Veterinary Integrative Sciences

Mapping the animal welfare research in Southeast Asia: A bibliometric analysis (1987–2025)

Ana Marquiza M. Quilicot — 2026-02-10

Animal welfare has emerged as a significant scientific and ethical concern in Southeast Asia, where biodiversity, culture and agricultural systems create unique challenges and opportunities. This study presents a bibliometric analysis of SCOPUS-indexed publications (1987–2025) to map research trends, productive contributors, leading institutions and countries, and thematic priorities in the region. A systematic search identified 298 relevant documents, analyzed using the Bibliometrix package (R, Biblioshiny) and VOSviewer for network visualization. Results show an annual growth rate of 8.60%, with most outputs being journal articles, prominently published in Animals. Thailand is the leading hub, driven by Chiang Mai University and extensive collaborations with the United Kingdom, the United States, and Australia. Authorship patterns follow Lotka's law, with a small cohort of prolific researchers and a broad base of occasional contributors. Thematic mapping reveals two dominant areas: region-specific concerns on Asian elephant and livestock welfare, and wider issues on wildlife trade, tourism impacts, and welfare assessment. Species analysis identifies two major research clusters: livestock/elephants and primates/insects, reflecting both agricultural and wildlife-related priorities. Overall, animal welfare research in Southeast Asia is expanding in number, thematic diversity, and global integration. Strengthening regional capacity, fostering interdisciplinary collaboration, and embedding local context into global welfare frameworks will be critical for sustaining growth and addressing both foundational and emerging challenges in animal welfare.

Comparison of growth promotion effects: Fermented non-medicinal parts of Scutellaria baicalensis vs. non-critical rare earth cerium oxide in yellow-feathered broilers

Liu Hongmei — 2025-11-28

This study investigated the effects of fermented Scutellaria baicalensis stem and leaves and Cerium Oxide (CeO₂) supplementation on the growth performance, slaughter performance, and immune function of yellow-feather broilers. The results demonstrated that the average daily feed intake (ADFI) was significantly higher (P < 0.05) in the treatment groups compared to the antibiotic-positive group. The group treated with 0.8% fermented Scutellaria baicalensis stems and leaves exhibited the high average daily weight gain and feed conversion ratio, surpassing the control group by 3.2% and 2.3%, respectively. Slaughter performance showed that the 0.8% Scutellaria baicalensis treatment group had greater chest depth, keel length, pelvic width, and tibia length than other groups. In contrast, the 500 mg CeO₂ treatment group exhibited the longest tibia length. Additionally, the slaughter rates of all treatment groups were significantly higher (P < 0.0001) than those of the control and antibiotic-positive groups. Immune function analysis revealed no significant differences (P > 0.05) in thymus and bursa indices; however, the thymus index was higher in groups with 0.8% Scutellaria baicalensis stem and leaves and CeO₂groups. Serum immunoglobulin analysis indicated that IgM and IgG levels did not significantly differ among groups, but CeO₂supplementation increased IgA levels, particularly in the 50 mg and 100 mg groups. These results illustrated that adding 0.8% fermented Scutellaria baicalensis stems and leaves to poultry feed effectively enhances improve the growth performance and carcass traits of yellow-feather broilers, and is a potential substitute for antibiotics in poultry production, compared to CeO₂ and Lincomycin hydrochloride.

Bacillus velezensis from the Muscovy Duck gut: A potential probiotic for controlling poultry pathogens

