Journal of Dairy Science

Continuous video offers a dynamic view of dairy-cow behaviour, but its value for precision nutrition depends on alignment with physiological context. We developed a dairy digital-twin framework that fuses identity-associated behavioural records from an established video-analytics layer with body weight, milk production, milk fat, parity and days in milk. The 16-cow analytical cohort was monitored for up to 11 days in one tie-stall barn, yielding 153 cow-days after quality exclusions applied before model fitting. NRC (2001) expected dry matter intake provided a transparent physiological reference compatible with the daily records. In matched leave-one-cow-out analysis, adding video-derived feeding duration to body weight, fat-corrected milk and days in milk reduced RMSE from 2.015 to 1.763 kg DM/day, MAE from 1.267 to 1.159 kg DM/day and MAPE from 4.5% to 4.2%, while R{superscript 2} increased from 0.500 to 0.617. A secondary reduced index achieved RMSE 2.362 kg DM/day and MAPE 5.8% across held-out cows. Cow-level analysis delineated the operating domain: median per-cow MAPE was 4.15%, whereas the sole cow at 15 days in milk had MAPE 28.8%. Two independently recorded veterinary events were temporally concordant with unusual feeding trajectories, providing descriptive biological context. Because the endpoint was NRC-derived, these metrics quantify reference reconstruction rather than accuracy against observed intake. By converting continuous behavioural events into auditable cow-day states, the framework links physical animals to physiologically contextualized digital counterparts and establishes a scalable foundation for operator-focused dairy digital-twin decision support.

The emergence of Highly Pathogenic Avian Influenza (HPAI 2.3.4.4b) in dairy herds in 2024 across 19 states in the United States of America has raised concerns regarding the potential national and global zoonotic impact. All recent modeling efforts implemented homogenous cattle-to-cattle (both intra and inter-herd) transmission models which did not capture the real-world heterogeneity in mixing of animals, individual variations in susceptibility and infectiousness and clinical incidences across pens and lactation groups. The aim of this study was to develop a heterogenous transmission model to estimate the epidemiological parameters for intra-herd HPAI transmission on Californian dairies. We developed a validated stochastic agent-based model to estimate the epidemiological parameters for intra-herd HPAI transmission on California dairies. The hierarchical agent-based model also parameterized stochastic cattle movements within-herd to simulate real dairy management practices. A cow-level SEIR transmission approach was assumed during the outbreak. A novel Bayesian Optimizer with Gaussian Process (BO-GP) was fitted to the agent-based model for validation which converged within 25-40 iterations (out of 100 per farm) with minimal loss over two distinct error metrics, namely, Poisson loss function and temporal distance metric. Our optimized simulations estimated an average R0 was around 10.7-10.8 across all farms within the first 15 days of observed outbreak on four dairy farms with a mean effective transmission rate of 4.5% per contact between susceptible and infectious cows within each pen. Our model demonstrated that the movement of cows between pens ensured localized clusters of outbreaks within the sub-herds (pen population) that prolonged the overall outbreak within farms. We estimated the total duration of infection between 14.5 and 28 days, which is higher than the estimates from the homogenous models. With an integrated hierarchical agent-based model combined with Bayesian approximation, we produced actionable insights on the epidemiology of intra-farm spread of HPAI within cow herds, thereby guiding both future model development and applied disease control strategy.

