Published: 2021-06-30

Identification of porcine circovirus type 2 (PCV2), type 3 (PCV3) and porcine parvovirus (PPV) in swine by multiplex PCR test

Phat X. Dinh, Trang T. T. Nguyen, Hiep L. X. Vu, & Thoai K. Tran
Electronic version: 30 Jun 2021 | DOI: 10.52997/jad.2.03.2021
Abstract | PDF (583.6K)


This study aimed to simultaneously detect three important viruses reported to be involved in the reproductive problems of sows. A multiplex PCR (mPCR) test was developed to provide rapid diagnosis of porcine circovirus type 2 and 3 (PCV2, PCV3) and to illustrate parvovirus (PPV) prevalence in sow herds. Three pairs of specific primers were designed to target PCV2 Cap gene, PCV3 Cap gene and PPV NS1 gene, with predicted mPCR products of 702 bp, 267 bp and 380 bp, respectively. The detection limit of mPCR was 100 copies/reaction per target gene. The mPCR was run against a panel of 94 swine serum samples whose infection status had been pre-determined by commercial real-time PCR kits. Sequencing of mPCR products performed with clinical serum samples accurately confirmed the results. Overall, the results indicated that the mPCR functioned accurately and specifically and matched 100% with the single-target real-time PCRs. The mPCR was developed successfully and can be used in routine diagnosis of PCV2, PCV3 and PPV.

Quantities and antibiotic resistance of microorganisms in some microbial products for animals in Vietnam

Hoa T. K. Ho, Nhi N. T. T. Nguyen, & Ngoc H. Le
Electronic version: 30 Jun 2021 | DOI: 10.52997/jad.4.03.2021
Abstract | PDF (649.1K)


The aims of the study were to look into the quantities of live beneficial microorganisms and antibiotic resistance of bacterial strains in several probiotic products used for food animals in the market. Ten probiotic products that claim to contain beneficial bacteria and fungi were examined. Eight products are said on the label to contain Lactobacillus spp., nine contain Bacillus spp., five contain yeasts and two have molds. The results showed that eight products did not have the microbial quantities or/and composition of microorganisms as saying on their labels. Of eight products which claim to contain Lactobacillus spp., the bacteria were isolated from only four, of which three had Lactobacillus counts at least ten-fold as low as the numbers on the labels. Spore-forming bacilli were isolated from all nine Bacillus-containing products. However, two products had the bacterial counts at least 10-fold as low as the numbers printed on the labels. Among five products stated to contain yeasts, the organisms were recovered from samples of only one. Seven Lactobacillus and fifteen Bacillus isolates from all samples that had bacterial growth were tested for their susceptibility against seven common antibiotics using Kirby-Bauer disk diffusion method. The results revealed that all the Lactobacillus isolates showed susceptibility to the tested antibiotics except kanamycin. All 15 Bacillus isolates were susceptible to ampicillin, kanamycin, and ciprofloxacin; five isolates were intermediately resistant to tetracycline; one isolates resisted erythromycin, and one isolates was resistant to vancomycin. The results of this study would provide information for farm practice in choosing antibiotics used together with antibiotics to maintain or/and restore the gut microflora after antibiotic treatment.

Relationship between the ratio of villous height:crypt depth and gut bacteria counts as well production parameters in broiler chickens

Dung T. N. Nguyen, Ngoc H. Le, Vinh V. Pham, Parra Eva, Forti Alberto, & Hien T. Le
Electronic version: 30 Jun 2021 | DOI: 10.52997/jad.1.03.2021
Abstract | PDF (878.8K)


The villous height to crypt depth (V:C) ratio is one of the most significant parameters which is associated with the nutrients’ absorption and greater body weight. The objective of this study was to assess the relationship between V:C ratio, gut bacteria counts and production parameters in broiler chickens. A total of 100 individual broilers were randomly selected from a farm with 40,000 Ross 308 chickens and slaughtered for sampling at three different ages including 14, 28 and 37 day old. Villous height and crypt depth were measured for each section of the small intestine to calculate V:C ratio. Intestinal score and gut microbiology including total coliforms, lactic acid bacteria and Salmonella prevalence were assessed. At day 37, besides those parameters, the carcass, breast, legs and wings were taken for weight measurements. Leg and breast color was also measured. Data were statistically analyzed by STATA software to explore the relationship between V:C and those parameters. The results showed the positive correlation between V:C of duodenum and the number of lactic acid bacteria at 28 days of age (P < 0.05). Moreover, the leg yield was negatively related to the V:C ratio of jejunum (P < 0.05). No significant correlations were found between V:C ratio and other parameters. The results indicated the potential of controlling V:C ratio to improve gut health and meat quality of broiler chickens and thus, further studies should be conducted to fully evaluate these correlations.