Nguyen Phuong Thuy — 2025-12-03

Bacterial diseases and antimicrobial resistance threaten the poultry industry, necessitating antibiotic alternatives. Probiotics, especially Bacillus species, are a promising solution. This study explored the gut of the Muscovy duck (Cairina moschata (Linnaeus, 1758)) as an untapped source for novel probiotic candidates. The objectives were to isolate native Bacillus strains from Muscovy duck guts, identify the most promising candidate, and characterize its probiotic potential by assessing its resilience and antimicrobial activity against key poultry pathogens. A total of 40 bacterial strains were isolated from the gut contents of 50 Muscovy ducks using a heat-shock enrichment method. All isolates were screened in vitro for their tolerance to simulated gastrointestinal conditions (pH 2.0 and 0.3% bile salts). The antimicrobial activity of their cell-free supernatants was assessed against Escherichia coli, Salmonella enterica, and Staphylococcus aureus using the agar well diffusion method. The most potent isolate was definitively identified by 16S rRNA gene sequencing. Isolate BD31 demonstrated exceptional tolerance to both acidic and bile salt conditions. Furthermore, it exhibited potent, broad-spectrum antagonistic activity, producing significant inhibition zones against E. coli (12.5 mm), S. enterica (11.8 mm), and S. aureus (8.5 mm). Molecular analysis identified this superior isolate as Bacillus velezensis with 99.76% sequence identity to the type strain. The Muscovy duck gut is a valuable source for novel probiotics. Bacillus velezensis BD31 displays superior gastrointestinal tolerance and potent antimicrobial activity, positioning it as an excellent candidate for a direct-fed microbial to control poultry pathogens. In vivo validation is warranted.

Analysis of local immune responses in chickens infected with Eimeria tenella

Pham Hoang Son Hung — 2025-12-15

Eimeria tenella is a major coccidian parasite in poultry, causing severe economic losses. Understanding the local immune response during E. tenella infection is essential for developing effective control strategies. This study investigated the transcriptional responses of T cell markers (CD3 and CD4), cytokines (IL-10, IL-12, IL-18, IL-22, IFN-γ, TGF-β1), and the chemokine K203 in experimentally infected chickens. Gene expression was analyzed using quantitative PCR, and histopathological changes were evaluated in hematoxylin and eosin-stained cecal sections. The expression of CD3 and CD4 genes showed an upward trend in infected chickens, suggesting potential involvement of T cells in the immune response, although this was not statistically significant. Several cytokines, including IFN-γ, IL-10, IL-18, IL-22, and TGF-β1, were significantly upregulated (p < 0.05), indicating a complex transcriptional response involving both pro-inflammatory and regulatory pathways. K203 expression increased markedly (approximately 60-fold, p < 0.001), consistent with enhanced chemotactic signaling and immune cell recruitment to the infection site. Histopathological examination revealed epithelial disruption and inflammatory cell infiltration in the infected group, correlating with the observed gene expression changes. Overall, this study provides insights into the transcriptional modulation of local immune mediators during E. tenella infection. While the results highlight possible involvement of T cell-associated and cytokine-mediated responses, further studies, particularly protein-level analyses, are needed to confirm the functional activation of immune cells and their specific roles in host defense.

Effects of Peperomia pellucida (L.) Kunth on the growth performances, and health of red hybrid tilapia (Oreochromis spp.)

Romalee Cheadoloh — 2026-01-08

Peperomia pellucida (PP), is an herb that has been proven rich in antioxidant property. However, the beneficial effects and mode of action of PP on disease resistance in fish are still unclear. In the present study, we revealed the potential impacts of PP on the growth performance, blood parameters, antioxidant capacity, immune-related gene expression and disease resistance against Aeromonas hydrophila in red hybrid tilapia, Oreochromis spp. Experimental fish were given a diet containing different doses of PP (100, 200 and 300 mg/kg diet) in triplicates for eight weeks. After feeding trials, the experimental fish were subjected to an intraperitoneal infection of A. hydrophila. Findings from the present study showed a significant (P < 0.05) improvement in growth performances (final weight, specific growth rate, and feed conversion rate), immune-related gene expression and disease resistance against A. hydrophila in fish fed PP supplemented diets in comparison to the control diet. Present study also demonstrated significant (P < 0.05) improvement in blood parameters by dietary PP provision. Dietary PP noticeably enhanced the antioxidant status of red hybrid tilapia with the increased activities of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in the liver. On top of that, upregulation of growth and immune-related genes such as Lysozyme G (LysG), nuclear factor kappa B (NF-κB), transforming growth factor-β1 (TGF-β1), heat shock protein 90 (HSP90), and beta actin (β-actin) were also observed in the dietary PP group. Overall, polynomial regression analysis revealed that dietary PP at the dosage of 108 – 151 mg/kg improved growth and health performances of red hybrid tilapia

Effects of commercial seaweed supplementation on in vitro methane production and milk performance in dairy

