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Vertical Oscillation Model of Sowing Machine Combined with Fertilization for Soybean

Nguyen Chung Thong, Le Minh Lu, Nguyen Xuan Thiet, Nguyen Thi Hanh Nguyen

Received: 10-08-2020 / Accepted: 23-02-2021
This study presents the result of building the vertical oscillation model of the conjugate machine (sowing machine combined with fertilization for soybean (G4B2 machine) and tractor). The fluctuations of special points on the conjugate machine are described graphically through numerical methods by Matlab software when the parameters of the stimulus function change, in two cases: the continuous stimulating function and the single stimulating function cosine form. The tractor has a four-link hinge knuckle at the back, when working in the free state, the G4B2 machine oscillation affected by tractor oscillation is very small. The point near the wheel of the G4B2 machine has a smaller amplitude of oscillation than the remote point.It is necessary to decrease the feeding speed when combining the machine through the rough ground with large amplitude (h0 > 0.15m) and small steps (S0 < 1.0m).
Effects of Tumeric Powder as a Dietary Supplementon the Performance and Immunityof Weaned Piglets

Cu Thi Thien Thu, Dam Thi Dung

Received: 24-08-2020 / Accepted: 07-12-2020
The study was conducted to evaluate the effects of turmeric powder in the diet on the growth performance, diarrhea rate and some immune parameters of weaned piglets. The study was performed on 60 weaned piglets of Duroc x (Yorkshire x Landrace) hybrid. The animals were divided into 4 completely randomized groups: control group (ĐC) used only the basal diet, no turmeric powder added, and experimental group 1 (TN1) used basal diet added 0.1% turmeric powder (1g turmeric powder/kg food) turmeric powder, experimental group 2 (TN2) used the basal diet supplemented with 0.3% turmeric powder and experiment 3 (TN3) used the basal diet with 0.5% turmeric powder supplementation. After 4 weeks of testing, the results showed that the final body weight of pigs in group TN3 with turmeric powder supplemented at 0.5% was heavier than that in groups TN1 and TN2 using turmeric powder at 1 and 0.3%, respectively. The supplementation of turmeric powder to the diet significantly reduced diarrhea rate of weaned piglets (P <0.05). The study results also showed that turmeric powder in the diet did not affect on feed intake and serum IgA, IgG, Interferon antibody concentration.
Effects of adding chicken egg yolk and caffeine in extender on the quality of goat semen

Ngo Thanh Trung, Tran Thi Chi, Vu Hai Yen, Nguyen Tuan Dung, Trinh Thi Linh Chi, Su Thanh Long

Received: 25-05-2020 / Accepted: 12-09-2020
The aims of this study were to assess the effects of adding chicken egg yolk and caffeine in TCG (Tris-Citrate-Glucose) extender on the quality of goat semen preserved some goat breeds in Vietnam. Semen samples of 9 bucks belonging to 3 goat breeds, including Saanen, Boer and Alpine, (3 bucks/breed) were collected using artificial vagina, then diluted at a ratio of 1:10 with TCG extender added 0%, 5%, 10%, 15%, and 20% chicken egg yolk and 0,02; 0,03 and 0,04g caffeine/l. The diluted semen samples were preserved at 5 and 15C, respectively. The sperm motility and sperm morphological parameters of the preserved semen samples were assessed and compared after 24h, 72h, and 120h of preservation. Results showed that addition of 0,03g caffeine/l in TCG extender gave a better quality of preserved goat semen at both temperatures. At 5C, TCG extender added 10% of chicken egg yolk gave a better quality of preserved goat semen and could be used for artificial insemination after 72h of preservation. At 15C, TCG extender added 15% of chicken egg yolk resulted in a better quality of preserved goat semen and could be used for artificial insemination after 24h of preservation.
Effects of Microbial Fermented Litter and Perches on Welfare and Growth Performances of Colored Broilers

Nguyen Cong Oanh, Han Quang Hanh, Nguyen Dinh Tien, Nguyen Thi Phuong, Vu Dinh Ton

