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• Selection ofArbuscular mycorrhizae and Rhizobium for Production ofBiological Materials Used to Revegetation for The Campus Scene

  Nguyen Thi Minh, Nguyen Thanh Nhan

  Received: 18-03-2016 / Accepted: 15-07-2016

   Abstract PDF (VIETNAMESE)

  Rhizobium and Arbuscular mycorrhizal (AM) fungi are capable of symbiosis with plant roots. Theybring many benefits to plant hosts as to stimulatethe growth and development of plants, increase drought tolerance and reduce disease incidence. Thisstudy was executed with the aimto isolate and select Arbuscular mycorrhizae and Rhizobiumstrainswitha high symbiosis for biological material production to revegetationofthe campusscence. Twostrains of Arbuscular mycorrhizal fungi and threeRhizobium strainswere selected thatexhibit fastgrowth, high vitalityand symbiosiswithplantsandcouldbe used for biological material production. The inoculation experiment withbiological materials to therevegetation ofgrass proved the establishment ofthesymbiosisof Rhizobium and Arbuscular mycorrhizal fungi withhost plants thatpromotedthe plant growth and developmentandimproved soil fertility. The vegetation coveringrate using biomaterial treatment wasvery high (95.63%), 1.75 times higher than thecontrol (54.6%) after 5 weeksof application.

• Preliminary Results on Applications of Reproductive Technology for Developing Industrial Rabbit Breeding

  Nguyen Thi Hong, Phan Ngoc Minh, Nguyen Thi Uoc, Duong Dinh Long, Nguyen Khac Tich, Nguyen Thi Hiep, Nguyen Thi Nhung, Nguyen Viet Linh, Bui Xuan Nguyen

  Received: 18-04-2017 / Accepted: 26-07-2017

   Abstract PDF (VIETNAMESE)

  Rabbits are suitable for livestock development for poverty reduction and sustainable agricultural development. At present, the development of rabbit breeding in the mode of industrial reproduction is of concern ofmany farms. In this report, we introduce some preliminaryresults on oestrus synchronization, preservationofsperms, combination of oestrus synchronizationwithartificial insemination (AI) for controllingreproduction of New Zealand rabbit in Vietnam. PMSG treatment has significantly improved receptivity of the doesandtreatment with 40 IU and 60 IU were more effective than with 20 IU in oestrus synchronization. TCG was more effective than EX1 in protection of rabbit sperms at 4oC. Both pregnant rate and litter size using AI after oestrus synchronization were higher than natural mating after normal eostrus.

• Technical Advances in Reproduction: Applications in Medicine and Agriculture

  Nguyen Van Thuan

  Received: 18-04-2017 / Accepted: 26-07-2017

   Abstract PDF (VIETNAMESE)

  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.

• Status of Reproductive Diseases and Clinical Treatment of Metritis of Buffalo Cows Raised in The Northern Provinces of Vietnam

  Nguyen Van Thanh, Nguyen Thi Thanh Ha

  Received: 18-04-2017 / Accepted: 26-07-2017

   Abstract PDF (VIETNAMESE)

  ABSTRACT

• Biochemical and Haematological Parameters of Female Dogs Infected with Pyometra

  Su Thanh Long, Nguyen Thi Hoa, Vu NhuQuan, Trinh Dinh Thau

  Received: 03-07-2017 / Accepted: 27-09-2017

   Abstract PDF (VIETNAMESE)

  Pyometra is a common reproductive disease in female dogs, which negatively affects the reproductive performance and results in high mortality in the case of delayed diagnosis and treatment. In this study, biochemical and the haematological parameters were assessed in healthy and diseased female dogs. The dogs consisted of two groups, group 1 (control) with 10 healthy dogs and group 2 with 10 pyometra-infected dogs. The results revealed that infected dogs showed a decrease in red blood cell count and haemoglobin and mean corpuscular volume while white blood cell count (neutrophil, lymphocyte and monocyte) increased. In addition, the liver enzyme value like GOT, GPT remained constant in both healthy and diseased dogs but the parameters related to kidney function such as urine and creatine production moderately increased..

