Published: 2018-12-31
Full Issue
Agribusiness and Economics
Application of SARIMA model to forecasting the natural rubber price in the world market
Electronic version:
31 Dec 2018
| DOI:
10.52997/jad.1.06.2018
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Abstract
This study was conducted to develop a forecasting model to predict the price natural rubber in the world market by using the Seasonal Autoregressive Integrated Moving Average (SARIMA). The dataset for model development was collectedfrom series data of average monthly closing average prices in the natural rubber - Ribbed Smoked Sheet No.3 (RSS3) on the Tokyo Commodity Exchange (TOCOM) for the period of January 2007 - September 2018. The RSS3 price on the TOCOM provided the reference price for natural rubber in the world market. It resulted SARIMA(2,1,2)(1,1,1)12 model was selected as the bestfit model. The model achieved 0.000 for Probability value (P-value); 8.86 for Akaike Information Criterion (AIC) and 9.01 for Schwarz Information Criterion (SIC); 6.68% for Mean Absolute Percentage Error (MAPE) and 21.43 for Root Mean Square Error (RMSE). This model was used to forecast the world’s natural rubber price during October 2018 - December 2020. This study may be helpful to the farmers, traders, and the governments of the world’s important natural rubber producing countries to plan policies to reduce natural rubber production costs and stabilize the natural rubber price in the future, such as by setting suitable areas for natural rubber plantation in each country, and defining appropriate and sustainable alternative crop areas in each country.
Animal Sciences, Veterinary Medicine, Aquaculture and Fisheries
Detecting toxin genes of Clostridium perfringens isolated from diarrhea piglets using multiplex PCR
Electronic version:
31 Dec 2018
| DOI:
10.52997/jad.4.06.2018
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Clostridium perfringens is currently classified into five types (A, B, C, D, E) based on the different toxins produced. TypeA and C are known as the causative agent of enteritis and enterotoxemia in newborn and young piglets with severe intestinal lesions including edema, hemorrhage and necrosis. A multiplex PCR (mPCR) was developed in order to quickly and early determine the presence of genotypes of C. perfringens based on their genes of cpa, cpb, cpb2 and cpe encoding alpha toxin, beta toxin, beta2 toxin and enterotoxin with predicted products of 324 bp, 196 bp, 107 bp and 257 bp respectively.
The detection limit of the mPCR assay was 1 × 103 copies/reaction for each gene. Sequencing of mPCR products performed with clinical samples collected from C. perfringens suspected pigs showed that the mPCR test functioned specifically. In conclusion, the developed mPCR test successfully detected the presence of genes cpa, cpb, cpb2 and cpe in the examined samples. Analysis of the bacteria isolated from field samples of diarrheal piglets collected in this study indicated that C. perfringens carrying gene cpa counted for 96.66% and 3.33% was identified as C. perfringens carrying genes cpa and cpb concurrently. Gene cpe was not found in this study, while gene cpb2 was detected coincidently in 73.33% of the samples with cpa gene. The results indicate that the prevalence of these four toxin genes is cpa, cpb2, cpb and cpe in decending order.
Species composition and catch of sharks, rays and skates in Ba Ria - Vung Tau and Binh Thuan provinces of Vietnam
Electronic version:
31 Dec 2018
| DOI:
10.52997/jad.5.06.2018
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Research on 2,626 individuals of sharks, rays and skates in total of 123 fishing boats were sampled during 2015 to 2016 in Ba Ria - Vung Tau and Binh Thuan provinces. The results identified 77 species of sharks, rays and skates belong to 22 families and 10 orders in Ba Ria - Vung Tau and Binh Thuan provinces. Of these, 57 species were recorded in Ba Ria - Vung Tau and 48 species in Binh Thuan. The families were found in the highest number of species such as Carcharhinidae family with 9 species, Dasyatidae family with 19 species and Rajidae family with 5 species. The total catch of sharks, rays and skates was 23,599 tons in Ba Ria - Vung Tau and was 24,355 tons in Binh Thuan. Sharks, rays and skates ratio made up from 0.2% to 0.5% in total catch landing from landing sites. Total length of sharks ranges from 21.0 cm to 366.0 cm, disc length of rays fluctuates from 11.0 cm to 248.0 cm and skates have a range from 0.7 cm to 152.0 cm in disc length.