Received: 18-08-2020 / Accepted: 14-09-2020
Effects of microbial fermented litter and perches on the welfare quality and growth performance were studied in colored broiler. A total of 360 broiler chickens (Ho × Luong Phuong) at four- weeks- old were housed in 4 treatment groups, 30 broilers per group and 3 replication pens, under semi-commercial conditions over 9 weeks. Birds were housed in one of 4 treatment groups including the control group (DC, chickens raising under rice husk bedding), TN1 (DC + bamboo perches), TN2 (DC + microbial fermented litter), and TN3 (combined both TN1 and TN2). The weight of bird individuals from pens was recorded weekly for performance assessment. At the end of the experiment, bird individuals from pens were held and kept for assessment of comb scratches, plumage cleanliness, hock burns, footpad dermatitis, and breast deformities. Results showed that the birds housed with TN1 and TN3 groups had a greater proportion of plumage cleanliness, crooked breast and a lower proportion of comb scratches compared to birds with DC and TN2 groups (P <0.05). Treatments did not significantly affect hock burns and footpad dermatitis (P >0.05). In addition, the treatment groups had no significant effect on parameters such as mortality rates, growth performances, and feed conversion ratio (P >0.05). It was concluded that colored broilers housed in pens supplemented withbamboo perches and both bamboo perches and fermented microbial litter under semi-commercial conditions have the potential of improving animal welfare without positive effects on the performance.
Influence of Nitrogen Fertilizer Rate on the Growth and Yield of Ly Son Garlic (Allium sativumL.) Plants in Sandy Soil at Quang Dien Commune, Thua Thien Hue Province

Phung Thi Bich Hoa, Pham Thanh

Received: 26-02-2020 / Accepted: 22-06-2020
Ly Son garlic (Allium sativumL.) is a high economic value crop. This is one of the first reports to evaluate the effect of nitrogen fertilizer application rate on the growth, development and yield of Ly Son garlic grown on the sandy soil inThua Thien Hue, Viet Nam. Four nitrogen fertilizer levelwere selected and tested in this study: 230kg N ha-1, 55kg N ha-1, 115kg N ha-1, 165kg N ha-1. Theresults showed that A. sativumwas suitable for growing and developing under the natural conditions of Thua Thien Hue. The growing duration of A. sativumranged from 120 to 145 days. Furthermore, the traditional fertilizer dosage (230kg N ha-1) gave the lowest yield;while, the nitrogen fertilizer level of 115kg N ha-1was the best treatment,which resulted inhigh yield and good growth in terms ofthe number of leaves per plant (6.1 leaves), pseudostem height (12.1cm), the weight of fresh bulb (5.73g), the weight of dry-bulb (0.45g) and the yield of A. sativum(6.03 t/ha), respectively. This result also demonstrated that the agro-biological characteristics, yield parameters such as bulb diameter and length, number of cloves per bulb of A. sativumplanted in that area have not been different comparing with the originally planted garlic grown in the areas of Ly Son, Quang Ngai province.
Free Vibration Analysis of Functionally Graded Porous Circular Cylindrical Shell Based on the first Shear Deformation Theory

Duong Thanh Huan, Tran Huu Quoc, Ho Thi Hien

Received: 14-04-2020 / Accepted: 20-07-2020
In this paper, an analytical solution based on the first-order shear deformation theory (FSDT) is used for the free vibration analysis of the circular cylindrical shell made of porous materials. The cylindrical shell is simply supported at two ends. The elasticity moduli and mass density of porous materials are assumed to be graded in the thickness direction according to symmetric distribution types. Based on Hamilton’s principle, the equations of motion are derived. To verify the reliability of the present solution, the comparisons between the obtained results and the availably published literature are performed for the isotropic cylindrical shell, and very good agreement is observed. The effect of porosity coefficient and geometrical parameters on natural frequencies of the shell are also investigated and discussed in details.
Dynamic Analysis of Functionally Graded Spherical Panel in Thermal Environment by Finite Element Method