• In VitroAnti-Bacterial Activity of Herbal Extracts against Staphylococcusspp. and Streptococcus spp. Isolated from the Metritis in Cows

  Nguyen Thi Thanh Ha, Nguyen Thanh Hai, Nguyen Nam Phuong, Nguyen Van Thanh

  Received: 18-04-2017 / Accepted: 26-07-2017

   Abstract PDF (VIETNAMESE)

  The use of antibioticsfor the cow metritis treatment has many advantages, however, raises concerns about antibiotic residues in the meat and dairy products as well as increasing antibiotic resistance of pathogenic bacteria. Herbs have been increasingly demonstrated their significant role in the pharmaceutical industry as a biosafety solutionandan alternative to synthetic chemical drugs. The present study aimed to examine the anti-bacterial activity of herbal extracts(Polyalthia longifolia var.Pendula, Lignum Caesalpiniae sappari, Excoecaria cochinchinensis Lour.,Clerodendron fragrans Vent, Wedelia calendulaceae Less, Cudrania tricuspidata, Pseuderanthemum (Ness)Radik, Lactuca indica L)against Staphylococcusspp. and Streptococcusspp.isolated from cow metritis. The resultsshowed that the extractionefficiency varied from 9.60% (Lignum Caesalpiniae sappari) to 14.32% (Wedelia calendulaceae Less). At the concentration of 100 mg/ml, all the extracts showed good anti-bacterial activity against Staphylococcusspp. and Streptococcusspp. For Streptococcusspp., the bacterial inhibition zone varied from 11.80 mm (Cudrania tricuspidata(Carr) to 25.00 mm (Clerodendron fragrans Vent). The diameter of the bacterial inhibition zone of Staphylococcusspp. varied from 10.28 mm (Cudrania tricuspidata(Carr)) to 25.30 mm (Wedelia calendulaceae Less). The extract solution of Clerodendron fragransVent and Wedelia calendulaceaeLess showed the highest anti-bacterial activity. This extract remained its anti-bacterial activity against Staphylococcus spp. and Streptococcusspp. at concentration of 0.20mg/ml.

• Effect of Time Destroying the Growing Point on Propagation Efficiency of Pineapple (Ananas comosus) cv. MD2

  Le Vinh Hung, Nguyen Thi Ngoc Diem

  Received: 25-03-2024 / Accepted: 21-06-2024 / Published: 25-07-2024

   Abstract PDF (VIETNAMESE)

  The pineapple variety MD2 has low, prolonged and ununiform shoot production under natural conditions. Therefore, it is very necessary to process buds simultaneously by destroying the growth tip to improve propagation efficiency for production. In this study, shoot tip/growing point was destroyed at time points (3.5, 4.5, 5.5, 6.5, 7.5 and 8.5 months after planting) and shoots of different sizes (4cm and 3 true leaves; 6cm and 4 true leaves; 8cm and 5 true leaves; 10cm and 6 true leaves; 12cm and ≥ 6 true leaves) were recorded. Research results show that mother plants shoots of 8.5 months after planting were treated and suckerss with a height of 4cm and 3 true leaves yielded 48.87 suckers/year. However, the plants were treated 7.5 months after planting combined yielded suckers with 8cm and 5 true leaves. The treatment time points and the size of the buds collected did not affect the sucker formation time ranging from 40.90 to 45.76 days and the survival rate after transplanting from 84.56 to 99.87%.

