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Adaptation to Climate Change in Agricultural Production of Farmer Householdsin Moc Chau District, Son La Povince

Bui Thi Khanh Hoa, Nguyen Dang Hoc

Received: 06-04-2023 / Accepted: 21-06-2023
This study aimed to reflect the situation of climate change and adaptation measures to climate change of farmer households in agricultural production in Moc Chau district.Primary data were collected through questionaires interviewing with 120 farmer households directly involved in agricultural production activities and in-depth interviews with 10 local staffs. The research results showed that to adapt many changes in local climate such as temperature and humidity raising, rainfall, sunshine hours reduction... as well as extreme weather phenomena such as chilling cold, biting cold, storms, floods, hails, hoarfrost..., Moc Chau farmer households have also taken several adaptationmeasures. These measures included shifting structure of crops and livestock, applying new varieties, adjusting farming techniques, repairing barns, moving cages, dredging mud, applying advanced technology to production, diversifying livelihoods... However, there were low application rate and non-homogeneous among households. The study also proposed some recommendations to improve adaptation to climate change in agricultural production of farmer households in Moc Chau in the near future.
Dietrary Essential Amino Acid Requirements of Fingerling Hybrid Catfish (Clarias macrocephalusX C. gariepinus) as Estimated by the Ideal Protein Approach

Nguyen Duy Quynh Tram, Le Duc Ngoan, Jan Erik Lindberg

Received: 27-02-2014 / Accepted: 26-04-2014
The requirement of essential amino acids (EAA) in hybrid catfish fingerling (Clarias macrocephalus x C. gariepinus) was estimated from the optimal dietary lysine requirement and the ideal EAA profile in catfish whole-body amino acid. Groups of 30 fish (4.0 ± 0.7 g) were stocked in triplicate in 130 L glass tanks and were fed semi-purified iso-nitrogenous diets (300 g crude protein (CP) kg-1 and 18.3 MJ gross energy (GE) kg-1) with increasing levels of lysine (40, 45, 50, 55, 60 and 65 g kg-1 CP). The results showed that the live weight gain (WG) and specific grow rate (SGR) increased (P<0.05) with increasing dietary lysine level. Subjecting the data of WG to the second-order polynomial analysis, the requirement of dietary lysine was estimated and was found to be 58.2 g kg-1 of CP. Therefore, the dietary requirements of EAA were estimated using whole-body amino acid profile.
Prevalence of Foot-and-Mouth Virus Infection and Risk Factors in Hotspots in Vietnam from October to December 2012

Nguyen Thu Thuy, Nguyen Van Long, Phan Quang Minh, Tran Thi Thu Phuong, Nguyen Quang Anh, Nguyen Ngoc Tien, Nguyen Dang Tho, Ngo Thanh Long, Nguyen Ba Hien

Received: 25-03-2014 / Accepted: 26-04-2014
A cross-sectional study together with a case-control study was carried to estimate the prevalence of foot-and-mouth (FMD) virus infection in animals in three provinces (Lang Son, Nghe An and Kon Tum) from October to December 2012. Serum and probang samples were taken from 884 cattles and buffaloes of 590 households. Information about risk factors were collected using a standardized questionnaire. Data analyses showed that FMD antibody was detected in all three provinces with a high level of 24.21% (95% CI 21.42-27.17) at the individual level and 29.83% (95% CI 26.16-33.70) at the household level; FMD virus belongs to serotype O and A. Cattles procured from unknown sources were a major risk factor, with the odds ratio (OR) of 5.27 (95% CI 2.22-12.52) times the OR for cattles kept by households. Control measures should be strictly taken at the household level. In addition, management of animal movement should be improved to stop spreading FMD virus.
Rapeseed Variety trial on Karst Plateau of Ha Giang Province

