Colostrum quality, intestinal microbiota and implications for health in young dairy calves

The early life of calves in southern Vietnam and in Sweden were studied in this thesis, with the focus on colostrum quality, gut microbial communities and antimicrobialresistant Escherichia coli. The first of four studies showed that most cows on smallholder farms in Vietnam produced colostrum of good quality and that only around 10% of calves suffered from failure of passive immune transfer. In a second study, bacterial communities in colostrum and in calf faeces samples collected at birth and at 14 days of age were identified by terminal restriction fragment length polymorphism (T-RFLP). The results showed that the microbial communities in colostrum and faeces differed in composition, with greater similarities in composition between colostrum and faeces from newborn calves than faeces from 14-day-old calves. Microbial composition also differed significantly between faeces from newborn and 14-day-old calves. Sequencing of 16S rRNA gene amplicons from a subset of faeces samples from healthy calves and calves treated for diarrhoea with antimicrobial drugs revealed significant differences between the groups, with higher relative abundances of Faecalibacterium and Butyricicoccus in healthy calves. In a third study, bacterial composition in intestinal contents and in mucosal scrapings collected from various gut segments in two- and seven-day-old calves was characterized by sequencing 16S rRNA gene amplicons using Illumina MiSeq. It was found that microbial community composition was associated with intestinal segment, with major differences in composition between proximal and distal parts of the gastrointestinal tract. However, microbial composition showed high similarity for segments in close proximity within the gut. Lactobacillus was present in quite high levels in the abomasum and duodenum, whereas Escherichia were more associated with the ileum, caecum, colon and faeces. Microbial composition and diversity altered with age and, although the microbiota in mucosa and gut content remained similar in general, certain microbial groups dominated in either mucosa or gut content. The fourth study revealed high levels of multidrug-resistance in Escherichia coli isolated from Vietnamese calves (53% of isolates tested), with blacCTM-M-1 (2 isolates), blacCTM-M-9 (1 isolate) and blacCMY-2 (1 isolate) being the main β-lactamase resistance groups detected. There was a high incidence of plasmid-mediated quinolone resistance (PMQR) genes in the E. coli isolates (21%). Overall, these results suggest that colostrum feeding and health are key factors affecting gut microbial community in the early life of dairy calves, but that antimicrobial resistance is an emerging problem on smallholder dairy farms in Vietnam

Phoebe Framework and Experimental Results for Estimating Fetal Age and Weight

Fetal age and weight estimation plays an important role in pregnant treatments. There are many estimation formulas created by the combination of statistics and obstetrics. However, such formulas give optimal estimation if and only if they are applied into specified community. This research proposes a so-called Phoebe framework that supports physicians and scientists to find out most accurate formulas with regard to the community where scientists do their research. The built-in algorithm of Phoebe framework uses statistical regression technique for fetal age and weight estimation based on fetal ultrasound measures such as bi-parietal diameter, head circumference, abdominal circumference, fetal length, arm volume, and thigh volume. This algorithm is based on heuristic assumptions, which aim to produce good estimation formulas as fast as possible. From experimental results, the framework produces optimal formulas with high adequacy and accuracy. Moreover, the framework gives facilities to physicians and scientists for exploiting useful statistical information under pregnant data. Phoebe framework is a computer software available at http://phoebe.locnguyen.net

Factors Affecting Firms’ Performance: The Case of Vietnam construction firms

In the context of Vietnam's international economic integration, improving the performance of enterprises is increasingly important because it not only affects businesses but also affects the development prospects of the economy. The purpose of the paper is to consider the impact of factors on the performance of listed construction companies in the period of 2012-2018. By means of an empirical analysis, this study uses Eviews econometric software and table data techniques. This study found the factors that positively impact on performance are asset structure, capital structure and firm size that negatively impact the performance of Vietnam listed construction firms. These findings support business administrators in selecting appropriate business and production plans to increase the operating performance of businesses in the construction industry. Keywords: Profitability, construction firms DOI: 10.7176/RJFA/11-2-15 Publication date: January 31st 202

