National Institute of Animal Sciences

Rabies remains a fatal zoonotic disease of major public health importance in Vietnam, with rising human and animal cases in recent years. Achieving effective control requires high vaccination coverage in dogs and cats, as well as a clear understanding of the behavioral factors influencing vaccination decisions. This cross-sectional analytical study aimed to assess vaccination coverage, examine determinants of proactive vaccination behaviors, and classify pet owners based on their knowledge, attitude, and practice (KAP) regarding rabies prevention in Duc Hue District, Long An Province, during the 2024 mass vaccination campaign. The study was conducted across 11 communes between January 10 and April 25, 2024. Data collection included a general household survey and a structured KAP questionnaire. Digital tools such as KoboToolbox, QGIS version 3.36, and RStudio version 4.5.1 were used for data entry, mapping, and statistical analysis. Logistic regression identified demographic and logistical variables associated with proactive vaccination behavior. Principal component analysis (PCA) and cluster analysis (CA) were used to classify pet owners into behavioral groups based on KAP score patterns. Ethical approval was obtained from Nong Lam University and the Long An People's Committee. A total of 6,899 of 8,776 pets were vaccinated, achieving a coverage rate of 78.6%, surpassing the national target of 70% for 2022-2025, although coverage varied widely across communes (60.63%-87.78%). Logistic regression revealed that higher education levels, specific occupations, shorter distance to veterinary services, and smaller total pet populations were significant predictors of proactive vaccination behavior. PCA and CA identified three distinct groups of pet owners. The group with higher education levels and farming occupations demonstrated the strongest KAP profile, while the lowest-performing group was associated with limited education and greater logistical challenges in accessing veterinary services. This study presents the first integrated behavioral-statistical classification of pet owners in southern Vietnam using PCA and clustering, providing a data-driven foundation for more targeted rabies vaccination interventions. Addressing logistical barriers, improving equitable access to veterinary services, and tailoring educational activities toward low-performing groups are essential for sustaining vaccination gains and advancing Vietnam's goal of achieving 80% coverage by 2030.

Domestic piglets often die of hypothermia, whereas Eurasian wild boar (Sus scrofa) thrives from tropical lowlands to subarctic forests. The thermoregulation of wild boar offers a natural experiment to uncover the genetic basis of cold adaptation. We conducted whole-genome resequencing on wild populations from cold regions (northern and northeastern Asia, with six samples) and warm regions (southeastern Asia and southern China, with five samples). By integrating publicly available data, we compiled a core dataset of 48 wild boar samples and an extended dataset of 445 wild boar and domestic pig samples to identify candidate genes related to cold adaptation. To investigate the functional effects of two candidate variants under positive selection, we performed CUT&Tag and RNA-seq using the northeastern Asian Min pig breed as a proxy for a cold-adapted population. Our study identified candidate genes associated with cold adaptation, which are significantly enriched in thermogenesis, fat cell development, and adipose tissue pathways. We discovered two enhancer variants under positive selection: an intronic variant of IGF1R (rs341219502) and an exonic variant of BRD4 (rs327139795). These variants exhibited the highest differentiation between populations of wild boar and domestic pigs in cold and warm region populations. Furthermore, these rare variants were absent in outgroup species and warm-region wild boars but were nearly fixed in cold-region populations. The H3K27ac CUT&Tag profiling revealed that the rs341219502 variant of IGF1R is linked to the gain of novel binding sites for three transcription factors involving regulatory changes in enhancer function. In contrast, the rs327139795 variant of BRD4 may result in the loss of a phosphorylation site due to an alteration in the amino acid sequence. Our study identified candidate genes for cold adaptation in wild boar. The variant rs341219502 in the IGF1R enhancer and the variant rs327139795 in the BRD4 exon, both of which were under positive selection and nearly fixed in populations from cold regions, suggest they may have originated de novo in these populations. Further analysis indicated that rs341219502 could influence enhancer function, while rs327139795 may affect amino acid alterations. Overall, our study highlights the adaptive evolution of genomic molecules that contribute to the remarkable environmental flexibility of wild boar.

Background and Aim:Low birth weight and within-litter variations are major challenges in swine production, often exacerbated by highly prolific sow lines. Nutritional interventions such as amino acid and probiotic supplementation have shown promise, but their combined effects remain unexplored. This study aimed to evaluate the individual and interactive effects of Bacillus subtilis QST 713 and L-arginine supplementation during late gestation on reproductive performance in sows.Materials and Methods:A randomized trial was conducted on 247 Landrace × Yorkshire sows allocated to four dietary groups from day 85 of gestation to farrowing: (1) Basal diet (control), (2) basal diet + B. subtilis, (3) basal diet + L-arginine, and (4) basal diet + both supplements. Reproductive outcomes–including individual birth weight (IBW), total litter birth weight (TBW), born-alive birth weight (NBABW), proportion of runt (<1.1 kg) and large piglets (>1.5 kg), and within-litter coefficient of variation in birth weight [CVBW])–were assessed. Linear and generalized linear mixed models were used for analysis.Results:Co-supplementation with B. subtilis and L-arginine significantly increased IBW (1434.7 g vs. 1310.0 g, p < 0.001), TBW (19.6 kg vs. 16.9 kg, p < 0.001), NBABW (18.1 kg vs. 15.9 kg, p = 0.006), and the proportion of large piglets (33.7% vs. 19.5%, p = 0.0002), while reducing runt piglet incidence (4.0% vs. 14.4%, p < 0.001). Neither supplement alone produced significant improvements. No treatment significantly affected litter size, CVBW, stillbirth, or mummification rates.Conclusion:Co-supplementation of sows with B. subtilis and L-arginine during late gestation produces synergistic impro-vements in piglet birth weight and litter quality. This strategy offers a practical and cost-effective approach to enhance swine reproductive efficiency.