The growth and performance of cattle is dependent on efficient feed conversion, facilitated by the gut microbiome, including both prokaryotic and eukaryotic organisms. Extrinsic factors such as management practices and intrinsic factors like age and genetics can shape these communities. To characterize the relative effects of such factors on the prokaryotic and eukaryotic microbiomes, fresh fecal samples from dairy heifers (n = 8), beef heifers (n = 8), bred beef heifers (n = 8), and adult beef cows (n = 8) were subjected to paired 16S rRNA (V4) and a novel 18S rRNA (V4-V5) metabarcoding assay, and 18S rRNA amplicons were annotated using two databases in parallel. Taxonomic resolution of 18S rRNA amplicons was excellent, with SILVA and EUKARYOME databases each providing better resolution of different groups of organisms. While no differences in eukaryotic richness or alpha diversity were detected, beta diversity differed in all pairwise comparisons except between beef heifers and bred beef heifers. Prokaryotic richness was lower in adult beef cows than the other groups, and beta diversity differed in all pairwise comparisons. Adult beef cows were the most distinct, characterized by replacement of fungal organisms with protozoa and loss of thermophilic bacteria in the eukaryotic and prokaryotic compartments, respectively. Among numerous differentially abundant features, dairy heifers harbored greater abundance of Cooperia oncophora while beef heifers contained greater abundance of Buxtonella sulcata and Mucor. Correlation network analysis revealed multiple significant positive and negative associations between bacterial, fungal, and protozoal features during maturation of the fecal microbiome. Collectively, these data highlight the richness and diversity of both the prokaryotic and eukaryotic compartments of the bovine fecal microbiome, and the influence of management practices and age on both communities. From a technical standpoint, these data demonstrate the ability to resolve fungal, protozoal, and metazoan organisms, including potential parasites and pathogens, with a single metabarcoding assay. They also highlight the nuanced differences between databases and the value of parallel analyses using more than one database.

Insect proteins represent a promising and more sustainable alternative to soybean meal in swine nutrition. However, high dietary inclusion levels often result in reduced animal performance, indicating that factors other than crude protein concentration should be considered. This study evaluated the protein quality and degradability of feed-grade defatted black soldier fly (BSF) meal in comparison with a conventional organic protein core for post-weaning piglets. Protein content, amino acid composition, reactive lysine, Maillard reaction markers, buffering capacity, and protein hydrolysability were determined. Our results showed that defatted BSF meal exhibited a protein content and amino acid profile comparable to those of the protein core but contained substantially higher levels of free amino acids. Accounting for free amino acids reduced the estimated lysine damage from 18.4% to 10.4%, highlighting the importance of considering free amino acids when determining reactive lysine. In addition, BSF meal exhibited a higher buffering capacity and lower protein degradability than the protein core. These findings provide new insights into the nutritional limitations of feed-grade BSF meal and suggest that a more accurate assessment of reactive lysine, together with dietary strategies to reduce buffering capacity, may improve its utilization in post-weaning piglet diets.

The study of animal personality has gained increasing attention in recent years, as researchers recognize that non-human animals exhibit stable individual differences in behaviour. In dairy cattle, understanding personality traits holds potential for improving animal welfare, enhancing management practices, and supporting productivity outcomes. However, validating the behavioural tests used to assess these traits remains a significant challenge. The present study aimed to evaluate the consistency and validity of five commonly used behavioural tests in dairy cows: the Human Approach Test (HAT), Sudden Test (SUD), Novel Object Test (NOT), Open Field Test (OFT), and Novel Surface Test (NST). These tests were chosen for their potential to assess personality dimensions that parallel components of human personality, particularly Openness, Neuroticism, Extraversion, and Agreeableness. Repeated assessments were conducted across three time periods to evaluate both intra-test (temporal) and inter-test (contextual) consistency. Results revealed that only the SUD exhibited significant behavioural consistency across all periods, suggesting its potential as a reliable tool for personality assessment. Additionally, a moderate correlation between the HAT and SUD was observed, indicating that these tests may capture overlapping personality traits. In contrast, the remaining tests (NOT, OFT, NST) lacked consistent behavioural patterns over time and across contexts, raising questions about their reliability and the complexity of trait expression. These findings highlight the challenges of identifying stable personality traits in cattle and emphasize the need for more rigorous validation of behavioural tests. This research contributes to the growing field of animal personality by providing insights into trait stability, the limitations of current testing methods, and the potential application of personality assessment in future livestock management practices.