  DOI: https://doi.org/10.1234/1fxw2a37

• Stilbenoids extracted from Gnetum montanumMarkgr.in Vietnam

  Nguyen Thi Viet Thanh, Vu QuocHuy, Le Yen Nhi, Tran Thi Anh Tuyet, Tran Minh Anh, Hoang Tran Nhu, Nguyen Khanh Linh, Nguyen Thi Kim Phuong, Nguyen Tien Thang

  Received: 03-11-2023 / Accepted: 12-06-2024

   Abstract PDF (VIETNAMESE)

  Gnetum montanumMarkgr.belongs to the Gnetaceae family. According to traditional medicine, this species has the effect of preventing leprosy, eliminating rheumatism, activating blood, and eliminating inflammation, and has been used in remedies for rheumatism, bone pain, and gout treatment. In Vietnam, there are variouscommercial products to treat arthritis and gout. With the goal of isolating compounds from this species in Vietnam, we used extraction methods with increasing polarsolvents and modern chromatography methods such as thin-layer chromatography. (TLC), column chromatography (CC), high-performance liquid chromatography (HPLC). Asa result, from the methanol extract of the G. montanumstem, four stilbenesgnetifolin E (1), gnetifolin K (2), isorhapontin (3), and trans-pinosylvin (4) were extracted and isolated. Their structures were determined by ESI-MS, 1D-NMR, and 2D-NMR combined with comparison with published spectral data.

• Effect of Composting Methods of Agricultural by-Products on Quality of Compost and Its Application in Cucumber Cultivation

  Thieu Thi Phong Thu, Chu Thi Dieu Linh

  Received: 03-01-2024 / Accepted: 28-05-2024

   Abstract PDF (VIETNAMESE)

  The experiment was conducted to determine suitable composting method to convert agricultural by-product into organic fertilizer and evaluate effect on the growth and yield of cucumber in 2023 spring season. The experiments were carried out at the field of the Faculty of Agronomy, Vietnam National University of Agriculture. The traditional aerobic composting and mix aerobic composting were tested to compost agricultural by-products consisting of rice straw, chicken manure and elephant grass. Research results showed that the mix aerobic composting method produced higher mass and quality of compost in comparison with traditional method. Combination treatment of mix aerobic compost with chemical nitrogen fertilizers had a positive effect on growth, development and yields of cucumber than other treatments.

• Effect of LED Light Intensity on Growth, Physiologyand Yield of Green Oakleaf Lettuce (Lactuca sativavar. Crispa)

  Nguyen Thi Phuong Dung, Vu Ngoc Lan, Tran Anh Tuan

  Received: 27-02-2024 / Accepted: 12-04-2024

   Abstract PDF (VIETNAMESE)

  Lettuce is high nutritional plant. Research was conducted to find the optimal LED light intensity for indoor hydroponic green oakleaf lettuce cultivation, contributing to ensuring the supply of safe vegetables for consumers and optimizing power consumption. The experiment was arranged in a randomized complete block design (RCBD) with three replicates. Evaluatingthe effects of four different light intensities (90-130-160-190µmol.m-2s-1 (under a combination of red, blue and green LEDs, spectral ratio: R660/B450/G550= 57/17/26) on growth, physiology and yield of hydroponic cultivated green oakleaf lettuce indoor was performed. The results showed plant height, leaf number, photosynthetic pigment content, leaf area, leaf thickness, root parameters, Brix and yield increased as light intensity increased. Among the lighting treatments, 190 µmol.m-2s-1 treatment had the best effect on the growth and yield of green oakleaf lettuce.

• Barriers and Solutions Proposed for Scaling - out the Sustainable Rice Productionin the Mekong River Delta

  Le Canh Dung, Vo Van Tuan

  Received: 11-02-2024 / Accepted: 12-04-2024

   Abstract PDF (VIETNAMESE)

  Sustainable rice production (SRP) is one of the solutions to help increase the value of rice, while contributing to reducing greenhouse gas emissions to achieve the government's Net zero goal. Implementing and scaling-out SRP meeting standards are a challenge for the rice industry and localities. This study aimed to assess the current situation,barriers and influencing factors to propose solutions for developing the SRP in the Mekong Delta. The study surveyed 318 farming households implementing the SRP standard in 3 provinces An Giang, Dong Thap and Can Tho in 2022. Besides descriptive statistics, the study used binary regression to determine influencing factors and level of compliance with SRP standards. The results show that about 7.2% of farming households met the SRP standard. The education level of the household head, land area size and contract production exerted a positive influence on the probability of meeting the SRP standard. Proposed solutions to increase the proportion of farming households that meet SRP standards are to improve farmer capacity, increase the proportion of young people in production, and improve straw collection and stubble treatment, local service infrastructure, and contract farming according to the rice value chain approach.

