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Optimizing Technological Parameters for Pectin Extraction from Dragon Fruit Peels

Tran Thi Dinh

Received: 23-02-2016 / Accepted: 05-05-2016
The peelsof dragon fruit contain high pectin contentand can be utilizedto extract pectin. In this study, the factors influencing pectin extraction were optimized. The optimal conditions were citric acid solvent extractionatpH 3.5,particel size of d ≤ 1 mmandsolvent/dragon fruit peel rato of 34.23/1 (v/w), at temperature 85°C in 35 min. Under these conditions, the extraction yield reached 13.81%.
Identification of Fungi and Bacteria Causing Postharvest Decay on Litchi Fruit and Development of Control Measures

Ha Viet Cuong, Tran Thi Dinh

Received: 10-03-2016 / Accepted: 16-05-2016
Litchi (Litchi chinensis Sonn), a specialty fruit, has an appealing natural red color, high nutritional value, and pleasant flavour. However, it is highly perishable and has a very short postharvest life due to microbial decay. This study aimed to identify the microorganisms causing postharvest decay on litchi fruit and to develop the control measures to inactivate them in vitro. Results on artificial infection and DNA sequencing demonstrated that Gluconobacter oxydans and Lasiodiplodia pseudotheobromae are the major cause of post-harvest diseases on litchi. Results on development of control measure showed that carbendazim inhibited Gluconobacter oxydans better than Lasiodiplodia pseudotheobromae. Nano silver could completely inhibit Gluconobacter oxydans and Lasiodiplodia pseudotheobromae at 10 ppm and 15 ppm, respectively. In conclusion, nano-silver effectively controlled the growth of pathogens on litchi after harvest.
Status of Hard Clam Farming in Some Coastal Provinces of North and Northern Central Vietnam

Bui Dac Thuyet, Tran Van Dung

Received: 26-07-2013 / Accepted: 22-10-2013
Hard clam farming in coastal provinces of North and Northern Central Vietnam has notably developed since last decade and this activity generates high income source for farmers, improving socio-economic development of many local communities. However, many farms are facing with difficulties due to frequent occurrence of massive death of cultured clam, lack of capital and unstable market for clam product. This study, therefore, investigated status of hard clam farming in some coastal provinces of North and Northern Central Vietnam in order to provide basic information for building technical and management solutions, contributing to stable development of hard clam farming in Vietnam. The results showed that Thai Binh province has the highest hard clam farming areas as well as clam production (1,984 ha, 30,130 tons), followed by Nam Dinh (1,271 ha, 5,123 tons), Thanh Hoa (960 ha, 7,700 tons), Quang Ninh (1,271 ha, 5,123 tons), and Ha Tinh (200 ha, 2,800 tons). About 84.1% surveyed farmers reported that their farms had at least one time of massive death of cultured clam and only 15.9% surveyed farms did not suffer with massive hard clam death. Even though the massive death of cultured clam may happen at any time, it usually occurs from February to May each year. Most of surveyed farmers supposed that changes in temperature, salinity and the decline of water quality were the main reasons for massive hard clam death in recent years. Lack of capital and unstable market are main constraints that most farms encounter with and require support from the government.
Effect of Postharvest Treatment on Quality Changes of Longan CvHuong Chi during Cold Storage

Tran Thi Dinh, Nguyen Thi Quyen

Received: 17-09-2015 / Accepted: 01-12-2015
Longan (Dimocarpus longan) fruit is one of the most popular fruits in Viet Nam. However, postharvest pericarp browning and rapid decay limit the postharvest life of longan fruit. In the present study, the effect of different postharvest treatments on fruit quality was investigated. The incidence of microbial disease, browning index, weight loss, polyphenol content and other nutrional quality attributes were determined at harvest and 10, 20, 30, 35 days after storage. Results suggested that pericarp browning, microbial disease, and fruit quality deterioration could be better delayed compared to the control at 35 days after storage by dipping fruits in carbendazim 0.1%, followed by oxalic acid 4 mM, finally packed in polypropylene bag with 0.008% of relative perforation area and stored at 4 ±1oC and relative humidity of 95%.
Some Biological Characteristics of Isaria javanica(Frider. & Bally) Samsom & Hywel-Jones Distributing at Pu Mat National Park, Nghe An