Vu Duc Chien, Bui Quang Thuat, Le Binh Hoang, Nguyen Trung Hieu

Received: 24-10-2013 / Accepted: 24-02-2014
Twoexotic rapeseed varieties, Agamax from Germany, Hyola 432 from Australia and a local rapeseedvarietywere evaluated on field where rice was grownprevious season in Dongvan Karst Plateau during 2012-2013. The resultsindicated thattwo exotic rapeseed varieties were adapted to the local weather and soil conditions and gavehigh seed yield per hectare basis (1.820-1900kg/ha) and good seed quality. Theaverage oil content of Agamax and Hyola 432 attained43.6% and 41.3%, respectively. These varietiescan be adopted to integrate into winter cropping structure in Hagiang province.
Evaluation of AtZAT12Gene Expression in Transgenic Arabidopsis

Le Thi Tuyet Cham, Vu Ngoc Thang, Vu Thi Thuy Hang, Tran Anh Tuan

Received: 26-05-2020 / Accepted: 20-07-2020
ZAT12 is one of the transcription factors response to abiotic stress, which has had higher expression of ZAT12 under oxidative, cold, and heat stressetc. ZAT12 links iron deficiency and oxidative stress responses through direct interaction with and negative regulation of FIT.However, in thisstudy,ZAT12 was regulated by ZAT12native promoter. This study aimed to generate ZAT12 with overexpression (ZAT12 Ox) in response to oxidative stress and Fe uptake. The attempts of this study were further selected thetransgene lines containing 2x35S::ZAT12 by observing the dry seed under fluorescent microscopegene sequencing and PCR. The growth and gene expression as well asZAT12 protein regulation of 2x35S::ZAT12 lines (ZAT12 Ox)were evaluated. As the results showed, the 4 positive lines(CH1-1, 1-4, 1-10 and1-14lines) with different growth were generated, of which the growth of CH1-1 line was inhibited. Expression of AtZAT12 gene induced to response to Fe deficiency, but not to H2O2supplemented treatment. ZAT12 protein of CH1-4 line also detected by Western Blot.
Recovery of vitamin E from deodorzing destillate of soybean oil purification

Bui Thi Bich Ngoc, Ly Ngoc Tram, Vu Duc Chien, Bui Quang Thuat

Received: 24-10-2013 / Accepted: 26-12-2013
Deodorizing distillate - major by-product from purifying soybean oil, which contains three high value compounds like fatty acids, tocopherols (vitamin E), and phytosterols, is useful material for obtaining vitamin E. Firstly, deodorizing distillate was dehydrated by Na2SO4 and then free fatty acids in deodorizing distillate were converted to ethyl esters with concentrated H2SO4 catalyst and 20 ; 1 ethanol : deodorizing distillate ratio (mol/mol) at 700C for 80 minutes. Secondly, the product mixture of ethyl esterification reaction was evaporated, alcohol and acid removed by water washing. Ethyl esters of fatty acids were removed by vacuum distillation at 5mbar and at 198 - 2250C. Phytosterols were separated from distillation bottoms by crystallization method with etanol at 50C to obtain crude vitamin E. It was extracted with two times ethanol, then crystallized at -150C to remove remnant phytosterol and other undesired substances. Finally, natural vitamin E with 90.8% purity was extracted on silica gel (0.063 – 0.200 m) column with eluted solvents, n-hexan : ethanol: 9:1.
Effect of Night Break Duration on Off-Season Flowering,Fruiting and Yield of Red Dragon Fruit Cultivar Tl5 in Gia Lam, Hanoi