Macrophages, alongside mammary epithelial cells, are major contributors to the innate immune response triggered by bacterial invasion of the mammary gland. To investigate breed-specific immune mechanisms, we stimulated monocyte-derived macrophages from Holstein and Normande cattle with Escherichia coli and Streptococcus uberis, two major mastitis pathogens. We monitored bacterial survival using [methode] and profiled gene expression via RNA-seq. E. coli exhibited significantly higher survival 6 hours post-infection compared to S. uberis (p < 0.05). Moreover, E. coli induced a robust transcriptional response, with 4403 differentially expressed genes (FDR < 0.05, |log2FC| > 1), versus only 813 for S. uberis. Qualitative differences were also observed: genes such as CCL2 and CSF1 were uniquely induced by S. uberis. Additionally, macrophages from Holstein and Normande cattle showed distinct expression profiles: 185, 45, and 174 genes were differentially expressed at steady state or after E. coli or S. uberis stimulation, respectively. These genes were enriched in immune-related pathways. Overall, our results demonstrate a stronger response to E. coli, although S. uberis specifically induces a subset of genes. The observed breed-specific differences may reflect underlying immune mechanisms that could influence disease susceptibility, warranting further functional validation.

Koalas within Australia are facing multiple threats from habitat loss, climate change and pervasive chlamydial disease. A safe and effective vaccine to protect koalas against chlamydia would be a welcome veterinary intervention to prevent this devastating disease which causes blindness, renal and reproductive pathology, infertility and mortality. However, over a decade of vaccine development and research trials has produced conflicting results, which vary from no observable indication of protective efficacy to a 64% reduction in chlamydia associated mortality. Given this discrepancy we conducted an independent analysis of data underpinning the highly cited publication demonstrating vaccine efficacy that was the basis for a permit for limited use in koalas. In doing so, we identified a substantial error in the way the data was encoded for analysis, which resulted in survival from birth to time of vaccination incorrectly being attributed to vaccination. After correction for this error, we show using the exact methods of the original authors that there was no significant difference in the survival or disease rate between vaccinated and unvaccinated koalas. Furthermore, we identified a substantial source of bias whereby animals with disease at their first health assessment were not excluded from the study and as those animals were generally not vaccinated, they were almost six times more likely to be included in the control group. Reanalysis including only koalas that were healthy on initial assessment and for which follow-up health assessments were performed, showed that vaccinated individuals were equally likely to contract disease or to die with disease; 18 of 143 vaccinated koalas (12.6%) developed disease and 3 (2.1%) died, compared to 63 of 439 control animals (14.4%) that developed disease and 11 (2.5%) that died. This study highlights the importance of randomised, observer blinded, placebo-controlled studies in veterinary settings to uphold scientific rigor and prevent stratification bias.

The gut-airway axis is increasingly recognised as an important determinant of respiratory health in livestock. However, the interactions among respiratory infections, microbial communities, mucosal barrier function, and microbial metabolism that underpin this axis remain poorly understood. Here, we combined longitudinal immunological, mucosal, microbiological, and metabolic analyses to characterise host-microbiota interactions during antibiotic treatment and experimental bovine respiratory disease (BRD). We found that the bovine respiratory tract is organised as a hierarchically structured mucosal ecosystem, with compartment-specific mucin expression patterns associated with distinct microbial communities. Within this framework, increasing respiratory pathogen loads were associated with greater clinical severity, oxidative stress, acute inflammation, and targeted alterations in mucosal regulation and microbial composition, while serum amyloid A emerged as the host biomarker most closely reflecting infection intensity. Although infection altered host and microbial states, antimicrobial treatment represented the dominant ecological perturbation. Antibiotic exposure reshaped both respiratory and intestinal microbial communities, reducing diversity, increasing community drift, and driving coordinated ecological transitions across the gut-airway axis that exceeded the effects of infection alone. Importantly, these compositional changes were accompanied by profound reductions in acetate, propionate, butyrate, and valerate, identifying short-chain fatty acids as a major functional consequence of gut microbiota disruption. Integrative multi-omics analyses revealed that mucosal organisation, microbial diversity, microbial metabolism, and immune activity were embedded within a highly structured gut-airway network. Together, these findings support a holobiont view of BRD in which disease outcomes emerge not only from pathogen-host interactions but also from ecological disturbances that propagate across interconnected mucosal compartments. Notably, antimicrobial treatment affected ecosystem structure and function more than infection itself, highlighting potential trade-offs between pathogen control and microbiota stability. Preserving microbial resilience and its metabolic functions may therefore represent an important component of future strategies to improve respiratory health and disease resilience in cattle.