• EffectofFly Ash on Organic Substrates andGrowth ofGerbera jamesonii

  Nguyen Thi Minh, Nguyen Tu Diep, Pham Minh Hieu

  Received: 12-06-2023 / Accepted: 07-03-2024

   Abstract PDF (VIETNAMESE)

  The purpose of this study was to determinethe effect offly ash ontheorganic substratesfor growing flower and ornamental plants in order to effectivelyreuse theagricultural and industrialwaste sources. The fly ash was added into rawmaterials toproduce organic substrate at different rates: 5%, 10%, 15% and 20% and incubated by the semi-aerobic method. The results indicated that the organic substrate from agricultural by-products supplemented with fly ash had goodnutritional content, limited presence of E. coliand Salmonella, withneutral pH, and acceptable heavy metal content(notexceeding QCVN 03-MT:2015/BTNMT standard) that ensures the growth and development of flowersand ornamentalplants. The experiment of growing Gerbera jamesoniion organic substrates supplemented with fly ash showed a cleareffect on growth rate, harvested yield, and the number of flowers harvested in the treatment supplemented with 15% fly ash with 1.75 flowers higher than the control without fly ash supplement 40%. Thefly ash rate of 10-15% appeared as appropriate range to add to the compost pile of organic substrates, of which 15% was most efficient for the growth of Gerbera jamesoniiand reduction of expenses during the crop care.

• Studying some Technical Measures to Improve the Yield and Quality of Van Ban Pear Variety in Lao Cai Province

  Vu Ngoc Lan, Nguyen Huy Duc, Tran Anh Tuan, Nguyen Thi Phuong Dung

  Received: 31-10-2023 / Accepted: 07-03-2024

   Abstract PDF (VIETNAMESE)

  The Van Ban pear is a fruittreethat brings high economic efficiency to local peoplein Lao Cai province which was at risk of eroding precious genetic resources due to the traditional farming practices of mountain people. Aims to effectively exploit and sustainably develop this pear variety, 3 experiments were conducted, including (1) Study on the effects of fertilization treatmentson growth, yield and quality of Van Ban pear variety; (2) Study on pruning combined with pulling branches techniques on growth, yield and quality of Van Ban pear variety; (3) Study on the effects of some soil moisture retention measures on growth, yield and quality of Van Ban pear variety. Research results indicatedthat applying 1,200 kg/ha of Viet Nhat synthetic NPK fertilizer (15 : 15 : 15 + TE) gavea high fruiting rate (4.47%); large fruit (353.1 g/fruit), high yield (213.9 kg/tree. Pruning branches three times a year combined with pulling branches once increasedfruit setting rate, number of fruits/tree, productivity, fruit setting rate (4.73%), fruit size (349.9 g/fruit) andthe actual yield reached190.3 kg/tree.The most optimal treatment to retain moisture was plant matter’s addition to the soil, combined with applying AMS-1 moisturizing agent at an amount of 0.1kg/tree. Fertilizing and moisturizing as above had enhancd fruit quality (increased dry matter content, total sugar, brix and vitamin C content) of Van Ban pear variety.

• Evaluation ofSalt Tolerance of Newly Collected Rice Accessions

  Nguyen Anh Dung, Vu Van Liet

  Received: 27-11-2023 / Accepted: 07-03-2024

   Abstract PDF (VIETNAMESE)