Using an accurate growth curve to estimate the suitable age for slaughter has many benefits for ostrich farming. This study was carried out to compare eight growth curve models for estimating body weight and monthly gain of ostriches raised in tropical conditions and then suggested the suitable slaughter age for these ostriches. Two hundred eighty-two ostriches (124 males and 158 females) were raised from birth to 12 months of age to measure individual monthly body weight, and the growth data was analyzed by R software. Eight growth functions (von Bertalanffy, Bridges, Janoschek, Gompertz, Logistic, Lopez, Richards, and Weibull) were used to create the growth curves of ostrich. The Weibull function was the best model among 8 tested models to describe the growth of both male and female ostriches, and the monthly gain (MG) reached the maximum at the 6th month of age. The maximum average monthly gain (AMG) was obtained between the 9th and 10th month of age for both males and females. The best-fit model in this study (Weibull function) suggests the suitable slaughter ages were estimated from the 9th to 10th month of age for both male and female ostriches, with estimated body weights of 93 kg for male and 90 kg for female.

The evolution of group living is associated with increased pressure from parasites and pathogens. This can be offset by greater investment in personal immune defences and/or the development of cooperative immune defences (social immunity). An enduring question in evolutionary biology is whether social-immune benefits arose in response to an increased need in more complex societies, or arose early in group living and helped facilitate the evolution of more complex societies. In this study, we shed light on this question through investigating how immunity varies intraspecifically in a socially polymorphic bee. Using a novel immune assay, we show that personal antibacterial efficacy in individuals from social nests is higher than that of solitary individuals, but that this can be explained by higher densities in social nests. We conclude that personal immune effects are likely to play a role in the social/solitary transition in this species. These patterns are consistent with the idea that social immunity evolved secondarily, following the evolution of group living. The flexibility of the individual immune system may have favoured a reliance on its use during the facultative phase early in social evolution.

The wide geographical distribution of Eurasian wild boar (Sus scrofa) provides a natural model to study the adaptation to cold climate. Here, we conducted whole-genome sequencing and analyses for wild boar populations from cold (northern and northeastern Asia) and relatively warm regions (southeastern Asia and southern China). With genome-wide scans of four methods, we detected candidate genes underlying cold-adaptation with significant enrichment of pathways related to thermogenesis, fat cell development, and adipose tissue regulation. We further found two positively selected variants, rs341219502 in IGF1R (Insulin-Like Growth Factor 1 Receptor) and rs327139795 in BRD4 (Bromodomain Containing 4), which showed the highest cold-warm differentiation among all regulatory and exonic variants, respectively. Allele frequency distribution revealed that they are absent in outgroup species and warm-region wild boar but nearly fixed in cold-region populations, suggesting their de novo origins in cold-region populations. The historical demography during the last 25,000-50,000 years does not support the hypothesis that the sweep signal on the two variants resulted from genetic drift. We also found three genes (SLCO1C1, PDE3A, and TTC28) with selection signals in both wild boar and indigenous human populations from Siberia, which suggests convergent molecular adaptation in mammals. Our study indicates that molecular adaptive evolution is underlying the remarkable environmental flexibility of wild boar.

Livestock manure and its management are significant sources of greenhouse gas (GHG). In most Southeast Asian countries, the current GHG emissions are estimated by the Intergovernmental Panel on Climate Change (IPCC) Tier 1 approach using default emission factors. Sun-drying is the dominant manure treatment in Vietnam, and in this study, we measured GHG emissions during manure drying using a chamber-based approach. Results show the emission factors for CH4 and N2O were 0.295 ± 0.078 g kg-1 volatile solids (VS) and 0.132 ± 0.136 g N2O-N kg-1 Ninitial, respectively. We monitored the total bacterial/archaeal community using 16S rRNA gene amplicon sequencing and measured the abundance of functional genes required for methanogenesis (mcrA), nitrification (amoA) and denitrification (nirK, nirS and nosZ) processes. Methane emission occurred only at the beginning of the drying process (days 1 to 3). The results of amplicon sequencing indicated that the relative abundance of methanogens also decreased during this period. Although some nitrification activity was detected, there was no significant N2O emission. These findings well describe the manure management system in south Vietnam and the GHG emission from this manure category, paving the way for higher Tier estimations using country-specific values.