Abstract Napier grass (Cenchrus purpureus, NG) is an important forage in tropical and subtropical livestock systems, but the extent of naturally occurring variation in its methane (CH4) production and its potential for selecting low-CH4 emitting genotypes remains poorly characterised. This study evaluated variation in CH4 yield among NG accessions, examined the effects of season and water stress, validated contrasting CH4 phenotypes across donor cows, and identified elite accessions combining low CH4 yield with favourable digestibility. A total of 750 NG samples representing 84 accessions grown under dry and wet seasons and moderate and severe water-stress were evaluated using a high-throughput in-vitro fermentation system. To further identify forages combining low-CH4 production with acceptable digestibility, a multi-trait selection approach was applied using biologically defined thresholds for CH4 yield and in vitro organic matter digestibility (IVOMD), followed by a weighted index assigning 60% weight to CH4 yield and 40% to IVOMD. Methane yield varied widely among accessions, ranging from 0.02 to 5.07 mL/g DM and was affected by growing conditions. Methane production was generally lower during the wet season, while water stress was associated with changes in forage quality and fermentation characteristics. Low-CH4 producing accessions generally had lower IVOMD, crude protein and metabolizable energy and relatively higher fibre than high-CH4 producing accessions. Accessions initially classified as low and high-CH4 emitters based solely on CH4 yield were subsequently validated using rumen inoculum from three individual donor cows. Although the magnitude of CH4 production varied among donors, the contrast between low- and- high-CH4 accessions was generally retained, supporting the robustness of accession differences in CH4 production. Several accessions also maintained relatively low CH4 production across contrasting season and water-stress conditions, indicating that favourable CH4 phenotypes were not entirely environment dependent. A multi-trait selection identified ten elite accessions that produced 0.019-0.810 mL CH4/g DM and had 55.2-69.0% IVOMD, whereas ten poor-performing accessions produced 2.80-3.89 mL CH4/g DM and had 50.1-54.7% IVOMD. Differences in hexose fermentation and CH4 produced per unit of fermented substrate further indicated contrasting fermentation efficiency between the groups. These results demonstrate substantial variation in NG and identify accessions with low-CH4 production, favourable digestibility and relatively stable performance across growing conditions. In conclusion, incorporating CH4 yield and digestibility into forage selection could support the development of lower-emission forage cultivars for sustainable climate-smart livestock production.

Background Street food vending is a major source of food supply in Nepal. Poor food hygiene practices among street food vendors pose a health risk by increasing the risk of foodborne diseases. Studies regarding food hygiene knowledge and practices are needed to improve public awareness. Therefore, this study aimed to assess food hygiene knowledge and practice among street food vendors and their associated factors in selected districts of Bagamati Province. Methods A community-based cross-sectional analytical study was carried out among 186 street food vendors of Districts located in central Nepal. Face-to-face interviews were conducted using a semi-structured questionnaire and an observation checklist. Knowledge and practice levels were categorized as good and poor. Chi-square test, Fisher's exact test, odds ratio, and Mann-Whitney U test were applied for data analysis. Results Less than half (39.8%) of the vendors had good food hygiene knowledge, while 91.4% of the respondents reported good food safety and hygiene practices. The education level of street food vendors was significantly associated with food hygiene knowledge (p = 0.001) and food safety and hygiene practices (p = 0.042). Significant association was not seen between overall food hygiene knowledge and overall food safety and hygiene practices levels. Conclusion The study identified a gap between food hygiene knowledge and self-reported food hygiene practices among street food vendors. Education, infrastructure, and regulations among street food vendors play a key role in good food hygiene practices more than knowledge alone. Policymakers should focus on training of food vendors, regular supervision, and monitoring of vending sites to enhance food safety.