Nguyen Thi Thu Huong, Nguyen Quoc Hung, Doan Van Lu

Received: 07-11-2019 / Accepted: 05-02-2020
The studywas aimed to establish atechnical protocol to extend the fruit harvest in Northern provincesfor off-season flowering of red-fleshed dragon fruit TL5 variety growingin Gia Lam, Hanoi. The study was conducted in 2 seasons of lighting, on October 20, 2016,and October 20, 2017. The lighting treatment used 60W incandescent light bulbs to supplement light from 10 pm to 3 am, in the 5 different lighting durations of 13, 16, 19, 22 and 25 nights. The experiment was arranged in RCBD, with 20 posts/treatmentforeach replication. The results showedthat in both seasons of lighting supplement, the treatments of lighting in 19, 22 and 25 nights were recorded with good flowering. The number of shoots per post-producing flower buds and number of stable flower buds per post in these lighting treatments reached 28.2-33.6 and 52.7-67.2 respectively, which were significantly different from those of the treatments with 13 and 16 nights of lighting. Actual yields in treatments of 19; 22 and 25 supplement nights reached 6.2 to 7.3 kg/post in both the 2 seasons, which were significantly different from those of treatments with fewer lighting days. Among the lighting treatments, the supplement in 22 nights was the most effective that the profits were increased to 150.8 million dong/ha in the first crop and 144.8 million dong/ha in the second crop.
The Effects of Blue Led Light ontheGrowth and Flavonoid Accumulation ofBasil (Ocimum basilicumL.) In Vitro

Nguyen Thi Thu Thao, Tran Hoai Nguyen, Do Thuong Kiet, Phan Ngo Hoang

Received: 24-10-2019 / Accepted: 02-04-2020
Basil is widely cultivated in Vietnam and mostly used for spice and medicinal purposes. In this study, in vitrobasil plants were cultivated under three blue LED light conditions (440, 450, and 460nm,respectively)byusing fluorescent lamps asthecontrol. After four weeks, the morphology, biomass, gas exchange in photosynthesis, chlorophyll, total sucrose, starch, phenol compounds and total flavonoid content of the plants were determined. Under the fluorescent light or blue LED of 450nm, the stem height was lower, but the number of leaves was greater, and the total leaf area was higher than those of plants grown under blue LEDs (440 and 460nm). Root dry mass percentage of the plants under blue LEDs decreased compared to that of the control. Blue LED at 440 and 460nmincreased the percentage of stem dry mass, whereas blue LED light (450nm) increased the percentage of leaves dry mass. Monochromatic blue light reduced photosynthetic rate, chlorophyll a, sucrose, starch, and phenol compounds content of leaves. However, blue LED light (450nm) maintained the carotenoid and flavonoid contents, chlorophyll a/b ratio in leaveswhich were rather highin comparison with the fluorescentlightof the control.
IMPACTS OF COMMUNITY BASED TRAINING ON PESTICIDE RISK REDUCTION

Do Kim Chung, Kim ThiDung

Received: 13-12-2013 / Accepted: 20-02-2014
Pesticide risks in terms of hazard and exposure are expected to reduce through community based farmer training. With this regards, a community based training program on pesticide risk reduction (PRR) has been implemented in Vietnam since 2007. With two data sets on 94 pesticide users before and after PRR training in PRR and control communes of Hanoi city and Thai Binh province, this paper shows that: The program has improved farmers’ awareness/knowledge and their behaviors in PRR, and enabled farmers to reduce hazards and exposure. Farmers used pesticides permited for vegetables, used more biopesticides and class III and IV pesticides. On the exposure side, positive impacts were more proper pesticide use techniques; use of more protective equipment and better unused pesticides and sprayer management. As a result, the environmental impact quotients were reduced sharply from 20% to 78%.
Antibiotic Resistance Profile and Molecular Characterizatin ofExtended Spectrumβ-lactamase (ESBL) - Producing Escherichia coli Isolated from Ducks

Hoang Minh Duc, Cam Thi Thu Ha, Tran Thi Khanh Hoa, Pham Thuy Linh, Hoang Minh Son