Duong Thanh Huan

Received: 26-12-2019 / Accepted: 14-02-2020
In this study, based on the first shear deformation theory (FSDT),a finite element model using a 3D-Degenerated shell element is developed for dynamic analysis of functionally graded spherical shell panel in the thermal environment. The modulus of elasticity is assumed to be temperature-dependent and graded in the thickness direction according to the simple power-law distribution,while the Poisson factor is assumed to be constant and the temperature is assumed to be nonlinear variation in the thickness direction. The numerical results are also compared with the results available in the literature to validate the present model. On the other hand, the effect of material parameters, geometric dimensions, boundary conditions; damping factor; ratio of forced frequency/natural frequency (ratio Ω/) on the dynamic behavior of FG spherical shell panel in the thermal environment are also investigated in detail and some useful conclusions are drawn.
Design and Manufacture Some Main Details of Metal Bending Machine

Nguyen Thi Thu Trang, Nguyen Ngoc Cuong, Nguyen Huu Huong

Received: 10-12-2019 / Accepted: 11-02-2019
Metal bending machine is a research result based on existing equipment and the use of engineering design software combined withtheexperimental works. Fabrication of this machine aimsto process many different types of parts from sheet metal billet by folding bending method. It can easily change of mold size and shapeaccording to the detailed machining requirements. The principle of deformation process is to use the punch and die to bend the blank of the sheet to create angles for the part. Bending machines are suitable for small production facilities or for practical training for students in mechanical technical training institutions. The technological parameters of the machine are calculated and selected based on the scope of the research and the purpose of processing detailed deformation.
Assessing Eutrophic Status and Environmental Factor Regulating Green Algae Community in Tri An Reservoir

Tran Thi Hoang Yen, Le Thi Luom, Pham Thanh Luu

Received: 24-07-2019 / Accepted: 24-10-2019
This study aimed to describe the eutrophication status and investigate the main environmental variables driving on the structure of the green algae communities in Tri An reservoir. Samples were monthly collected at 6 stations from March 2016 to February 2017. Eutrophication status was assessed by using the Trophic State Index (TSI). The correlation between green algae communities and environmental parameters was determined by Canonical Correspondence Analysis (CCA). A total of 98 species classified into 31 genera, 16 families, 6 orders, 4 phylawere recorded with a clear dominance of Staurastrumand Scenedesmus. Results of TSI index indicated that water quality in Tri An reservoir was classified as eutrophic to hypertrophic states. The CCA analysis showed that the green algae community was influenced by multivariate factors such as NO3-, PO43-, total P, total N, DO and turbidity. The TSI indexreflected well for eutrophic condition and could be used as a potential application for bio-monitoring of surface water.
Effect of Planting Density and Fertilizer Level on Growth and Yield of the Potato Variety KT4 in Thanh Tri, Hanoi

Nguyen Thi Thu Huong, Tran Thi Thiem

Received: 26-08-2019 / Accepted: 10-10-2019
This study was conducted to evaluate the effects of planting density and fertilizer level on the growth and yield of the potato variety KT4 grown in Thanh Tri, Hanoi. The field experiment was a split-plot designwith three replications. Plant density was main factor with3 levels: 4 tubers/m2(M1), 5 tubers/m2(M2) and 6 tubers/m2(M3); the sub-factor consisted of three fertilizer levels(kg/ha): 120N: 120P2O5: 120K2O (P1); 150N: 150P2O5: 150K2O (P2); 180N: 180P2O5: 180K2O (P3). Theresults showed that there weresignificant differences(P≤0.05)in plant height, leaf area index, dry matter, yield components and tuber yield when plant density increased from M1 to M2 and fertilizer application level increased from P1 to P2. However,there was no significant differencesin the above parameters between M1 and M2 as well as between P2 and P3. In addition, the effect of interaction between plant density and fertilizer level was significant for tuber yield. The highest tuber yield (26.21-27.44 tons per ha-1)was found at M2 and M3 density combining with P2 and P3 fertilizer leves.
Design and ManufactureofMini-Stamping Machine with Compressed Air for Deformmation of Sheet Metal