Nguyen Thi Thuy, Nguyen Viet Tung, Tran Ngoc Lan, Thai Thi Ngoc Lam

Received: 06-01-2015 / Accepted: 22-07-2015
Field surveys of entomopathogenic fungi were carried out in Pu Mat National Park from 2011 to 2013. A total of 18 strains of Isaria javanica were collected, isolated and identified of which 6 strains infecting Lepidopteran larvae, 8 strains infecting Hymenopteran adults and 4 strains infecting spider adults. Specimens were found in the leaf litter with 66.67% and on the leaf underside with 33.33%. A white to ash gray powdery layer covers some parts or most of the host body. Conidiophores are vertical single or branching; phialides cylindrical basal part, thin neck, 8.4-14.2x2.2-2.8 µm in size; conidia fusiform, sometimes cylindrical, smooth-walled, hyaline then turning cream, light gray orash gray whenmature, 4.5-7.4x1.4-1.7 µm in size. Colonies on PDA at 25oC are relatively fast growing with diameter 23.14 mm after 9 days. The conidia appear on the 3rd day showing white colourand then turning cream and to light gray or ash gray at maturity.
In VitroHaploid Production by Anther Culture of Dong Du Mustard (Brassica juncea)

Nguyẽn Thanh Hải , Dang Thi Thanh Tam

Received: 13-10-2014 / Accepted: 22-07-2015
Androgenesis is a phenomenon in which microspores are made to bypass the sexual pathway and follow the sporophytic mode of development to generate new plants without the intervention of fertilization under in vitro conditions. Micorospore culture provides an ideal system, with a large, relatively uniform population of haploid cells, for use mutant selection, genetic transformation and in studies on the molecular mechanism of induction of androgenesis and embryogenesis. This paper aimed at establishing a protocol for anther microspore embryogenensis in traditional variety of Brassica juncea (Dong Du mustard). Five haploid lines was created from anther microspore culture. The results showed that, medium and plant growth regulator concentration had a pronounced effect on androgenic response in anther microspore cultures of Brassica juncea (Dong Du mustard). The medium B5 is the most suitable for morphogenesis of anther microspores culture. The highest percent of embryogenensis (2,33%) was obtained B5 medium supplemented with α-NAA 0,5 mg/l and Kinetin 1 mg/l. MS medium supplemented with IAA 0,5 mg/l, BA 0,5 mg/ l, 3% sugar and 8 g / l agar was capable of regenerating seedling from embryos. MS medium supplemented with 1,0 mg/l BA was optimal for shoot multiplication with a rate of 3.94 after four weeks. MS medium with 0,5 mg/l α-NAA was appropriate for root induction in terms of root number per shoot (6.54 root/shoot) and average length of root (3.68 cm) after three weeks.
Gene Expresssion of Cytokine and Toll-like Receptor Signaling molecule mRNA in Peripheral Blood Mononuclear Cells (PBMCs) from Pigs Co-infected with Porcine Reproductive and Respiratory Syndrome Virus and Porcine Circovirus

Dong Van Hieu, Phan Hong Dien, Tran Thi Huong Giang, Wen Bin Chung

Received: 18-03-2015 / Accepted: 18-05-2015
Field and experimental studies have shown that co-infection of PRRSV and PCV2 in pigs were quite common and thus the interactions between both viruses in the host might be critical to the pathogenesis of the disease. The exact interaction mechanisms are unknown and remained to be elucidated. In this study, the expression of cytokine mRNA as well as Toll like receptor signaling molecules associated with innate immunity in peripheral blood mononuclear cells (PBMCs) from pigs infected with PRRSV and/or PCV2 were investigated. Cytokine mRNA and TLR signaling molecule expression were determined by quantitative real-time polymerase chain reaction. Co-infection of pigs with PRRSV and PCV2 led to up-regulated expression of IL-1β and IL-10 mRNA and down-regulated expression of TNF-α and IL-6, IFN-α and IFN-β in PBMCs of pigs co-infected with PRRSV and PCV2. An increased expression of CD14 mRNA was noticed in pigs co-infected with PRRSV and PCV2. A down-regulated expression of IRF-1 and IRF-3 mRNA might also suppress the expression of IFNs that leads to the enhanced replication of PCV2 in pigs co-infected with PRRSV and PCV2.
Study on the Anti-bacterial Activity of EssentialOils from Perilla Leaves