  This study was carried out to evaluate agronomic characteristics, salttolerance and the presence of QTL Saltolof newly collected rice accessions throughfield experiment,artificial salinity treatment and molecular identification. The experiments on agronomic characteristics and salt tolerance were carried out according to the method of IRRI, 1997 and 2013 at the FieldCrops Research Institute, Gia Loc district, Hai Duong province whilemolecular marker analysis was conducted at Vietnam National University of Agriculture, Gia Lam district, Ha Noi city. Theevaluation results showed that the rice accessions were diverse in growth duration, plant height, flag leaf length, and panicle length. Out of 39 accessions, 6 promising ones were selectedwith good salt tolerance: Lua soi, M3, HHZ8-SAL6-SAL3-SAL1, HHZ8-SAL6-SAL3-Y2, HHZ12-SAL8-Y1-SAL1 and Hasawi IRGC 16817and 22 rice accessions carrying SaltolQTL. Thus, the selection of materials for breeding salt-tolerant rice varieties should combine the evaluation of agronomic characteristics with artificial salt tolerance assessment and molecular markers.

• EffectofFly Ash on Organic Substrates andGrowth ofGerbera jamesonii

  Nguyen Thi Minh, Nguyen Tu Diep, Pham Minh Hieu

  Received: 12-06-2023 / Accepted: 07-03-2024

   Abstract PDF (VIETNAMESE)

  The purpose of this study was to determinethe effect offly ash ontheorganic substratesfor growing flower and ornamental plants in order to effectivelyreuse theagricultural and industrialwaste sources. The fly ash was added into rawmaterials toproduce organic substrate at different rates: 5%, 10%, 15% and 20% and incubated by the semi-aerobic method. The results indicated that the organic substrate from agricultural by-products supplemented with fly ash had goodnutritional content, limited presence of E. coliand Salmonella, withneutral pH, and acceptable heavy metal content(notexceeding QCVN 03-MT:2015/BTNMT standard) that ensures the growth and development of flowersand ornamentalplants. The experiment of growing Gerbera jamesoniion organic substrates supplemented with fly ash showed a cleareffect on growth rate, harvested yield, and the number of flowers harvested in the treatment supplemented with 15% fly ash with 1.75 flowers higher than the control without fly ash supplement 40%. Thefly ash rate of 10-15% appeared as appropriate range to add to the compost pile of organic substrates, of which 15% was most efficient for the growth of Gerbera jamesoniiand reduction of expenses during the crop care.

• Studying some Technical Measures to Improve the Yield and Quality of Van Ban Pear Variety in Lao Cai Province

  Vu Ngoc Lan, Nguyen Huy Duc, Tran Anh Tuan, Nguyen Thi Phuong Dung

  Received: 31-10-2023 / Accepted: 07-03-2024

   Abstract PDF (VIETNAMESE)

  The Van Ban pear is a fruittreethat brings high economic efficiency to local peoplein Lao Cai province which was at risk of eroding precious genetic resources due to the traditional farming practices of mountain people. Aims to effectively exploit and sustainably develop this pear variety, 3 experiments were conducted, including (1) Study on the effects of fertilization treatmentson growth, yield and quality of Van Ban pear variety; (2) Study on pruning combined with pulling branches techniques on growth, yield and quality of Van Ban pear variety; (3) Study on the effects of some soil moisture retention measures on growth, yield and quality of Van Ban pear variety. Research results indicatedthat applying 1,200 kg/ha of Viet Nhat synthetic NPK fertilizer (15 : 15 : 15 + TE) gavea high fruiting rate (4.47%); large fruit (353.1 g/fruit), high yield (213.9 kg/tree. Pruning branches three times a year combined with pulling branches once increasedfruit setting rate, number of fruits/tree, productivity, fruit setting rate (4.73%), fruit size (349.9 g/fruit) andthe actual yield reached190.3 kg/tree.The most optimal treatment to retain moisture was plant matter’s addition to the soil, combined with applying AMS-1 moisturizing agent at an amount of 0.1kg/tree. Fertilizing and moisturizing as above had enhancd fruit quality (increased dry matter content, total sugar, brix and vitamin C content) of Van Ban pear variety.