Abstract The gayal (Bos frontalis) is an endangered semi-domesticated bovine species renowned for its high-quality beef. However, its semi-feral lifestyle, ongoing habitat fragmentation, and extensive genetic introgression from sympatric local cattle have led to dramatic population decline and severe erosion of purebred genetic integrity, posing substantial challenges to its conservation and utilization. To address the urgent demand for rapid, non-invasive, and field-compatible germplasm identification, we developed an integrated artificial intelligence (AI) framework that predicts genomic admixture composition from external morphological images. We constructed a comprehensive dataset comprising 6,245 morphological images and matched genomic sequences from 52 gayals maintained at the Yunnan Provincial Gayal Conservation Farms. Following a preliminary evaluation of nine deep learning models, five were incorporated into a anatomical segment-based multi-modal pipeline, among which Inception_V3 delivered the optimal overall performance. To enhance simultaneous extraction of local fine-grained features and global structural information, we further designed an innovative HybridInceptionViT model by integrating the multi-scale Inception module with the Vision Transformer (ViT) framework. This hybrid model significantly outperformed the baseline Inception_V3, boosting the accuracy of phenotype-derived prediction against genomic admixture estimate from 69.69% to 87.87% (absolute error <15%). This study establishes a practical, low-cost "phenotype-to-genotype" tool for rapid on-site gayal germplasm screening, offering a scalable strategy for the conservation and breeding management of endangered livestock, and holds broad application prospects for agricultural and livestock production systems.

Dairy-free foods must reproduce diverse functions of dairy, from foam stabilization in a latte to acid-gel structure in yogurt and melt-stretch behavior in mozzarella. Public consumer benchmarks rarely compare these categories under a common protocol. Here we analyze data from the NECTAR Taste of the Industry 2026 study, a blinded, randomized, in-person evaluation of commercial dairy-free products and dairy benchmarks. The full study included 2,183 consumers and 112 products across ten categories, with 3,220 product evaluations and 79,027 recorded survey responses, including 35,762 product-linked responses. The ten categories included barista milk, butter, cheddar, cream cheese, creamer, ice cream, fluid milk, mozzarella, sour cream, and Greek style yogurt. Within each category, we compare a dairy benchmark with the dairy-free product selected post hoc as the category leader. Participants rated overall liking, flavor, texture and mouthfeel, appearance, similarity to dairy, and purchase intent on seven-point scales and completed check-all-that-apply questions. In exploratory category-specific equivalence tests using a chosen margin of {+/-}0.05 points, barista milk, creamer, and fluid milk meet this margin. Mozzarella has the largest paired deficit of -1.46 points (unadjusted, p < 0.001), followed by Greek style yogurt and butter; all three remain significant after Holm correction across the ten primary comparisons. Descriptive penalty analysis associates off-flavor, artificial or chemical notes, stale or cardboard notes, bitter taste, and lingering aftertaste with the largest reductions in liking. Together, these results establish the first open sensory benchmark for dairy and dairy-free products, demonstrate that sensory parity is already achievable in several beverage categories, and identify the product categories and sensory attributes that offer the greatest opportunities for future innovation.

Background: Microbiome research has linked microbial community structure to host phenotype, but translating microbiome-based discovery into defined interventions with reproducible long-term host effects remains challenging. We evaluated whether a defined four-member consortium of rumen native microorganisms identified through associations with host phenotype could influence herd retention. Cull outcomes (sold or died vs. retained in herd) were analyzed across 20 controlled commercial dairy trials encompassing more than 40,000 cattle housed across 110 experimental pens, with each trial conducted for at least 5 months. Treatment pens received a defined daily dose of Galaxis Frontier (GF, Native Microbials, San Diego, CA), containing Pichia kudriavzevii, Clostridium beijerinckii, Ruminococcus bovis, and Butyrivibrio fibrisolvens, incorporated into the ration; control and treatment groups were otherwise managed equivalently. Cow-level time to culling was modeled within each trial, accounting for pen-level clustering, and trial estimates were combined using random-effects meta-analysis. Results: Daily treatment with rumen native microbes was associated with a 9% lower hazard of culling across 20 trials (hazard ratio = 0.91, 95% confidence interval: 0.86-0.96; P < 0.001). Between trial heterogeneity was negligible, and treatment effects were not significantly moderated by breed or geographic region. Detailed health records from one trial were examined to further characterize health outcomes associated with GF; treatment was associated with fewer transition-related disorders, particularly ketosis and metritis, whereas mastitis and lameness were largely unaffected. These findings suggest that the health effects associated with GF may be more pronounced for disorders linked to physiological and metabolic adaptation during the transition period than for health events more broadly. Conclusion: Across diverse commercial dairy environments, treatment with a defined consortium of rumen native microbes was associated with improved dairy cow retention. The consistency of this association across independent trials provides large scale evidence that targeted application of native microorganisms can translate into reproducible, long-term outcomes for the host. Complementary health event data suggest that improved transition period health and metabolic stability may contribute to this effect. These findings support the potential for microbiome targeted interventions to influence productive longevity under commercial conditions.