Nattapong Saeng-in — 2026-01-14

This study aimed to evaluate the effects of commercial seaweed supplementation on ruminal fermentation, methane production, and milk performance in dairy cows during prepartum and postpartum periods. The experiment consisted of two parts. Experiment 1 assessed the impact of seaweed on rumen digestion using the in vitro gas production technique with rumen fluid collected from two Holstein Friesian cows (with an average body weight of 427 ± 10 kg and an average age of 3 years). Total gas, methane, pH, ammonia-nitrogen (NH₃-N), volatile fatty acids (VFA), and microbial biomass yield were analyzed in a completely randomized design. Experiment 2 consisted of on-farm trials conducted at two commercial dairy farms. At Thongsak Farm, twenty prepartum cows (18.16 ± 1.06 kg/day milk yield; 420 ± 25 kg BW) were evaluated from 30 days before to 90 days after calving and assigned to either the control (TMR only) or treatment (TMR + 40 g seaweed/day) group. Feed intake was recorded daily, while blood samples were collected three times and milk samples seven times throughout the experimental period. At Somsak Farm, another twenty postpartum cows (16.5 ± 1.0 kg/day milk yield; 425 ± 25 kg BW; 100.05 ± 67.25 DIM) were evaluated for 30 days using the same treatment structure and sampling protocol as in the prepartum trial, with feed intake and milk production recorded concurrently. In vitro results showed that seaweed supplementation significantly enhanced gas production at 2 hours (7.27 vs 6.61 mL/200 mg DM) and reduced methane production (5.22 vs 2.30 mL/200 mg; p < 0.05). On-farm results showed a tendency toward higher milk yield in the seaweed group, along with increased protein, total solids, and solids-not-fat. Blood profiles remained within normal ranges, indicating no adverse effects. Seaweed supplementation improved rumen fermentation efficiency reduced methane emissions and positively influenced milk yield and composition in dairy cows without compromising animal health.

Histopathological characterization of age-related intestinal lesions and fibrosis in naturally coccidia-infected Asian sea bass (Lates calcarifer)

Theerayut Thongrin — 2026-01-19

Intestinal coccidiosis is an important protozoan disease in marine teleosts, particularly under aquaculture conditions. In juvenile Asian sea bass (Lates calcarifer), infection leads to severe intestinal injury accompanied by inflammation and fibrotic remodeling. This study aimed to characterize inflammatory and fibrotic responses to piscine intestinal coccidia in fish at different developmental stages. A total of 88 intestinal samples from naturally infected juvenile Asian sea bass aged 60 and 90 days (44 samples per group) were collected from marine cage farms in Satun Province, Thailand. Intestinal tissues were processed using standard histological methods, stained with hematoxylin and eosin (H&E) for lesion evaluation, and Picro-Sirius Red for fibrosis assessment. Lesion severity (inflammation, extended inflammation, necrosis, congestion, and desquamation) was graded semi-quantitatively, and fibrotic areas were quantified under polarized light. Statistical comparison between age groups was performed using the Mann–Whitney U test. The 60-day-old fish exhibited significantly higher levels of inflammation (p = 0.000), extended inflammation (p= 0.001), necrosis (p = 0.038), and congestion (p = 0.000) compared to the 90-day-old group, whereas desquamation did not differ significantly (p = 0.685). In contrast, fibrosis was more pronounced in the 60-day-old fish (p < 0.05), indicating stronger fibrotic activity associated with persistent inflammation. Intestinal coccidiosis in juvenile Asian sea bass induces marked inflammatory injury in younger fish and subsequent fibrotic remodeling in older fish. These findings highlight the dynamic progression of intestinal pathology and emphasize the importance of early disease management to minimize long-term intestinal damage in aquaculture systems.