• Evaluation ofSalt Tolerance of Newly Collected Rice Accessions

  Nguyen Anh Dung, Vu Van Liet

  Received: 27-11-2023 / Accepted: 07-03-2024

   Abstract PDF (VIETNAMESE)

  This study was carried out to evaluate agronomic characteristics, salttolerance and the presence of QTL Saltolof newly collected rice accessions throughfield experiment,artificial salinity treatment and molecular identification. The experiments on agronomic characteristics and salt tolerance were carried out according to the method of IRRI, 1997 and 2013 at the FieldCrops Research Institute, Gia Loc district, Hai Duong province whilemolecular marker analysis was conducted at Vietnam National University of Agriculture, Gia Lam district, Ha Noi city. Theevaluation results showed that the rice accessions were diverse in growth duration, plant height, flag leaf length, and panicle length. Out of 39 accessions, 6 promising ones were selectedwith good salt tolerance: Lua soi, M3, HHZ8-SAL6-SAL3-SAL1, HHZ8-SAL6-SAL3-Y2, HHZ12-SAL8-Y1-SAL1 and Hasawi IRGC 16817and 22 rice accessions carrying SaltolQTL. Thus, the selection of materials for breeding salt-tolerant rice varieties should combine the evaluation of agronomic characteristics with artificial salt tolerance assessment and molecular markers.

• Isolation and Characterization of Lasiodiplodia theobromaeStrain Causing Dieback Disease on Grape in Ha Noi and Hung Yen

  Nguyen Thanh Huyen, Dang Thi Thanh Tam, Do Thuy Hien

  Received: 30-08-2023 / Accepted: 25-12-2023

   Abstract PDF (VIETNAMESE)

  Dieback is one of the most common diseases on grape that is caused by fungi belonging to the Botryosphaeriaceae family. Among these fungi, Lasiodiplodia theobromaehas been identified as the most virulent species. Unfortunately, the current treatments for this disease are still challenging and not truly effective. This study was conducted to determine the causative agent and biological characteristics of the grape dieback-causing fungus in Hanoi and Hung Yen as a basis for guiding effective measures in the prevention and treatment of dieback. From grape samples showing dieback disease collected in Hanoi and Hung Yen, three fungal strains were isolated through culture on the PDA medium and these strains were subsequently re-infected onto leaves and stems of grapes. Among them, CK1 and DN1 strains showed similar mycelial characteristics and pathogenicity. Therefore, the CK1 strain was selected for further experiments. Through the molecular identification method with the ITS1/ITS4 primer pair, the CK1 strain was confirmed asLasiodiplodia theobromae and was named L. theobromae CK1. L. theobromae CK1 exhibited good growth on the PDA medium, and the optimal conditions for the strain were 35C and a pH in the range of 6-8. In addition, during its growth, this fungal strain was also capable of producing cellulase, xylanase, and pectinase.

• EnhancingTechnical Efficiency ofDairy Farmers Through Value Chain Financing: ACaseStudy in Duy Tien Town, Ha Nam Province

  Bui Thi Lam, Le Thi Thanh Hao, Bui Thi Nga, Vu Ngoc Huyen

  Received: 28-07-2021 / Accepted: 20-11-2023

   Abstract PDF (VIETNAMESE)

  This study was conducted to analyzethe determinants ofdairyfarmers’ technical efficiency in Duy Tien town, Ha Nam province by using Stochastic Frontier Analysis (SFA). Research results show that the technical efficiency of localdairy farmers reached 77.8%, ranging from 13.8% to 96.9%. To improve thetechnical efficiency, dairy farmers need to change in the input usage, such as: (i) reducing synthetic feedsand increasing green ones; (ii) paying more attention to disease prevention and treatment (i.e., veterinary cost); (iii) increasing breeding areas; (iv) moving dairy farming from residential areas to concentrated livestock areas; and, (v) scaling up the herd size to achieve the economies of scale. In addition, receiving technical support from purchasing enterprises (internal finance) and accessing banking credit (external finance) play important roles in improving technical efficiency and income of households. These are the two core activities in the agricultural value chain financing approach, howeverthis approach is still not popular in Vietnam.