Micronutrient deficiencies are prevalent in Madagascar, where diets rely heavily on starchy staples and access to animal-source foods is limited. Small dried fish (SDF) are widely available, yet their nutritional value and health risks remain poorly documented. We combined market surveys, taxonomic identification, and micronutrient and heavy metal analyses of nine SDF types collected along National Road 7. The samples encompassed 33 fish families, were dominated by small pelagic species (Clupeidae and Engraulidae), and were appreciated by consumers. A daily portion (5 g for infants; 10 g for young children and women of childbearing age) contributed substantially to Recommended Nutrient Intakes (RNIs). Across samples and groups, SDF were rich (>30% of RNI) in selenium and, for infants and young children, in calcium. All samples were a source of (>15% of RNI), or rich in, phosphorus, whereas iron contributions were more variable but often substantial. Several samples exceeded 100% of RNIs for selenium, calcium, iron, or manganese in infants and young children, and some were also sources of magnesium and, less frequently, zinc. Vitamin A was absent from sun-dried samples but detected in a smoked freshwater type. Heavy metal concentrations varied markedly, and portions of several types led to estimated exposures to inorganic arsenic or cadmium exceeding reference values, whereas freshwater species and some pelagic types showed a more favorable nutrition-risk balance. Overall, SDF are affordable, nutrient-dense foods with strong potential to alleviate micronutrient deficiencies in Madagascar, while highlighting the need for type-specific guidance to balance nutritional benefits and contamination risks.

Beef cattle farming plays a crucial role in the livestock-related economies of both Italy and Argentina. Although both countries have grazing systems of meat production, the heterogeneity of those systems leads to different parasitological scenarios regarding epidemiology and the presence of resistance to commonly used anthelmintic drugs. Considering ivermectin (IVM) is the most widely used anthelmintic for treating gastrointestinal nematode (GIN) infections in cattle, the current studies evaluated the efficacy of ivermectin (IVM) given subcutaneously (SC) to both young calves and adult cows in ten (10) commercial cattle farms from Italy (A to E) and Argentina (F to J). The work was complemented with the assessment of the IVM plasma exposure and disposition kinetics both in young and adult animals. While adult cows and young calves were included in the study performed in Italy (Campania region), only calves aged 8-14 months old were selected to perform the efficacy trials in Argentina (central area of the Buenos Aires province). Fifteen (15) calves/cows naturally infected with GINs were treated with IVM (0.2 mg/kg) in each of the Farms. The therapeutic response (efficacy) was determined at 14 days after treatment by the faecal egg count reduction test. Six (6) adult cows and eight (8) young calves treated with IVM were randomly selected to perform the pharmacokinetic (PK) study with blood samples being taken 2 h and 21 days post-treatment. Drug concentrations were measured by HPLC. Similar IVM PK trends were obtained for both adult and young cattle. The IVM systemic exposure (expressed as AUC) obtained for adult cattle (380{+/-}158 ng.d/mL) was similar to that observed in calves group (313{+/-}85.5 ng.d/mL). No statistical differences between animals from both ages were observed for the most representative PK parameters (P>0.05). Surprisingly, while in Argentina IVM resistance was present in all the farms evaluated (90% CI = 0%-95%), in Italy a fully susceptible nematode population was presented in three farms (90% CI = 96%-100%) and only a very low level of IVM resistance was detected in the rest of the farms (90% CI = 92%-98%). Whereas Cooperia spp. and Haemonchus spp. were identified as the principal genera exhibiting resistance to IVM in Argentina, Cooperia spp., Ostertagia spp., and Oesophagostomum spp. were reported to display low levels of resistance under the Italian field scenario. In conclusion, IVM can be safely and effectively used in both young and adult cattle with similar disposition kinetic patterns. While its therapeutic response is failing under the conditions investigated in the Argentinian farms, its efficacy remains notably high in the Italian region under study. However, the use of IVM, as well any other active antiparasitic principle, should always be preceded by a diagnostic assessment of the nematode populations resistance status.