Received: 19-03-2024 / Accepted: 12-04-2024
This study aimed to determine the phenotypic and genotypic antibiotic resistance profile of ESBL-producing E. coliisolated from ducks. A total of 50 rectal swab samples from ducks were collected at markets in Gia Lam district, Hanoi city. The isolates in this study were all resistant to streptomycin, ampicillin, tetracycline, ceftazidime and cefotaxime. Besides, they also exhibited high resistance rates to sulfamethoxazole/trimethoprim (95.65%), gentamicin (91.3%)and chloramphenicol (91.3%). The lowest resistance rate was recorded with cefoxitin (30.43%) and 100% isolates were susceptible to meropenem. Interestingly, all of these isolates were determined as multidrug resistant strains. The result of phenotypic detection of ESBL indicated that 100% (20/20) presumptive ESBL producing E. colistrains were able to produce ESBL Among them, 50% (10/20) isolates carried blaTEM gene,25% (5/20) haboured blaCTX-M-1, 10% (2/20) habour blaCTX-M-9, and 15% (3/20) carried both blaCTX-M-1 and blaTEMsimultaneously.
Design and Fabrication of Feed Mixing Machine for Livestock Production in Rural Areas

Hoang Xuan Anh, Tong Ngoc Tuan

Received: 26-03-2013 / Accepted: 27-08-2013
Nowadays, livestock develops in the direction of combining industrial livestock husbandry with traditional livestock keeping (household) under an appropriate scale which is much larger than the that in the past time period. This not only requires suitable animal feed processing machines in general but also suitable feed mixers in particular. 50kg-per-batch feed mixer can be used to mix various types of feed. Moreover, this type of equipment is easy to fabricate, install, remove and clean. The machine is suitable for farm economic models, small-scale or household level. The machine can be used to blend feed from the raw crushed materials (natural origin), or concentrate feed with locally available raw materials at the request of the producer.
Estimating Consumers’ Willingness - to- Pay for Safe Pork Products in Gia Lam District

Le Thanh Ha, Do Quang Giam, Tran Quang Trung

Received: 26-04-2021 / Accepted: 15-06-2021
The study evaluated consumers' willingness to accept prices for safe pork in Gia Lam district by comparing and applying two models (Multinomimal logit regression - MNL and Order logit regression - OLR) to estimate the factors affecting price willingness. Using the Cluster Convenient sampling, the research surveyed 90 consumers about the willingness to accept prices of consumers in Gia Lam district. The willingness to pay for safe pork in Gia Lam district was significant with the large proportion to pay at 20% or 30% higher price than for conventional pork. Both the MNL and OLR models were significant when explaining the willingness to pay for pork in a case study in Gia Lam. According to the estimation results of the MNL model, at the price of 20% compared to conventional pork, we found some statistically significant factors that affected the willingness to pay for pork are age and educational level, income of respondents. At the price of 30% higher than the conventional meat, statistically significant factors were age, belief in food -safety and awareness of health; at a price of 50% higher than conventional pork, statistically significant factors are education, belief in food -safety and awareness of health, gender, age, income, education. The OLR model estimated results showed that variables including gender, age, occupation, income, education, belief in food -safety and awareness of health were statistically significant. Evaluating the predictive accuracy of the two models showed that the MNL model has higher accuracy than the OLR model.
Factors Affecting the Efficiency of Rapid Vitrification of in vitroBovine Embryo

Nguyen Thi Ngoc Anh, Nguyen Duc Truong, Nguyen Thi Thu Trang, Nguyen Van Thanh, Do Thi Kim Lanh

Received: 17-04-2023 / Accepted: 29-08-2023
The research was conducted to improve the quality of in introbovine embryo vitrification. Bovine oocyteswere matured thenfertilizedwith frozen-thawed semen at1, 2or 5× 106sperm/ml for 6 hours to find the optimal conditions. Theblastocysts were then rapidly frozen in the medium using TCM199+BSA (Tissue culture medium-199+Bovine serum albumin) or DPBS+FBS (Dulbecco's phosphate-buffered saline+Fetal bovine serum). There was no significant difference in the maturation rateof oocytes matured in BO-IVM or TCM-199 medium. In vitrofertilized bovine oocyteswith frozen-thawed sperm atconcentration of 2 × 106sperm/ml for 6 hours gave the highest fertilization and blastocyst rate. The survival rate after thawing of bovine embryosfrozenin DPBS+FBS and TCM199 + BSA medium was92.96% and 82.71%, respectively, however, there was no significantdifference between the groups. Thehatching rate after thawing of embryos vitrified in TCM 199 + BSA medium reached 54%, significantly higher than that ofembryos vitrifiedin DPBS+FBS medium (28.8%). Inthe gene-edited embryo group, the number of survival embryos after thawing reached 96.03 % compared to 88.82 % in the IVF group. The source of oocytesalso affected the survival rate of embryos after thawing.
Growth Rate, Carcass and Meat Quality of Crossbreds between F1(LandracexYorkshire) Sows and (PiétrainxDuroc) Boars with Piétrain ReHal Genetic Difference