Nguyen Thi Thu Trang, Nguyen Huu Huong

Received: 28-11-2018 / Accepted: 20-02-2019
A mini-stamping machine model using compressed air was designed on the basis of the existing equipment and technical design softwares combined with the results of calculations. The machine model is intended for use in training andscientific research. Technological parameters of the machine were calculated, determined and selected based on the shape, size and materials of the parts to be manufuctered. Mini stamping machine using compressed air can be fabricated in variable types of parts thanks to the quick, convenient structure and shape change of the forming machine. Based on the design drawings, the parts and part cluster were manufactured and assembled into a complete machine model and applied to the processing of sheet metal forming.
Design and Manufacture ofDrying Mixer in the Production of Organic FertilizerandOrganic Microbial Fertilizerfrom Poultry Manure

Hoang Xuan Anh, Tong Ngoc Tuan, Nguyen Huu Huong

Received: 13-11-2018 / Accepted: 05-03-2019
At present, for the rapid drying of poultry manure, high price drying mixer must beimported. Thus, design and manufacture of a small size dryer are required to produce organic fertilizer from poultry manure and to reduce poultry manure processing time, improve the quality of organic fertilizer, reduce investment and production costs, and reduce environmental pollution. Combining theoretical and experimental research and using graphic design software such as SolidWorks, AutoCAD, and Inventor were employed to select the structure, operating principles and specification of technical parameters and to test working performance of themixer. Drying machine with the capacity of 500kg/batch was of lightweight structure and easy to manufacture and install, operate and clean. The machine was of low cost, suitable for processing poultry manure into organic/microbial fertilizers and for drying various types of livestock wastes. In addition to the poultry manure processing, the machine can be used for drying or mixing complete feeds from ground raw materials of naturally-derived or concentrate feeds with locally available ingredients.
Effect of Chitosan Concentrationson the Quality and Shelf Life ofThach That PersimmonFruits

Nguyen Thi Hanh

Received: 24-05-2024 / Accepted: 18-01-2019 / Published: 31-05-2024
The objective of this study was to identìythe most suitable chitosan concentration for postharvest storage of Thach That persimmon (Diospyros kakiThunb.)fruits.Thepersimmonfruitswere firstly exposed toethylene, then treated with different chitosan concentrations of 1%; 1.5%; 2.0% and 2.5%, and finallystored under cold temperature (6-80C). Results showed that chitosan treatment considerably reduced the quality degradation of persimmons during the storage period. Chitosan concentration of 2.0% yieldedlowestweight loss, slowest change infruit color and firmness. Other biochemical parameters such as total acidity, tannin content reduced most slowly while the total sugar content increased most slowly in all samples. Using chitosan concentration of2.0%,Thach Thatpersimmonfruitscan be stored for25 days under cold temperature with good quality.
DOI: https://doi.org/10.1234/cka6zm46
Effect of Technological Parameters on Separation of Omega-3 and Omega-6 FattyAcids from Perilla Seed Oil

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

Received: 21-07-2018 / Accepted: 01-10-2018
This research was carried out to identify optimal protocol for separating omega-3 and omega-6 fatty acids from perilla seed oil with high yield and quality. The perilla oil was first hydrolyzed into fatty acids by sodium hydroxide solution in 80% ethanol to yield free fatty acids. The next step was to enrich the polyunsaturated omega-3 and omega-6 in the resultant fatty acids mixture via complexation with urea in ethanol. The suitable conditions of complexation were as follows: urea to fatty acid ratio of 2:1 (w/w), ethanol to fatty acid ratio of 9:1 (v/w), and complexation temperature of 0C for 5 hrs. The total content of omega-3 and omega-6 fattyacids accounted for 94.86 % in the final product.
Designing A 3-Roller Sheet Bending Machine Suitable for Requirements of Small Production Operations

Nguyen Huu Huong, Tong Ngoc Tuan

Received: 21-03-2018 / Accepted: 11-06-2018
Calculation and design for a 3-roller sheet bending machine for small production operationswere based on theoretical studies and real manufacturing practices. Dimension parameters of the machine were calculated based on materials used in manufacturing process and machinery parts. The bending machine can manufacture machinery parts with different diameters and heights by using some types of steel with thickness from 1 to 4 mm, length from 400 to 2000 mm and width from 50 to 800 mm. Based on design drawing, a 3-roller sheet bending machine was manufactured and used for manufacturing machinery parts.
Establishment of ASimple and Efficient Transformation Protocol for Hairy Root Induction of Wild Bitter Melon (Momordica charantia L.var. abbreviata Ser.)

