Vietnam Journal of Agricultural Sciences

This study explored a sustainable approach to agricultural waste management by converting spoiled eggs into high-quality liquid fertilizers. Egg-based fertilizers (EFs) produced from different input compositions were characterized for their physicochemical properties, and the most suitable EF was further evaluated for its effects on the growth, physiological performance, and yield of Malabar spinach (Basella alba). Three treatments were prepared: EF1 (spoiled eggs without chicks), EF2 (spoiled eggs with chicks), and EF3 (a 1:1 mixture of both). EF1 contained the highest levels of total nitrogen (6.09 g L-1), total and available phosphorus (1.05 and 0.80 g L-1 P₂O₅, respectively), and total calcium (3.79 g L-1 CaO), with no detectable Escherichia coli or Salmonella. EF3 exhibited the highest potassium content (1.16 g L-1 total and 1.04 g L-1 available K₂O). In a field trial, EF1 was applied at 1.0%, 1.5%, and 2.0%, and compared with a commercial organic fish fertilizer and an unfertilized control. Applications of EF1 at 1.5% significantly enhanced shoot length, leaf dimensions, SPAD, leaf area index (LAI), and yield (6.3 and 11.9 t ha-1 at 21 and 37 days after planting, respectively). Yield showed strong positive correlations with leaf length (r = 0.96**), leaf width (r = 0.92**), SPAD (r = 0.84**), and LAI (r = 0.90**), supporting the observed treatment effects. Nitrate concentrations in all the treatments remained below 150 mg kg-1, within safe limits for leafy vegetables. Overall, EF1 at 1.5% represents a safe, effective, and sustainable fertilization option for Malabar spinach production.

The study investigated the effects of fish protein hydrolysate (FPH), derived from fish processing by-products, on the growth, yield, and quality of lettuce (Lactuca sativa L.) grown in a static hydroponic system. Four nutrient treatments were evaluated: a control using a commercial inorganic Snap solution (T1) and three FPH-based solutions at concentrations of 300ppm (T2), 600ppm (T3), and 900ppm (T4). Results showed that the 600ppm FPH treatment (T3) significantly enhanced plant growth and physiological performance compared with the control. Lettuce under T3 achieved the greatest root length (21.4cm), canopy diameter (27.6cm), SPAD value (38.5), and fresh yield (438.2 g plant-1), representing a 22-30% increase over T1. Quality attributes also improved under moderate FPH application. Vitamin C content increased to 10.5 mg 100 g-1 in T3 compared with 7.5 mg 100 g-1 in the control, while nitrate concentration decreased markedly from 398.5 to 242.1 mg 100 g-1. Soluble solids content rose from 3.7 to 4.2°Brix, indicating improved sweetness and flavor. No Escherichia coli or Salmonella spp. contamination was detected in any treatment, confirming product safety. Overall, the application of 600ppm FPH provided an optimal balance between yield, nutritional quality, and microbial safety. These findings demonstrate that fish protein hydrolysate offers a cost-effective and sustainable nutrient alternative for hydroponic lettuce production, promoting circular resource utilization and environmentally friendly agriculture.

This study was conducted to evaluate the effects of drinking water sources on the growth performance and carcass yield and quality of commercial Cherry Valley ducks raised in the coastal area of Thai Thuy (formerly Thai Binh province). A total of 225 Cherry Valley ducks (81 males and 144 females) were randomly assigned to one of three treatments corresponding to different drinking water sources (filtered water, tap water, and pond water), with three replicates of 25 ducks each. The results showed that water source significantly influenced the final body weight and average daily gain, with ducks receiving filtered or tap water performing better than those given pond water (P <0.05). However, weight gain, feed intake, and the feed conversion ratio were not affected (P >0.05). Carcass yield was generally unaffected by the drinking water source, except for thigh weight, while meat quality traits such as pH and color varied notably across the different water sources. Sex had a clear effect on growth and meat quality, with male ducks showing faster growth and higher thigh pH (P <0.05), while females exhibited greater breast water loss (P <0.05). The interaction between water source and sex also influenced the final body weight, growth rate, and several meat quality traits (L*, a*, pH15, b*) (P <0.05).