Nguyen Thi Hoang Lan, Bui Quang Thuat, Le Danh Tuyen, Nguyen Thi Ngoc Duyen

Received: 26-08-2014 / Accepted: 10-03-2015
The experiment was carried out to examine the anti-bacterial effects of essential oil from perilla leaves on eight spoilage and food poisoning bacteria strains (Escherichia coli, Salmonella, Pseudomonas fluorescens, Pseudomonas aeruginosa VTCC-B-657, Bacillus cereus, Bacillus subtilis, Staphylococcus aureus, Streptococcus feacium). The results indicated that perilla essential oil had anti-bacterial effects against all the above bacterial strains, except P. aeruginosa. The effect of perilla essential oil on gram-positive bacteria was stronger than that on gram-negative bacteria. The pure essential oil completely inhibited four strains of gram-positive bacteria, including Bacillus cereus, Bacillus subtilis, Staphylococcus aureus and Streptococcus feacium, and one strain of gram-negative bacteria, namely P. fluorescens. The Minimum Inhibitory Concentration (MIC) was more than 8192 µg/ml for both Escherichia coli and Salmonella and from 1024 µg/ml to 4096 µg/ml for the other five studied strains.
Learner Profile Model –A Whole Approach

Phan Thi Thu Hong, Nguyen Van Hoang

Received: 04-10-2013 / Accepted: 22-12-2013
An intelligent learning environment (ILE) can adapt the educational interaction to the specific needs of the individual learner according to learner profile. Learner profile is all information which the system holds about the learner. The learner profile also provides guidances and supports to teachers and the assessment systems. Therefore, learner profile has become an interesting field in e-learning researches. The main problems in learner profile researches are how to choose a good learner profile model (or what information should be stored?) and what is a good representation of learner profile for a specific user in a specific context? In this paper, we first review some e-learning systems and related papers to identify a good viewpoint which allow us to identify information which is needed in a learner profile. We then propose a learner profile model based on that view and how to present the information in the learner profile.
Experimental Method to Identify the Pull-Grip Characteristics of the Moving Chain Parts

Dao Huu Doan, Nguyen Ngoc Que, Nong van Vin, Pham Thi Thu Hang

Received: 17-09-2013 / Accepted: 20-12-2013
The pull-griping characteristics of the moving chain parts are the most important economical determinant of tractor. These characteristics are also used to determine the completeness of the structure in designing and manufacturing tractor. Studying the pull-griping characteristics of the moving chain parts based on the theory of the chain-soil relationship provides reliable results because of the complexity of the interaction between the moving chain parts and soil. Therefore, only experimental methods can yields quantitative results. The present paper described the experimental methods to identify the pull-griping characteristics of the moving chain parts on the field.
Current Status of Coffee Cultivation and Production Efficiency on Basaltic Soils in Krong Nang District, Dak Lak Province

Pham The Trinh, Phan Xuan Linh, Dao Chau Thu, Tran Minh Tien

Received: 07-06-2013 / Accepted: 27-08-2013
Coffee production plays an important role in the economic structure of Krong Nang district. Total area of coffee production in Krong Nang district amounts to 26,013 ha, of which 25,662 ha are in the harvesting period, accounting for 13.45% of total area under coffee in Dak Lak province. More than 80% coffee acreage in the district is cultivated on basaltic soils and coffee is considered as the highest economic crop in Krong Nang district. Survey results showed that the coffee farming households could be divided into three groups: the high economic efficiency group occupied around 20% total surveyed households with average coffee yield of 4.3 tons per ha and net profit of VND 99.91 million per ha; the medium and low economic efficiency groups ocupied 44% and 36% of total surveyed households, with yield of 3.05 tons and 1.85 tons per ha, and profit of 69.8 million VND and 37.34 million VND per ha per year, respectively.
Sorption Isotherm Curve of Freeze Dried Salmon Product