Nguyen Thi Thu Trang, Vu Thi Dao, Bui Minh Tri

Received: 28-09-2016 / Accepted: 13-02-2017
Wild bitter melon (Momordica charantia L. var. abbreviata Ser.) is known as a valuable vegetable and herb. It contains several important bioactive substances, including glycoside, saponin, alkaloide, triterpen and steroide. This study was carried out to establish a simple and efficient transformation protocol for inducting hairy roots of wild bitter melon by using strain TR7 of Agrobacterium rhizogenes which carries pPE113 binary vector harbouring e-gfp gene. Major parameters were optimized including, the age of plant and position for injection. The results indicated that highest hairy root induction frequencies was about 69.66-73.33% when seven-day-old seedlings were used to infect with the bacterium using hypocotyl. After regeneration and selection, thirty putative root clones of 4 specific phenotypes, i.e. white hairs, fast growth and branching on hormone-free MS medium, were obtained. The average GFP expression rate in 4 specific phenotypic groups were about 46.7%. PCR analysis using specific primers for rolA gene and virD gene confirmed the presence of the rolA gene and absence of virD gene in the genome of four hairy root lines. It was suggested that this simple transformation protocol can be applied for hairy root induction of other varieties as well.
Effect of Processing Conditions on Extraction Yield of Corn Oil

Nguyen Thi Hoang Lan, Nguyen Thi Quyen, Nguyen Ngoc Cuong

Received: 25-07-2016 / Accepted: 06-12-2016
The study was carried out on corn kernels withoil content of 3.36 - 5.73% on dry matter basis in order to select the most suitable variety for oil extraction. The main processing parameters were also examined in order to select the best values which enhance the extraction yield and thequality of the extracted oil. The optimized processing conditions are briefly described as follows. Corn kernels were ground to particle size of 0.1 mm to 0.25 mm in diameter. The ground corns were then extracted two times by n-hexane at a ratio of 1 g ground corn to 8 mL solvent for 5 hours (the first time) and ratio of 1 g ground corn to 4 mL solvent for 2 hours (the second time). Extraction was carried out at 69oC. The extract was then evaporated by rotary vacuum equipmentto collect corn oil. The corn oil obtained has high levels of unsaturated fatty acids and vitamin E, and can be used as raw material in the production of functional foods and pharmaceuticals.
Phisical Model of the Vertical Cone-Shaped Screw Mixer

Luong Thi Minh Chau

Received: 29-01-2016 / Accepted: 10-06-2016
Physical model built for the vertical cone-shaped screw mixer consists of two physical models to determine the capacity and productivity of the vertical cone-shaped screw mixer. Based on the physical models we built vertical cone-shaped screw mixers identical with that of optimum parameters. Research process for the different machine models to raise productivity in calculating, design, manufacturing can be shortened but vertical cone-shaped screw mixers with optimal work fitting to the different power and productivity could be achieved.
In vitroPropagation of Daylily (Hemerocallis fulva)

Nguyen Thi Lam Hai, Pham Thi Minh Phuong, Trinh Thi Mai Dung

Received: 21-01-2016 / Accepted: 28-06-2016
Hemerocallis fulva is considered as a crop with high ornamental and medicinal value. In this study, we initially determined the basic parameters of the in vitro multiplication for H. fulva, including appropriate in vitro initiation medium, culture medium, and rooting and hardening media for H. fulva. The results showed that the optimal medium for in vitro initiation culture was MS + 1 mg/L BA + 1 mg/L -NAA. The suitable medium for in vitro shoot multiplication was MS + 1 mg/L BA + 1 mg/L IAA; The rooting medium was MS supplemented with 0.5 mg/L -NAA; Highest efficiency for hardening of Hemerocallis fulva in vitro-derived plantlets in green house was achieved with moist alluvial soil.
Effect of Postharvest Treatment With1-Methylcyclopropene on the Quality and Storage Life of Green Onionin Atmospheric Condition