Hypothermic storage at 4°C offers a practical and low-cost approach for short-term handling of bovine in vitro-produced (IVP) embryos; however, optimal buffering conditions and storage limits for preserving embryo viability remain insufficiently defined. This study evaluated how varying HEPES concentrations and storage durations influence post-chilling survival and developmental competence of Day 7 IVP blastocysts. Across treatments, TCM199 supplemented with 50% FBS supported the highest embryo recovery, and the response to HEPES showed a clear concentration-dependent pattern. Moderate buffering markedly improved embryo stability, with embryos stored in 25-mM HEPES exhibiting the highest post-storage survival and hatching rates (approximately 63% and 37%, respectively). In contrast, insufficient (0 mM) or excessive supplementation (≥ 50mM) resulted in substantially reduced developmental performance, confirming that an intermediate buffering range provides the greatest protection during chilling. Storage duration further shaped embryo outcomes. Embryos maintained relatively high viability between 24-48h of hypothermic exposure (survival ~54-62%), whereas prolonged storage led to a sharp decline in developmental potential, with hatching becoming rare or absent beyond 72h. The total cell number also decreased markedly after extended storage, indicating progressive structural compromise. These findings identify an optimal HEPES range and a practical storage window that together enhance the success of hypothermic preservation of bovine IVP embryos. The study establishes biologically validated parameters that can support the development of reliable, low-cost protocols for embryo storage and transport in research and field applications.

Pork is considered one of the major vehicles for Salmonella transmission to humans. This study aimed to determine the prevalence, serovar distribution, and virulence gene profiles of Salmonella isolates recovered from pig carcasses and pork in Thai Binh province. A total of 192 samples, comprising carcass swabs and pork samples, were collected from slaughterhouses and wet markets. Salmonella was detected in 22.92% (44/192) of the samples, with prevalence rates of 25.00% (24/96) in slaughterhouses and 20.83% (20/96) in wet markets. Among the 44 Salmonella isolates, only S. Typhimurium (31.82%, 14/44) and S. Virchow (4.55%, 2/44) were identified using the PCR-based serotyping assay targeting five selected serovars, whereas 63.63% (28/44) of the isolates remained untyped. The virulence genes invA, msgA, tolC, lpfC, pagC, and spaN were detected at relatively high frequencies of 100%, 90.91%, 77.27%, 72.73%, 70.45%, and 70.45%, respectively. In contrast, the spvC gene was found in only 4.5% of the isolates, whereas none carried the cdtB gene. The results of ESBL test showed that 27.27% (12/44) of the isolates were ESBL producers carrying blaCTX-M-1, blaCTX-M-9, and blaTEM genes. The detection of ESBL-producing Salmonella in carcasses and pork highlights a potential public health risk and underscores the need for enhanced food safety surveillance and intervention measures to reduce Salmonella contamination.

This study provides the first comprehensive assessment of the species composition and distribution of coral reef fish populations on the seamounts of Tho Chu Archipelago. Surveys were conducted during the Northeast monsoon (December 2023) and Southwest monsoon (July–August 2024) seasons across 24 transects spanning depths 11-30m. A total of 83 species from 45 genera, 23 families, and 13 orders were recorded. The most abundant families were damselfishes (Pomacentridae) with 19 species and wrasses (Labridae) with 15 species. Species richness was the highest in the shallow reef crest (11-15m; 70 species) and declined markedly toward the deeper reef foot (26-28m; 18 species). The overall diversity was high (H’ = 4.93), with a relatively even species distribution (J’ = 0.77). Mean fish density reached about 250 individuals per 500 m2, dominated by small-size fishes (< 10cm in total length). The Bray-Curtis similarity index revealed distinct depth-related groupings, with strong overlap in mid-depth communities. The findings provide baseline ecological data on species composition, density, and depth-related distribution patterns, serving as scientific evidence for marine conservation planning and sustainable fisheries management in offshore waters.

This study evaluated the effects of dietary supplementation with a fermented betel leaf preparation on the growth performance, feed utilization, and resistance to Aeromonas veronii infection in common carp (Cyprinus carpio). A six-week feeding trial was conducted using four diets: PF0 (control), PF2 (2 g kg-1), PF5 (5 g kg-1), and PF10 (10 g kg-1). After the feeding period, fish were challenged with A. veronii, and the cumulative mortality rates were recorded over 14 days to assess disease resistance. The results showed that supplementation at 10 g kg-1 significantly enhanced growth performance, while the feed utilization indices did not differ among treatments. Survival during the feeding period remained 100%, indicating that the fermented preparation was safe for fish. The PF10 group exhibited the lowest cumulative mortality (22.73%), followed by PF5 (35.38%), with both values significantly lower than the control (46.67%), demonstrating the immunoprotective potential of the fermented product. Overall, the findings indicate that the dietary inclusion of fermented betel leaves, especially at 10 g kg-1, can improve growth, maintain the feed conversion ratio, and enhance resistance to A. veronii infection in common carp, contributing to safer and more sustainable aquaculture practices.