Nguyen Xuan Duy, Nguyen Anh Tuan

Received: 28-11-2012 / Accepted: 03-01-2013
Sorption isotherm curve of freeze dried (FD) product was investigated at 20oC, 30oC, and 40oC. Experimental data obtained were verified by eight mathematical models including BET, Bradley, GAB, Halsey, Henderson, Kühn, Mizrahi, and Oswin. Eight models agreed well with experimental data (R2= 0.9374-1,0000) when water activity (Aw) varied from 0.12 to 0.43. However, when Aw is extended ranging from 0.12 to 0.93, only four models named as GAB, Kühn, Halsey and Oswin still show a good agreement with the experimental data. These models can be used in predicting water absorption of FD salmon product at 20oC, 30oC, and 40oC withacorrelation coefficient (R2) ranged from 0.9776-0.9917, 0.9867-0.9991, 0.9821-0.9920 and 0.9464-0.9995, respectively. Errors between experimental and calculated data from the four models were 5.1%, 4.9%, 8.7% and 9.4%, respectively. Water monolayer value is determined at approximately 5%.
Analyzing Causes of Failurein Contract Farming Enforcement betweenFarmer and Entrepreneur in Vietnam

Tran Quoc Nhan, Ikuo Takeuchi

Received: 08-10-2012 / Accepted: 20-12-2012
This paperreviewedresults of empirical studies of contract farmingin Vietnam and other countries. The study aimedat clarifying the conceptsof contract farming, advantagesand disadvantagesof contract farming and as well as analyzingfactors affecting contract enforcement in Vietnam. The results showedthat farm products trading under the contract between farmers and entrepreneurs in Vietnambasically has similar characteristicwith contract farming in other countries.It can be indicated that there are five models of contract farming arrangements existing in Vietnam including centralised model, nucleus estate model, multipartile model, informal model and intermediary model. Factors related to contracting context such as weakinstitutionalization of contract enforcement, market price uncertainty, low and undiversified benefits of contractand “weak market pressure”areconsidered as critical factors stronglyaffecting week enforcement ofcontract between farmers and enterprises in Vietnam.
Functional Roleof Mould Strains in Production of Rice Wine

Nguyen Ngoc Hoa, Dang Xuan Nghiem

Received: 07-03-2012 / Accepted: 17-05-2012
This investigation on the possible role of mould in production of traditional rice wine was carried out with the 4 candidate mould strains which were selected from 21 mould strains isolated from traditional rice wine starters and traditional soysauce starters. The 4 mould strains were preliminarily identified and named as M3 (Rhizopus spp.), M10 (Rhizopus spp.), M16 (Aspergillus oryzae), and M18 (Endomycopsisfibuliger). M10, M16 and M18 strains expressed very strong extracellular enzyme activities (amylase, protease, cellulase), while M3 strain had weak extracellular protease and cellulase activity and no extracellular amylase. Noteably, the yield of rice wine of the traditional alcoholic fermentation was not increased when large amounts of the biomass of the 4 isolated mould strains were added. There was a strong correlation between the pH of fermention liquid and the final yield of wine. The lower the pH of fermentation liquid was, the lower the yield of wine. Moreover, all 4 mould strains were determined to have no role in the formation of aldehyde, methanol and higher alcohol in rice wine products.
Methods for Findings Single Nucleotide Polymorphisms

Nguyen Van Dinh, Pham Ha Thuy

Received: 05-01-2012 / Accepted: 15-05-2012
Single nucleotide polymorphism (SNP), one of the most popular variant of the DNA of the organism. The SNP studies have important roles in biological research, gene mapping, selected animals and plants. The contents of the article presents an overview of SNP detection methods are now widely used around the world.
Using Formulated Diets for Growth-Out Trial of Bragid Catfish (Mystus nemurus) in Cages in Reservoir at Yen Thanh District, Nghe An Province