Level of Corporate Social Responsibility Disclosure and Financial Performance: A Case Study in Ho Chi Minh City, Vietnam

Research aims: This study examines the influence of firm size, firm age, current ratio, and type of audit company on the corporate social responsibility disclosure level and its impact on the financial performance of listed enterprises in Vietnam.Design/Methodology/Approach: Financial data were collected from the annual reports of 109 enterprises listed on the Ho Chi Minh City Stock Exchange, Vietnam, from 2016 to 2020. This research employed the Random Effects Model (REM), Fixed Effects Model (FEM), and Feasible Generalized Least Squares (FGLS) to deal with the drawbacks of the regression models, as mentioned.Research findings: The findings support the positive influence of firm size, firm age, and the type of auditing firm on the level of CSR information disclosure of listed manufacturing enterprises. Also, the extent of CSR disclosure positively affected financial performance, confirming the positive relationship between CSR disclosure level and financial performance.Theoretical contribution/Originality: This study contributes to governance theory by expanding and combining stakeholder and legitimacy theories with criteria for measuring the level of CSR disclosure in the Vietnamese context. Therefore, the study results are a valuable reference for theorists who tirelessly pursue the CSR topic.Practitioner/Policy implication: This study proposes recommendations for practitioners who should focus on enhancing the level of CSR disclosure to generate more benefits and result in better financial performance. Also, policy implications should be raising the senior managers’ awareness of the level of CSR disclosure, firm size, firm age, and type of audit and establishing a stable legal framework for the level of CSR disclosure in line with international standards and practices.Research limitation/Implication: The sample data were only collected from manufacturing companies listed on Ho Chi Minh Stock Exchange, and the analyzed content and measurement of the level of CSR disclosure primely relied on the enterprises’ annual reports

Investigating the elements influencing the psychological issues of reform school students

Reformatory students are those whose deviant behaviors and habits prevent them from receiving education under normal educational conditions. These students frequently lead a careless, undisciplined lifestyle, being unwilling to work and learn eager to play and demanding. Therefore, when they are admitted to reformatories with severe study and lifestyle requirements, they have great psychological difficulty adjusting to their new environment. Students’ psychological issues in adapting to reformatory learning and living regimes are difficult and psychological deficits make it challenging for students to adapt to reformatory learning and living conditions. In Vietnam, 665 students from reformatory schools were polled to determine the causes of psychological issues. According to the findings, a variety of elements contribute to students’ psychological difficulties. Individual student conditions such as health, awareness, attitudes and actions as well as inappropriate habits, living without goals or aspirations, etc. are on the subjective side of the equation. On the objective side are the students’ conditions, family, education and psychological obstacles brought on by less-than-ideal circumstances which will make it more difficult for community students to adapt. Both the new school and society must pay more attention to reformatory students in order to establish the conditions necessary for successful integration into the new school and ultimate readmission into society for these students

Factors affecting the creativity of high school students

Creativity is a vital personality quality of each individual. Each person has their potential for creativity, and it can be nurtured and developed in an appropriate and safe environment. The purpose of the study was to find out which factors from schools and students themselves affect creativity as well as the association between creativity and age, gender and giftedness of students, which then a basis to adjust and establish appropriate methods from schools, families, and students themselves to develop elements and their creativity. The study was conducted on 108 high school students in three grades from giftedness and non-giftedness schools. The data was collected through a survey method using a self-constructed questionnaire and drawing creativity test TCT-DP to determine students' creativity levels and personal information. The study's finding, which uses mathematical methods and one-way analysis of variance, reveals that factors affecting elements and creativity level are objective factors including education environment from school; behavior of teachers, and subjective factors including interests, perspectives, and thoughts of students. It was also found that there were no significant differences in the components of creativity and creativity among students in different grades, gender, and groups of giftedness schools