Comparative observation of the organ development and health of the tropical oyster Crassostrea belcheri (Sowerby, 1871) in hatchery and wild farming sites

Supatcha Chooseangjaew — 2026-01-23

The tropical oyster, Crassostrea belcheri, is an important, high-value seafood in aquaculture in Thailand. Understanding the development and physiological responses of C. belcheri in different rearing conditions is essential for sustainable production. This study compared the histological structures, mucus-secreting cell (MSC) distributions, and gonadal development of C. belcheri sampled from a hatchery (HAT) and three open-sea farming sites. The sampled oysters were classified into five categories based on shell height: 1.0–2.5 cm, 2.6–4.1 cm, 4.2–5.7 cm, 5.8–7.3 cm, and 7.4–8.8 cm. Size- and site-dependent differences in organ morphology were observed. In the largest HAT oysters, the average gill lamella length was 128.8 ± 7.3 µm; average mantle epithelium thickness 14.1 ± 1.0 µm and average digestive tubule diameter 86.5 ± 2.2 µm. All three morphometrics differed significantly across the four sites (p < 0.05). Four MSC morphotypes were observed. Gonadal development followed a protandric pattern, with male gametogenesis observed in oysters smaller than 5.8 cm and female oogenesis being dominant in larger individuals (> 5.8 cm). Oocyte maturation across sites was consistent rather than site dependent. Histopathological evaluation using the Health Assessment Index (HAI) revealed sublethal tissue alterations, including epithelial atrophy, digestive tubule regression and gill lamellar fusion, with a mean HAI score of 3.7 ± 1.2 for wild-farmed oysters compared with 1.8 ± 0.9 for HAT samples. These findings underscore strong associations between oyster size, environmental conditions and organ development, and the potential of MSC density and histopathological lesions as reliable biomarkers for aquaculture monitoring and health management in C. belcheri

Optimization of broiler growth and organ traits: Insights from a meta-analysis of feed form effects

Dwi Robiatul Adawiyah — 2026-01-30

Feed form is an essential factor influencing nutrient use, feeding behavior, and overall efficiency in broilers. Since feed represents the largest portion of production costs, there is a need to select the appropriate feed to improve performance and profitability. Therefore, this meta-analysis aimed to examine the effects of feed form on broiler performance, carcass traits, and organ development using 283 data points from 46 published studies. Data reliability was assessed using a fail-safe number (Nfs), which showed robust parameters for daily feed intake (Nfs > 620) and daily weight gain (Nfs > 1000), while mortality and organ weight had low values. The results showed that feed form significantly improved (P < 0.05) broiler performance, particularly conversion ratio and final body weight. However, high heterogeneity (I² > 80%) showed that differences in diet composition, management, and environmental conditions strongly influenced the outcomes. Carcass traits significantly improved (P < 0.05), with increased weight observed in the total carcass, breast, thigh, and wing. Abdominal fat deposition showed a relatively smaller but significant (p<0.05) reduction. The effect on organ development was variable, with gizzard and pancreas weights decreasing significantly (P < 0.05), indicating low mechanical and enzymatic demands of processed feeds, while liver weight was unaffected. Intestinal morphology showed mixed outcomes, with significant (P < 0.05) reductions in duodenum length and non-significant trends for jejunum and ileum lengths. This indicated that feed form substantially enhanced broiler productivity, carcass quality, and feed efficiency. However, variability across studies showed the need to consider management and environmental factors, indicating the need for future investigation to identify sources of heterogeneity.

Atypical lethal systemic granulomatous inflammation caused by Pseudomonas aeruginosa in a green iguana (Iguana iguana): A postmortem case report

Patanakorn Petaipanakij — 2025-12-08

A 5-year-old male green iguana (Iguana iguana) from a privately maintained outdoor enclosure was submitted for necropsy following a brief period of lethargy and anorexia, which rapidly progressed to death. A gross examination revealed coelomic and pericardial effusions, pulmonary consolidation, multifocal nodular lesions in multiple organs, most prominent and numerous in the lungs, accompanied by verrucous endocarditis. The histopathology report indicated widespread heterophilic and histiocytic granulomas with central necrosis and basophilic bacterial remnants in the lungs, heart, liver, and spleen. Microbiological cultures yielded Pseudomonas aeruginosa from coelomic and pericardial effusions, while special stains (acid-fast, PAS) and PCR for Mycobacterium spp. were negative, thereby ruling out mycobacterial and fungal infections. This is the first report of systemic granulomatous inflammation caused by Pseudomonas aeruginosa in a green iguana, underscoring its pathogenic potential in reptiles housed under suboptimal husbandry conditions and highlighting the importance of comprehensive diagnostics in exotic species.