Nguyen Quang Huy, Nguyen Thi Hong Tham, Tran Minh Hieu, Nguyen Duong Duc, Phan Gia Thanh, Tong Hoai Nam

Received: 28-03-2012 / Accepted: 25-05-2012
Four isoenergic feed pellets of different protein and lipid levels, namely D1 (35% Pr, 10% L), D2 (42% Pr, 10% L), D3 (42% Pr, 5% L) and D4 (35% Pr, 5% L), were used to investigate the growth of bagrid catfish Mystus nemurus in cages breed in water reservoir in Yen Thanh, Nghe An. Experimental fish of initial size of 47.0 ± 1.2 g were fed twice a day to satiation in 85 days. Fish fed on diet D2 which contained the highest protein and lipid levels showed the best growth rate and the lowest feed conversion ratio (P <0.05). Fish fed on D4 diet with the lowest in protein and lipid content yielded the lowest growth rate and protein efficiency ratio and the highest feed conversion ratio (P <0.05). Fish fed on diet D3 gave similar growth rate, protein efficiency ratio to those fed on diet D1 but had a lower feed conversion ratio (P <0.05). Survival rates of fish from all feed treatments were high (93.0-96.0%) and no significant difference was found among treatments. Based on these results, diet D2 (42 % protein and 10 % lipid) was recomended for maximizing growth rate and feed utilization of Mystus nemurus.
Research and Apply Automatic Submerged Arc Welding Technology to Weld Q345B High-Strength Low-Alloy Steel

Nguyen Huu Huong, Tong Ngoc Tuan

Received: 04-07-2016 / Accepted: 25-12-2016
Based oOn the currentavailableequipments, constructing an experimental model combining with equipment system, attachment and automatic submerged arc welding machine to weld Q345B high-strength low-alloy (HSLA) steel with T-letter shapedjointwith,a thickness of plates isof5 mm and 8 mm,respectively. Based on theoretic research into on automatic submerged arc welding technology, experimental welding,using design ofexperimental designsand,data processing were performed to find out parameters of for welding conditions to serve welding process of Q345B steel. Through the initial survey,fix somewith constantparameters and experimental welding with about input parameterintervals and evaluating output parameters, determining the followingparameters of welding conditionswere determined: welding current Ih≈ 440 Aand,welding speed Vh≈ 19,.6 m/h. With parameters of welding conditions that were determined,combining with technological elementsand specific structure, T-letterjoint that was weldinged toensureproducedgood form, dimension and quality.
Vietnamese Consumers’ Awareness of Organic Foods: A Case Study in Hanoi City

Ngo Minh Hai, Vu Quynh Hoa

Received: 02-07-2016 / Accepted: 22-09-2016
Expanding the market share of organic foods faces many difficulties in developing countries like Vietnam. One of the most important reasons is inadequate perception of organic foods due to limited information. The study examined Vietnamese consumers’ perception, and identified factors affecting the awareness of organic foods in the country. We interviewed 203 consumers randomly chosen at big supermarkets in Hanoi city. Through using descriptive statistics and applying ordered logit model, our study showed that only about 10% of the consumers had adequate awareness of organic food, while a half only heard of it but did not understand about organic term. Forty percent of remaining people have never heard of organic foods. Specific factors affecting the Vietnamese consumers’’ perception of organic foodare the product origin/label, food safetyevaluation and consumers’, education, age and occupatio.
Numerical Simulation of Hydroforming Process for Thin Products

Nguyen Thi Thu Trang

Received: 25-01-2016 / Accepted: 12-07-2016
Metal forming is a basic mechanical industry. It allows the manufacturingproducts with complex shapes and size.Hydroforming process is a special drawing method. In the last years, this method is often used for forming of thin products with complicated geometry in the airplane and automotive manufature, because it hasmany advantages compared with conventional deep drawing process. Nevertheless, at present in Vietnam the hydroforming design islargelybased on the experience.In this paper, the author apply software Eta/Dynaform for simulation ò the hydroforming process of thin product to optimeze the deep drawing hydroforming process.
RestoringShaft of Stone Sawing Machine Using Build- Up Welding Method