Efficacy of organic acids as an alternative to antibiotic growth promoters in weaned pigs
Electronic version:
31 Dec 2018
| DOI:
10.52997/jad.2.06.2018
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The objective of the experiment was to compare effects of dietary supplementation of organic acids (ProHacid Advance, PRO) and antibiotics on growth performance, diarrhea incidence, frequency of antibiotic treatment, and E. coli shedding in weaned pigs. A total of 224 crossbred weaned pigs [(Yorkshire x Landrace) x Duroc; 29 days old)] were allotted to 1 of 4 treatments with 7 replicate pens of 8 pigs each according to sex, litter origin and weight in an RCBD. The 4 dietary treatments included (1) basal diet + 50 mg/kg neomycin and 10 mg/kg enramycin (positive control, PC), (2) basal diet without antibiotics (negative control, NC), (3) As 2 + 0.25% PRO, and (4) As 2 + 0.5% PRO. Over a 4-week study, the results showed that there were no differences in the average daily gain and average daily feed intake of pigs among the 4 treatments (P = 0.328). However, pigs fed the PC diet (1.642) and 0.25% PRO-supplemented diet (1.641) had a lower feed to gain ratio (P < 0.05) than those fed the NC diet (1.808). The diarrhea incidence of pigs fed the 0.25% PRO-supplemented diet (7.36%) was lower (P < 0.01) than that of pigs fed the PC diet (11.61%), NC diet (16.70%), and 0.5% PRO-supplemented diet (10.08%). The frequency of antibiotic treatment of pigs consuming the 0.25% PRO-supplemented diet (4.67%) was lower (P < 0.01) than that of pigs consuming the PC diet (7.33%), NC diet (9.53%) and 0.5% PRO-supplemented diet (7.65%). No differences were found in the number of fecal E. coli among the 4 treatments. In brief, 0.25% PRO added to a nursery pig diet would be considered a potential alternative to the use of antibiotics in feed, but further research on this aspect is needed.
Field assessment of the efficacy of M.B., LIBDV and Winterfield 2512 strain vaccines against infectious bursal disease in chickens
Electronic version:
31 Dec 2018
| DOI:
10.52997/jad.3.06.2018
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Live virus vaccines are very important parts of the prevention of Infectious Bursal Disease (IBD) in chickens. However, the successful IBD vaccination depends on IBD field pressure, vaccination technique, the immune status of the chicken, and especially IBDV strains used in the vaccines which are able to break through a higher level of maternal-derived antibodies (MDA). The objective of this field study was to compare the efficacy of a new vaccine based on M.B. strain to other commercial vaccines (LIBDV and winterfiled 2512) in terms of speed of antibody immune response and interference to Newcastle Disease (ND) vaccination. Six houses of broilers, each with 15,000 to 16,000 chickens, were divided into two groups: (1) vaccinated with M.B. strain (group A) and (2) vaccinated with LIBDV or 2512 strains (group B). Blood samples were collected prior to the 1st IBD vaccination, and at 21, 28 and 35 days of age for IBD and ND antibodies. Comparison of lesion scores and uniformity of the bursa of Fabricius (BF) at 28 and 35 days of age was carried out. Results showed that both groups had good immune responses, but group A showed significantly higher IBD antibody titers at 28 and 35 days of age. Antibody titers for ND and histopathological lesion scores of the BF were not significantly different between the 2 groups. The BF in group A was more uniform and had fewer lesions when compared with that in group B. In conclusion, the IBD vaccine with an M.B. strain can provide better immunological efficacy than LIBDV and 2512 strains.
Biotechnology
Concentrations of heavy metals in water from the Southern coast of Vietnam
Electronic version:
31 Dec 2018
| DOI:
10.52997/jad.6.06.2018
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Concentrations of heavy metals (As, Cd, Pb and Hg) in water collected from seven coastal provinces between December 2012 and December 2015 were evaluated. The average total concentrations (µg/L) of As, Cd, Pb and Hg in water ranged from 2.90 to 6.38, < 0.039 to 0.322, 4.26 to 10.5 and < 0.01 to 0.118, respectively. The average concentrations (µg/L) of As, Pb and Hg in suspended particulate matters (SPM) ranged from 0.392 to 7.32, 0.365 to 18.7 and 0.01 to 0.038, respectively; whereas, Cd concentrations were not detected in most of SPM samples. There were positive linear relationships between concentrations of heavy metals in water and SPM, except for Cd. The results showed that the concentrations of metals analyzed in water remained below quality guidelines for the protection of aquatic life recommended by the international and Vietnamese organizations. However, As levels in 2/103 and 5/103 of watersamples exceeded the QCVN 10:2015/BTNMT for maximum permitted level using for aquaculture and aquatic life protection (20 µg/L) and the Canadian water quality guidelines for the protection of aquatic life (12.5 µg/L), respectively.