Genetic analysis of African swine fever virus based on major genes encoding p72, p54 and p30

Duy T. Do, Hop Q. Nguyen, Duyen T. M. Nguyen, Nam M. Nguyen, Dung T. N. Nguyen, & Han T. Q. Luu
Electronic version: 30 Jun 2021 | DOI: 10.52997/jad.3.03.2021
Abstract | PDF (633.2K)


African swine fever (ASF) is reported as a highly contagious hemorrhage lethal disease of domestic and wild swine. The causative agent of ASF is a large enveloped DNA virus with a complex structure. There are twenty-four ASFV genotypes described to date. However, in Vietnam, only genotypes II had been previously described. The genetic characterization of ASFV enhances the understanding of ASF epidemiology in terms of the extent, severity, source, and potential genetic variations among ASFV strains circulating in Southern Vietnam. Twenty ASFV strains were collected from pigs with ASFV-infected clinical signs from 10 provinces during 2019 - 2020. Partial B646L (p72) gene, complete E183L (p54), and CP204L (p30) genes were amplified, purified, and sequenced. Phylogenetic analysis confirmed the circulation of genotype II by both the partial B646L (p72) and full-length E183 (p54) gene sequencing. Analysis of the p72, p54, and p30 regions did not indicate any change in the nucleotide and amino acid sequences among these strains. The results of this study revealed that these ASFVs shared high homology to ASFV isolates detected in Northern Vietnam and China.

Efficacy of a commercial supplement added to drinking water in broilers fed aflatoxin-contaminated diets

Tung M. Che, Hien T. Le, Vi Q. Tran, Matthieu Le-Goff, & Phat T. Luong
Electronic version: 30 Jun 2021 | DOI: 10.52997/jad.5.03.2021
Abstract | PDF (486K)


The objective of the experiment was to evaluate effects of water supplementation with a commercial supplement (VitalSea®) on growth performance, mortality and serum concentrations of aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) in broilers fed diets with aflatoxin (AF) contamination. A total of 960 day-old mixed-sex chicks (Ross 308, initial BW: 46.28 ± 0.25 g/chick) were randomly assigned to 1 of 4 treatments. The treatments included (1) basal diet without AF contamination and supplementation (negative control, NC), (2) AF-contaminated diet without supplementation (positive control, PC), (3) AF-contaminated diet + water supplementation with 0.5 mL VitalSea®/10 kg BW (VitalSea 1) and (4) AF-contaminated diet + water supplementation with 1.0 mL VitalSea®/10 kg BW (VitalSea 2). Each treatment was replicated with 8 pens of 30 birds (50% male, 50% female) each. Contaminated diets containing 30 µg AF/kg were fed to birds for Phase 1 (d 1-21) only. Water supplemented with VitalSea® was administered to birds for 5 days (d 22-26). In Phase 1 (d 1-21), there were no differences in ADG and ADFI among treatments (P > 0.05). In Phase 2 (d 22-35), there was a trend that the ADG of VitalSea 1 (68.66 g/d) and VitalSea 2 (68.56 g/d) was higher (P < 0.06) than that of the PC (62.61 g/d). Water supplemented with VitalSea® improved the FCR of broilers compared with the PC (P < 0.01). Over a 5-week study, broilers of the PC had a worse FCR than those of the other treatments (P < 0.01). At d 21, the serum LDH concentration of the PC was higher than that of the NC (P = 0.026). Briefly, addition of VitalSea® to drinking water for 5 days improved growth rate and feed efficiency of broilers fed AF-contaminated diets.