Tong Ngoc Tuan, Le Van Tuan

Received: 04-04-2015 / Accepted: 12-07-2016
The shaft of stone sawing machine in working process often occurs faulty. Common form of fault is the wornnessover limited dimension at the center shaft. One of the methods that brings high efficiency andmeeting in time for manufacturing might berestoration of theshaft using build- up welding methodtoachieve the desired dimension. Based on theoreticalresearch onwelding technology, shielded metal arc welding for building- up weldwas selected. This is one of the methods that can be easily usedwith availableequipments. Equipmentselection, welding condition, manufacturing process, manufacturingcondition, andqualityevaluation were done to ensuregood operation after machine assemblage. Different equipmentswere used to test the shaft forroughnessandhardnessand the shaft quality was checked by operation trials. Fivesamples wereselected forrestoration and quality evaluation. Relying on all evaluating methods, all shafts have good quality.
Technical Advances in Reproduction: Applications in Medicine and Agriculture

Nguyen Van Thuan

Received: 18-04-2017 / Accepted: 26-07-2017
In mammals, reproduction is the ability to generate next generation through the fertilization of a mature egg and a sperm. Nowadays, with the development of modern reproductive biotechnology, several advanced techniques have been applied and able to generate new generations from somatic cellsandstem cells or from immature eggs and sperms. In the present paper, the advances in reproduction over the past 20 yearsare sumarized and presented including: (1) intracytoplasmic sperm injection (ICSI) and application of this method to treat infertility and production of transgenic animals, (2) round spermatid injection (ROSI) and itsapplication on treatment of infertility without spermatozoa, (3) Somatic cell nuclear transfer (SCNT), also known as animal cloning, and (4) the method to generate new generation by pluripotent stem cells injected into tetraploid blastocysts.The application potential of the modern reproductive methods in medicine and agriculturewas discussed.
Experimental Rearing of Common Carp (Cyprinus carpio) Fingerlings using Biofloc Technology with Carbohydrate Source from Molasses and Corn Starch

Do Dang Khoa, Nguyen Tuan Duy, Kim Van Van, Thai Thanh Binh

Received: 05-04-2022 / Accepted: 15-08-2022
This study was conducted to investigate the water quality, growth, survival rates and feed conversion ratio (FCR) when rearing common carp (Cyprinus carpio) fingerlings by using biofloc technology (BFT) with carbohydrate source from molasses (RĐ)and corn starch (BN). Common carp fingerlings (33.5 ± 1.15 g/fish) were randomly stocked in 9 tanks (267 l/tank) at a density of 150 fish/m3(40 fish/tank) with three experiments: experiment 1 (BFT-RĐ) and experiment 2 (BFT-BN) were reared in biofloc system with molasses and corn starch, respectively, as a carbon source with C:N ratio of 20:1, whereas the control experiment (ĐC) was reared at similar intensity without biofloc technology and exchange 50% water/day. Fish was fed on demand with 35% protein diet. The result showed that after 60 days rearing water quality in BFT-RĐ was maintained better than that in BFT-BN and the control. The survival rate (98.33± 1.44%) and average daily weight gain (0.69 ± 0.05 g/fish/day)of common carp in BFT-RĐwere highest in BFT-RĐ (P <0.05)compared with the other treatments. Common carp in BFT-RĐ had the lowest FCR (1.53 ± 0.02) (P <0.05) comparedto BFT-BN (1.58 ± 0.02) and the control (1.73 ± 0.03).
Study on Extraction and Separation of Anthocyanin from Hibiscus Sabdariffa Calyx. Application to Produce the Rapid Indicator Paper of Detecting the Borax in Food