Pham Thi Dao, Nguyen Van Thang, Vu Dinh Ton, Do Duc Luc, Dang Vu Binh

Received: 22-01-2013 / Accepted: 18-03-2013
The study was carried out at 3 pig farms in Hai Dương and Hưng Yên from March 2011 to January 2013 to evaluate growth rate and carcass quality of F1(Landrace x Yorkshire) (F1(L x Y)) sows mated with F1(Piétrain x Duroc) (PiDu) boars with Pietrain ReHal genetic constitution (25, 50 và 50%: PiDu25, PiDu50, PiDu75). The results showed that these crossbreds obtained high growth rates and low feed conversion ratio (FCR) (829.42 g/day and 2.31 kg/kg; 797.78 g/day and 2.33 kg/kg; 765.79 g/day and 2.38 kg feed/kg weight gain, respectively). Lean meat percentage of PiDu25 x F1(L x Y), PiDu50 x F1(L x Y) và PiDu75 x F1(L x Y) were 54.66, 56.32 and 59.97 %, respectively. Lean meat percentage of PiDu75 x F1(L x Y) was higher than that of PiDu25 x F1(L x Y) and PiDu50 x F1(L x Y). The meat quality traits in terms of pH, colour drip loss, and firmness of 3 crossbreds were normal. Crude protein of musculus longissimus dorsi of crossbreds was 21.53, 22.18 and 22.63%. The research suggests that using crossbed boars PiDu25, PiDu50, PiDu75 to mate with F1(L x Y) sows helps to obtain high performance in pig farms.
Growth Performance and SemenQuality of the Stress Negative Piétrain BoarsRaised at the Animal Farm of Hanoi University of Agriculture

Ha Xuan Bo, Do Duc Luc, Bui Van Dinh, Bui Huu Doan, Vu Dinh Ton, Dang Vu Binh

Received: 30-01-2013 / Accepted: 23-04-2013
This study was carried out on 10 stress-negative Piétrain boars including 3 pigs of halothane genotype CC and 7 of CT at the pig breeding farm of Hanoi University of Agriculture in order to evaluate effects of season (Spring, Summer and Autumn) and halothane genotype (CC and CT) on the production performance and semen traits. The results showed that the difference in daily average gain was not significant between CC (559.57 g/day) and CT boars (546.31 g/day). The halothane genotype did not affect semen traits (P>0.05) except ejaculation volume (P<0.001). Ejaculation volume of CC genotype (270.95ml) was higher than that of CT (220.82ml). Season had significant effect on ejaculation volume, sperm concentration and pH of semen (P<0.001) as well as total number of sperms moving straight ahead per each ejaculation (P<0.05). Semen volume was highest in autumn (293.02 ml) followed by summer (195.00 ml) and spring (190.86 ml) while this tendency was inverse for sperm concentration. Total number of sperms moving straight ahead per each ejaculation was highest in autumn (47.15 billion) followed by spring (45.20 billion) and lowest in summer (36.74 billion). Semen traits of the stress-negative Piétrain boars were in accordance to the standards of technical criteria for animal breeding accoprding to the Decision No. 1712/QĐ-BNN-CN (Ministry of Agriculture and Rural development, Vietnam), except sperm motility and growth performance were lower than specified.
Study on Genetic Diversity in Taro (Colocasia esculenta) by DNA Markers