• Swine Diarrhea Syndrome in Pre-weaning Piglets and Associated Risk Factors in Industrial Pig Farm

  Nguyen Van Trong, Nguyen Ngoc Dinh, Nguyen Van Thai

  Received: 17-04-2023 / Accepted: 29-08-2023

   Abstract PDF (VIETNAMESE)

  Diarrhea in pre-weaning piglets is one of the most common diseases in modern pig production, causing high mortality, reducing growth rate and increasing treatment costs. This prospective study on a commercial pig farm was conducted to identify the diarrhea prevalence, the factors associated with diarrhea, and the effect of diarrhea on weaning weight of piglets. The results showed that the proprtion of cumulative diarrhea for 21 days in suckling piglets was 36.70% (95% CI 32.91-40.62) with a mortality rate of 0% (95% CI: 0-0.59). Neonatal piglets experienced diarrhea from 1 day of age (11.86%), peaked at day 5 (22.6%), then gradually decreased and kept at a low level from 11 days of age to weaning. There were 3 factors associated to diarrhea in suckling piglets including birth weight of piglets, diarrhea inflicted sows and metritis inflicted sows. The factors of diarrhea duration and birth weight were related to maternalassociated weaning weight of piglets.

• Effects of Stocking Density on Growth Performanceand Body Surface Temperature in Broilers

  Che Minh Tung, Nguyen Thi My Nhan

  Received: 17-04-2023 / Accepted: 29-08-2023

   Abstract PDF (VIETNAMESE)

  The objective of this study was to evaluate effect of stocking density on growth performance and surface temperature of different body parts in broilers. A total of 1000 one-day-old broiler chicks (Ross 308) were assigned to two treatments in a completely randomized design. The stocking density treaments were (1) 9 chicks/m2(SD 9) and (2) 13 chicks/m2(SD 13). Each treatment had 20 replicate pens (50% female and 50% male/pen). The experimental results showed that there was no difference in average daily weight gain between two treatments (P >0.05). However, broilers in the SD 9 group had a better feed conversion ratio than those in the SD 13 group (P = 0.048). The survival rate of broilers in the SD 9 group (99.8%) was greater (P <0.001) than that of broilers in the SD 13 group (95.8%). Moreover, the body surface temperature of broilers in the SD 9 group (32,3C) was much lower (P = 0.003) than that of broilers in the SD 13 group (36.0C). A similar trend was also observed for the shank and neck surface temperature of broilers (P <0.05). Briefly, the stocking density of 9 broilers/m2improved the feed conversion ratio, survival rate and body surface temperature of broilers as compared with the stocking density of 13 broilers/m2.

• Characterization of Potential Cellulose-Degrading Bacteria Isolated from by-Products of Wood Processing

  Dang Thi Thanh Tam, Tran Thi Yen, Nguyen Thanh Huyen

  Received: 03-03-2023 / Accepted: 04-08-2023

   Abstract PDF (VIETNAMESE)

  Cellulase is an enzyme used in many fields, such as agriculture, industry, and medicine. Among microorganisms capable of synthesizing cellulase, bacteria are evaluated as having high enzyme activity, stability, and limited environmental pollution. This study was conducted to isolate and characterize bacteria strains with high ability to degrade cellulose, which can serve as a basis for research treatment methods for cellulose-containing agricultural by-products more effective. From wood processing by-products collected in two provinces, Hung Yen and Hanoi, by inoculating method on a selective medium containing 1% CMC (Carboxymethyl cellulose), 23 strains of bacteria capable of degrading CMC (carboxymethyl cellulose) were isolated, two strains, C4 and C2,1 were potential strains showing high ability to degrade carboxymethyl cellulose. Colony morphology, cell morphology, and biochemical characteristics showed that both strains belonged to genusBacillussp. After evaluating effects of culture conditions on cellulase activity of two selected strains, strain C4 synthesized cellulase with the highest activity when cultured in LB medium, shaking condition, at 35C, pH 8.0 for 24 hours; while strain C4 synthesized cellulase with the highest activity when cultured in LB medium, shaking condition, at 35C, pH 6,0 for 72 hours. Finally, evaluation of the ability to decompose rice straw and rotten wood in vitroshowed that the efficiency of these strains increased 3.02-4.22 times compared with the control.

