Hong tomato cultivar to identify suitable time for harvest and consumption. Tomatoes were harvested at 5 ripening stages (RS) for analysis of bioactive compounds, in which phenolic contents and antioxidant activities were measured by Folin-ciocalteu and DPPH methods, respectively. During ripening, vitamin C content increased dramatically from 2.25 to 27.17 mg/100 g fresh weight (FW) from RS1 (green) to RS5 (red, soft). The accumulation of phenolic compounds increased significantly from RS1 to RS3 (light orange-yellow color), then almost unchanged to RS5. Carotenoid content rised intensely during ripening; At RS1 carotenoid content was 598.81 μg/100 g FW, and then increased of 12.6 times at RS5. Antioxidant activity increased dramatically from RS1 to RS3, then remained unchanged to RS5. This increase would be due to the accumulation of in phenolics and carotenoids during maturation. RS5 seems to be the suitable for consumption due to its high content of bioactive compounds.
Assessment of Genetic Diversity and Genetic Difference between Two RiChicken Lines and Other Chicken Breeds

Ngo Thi Kim Cuc, Nguyen Thanh Son

Received: 07-03-2018 / Accepted: 05-07-2018
This study aimedto assess genetic diversity and genetic difference between two Ri chicken lines and other chicken breeds using 15 microsatellitemarkers. The resultsshowed that genetic diversity of Ri hoa mo chicken and Ri vang rom chicken lines was 0,682 and 0,647, respectively. The inbreeding coefficientofRi hoa mo chicken and Ri vang rom chicken lines was 0.01 và 0.042, respectively. There was no genetic difference between Ri Hoa mo chicken and Ri vang rom chicken lines. However, the highestgenetic distance was found between Ri vang rom chicken and Luong Phuong chicken. The genetic dissimilaritiy among chicken populations was related to their geographical distribution. Ri hoa mo chicken and Ri vang rom chicken were in the same group while chicken populations from the northern part and the southern part showed genetic differentiation andseparatedfrom the Chinese breed.
Oestrus Inductionin Cows in Ba Vi District Using Viet Nam’s Progesterone Release (ProB)

Giang Hoang Ha, Pham Van Gioi, Su Thanh Long

Received: 06-07-2018 / Accepted: 08-09-2018
The study was performed to evulate the efficacy of “made-in Vietnam” progesterone releasing device in regulating the reproductive cycle of dairy herd in Bavi district, Hanoi, from February 2017 to November 2017. That applying of Ovsynch plus intravaginal device (ProB in the experimental group; CIDR® in the control group) resulted in high rate of estrus expression in both groups; especially during the period of 2-3 days post-treatment. In addition, the estrus rate according to BCS and parity of the cows was also assessed, which revealed that the cows with lower parity were more active with the protocol than those with higher parity (above 3th parity). It is also noted that the distribution of oestrus cows mainly concentrated on the BCS ranging from 2.75 to 3.0. With the feasible results of determinating the vaginal irritation as an effect of the devices, the authors tentatively recommended introducing ProB to dairy cows across the country.

326 - 350 of 500 items << < 9 10 11 12 13 14 15 16 17 18 > >>

Search

Advanced filters

Search Results