Trace metal (TM) contamination in post-mining soils represents a long-term environmental risk due to potential leaching into groundwater. This study applied an integrated risk assessment approach—combining sequential extraction, in situ soil solution sampling, and HYDRUS-1D modelling—to evaluate TM behaviour along the soil–groundwater pathway at a recently abandoned bauxite mining site in the Central Highlands of Vietnam, currently used for cassava cultivation. Our results revealed that less than 1% of the total TM concentrations (As, Cu, Zn, Pb) are mobilizable, indicating a negligible risk of groundwater contamination under the current conditions. This low mobility is primarily attributed to strong sorption by Fe- and Al-(hydr)oxides, despite the moderately acidic soil pH (5.3 ± 0.2). With the exception of Pb, the in situ soil solution samples showed consistently higher TM concentrations than predicted by sequential extraction (1.1–4.9-fold higher). This trend suggests that natural complexation with dissolved organic matter and minor redox fluctuations may enhance TM mobility more than estimated by lab experiments under controlled conditions. Simulation of the soil water balance indicated an annual infiltration of 3,654mm, evapotranspiration of 845mm, and seepage of 2,809mm, with TM loads far below admissible regulatory limits. However, continuous monitoring is recommended, as potential changes in pH, organic matter, or precipitation patterns could alter TM solubility and increase leaching risks in the future. These findings demonstrate that total TM concentrations may serve as valid first-order approximation for risk assessments in similar tropical post-mining soils, though site-specific conditions should always be considered.

The Mekong Delta—Vietnam’s agricultural heartland—is increasingly threatened by climate change, saline intrusion, and upstream dam construction, posing serious risks to its role as a major global rice supplier. This study examined how public investment in irrigation infrastructure affects agricultural output in the region, addressing a critical gap in understanding the role of water management in enhancing agricultural resilience. Using panel data from 13 provinces between 2009 and 2023, we applied a feasible generalized least squares (FGLS) model based on a Cobb-Douglas production function to estimate the determinants of the agricultural gross regional domestic product (GRDP). The results showed that irrigation investment significantly boosts agricultural productivity. While labor, capital, and land remain essential inputs, rainfall appeared to have little effect—highlighting the importance of regulated water infrastructure in mitigating climate variability. These findings align with previous regional studies and reflect the Delta’s reliance on labor-intensive rice farming supported by engineered water systems. By incorporating environmental factors and current climatic trends, the study provides new empirical evidence on the region’s agricultural dynamics. It underscores the vital role of irrigation in ensuring food security and economic sustainability, offering insights for climate adaptation and infrastructure policy in environmentally vulnerable regions.

This study focused on estimating the level of technical efficiency in beef cattle production in the alluvial river areas near the Hung Yen urban center, using cross-sectional data collected from 150 beef cattle households. The data envelopment analysis was applied for technical efficiency estimation, and a Tobit modelling approach was employed to identify the determinants of technical efficiency. The results indicated that beef cattle production in the study area is characterized by a high and relatively homogeneous level of efficiency, with a mean technical efficiency under a variable return to scale​ of 95.4%. The key factors that positively enhanced technical efficiency included the farmer’s education level, the proportion of household income derived from beef production, and the number of cattle sold. Dependence on purchased roughage and excessive warehouse area per head were found to significantly reduce efficiency. These findings suggest that competitiveness can be achieved by capitalizing on scale advantage through encouraging herd consolidation or moderate scale expansion. Furthermore, policies should promote on-farm forage development to reduce farmer reliance on unstable external feed markets, and extension programs should be strategically targeted towards technically oriented and educated farmers who show a higher capacity to adopt innovations.

Understanding the genomic basis of indigenous livestock is essential for both conservation and sustainable improvement. Korean native chickens (KNCs), although representing a small fraction of the poultry industry in Korea, are distinguished by their unique meat quality, robustness, and adaptability. Recent genomic studies have investigated their genetic diversity, evolutionary history, and economically important traits. High-density SNP arrays and population structure analyses have clarified the distinct identity of KNC lines, while runs of homozygosity have provided insights into inbreeding, conservation progress, and functional loci. Selection signature analyses have identified candidate genes related to growth, metabolism, reproduction, and immune function, reflecting line-specific adaptation. Genome-wide association studies have further identified variants associated with taste-active compounds, fatty acid composition, and growth traits, offering a foundation for genomic selection. Moreover, research on disease-related genes, such as the major histocompatibility complex B genes, has documented substantial genetic variability in KNCs, establishing important genomic resources for subsequent studies on avian immunity and pathogen response. Together, these findings highlight KNCs as valuable reservoirs of genetic variation with implications for both conservation and breeding. More broadly, the genomic insights obtained from KNCs provide a cautious yet informative model for indigenous livestock worldwide, demonstrating how genomic tools can support sustainable breeding programs that balance biodiversity preservation with productivity.