Vu Thi Kim Oanh, Vu Thi Hang

Received: 15-10-2015 / Accepted: 05-05-2016
The aim of this study is to identify the optimum mode of postharvest treatment with 1-methylcyclopropene (1-MCP) forgreen onion (Allium fistulosum) in order to remain quality and prolong storage life at ambient condition. The two factors, concentration of 1-MCP and time exposed to 1-MCP, were taken into account. Singer factor experiment on concentration of 1-MCP was carried out first (with 6 concentrations of 0; 100; 200; 300; 400; 500ppm) along with 8 hours exposed to the chemical. Then the singer factor experiment on time exposed to 1-MCP was conducted (with 5 levels of 2; 5; 8; 11; and 14hours) along with the best 1-MCP concentration selected from previous experiment. Analyzed parameters include yellowingrates, chlorophyll, vitaminC content and their changes during storage period. The best green onion was obtained from the treatment with 200ppmfor8 hours exposed to 1-MCP. Also, two factors experiment was made in order to see interactions between them and look for the most optimal modeof 1-MCP postharvest treatmentforgeen onion. The results showed that the treatment laid on 208,9 ppm 1-MCP for 7 hours 44 minutes gave highest quality green onion in atmospheric condition.
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%.
MEAT QUALITY COMPARISON BETWEEN FAST GROWING BROILER ROSS 308 AND SLOW GROWING SASSO LAYING MALES REARED IN FREE RANGE SYSTEM

Nguyen Duy Hoan, Mai Anh Khoa

Received: 25-09-2015 / Accepted: 09-12-2015
Trong chăn nuôi gà đẻ trứng, gà trống thường bị loại thải ngay khi vừa mới nở. Tuy nhiên, để đáp ứng xu hướng sử dụng các sản phẩm sạch của người tiêu dùng ngày nay, thay vì loại thải, gà trống mới nở được đưa vào nuôi chăn thả. Với ý tưởng như vậy, chúng tôi tiến hành thử nghiệm nuôi gà trống hướng trứng Sasso (dòng lớn chậm) và gà hướng thịt Ross 308 (dòng lớn nhanh) trong trong điều kiện thả vườn và so sánh chất lượng thịt của chúng. Sáu mươi gà của mỗi giống nuôi nhốt đến 21 ngày tuổi với mật độ 6 gà/m2, sau đó gà được nuôi chăn thả với mật độ 5 gà/m2.. Gà thí nghiệm được nuôi theo quy trình của Bộ NN & PTNT(2010). Tại hai thời điểm 49 và 90 ngày tuổi, tiến hành mổ khảo sát để phân tích, so sánh chất lượng thịt gà trong hai lô thí nghiệm. Đánh giá chất lượng cảm quan thịt gà sau khi chế biến bằng cách chấm điểm dựa trên 6 tiêu chí: màu sắc, mùi, độ mịn thớ thịt, độ giữ nước, vị và sự chấp nhận tổng thể của người nếm. Kết quả cho thấy các chỉ tiêu về khối lượng sống, khối lượng thịt xẻ, khối lượng thịt ngực và tỷ lệ mỡ bụng ở gà hướng thịt Ross 308 cao hơn so với gà trống hướng trứng Sasso ở tất cả các giai đoạn tuổi (P > 0,001). Độ pH của thịt gà Ros 308 tại thời điểm 24 giờ cao hơn pH thịt gà trống Sasso. Về mầu sắc, thịt gà trống Sasso được đánh giá đậm hơn so với gà trống Ross 308 (P > 0,001). Kết quả đánh giá cảm quan cho thấy thịt gà trống hướng trứng Sasso ngon hơn thịt gà Ross 308 (P > 0,01) tại thời điểm 90 ngày tuổi.
GrowthPerformance, BackfatThickness and Selection Orientation for Duroc, Landrace and Yorkshire Boars Raised atDABACO Nuclear Breeding Pigs Company