Nguyen Van Giang, Vu Ngoc Lan, Tong Van Hai

Received: 08-12-2012 / Accepted: 23-01-2013
In this study, we used DNA markers (5 RAPD markersand 5 SSR markers) to screen genetic diversity in 60 samples of taro(Colocasia esculenta)that collected. Total 67 alleleswere amplified by RAPD markers, in that has 47 polymorphic alleles. 20 alleleswere amplified by SSRmarkersand 9 alleles were polymorphic. From the electrophoresis PCR products of these two directives, 60 taro accessions were grouped into 12 clusters with similarity coefficients of 0.8 by NTSYSpc 2.1 software. The information found in this study may be used for taro conservation and breeding programs.
The Effects of Growing Medium and Seed Rhizome Weight on the Growth, Yield and Economic Return of Ginger (Zingiber officinaleRosc.)Grownin Bags

Mai Thi Thuy, Ninh Thi Phip

Received: 01-03-2013 / Accepted: 19-08-2013
Two experiments were conducted to study the influence of growing medium (cv. Trau) and weight of seed rhizomes (cv Gie) on the growth, yield of ginger grown in bags. The bags were made of cement bag material with 40x40cm size. Ginger cultivar Trau was planted in bags containing 100% soil; 100% sand; 100% rice husk; soil – rice husk (1:1); soil – sand (1 :1); sand – rice husk (1 : 1); soil – sand – rice husk (1 : 1 : 1). Cultivar Gie consists of four different weight of seed rhizomes, i.e. 4 g, 8 g, 16 g and 32 g. The treatments were arranged in RCBD with three replications; the bags were placed under three-year old mango canopy with 70% natural light at the Faculty of agronomy, Ha Noi University of Agriculture. Growing medium significantly effected the growth and dry rhizomes yield of ginger. Trau ginger grown in soil – rice husk (1:1), 100% sand and soil – sand – rice husk (1:1:1) had higher growth and rhizomes yield than the other growing media. With Gie cultivar, number of pseuodstems per plant, number of leaves per stem, leaf size, leaf area, dry matter weight and yield component parameters of ginger increased proportionately with seed rhizome weight. Growing in medium of soil – sand – rice husk (1:1 :1) brought about highest yeild (53.8 million dong). 32 g seed rhizomes yielded in significantly higher rhizome yield than the other treatments, however, highest economical efficiency was obtained with 16g rhizome as seed.
Effectof Temperature and Salinity on EmbryonicDevelopment of Tiger Grouper (Epinephelus fuscoguttatus)

Vu Van Sang, Tran The Muu

Received: 23-10-2012 / Accepted: 25-12-2013
The experiments were carried out to evaluate the effects of temperature and salinity on embryonic development of the Tiger grouper (Epinephelus futcoguttatus)and to determine the optimal temperature and salinity for incubation of Tiger grouper eggs. The fertilized egg of Tiger grouper was incubated in a series of 1L-glass beakers at a density of 100 eggs/L and divided two separated trials. The first experiment was conducted at five temperature levels of 23ºC, 26ºC, 29ºC, 32ºC, 35ºC, each treatment was run in triplicate. The second experiment was implemented at different salinity of 23‰, 26‰, 29‰, 32‰, 35‰. The study results clearly show that the highest hatching rate (89.6 ± 3.2%) and the lowest deformity rate (6.3 ± 0.4%) were obtained in the treatment which were incubated at 29oC compared to the others (P<0.05). The second experiment demonstrated that the salinity of 32 -35‰ are suitable for incubation of tiger grouper egg as the highest hatching rate of 83.4 -85.6% and the lowest deformity rate of 1.79 -1.85% were obtained (P<0.05). In conclusion, among the treatments, the temperature of 29ºC and salinity of 32 and 35‰ are the best conditions for Tiger grouper eggs incubation.
Automatic Quality Assessment of Potato Tuber Seeds using Computer Vision