Accumulation and distribution of lead (Pb) in different tissues of Lucky bamboo plants (Dracaena sanderiana)

Lien B. Ho, Biet V. Huynh, & Tuyen C. Bui
Electronic version: 30 Jun 2021 | DOI: 10.52997/jad.7.03.2021
Abstract | PDF (1.8M)


Lucky bamboo plants (Dracaena sanderiana) were used to study the accumulation and distribution of lead (Pb) in tissues of root, stem and leaf, as well as the impact of lead accumulation on the anatomical structure of these tissues. Dracaena sanderiana plants were exposed to Pb(NO3)2 solution at the Pb concentrations of 0; 200; 400; 600; 800; 1,000; 2,000; 3,000 and 4,000 mg/L for 60 days. The results showed that the more the Pb concentration was used, the more the amount of lead was accumulated and deposited. The tolerance limit of Dracaena sanderiana was 800 mg/L of Pb in water. The lethal concentration for plants was 4,000 mg/L Pb. When the concentrations of Pb in the solution were higher than the tolerance limit of the plant, the growth of Dracaena sanderiana could be inhibited. Dracaena sanderiana could accumulate up to 39,235 mg/kg Pb in the presence of Pb at 800 mg/L. Lead was accumulated mainly in roots (97.5%) and deposited mainly in the cell walls and the spaces between cells in tissues of roots. In the stems and leaves of Dracaena sanderiana, lead accumulation was limited and distributed mainly around vascular bundles. Lead accumulation caused changes in the anatomical structure of root, stem and leaf tissues. The accumulation and distribution of Pb is mainly in the cell walls and the space of cells; it could be a detoxification mechanism for Pb of Dracaena sanderiana.

Genetic relationship analysis of Dendrobium anosmum Lindl. var. semialba based on the chloroplast matK and rbcL genes

Dien T. K. Pham, Biet V. Huynh, & Truong Mai
Electronic version: 30 Jun 2021 | DOI: 10.52997/jad.6.03.2021
Abstract | PDF (634.5K)


Dendrobium anosmum Lindl. var. semialba has variants of flower shapes. Currently, it has high economic value and is favored on the market. In this study, the genetic relationship of Dendrobium anosmum Lindl. var. semialba species was determined based on the analysis of chloroplast matK, rbcL gene sequences. The matK and rbcL genes of twelve species were amplified and their DNA sequenced. These DNA sequences were compared, calculated genetic distance and constructed phylogenetic tree. The results showed that 100% of samples were amplified and sequenced successfully. The analysis of matK sequences showed that 12 species had very high genetic similarity with the low genetic distance of 0 - 0.001; the nucleotide sequences were almost unchanged except for one variable nucleotide position in TB1 and TB1 was in a separate branch of the phylogenetic tree. The analysis of rbcL sequences showed that all species had a low genetic distance of 0 - 0.012 and had 7 mutant positions in nucleotide sequences of TB1 and TB5. These species were in a separate branch of the phylogenetic tree while the other species were grouped in the other branch of the phylogenetic tree. The study provided a reliable molecular database of the Dendrobium anosmum Lindl. var. semialba for identification, classification, biodiversity assessment and conservation of genetic resources.

Influence of spray-drying conditions on the physicochemical properties of red-fleshed dragon fruit (Hylocereus polyrhizus) powder made from peel and flesh

Diep T. N. Duong, Quan A. Do, Ngoan H. Nguyen, Tram P. N. Pham, Trang L. H. Do, Diep T. N. Duong, & Binh Q. Hoang
Electronic version: 30 Jun 2021 | DOI: 10.52997/jad.8.03.2021
Abstract | PDF (600.7K)


Pitaya production has been increasing, that offers abundant material for food processing. New product development would greatly add value for this produce. The present study focused on the effects of spray-drying conditions such as coating material concentration and spray-drying temperature on the physicochemical characteristics of red-fleshed dragon fruit powder made from peel and flesh. The sample quality was influenced by two experimental factors, which were the maltodextrin concentration and the spray-drying inlet temperature. The samples spray-dried at 140oC to 150oC with 15% maltodextrin (w/w) gave the powder with the highest betacyanin, polyphenol, and vitamin C retention results (97.62 - 98.86%, 90.66 - 91.63%, and 63.40 - 63.68%, respectively). The moisture content, water activity and solubility of the sample was 3.88% to 4.27%, 0.26 to 0.28 and 99%, respectively. Red-fleshed dragon fruit powder made from flesh and peel has numerous potentials in the beverage industry.