Nguyen Thi Hien, Nguyen Thi Thanh Thuy, Nguyen Thi Loan

Received: 29-05-2012 / Accepted: 12-08-2012
The extraction and purification of anthocyanin pigments from calyx of Hibiscus sabdariffa, and its use as potential rapid indicator paper for detecting the borax in food were investigated. By using the colour comparison and the differential pH methods, the optimal conditions for pigment extraction were identified as follows: ethanol solvent to water is 50:50 with supplement 1% HCl; the ratio of solvent per raw-material is 14 ml/1g; extracting duration is 6 days. By fractional extraction method, the crude anthocyanin pigments are isolated from extracts of Hibiscus calyx. The concentration of pigments in the dry and fresh material was 15.2% and 1.06%, respectively. The acidity of the dry ingredients is 3.37 mldH+ /1g of raw material, the acidity of the dry pigment is 3.83 mldH+/1g of colour substance, respectively 0.58 mldH+ /1g dry material and the acid reduced 83%. By surveying several conditions for production of the indicator paper, the appropriate parameters are selected with color dilution of 1gram of dry colour substance to 400ml distilled water ratio; duration of color impregnated on paper is 120 seconds; the duration of indicator paper exposure to food (or food fluid) is 90 seconds. A minimum level of the indicator paper for detecting the borax is identified as 40 mg/1 kg of food. This result has shown that the minimum detectable limit is equivalent to turmeric paper. As for sensitivity, when testing on a number of food materials, the similar results were also been obtained.
Study on Efficiency of Agricultural Land Use in Nghi Truong Commune, Nghi Loc District, Nghe An Province

Do Thi Tam, Nguyen Thi Hai

Received: 24-04-2013 / Accepted: 20-06-2013
In the study, random sampling method is used by selecting 90 households from three hamlets to analyze the efficiency of crops, cropping systems and some land use types (LUTs) in Nghi Truong commune. Currently, there are 5 LUTs and 15 land utilazation types. Fruit LUT has the lowest economic efficiency with a added value of 15.55 mil.VND per hectare which is only 0,08 times as high as that of Aquaculture LUT and 0,25 times as high as that of paddy rice–upland crops LUT. Aquaculture LUT has the highest economic efficiency with a added value of 188.95 mil. VND per hectare which is 8.5 times as high as that of paddy rice LUT and 3 times as high as that of paddy rice–upland crops LUT. Some land utilazation types which require high labor investment and added value are fish and watermelon - winter rice – vegetables. The ratio of N:P:K fertilizer used for crops was unbalanced compared to the standard. Most types of pesticides were used with excessive levels in comparison with the instructions on their packs.
Optimization of Herbal Supplements in Broilers Diet for Decreasing Total Cholesterol in Blood Plasma of Chicken by using Response Surface Methodology

Ha Xuan Bo, Vu Viet Anh, Dang Thuy Nhung

Received: 16-11-2021 / Accepted: 01-03-2022
This study was conducted to optimize the levels mixed herbal supplements in broilers diet for decreasing total cholesterol in blood plasma of chicken at 8 and 16 weeks of age. Six herbals supplements, garlic (Allium sativum), Chinese wedelia (Sphagneticola calendulacea), perilla (Perilla fruitescens var. crispa), turmeric (Curcuma longa), ginger (Zingiber officinale), and green tea (Camellia sinensis) were supplemented in the diet. A total of 126 male Dong Tao chickens were raised in animal farm of Vietnam National University of Agriculture from April 2021 to September 2021. This study was designed in two experiments: 1) Plackett-Burman matrix was designed to study the factors that affect total cholesterol content, 2) Response surface method (RSM) with central composite design (CCD) matrix was designed to optimize the levels mixed herbal supplements in diet. Garlic, turmeric, ginger, and green tea that have significantly contributed to total cholesterol in blood plasma was selected to design a matrix for modeling optimal point. The result of response surface method (RSM) with central composite design (CCD) showed the minimum value of total cholesterol 2.80 mmol/l (8 weeks of age) and 2.70 mmol/l (16 weeks of age) with level supplement of garlic (0.833 and 0.882 g/kg), turmeric (0.420 and 0.441 g/kg), ginger (1.411 and 5.400 g/kg), and green tea (5.221 and 6.215 g/kg), respectively. The lowest value of total cholesterol in the practical model was 2.80 mmol/l and 2.70 mmol/l.

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