Ammonia oxidation capacity of bacillus bacteria in swine wastewater after biogas treatment

Nitrogen removal with biological methods plays a crucial role in wastewater treatment technology. The treatment begins with the oxidation of ammonia to nitrite to facilitate the subsequent nitrification and denitrification. Various strains of ammonia-oxidising bacteria have been reported. In this study, we use three Bacillus bacteria isolated from swine wastewater to oxidise ammonia. Different initial densities (103, 104, 105, and 106 CFU·mL–1) of each strain were examined. The results show that the combination of all the bacteria at a ratio of 1:1:1 and a density of 105 CFU·mL–1 exhibits the most effect. The findings contribute to the diversity of ammonia-oxidising bacterial species and pose a great potential for applying these strains in wastewater treatment

Ownership Concentration and Accounting Conservatism: The Moderating Role of Board Independence

The purpose of this study is to examine the moderating effect of board independence on the relationship between ownership concentration and accounting conservatism. Using fixed-effect regressions for a sample of 165 Vietnamese listed companies from 2007 to 2017, the results revealed that the proportion of outstanding shares owned by the largest shareholder is negatively associated with accounting conservatism and board independence plays a moderating role in this relationship. Our results are robust after applying alternative measures of the largest ownership and correcting for potential endogeneity using fixed-effects regression with instrumental variables. Overall, our evidence shows that firms with concentrated ownership should keep a high non-executive ratio to maintain accounting conservatism. In other words, increasing the number of non-executive directors on boards in firms with a substantial proportion of shares held by the largest shareholder is likely to strengthen the information environment, giving financial reporting more credibility.JEL Classification: G30; G32. Doi: 10.28991/ESJ-2023-07-01-07 Full Text: PD

Nitrite metabolism of several bacterial strains isolated from abattoir and swine wastewater after biogas treatment

In nitrogen treatment with biological methods, nitrite metabolism is an intermediate process that facilitates other processes involving different bacteria strains. In this study, we isolated two nitrite-oxidising bacteria strains from abattoir wastewater and wastewater from biogas tanks of an industrial pig farm in Ha Tinh province. The bacteria strains grow, develop, and metabolise nitrite at pH 6–8 and 30–37 °C. The samples with the nitrite concentration up to 750 mg·L–1 were oxidised within four days of incubation, and the nitrite metabolism rate was proportional to the concentration of nitrite tested. Under severe conditions (salinity up to 3% NaCl, a low dissolved oxygen level of 0.1 mg·L–1), the two isolated bacterial strains exhibited their effective growth and nitrite metabolism capacity. The results enrich the database of nitrite-oxidising bacteria and are prospective in wastewater treatment

High level of multidrug-resistant Escherichia coli in young dairy calves in southern Vietnam

This study investigated the occurrence of antimicrobial-resistant Escherichia coli in dairy calves in southern Vietnam. Fecal samples were taken directly from the rectum of 84 calves from 41 smallholder dairy farms, when newborn and at 14 days of age for isolation of E. coli. Escherichia colistrains were isolated from 144 of the 168 fecal samples tested. Of the 144 E. coli isolates, 40% were found to be susceptible to all 12 antimicrobial drugs tested and 53% of the E. coli isolates were resistant to at least three antimicrobials. Calves were colonized with antimicrobial-resistant E. coli already on the day of birth. Resistance to tetracycline was most common, followed by resistance to sulfamethoxazole, ampicillin, trimethoprim, and ciprofloxacin. Four isolates carried a gene encoding for extendedspectrum cephalosporinases (ESC), and these genes belonged to blaCTX-M group 1 (2 isolates), blaCTX-M group 9 (1 isolate), and blaCMY-2 (1 isolate). Thirty-three isolates had a plasmid-mediated quinolone resistance (PMQR) phenotype, and 30 of these carried the qnrS gene. These results are of importance for management routines of dairy cattle to prevent the spread of antimicrobial resistance