Dang Thi Thuy Huyen, Nguyen Thi Duyen, Ngo Tri Duong, Nguyen Van Dieu

Received: 06-01-2023 / Accepted: 27-01-2023
This study aimedto design an automaticmodelfor quality assessment of potatotuber seeds by applying computer vision. In the study, a number of sproutsandtuber scab diseases (Actinomyces scabiesand Helminthosporium solani) were selected to evaluate the quality of potatotuber seeds. Apicture of the object was taken by Pi 2/3 camera and sentit to Raspberry Pi 4B embedded computer to process the received image with the YOLO-v4 algorithm. Initially,the model drew conclusions about the quality of the seed potatoes through counting the number of sprouts and identifying scabdiseases on tubers with an average processing time of 0.147 seconds. The rate of accurate identification of the diseaseson infected tubers was 93.33% with Actinomyces scabiesand94.74% with Helminthosporium solani.95.56% of sprouted tubers were counted correctly. This evaluation model can be used in an automatic sorting potato seed tubers before planting.
Reproductive performance of the nucleus herd of stress negative Piétrain and Duroc swine raised at the animal farm of Hanoi University of Agriculture

Do Duc Luc, Ha Xuan Bo, Nguyen Chi Thanh, Nguyen Xuan Trach, Vu Dinh Ton

Received: 12-11-2012 / Accepted: 24-12-2012
A study was carried out from December 2011 to August 2012 to evaluate reproductive performance of nucleus herd of stress negative Piétrain (Piétrain) and Duroc pigs raised at the experimental farm of Hanoi University of Agriculture. A total of 35 gilts, including 21 Piétrain (11 with halothane genotype CC and 10 with CT) and 14 Duroc CC gilts were monitored for their reproductive performance. Piétrain boars (3 CC and 5 CT) were mated to Piétrain and Duroc gilts to produce Piétrain purebred and crossbred Piétrain x Duroc pigs. Results showed that genotype of the boar and the sow affected body weight and litter weight at birth and at weaning (P<0.05). Total number of pigs born, number born alive, number alive to weaning, individual bodyweight at birth, individual bodyweight at weaning, litter weight at birth, litter weight at weaning, survival rate at birth, survival rate to weaning were 9.91, 9.26, 8.11 piglets, 1.4, 6.4, 12.97, 51.96kg, 94.32 and 88.55%, respectively. Body weight and litter weight at birth and at weaning of piglets from Piétrain CC boars were higher than those of piglets from Piétrain CT boars (P<0.05). Reproductive performance was highest for Duroc CC sows, followed by Piétrain CC and lowest for Piétrain CT sows (P<0.05). Reproductive performance of the nucleus herd could be improved by using Piétrain CC boars mated to Piétrain CC sows and Duroc CC sows.
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.
Effect of Rearing Density on Growth, Survival and Reproductive Performance of White Leg ShrimpBroodstockSPF (Litopenaeusvannamei)

Vu Van Sang, Nguyen Quang Trung, Vu Van In, Tran The Muu

Received: 03-09-2012 / Accepted: 15-12-2012
Three stocking densities of 6, 9, 12 heads/m2 of white leg shrimp broodstock SPF (Litopenaeus vannamei) were conducted in series of 14m2 indoor composite tanks at 28-29ºC and salinity of 28-30‰ under biosecurity control. Shrimp were fed 4 times a day with 50% blood worm and 50% fresh squid under water exchange of 100%/day. For induced breeding, eye ablation was applied to female after 30 days intensive rearing. There was no significant difference in growth, survival, rate of mating and spawning, fertilization and hatching rate among treatments (P>0,05). However, reproductive performance was significantly better in shrimp rearing at 6 and 9 heads/m2 than in those reared at 12 heads/m2 (P<0.05), reaching mature rate: 78.2-79.52%; number of spawning/female: 2.49-2.51; spawning fecundity: 152.600 - 153.200 eggs/female/spawn; average Nauplii/female: 123.9 - 127.5 x 103. Samples of broodstock shrimp, larvae and fresh food were found negative for WSSV, YHV, TSV, MBV and IHHNV.
Xác định độ tiêu hóa của một số nguyên liệu thực vật đối với cá trắm cỏ (Ctenopharyngodon idella)