Doan Phuong Thuy, Pham Van Hoc, Tran Xuan Manh, Luu Van Trang, Doan Van Soan, Vu Dinh Ton, Dang Vu Binh

Received: 09-12-2015 / Accepted: 13-01-2016
The study aimed to evaluate the growth performance, backfat thickness and selection orientation for boars raised at Dabaco nuclear breeding pigs company. The data on individual productivity of Duroc, Landrace and Yorkshire pigs from 246, 524 and 466 individuals, respectively, were statistically analyzed to evaluate the influencing factors by SAS 9.1.3, estimate heritability parameters by VCE 6.0.2, and to predict breeding value by PEST 4.2.3. The results showed that three boar groups attained high daily weight gain, i.e. 785.23, 796.25 and 794.78 g/day, respectively and 11.75, 12.10 and 12,07mm, respectively, for backfat. Heritability estimates of ADG and backfat were 0.20-0.29 and 0.42-0.52, respectively. The sires with high breeding values for each trait predicted by BLUP also produced progeny with high breeding values. The variation in genetic tendency over the years for ADG as well as backfat suggests the necessity of selective orientation based on BLUP to genetically improve the two traits for the boars raised at the company.
Effect of Cold Stress at Germination Stage on the Growth of Selected Rice Lines Developed from the Cross between IndicaIR24 and JaponicaAsominori

Nguyen Van Loc, Tang Thi Hanh, Pham Van Cuong

Received: 05-05-2014 / Accepted: 18-07-2014
The present study aimed to estimate the effects of cold treatment on growth of 73 chromosome segment subtitution lines(CSSLs) of rice developed from the cross between IndicaIR24 and Japonica Asominori.The experiment was conducted in two plant growth chambers (capacity: 300 litters) with different temperature conditions: 130C (cold stress treatment) and 280C (control temperature). Seeds of 73 genotypes were germinated in cold stress and control temperature conditions in7 days and then cold recovery was done in normal condition (280C) for 3 days.All growth parameters such as coleoptile and radicle were lower under cold treatment than those under control condition. The results showed that cold stress reduced radicle length from 55 to 100% and coleoptile length from 82 to 100% and dry mater accumulation more than 60%.A close relationship was found between dry matter accumulation of coleoptile and cold tolerance. Ten potential lines were selected namely IAS 17, IAS 19, IAS 66, IAS 72, IAS 5, IAS 30, IAS 23, IAS 21, IAS 2 and IAS 26 which could be used as materials for rice breeding.
Factors Affecting the Hatchability ofChicken’Eggs

Nguyen Thi Tu, Dang Thai Hai, Ngo Thi Thuy

Received: 27-03-2014 / Accepted: 30-05-2014
eAn experiment was conducted to evaluate several factors affecting the hatchability of Luong Phuong’ eggs on the multi-period incubator in a completely randomized design. The results showed that prolonged egg storage time reduced the rate of embryonated eggs and hatchability but increased embryonated egg mortality. The relationship between egg storage time and embryonated egg rate was strong inversely correlated (r = -0,919; P<0,05). Spawning time during a day affected hatchability. The percentage of embryonated eggs and hatching rate reached the lowest in the egg plots laid before 7am. The highest rate was recored in the egg plots laid from 11am to 13 pm (P<0,05). There was no significant difference in the remaining spawning times. The age of hens also affected hatching parameters (P<0,05). The highest quantity and proportion of embryonated eggs were obtained in laying hen aged between 32-34 weeks. The percentage of hatched/embryonated eggs was lower at 27 weeks of age compared to that of 33-36 weeks of age (P<0,05). The highest hatchability was recorded in eggs weighing from 52-56g. Eggs having shape index in the range from 1.31 to 1.35 had higher hatchability than others (P<0.05). Egg disinfection by formaldehyde showed better hatchability compared to that disinfected by nebutol (P<0,05).

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