• In vitroPropagation of Gardenia jasminoides Ellis

  Dinh Thi Thu Le, Bui Thi Hai Hoa, NguyenThi My Uyen, Doan Thi Thuy Hang, Ninh Thi Phip, Nguyen Xuan Truong, Pham Van Cuong, Dinh Truong Son

  Received: 07-12-2022 / Accepted: 07-03-2023

   Abstract PDF (VIETNAMESE)

  Gardenia (Gardenia jasminoidesEllis) is not only valuable as a food but also a medicinal plant used in the treatment of illnesses including jaundice, headaches, fever, inflammation, hepatic disorders, and hypertension.The current study aimed to establish an efficient protocol for in vitropropagationof Gardenia jasminoidesEllis with high multiplication rate and healthy plants. The pre-mature Gardenia fruits were the most suitable plant parts for initiation of in vitroculture. Seeds sterilized using 0.5% Presept solution for 10 minutes gave the highest sterilization (94.67%) and germination rate (90.59%). MS medium supplemented with 1.5 mg/lbenzyladenine gave multiplication rate of 7.29 shoots/explant. MS medium supplemented with 30-40 g/l sucrose and 150ml of coconut water/l gave vigorous growth of microshoots and good shoot quality. MS medium supplemented with 0.5 mg/l IBA or half-strength of MS medium recorded100% rooting rate, normal root morphology, and well growing plants.

• Favorable Culture Conditions for Mycelial Growth of Mutated Strain DTL1,25of Lingzhi Mushroom (Ganoderma lucidum)

  Nguyen Thi Giang, Pham Thi Thu, Pham Bich Hien, Pham Xuan Hoi

  Received: 27-09-2022 / Accepted: 20-12-2022

   Abstract PDF (VIETNAMESE)

  The objective in this study was to determine the optimal nutrient environment and culture conditions for mycelial growth of mutated strain DTL1,25 of Lingzhi (Ganoderma lucidum). Each treatment was randommized complete block design andreplicated three times. The results of the experiment indicated that in the first stage of propagation, the optimal medium for mycelial growth was the background medium from the extract of 200g barley seeds supplemented with 2% glucose, 0.1% malt extract and 2% agar with medium pH of 6 and temperature at 26 ± 1C. In the second stage of propagation, mycelium growth of the mutant strain DTL1,25 was improved on environment consisting of 99% rice grain + 1% CaCO3with autoclaving mode at 121C for 120 minutes. At the third stage, the optimal composition included 99% rice grain + 1% CaCO3with autoclaving mode at 121C for 150 minutes.

• Review: Bacteriocins - Classification, Antibacterial Activities and Applications

  Ninh Thi Thao, Nong Thi Hue, Dinh Truong Son, Nguyen Xuan Canh

  Received: 01-06-2022 / Accepted: 27-09-2022

   Abstract PDF (VIETNAMESE)

  Bacteriocins produced bybacteria are ribosomally synthesized peptides or proteins with antimicrobial activity that either kill or inhibit the growth of closely-related or non-related bacterial strains. Bacteriocins appear to be a weapon against microorganisms due to their specific properties of natural origin, high structural and functional diversity and heat stability. Recent studies have identified bacteriocins for application in food technology as natural bio-preservatives or in agriculture as biological control agents. Bacteriocins also present a potential approach for the treatment of pathogenic microbial infections and cancer diseases in humans and a promising alternative for replacing conventional antibiotics to treat multidrug-resistant bacteria. However, the majority of application-oriented studies were mainly conducted in laboratory conditions and focused on bacteriocins from Gram-positive bacteria. In this review, we summarized the classification and antibacterial activities of bacteriocins as well as discussed current achievements and potential applications of bacteriocins in the food preservationand inagricultural and pharmaceutical fields. Our paper provides an overview of bacteriocins, thus, orients the application of bacteriocins in Vietnam.