Investigation of fermentation conditions for Candida bombicola ACTT22214 from molasses and soybean oil for sophorolipid production
Electronic version:
31 Dec 2018
| DOI:
10.52997/jad.7.06.2018
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Sophorolipid (SL) is a biosurfactant belonging to the glycolipids group and was produced by harmless Candida bombicola ACTT22214 and has been widely used in many fields in our life. In order to search for appropriate condition for C. bombicola fermentation producing SL with high efficiency, this study focused on the investigation of the soy oil concentration, molasses concentration, fermentation time, pH and temperature. SL products were tested for antimicrobial activity, antioxidant, emulsifier, foaming ability. The highest content of SL was 43.27 ± 0.30 g/L under conditions of: soybean oil content 5%, molasses content 150 g/L, fermentation time 7 days, pH = 5, 28oC fermentation temperature. The antibacterial activity of SL was good: the highest resistance to Candida albicans (16.33 ± 1.15 mm), good resistance to Bacillus spizizenii (13.67 ± 0.58 mm), resistance to Staphylococcus aureus (12.67 ± 1.15 mm), relatively weak resistance to Pseudomonas aeruginosa (11.33 ± 0.58 mm) and Escherichia coli (9.67 ± 0.58 mm). The antioxidant capacity of SL was quite high with an IC50 value of 6.024 mg/mL. The emulsifying capacity of SL was equivalent to the emulsification of the tween 20 at a concentration of 5 – 10 mg/mL. SL had the ability to foam evenly from concentrations of 5 to 20 mg/mL but not higher than the corresponding concentrations of tween 20, SL was smooth, even, stable longer than tween 20.
Food Science and Technology
Total phenolic content and antioxidant activity of sesame cake aqueous extracts
Electronic version:
31 Dec 2018
| DOI:
10.52997/jad.10.06.2018
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The objective of this study was to investigate the efficiency of phenolic extraction and antioxidant activity from sesame cake using water extraction method and to evaluate the possibility of employing microwave irradiation to improve the extraction yield. The result showed that extraction temperature had major influence on total phenolic content and antioxidant activities of the extracts, whereas extraction time was found to be insignificant. The optimum extraction condition recommended were 90oC for 30 min in this research. Furthermore, microwave pre-treatment at 120 s could have significantly positive influence on the overall extraction yield, especially the total phenolics and antioxidants based on FRAP assay. Therefore, the obtained results suggest that sesame aqueous extracts could be a source of antioxidants with more feasible applications in food as well as other industries.
Effects of film coating materials on the quality of postharvest ‘Sanh’ orange fruits (Citrus nobilis var. Typica) during storage
Electronic version:
31 Dec 2018
| DOI:
10.52997/jad.8.06.2018
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Postharvest orange fruit coating is an effective method to replace natural waxes which lost during washing and handling.The coatings can reduce water loss and impart gloss to the fruit. In this study, the oranges were stored at room temperature (30 ± 2oC) with five coating materials: polyethylene (PE), and polypropylene (PP) bags, polyvinyl chloride (PVC) film, Citra Shine preservatives and 1% chitosan and the control were used. Some typical nutritional values and weight loss were determined during storage time. Research results show that PVC coated ‘Sanh’ oranges could be prolonged their shelf life up to 25 days with low damage ratios (7.10%, lower than other bags) which were acceptable in appearance with green peel color. Ascorbic acid content still maintained at a high level (12.32 mg/100 g), and weight loss relatively low (13.91%). Moreover, pH (3.77) and TSS (9.70) values did not significantly change during storage time.
Factors affecting betacyanin stability in juice of LD5 Red-fleshed dragon fruit (Hylocereus polyrhizus)
Electronic version:
31 Dec 2018
| DOI:
10.52997/jad.9.06.2018
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In Binh Thuan province (Vietnam), the red-fleshed dragon fruit (Hylocereus polyrhizus), concretely LD5 variety majorly grows and contains a large amount of betacyanin, a natural colourant that potentially applied to many products in the food industry. In this study, the processing factors possibly influencing the betacyanin stability in the red-fleshed dragon fruit juice were in turn investigated. The heating treatment included 2 factors: temperature (65, 75 and 85oC) and heating time (10, 20 and 30 minutes); while the pH values ranged between 3.0 to 7.0 and the ascorbic acid addition varied in concentrations (0.1, 0.2, 0.3, 0.4 and 0.5% w/w). The processed fruit juice was stored in different packaging materials (plastic and glass) with and without light exposure for 5 weeks to monitor the retained betacyanin. The results showed that the betacyanin was remained with the highest proportion (0.84 ± 0.02) at 0.3% ascorbic acid addition, pH 4.0 and heat treatment at 65oC for 10 minutes. In storage without light exposure, both plastic and glass packaging materials kept efficiently betacyanin in fruit juice. However, the glass material represented better efficiency in the betacyanin remaining than the plastic material did