Tran Thi Nang Thu

Received: 30-10-2012 / Accepted: 22-12-2012
Nghiên cứu này nhằm mục đích xác định độ tiêu hóa của cá trắm cỏ (Ctenopharyngodon idella) đối với 3 loại nguyên liệu là cám gạo, bột ngô và bột sắn. Việc xác định độ tiêu hóa của các dưỡng chất trong các nguyên liệu có nguồn gốc thực vật được thực hiện theo phương pháp gián tiếp có sử dụng chất đánh dấu Cr2O3. Cám gạo cho kết quả cao về độ tiêu hóa vật chất khô (80,3%), protein (87,9%) và chất khoáng (97,4%). Tương tự bột ngô cũng cho kết quả khá cao về độ tiêu hóa vật chất khô (88,9%), protein (84.9%) và chất khoáng (92,7%). Không có sự khác biệt có ý nghĩa thống kê khi so sánh độ tiêu hóa các dưỡng chất của cám gạo và bột ngô đối với cá trắm cỏ. Độ tiêu hóa chất khô, protein và chất khoáng của bột sắn lần lượt là 80,3%, 87,9% và 14,3% và thấp hơn so với của cám gạo và bột ngô. Kết quả bước đầu này cho thấy cá trắm cỏ tiêu hóa cám gạo và bột ngô tốt hơn bột sắn.
Effectiveness of Rice Straw Burrying with Microbial Products in Rice Production Following Organic Production Direction at Gia Lam, Ha Noi

Pham Tien Dung, Nguyen Xuan Xanh

Received: 15-01-2012 / Accepted: 21-05-2012
A study of burrying rice straws combined with two microbial product treatments (Bio-plant and Trichoderma) was conducted in spring rice and summer rice seasons on Red River alluvial soils of Ha Noi University of Agriculture. The experiments were arranged in randomized complete block design. Research results pointed out that rice straw burrying with and without microbial product treatment led to differences in growth and development of rice plants. Observations indicate statistically significant differences in leaf area index (LAI) and dry matter accumulation, yield components and grain yield. The use of Bio-plant product combined with rice straw burrying brought higher rice yield than Trichoderma product and control (without microbial treatment, with the summer crop yield of 40.5; 38.0 and 36.5 quintal ha-1, respectively. The treatment of rice straws with Bio-plant product gave higher income by VND 5.2 to 6.5 millions per crop hecta-1.
Effects of Gamma Co60Irradiation for Some Local and Imported Rice Varieties

Nguyen Thi Mien, Nguyen Trong Khanh, Tran Van Quang

Received: 05-08-2021 / Accepted: 29-10-2021
This study was carried out to effects of gamma ray irradiation of irradiation Co60 source forsome local and imported rice accessions. This experiment was designedwith 3 dose (200Gy, 300Gy and 400Gy) on the mutagenesisof three rice (12% seed humidity). At generation M1, the results showed that the seed germination and survival percentage of all rice accessions decreased with the increase of the irradiation doses. Mutated plants with shorter growth duration, lower plant height, more upright flat leaves appeared, greater tillering capacity with high mutation frequency at irradiation dose of 200Gy, 300Gy for imported rice varieties NN1, NN3 in the M2generation. The mutation appeared with very low frequency when irradiating the local rice variety Khau Mang. Selection on M3generation of 200Gy and 300Gy irradiation treated varieties NN1 and NN3 picked up some promising rice lines with short growth duration, short plant height, more upright flat leaves appeared and high tillering capacity. To sum up, gamma Co60irradiation at 200Gy and 300Gy dose on dried seeds could renovated some agronomic traits such as growth duration, plant height, flag leaf morphology and tillering capacity on two imported rice varieties NN1 and NN3.

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