The exponential increase in the number of genotyped animals, combined with the availability of high-density SNP chips has introduced computational challenges for routine genomic evaluations, particularly during the construction of the genomic relationship matrix. Although higher-density SNP panels can facilitate the identification of causal mutations, their use substantially increases computational requirements without a proportional gain in genomic prediction performance. To optimize computational efficiency while maintaining accuracy of genomic predictions, this study compared five SNP selection strategies (i.e., random sampling, random sampling with inclusion of informative SNPs, linkage disequilibrium (LD)-based pruning, a Shannon entropy-based machine learning approach, and [[EQUATION]]-based prioritization) to develop reduced-density panels for Nellore cattle. Using high-density (HD) genotype data comprising 437,650 SNPs from 304,782 animals (after quality control) as reference, three reduced-density panels (25K, 45K, and 65K SNPs) panels were tested across five traits (i.e., Age at first calving, Stayability, Weaning weight, Yearling weight, Muscling) with diverse genetic architectures. Genomic estimated breeding values (GEBVs) derived from these reduced panels were compared to those obtained from the HD reference panel using Pearsons correlations, under both genomic best linear unbiased prediction (GBLUP) and single-step GBLUP (ssGBLUP) methods. In the GBLUP model, prediction accuracy generally improved with increased marker density. Random selection with and without the informative SNPs consistently yielded the highest accuracies, whereas the [[EQUATION]]-based approach showed the lowest agreement with the HD reference across all densities. In contrast, ssGBLUP demonstrated strong robustness to marker reduction, producing uniformly high correlations {approx}1.00) across all SNP densities and selection strategies. These findings indicate that optimized low-density SNP panels maintain prediction accuracy comparable to HD panels, offering a cost-effective tool for large-scale genomic evaluations.

ABSTRACT Objective: Skeletal muscle growth rate differs substantially among diverse pig breeds. In the present study, RNA-seq was performed to identify differentially expressed genes (DEGs) across pig breeds with distinct growth rates. CCND2 showed obvious differential expression among pig breeds. Although CCND2 is essential for cell cycle control, its biological function in skeletal muscle differentiation has rarely been reported. This work aims to identify DEGs in pig breeds with different growth rates and explore CCND2 role in porcine skeletal muscle development. Methods: RNA-seq was performed to identify differentially expressed genes (DEGs) across pig breeds with distinct growth rates. Weighted gene co-expression network analysis (WGCNA) was used to identify gene modules potentially associated with skeletal muscle growth and development. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis was performed to validate the role of CCND2 in skeletal muscle differentiation. Results We identified 5,416, 4,846, and 2,777 DEGs in the Duroc pig (DU) vs. Jiangquan black pig (JQ), DU vs. Laiwu pigs (LW), and JQ vs. LW comparison groups, respectively. WGCNA identified two gene modules (lightgreen and darkmagenta) potentially associated with skeletal muscle growth and development. CCND2 exhibited differential expression in comparisons between DU vs JQ and DU vs LW, with higher expression observed in Duroc pigs. qRT-PCR analysis revealed that overexpression of CCND2 at day 6 (D6) of cell differentiation significantly increased the expression levels of CCND2 gene and markers of myogenic differentiation (p < 0.05). Conversely, knockdown of CCND2 significantly decreased the expression levels of CCND2 gene and myogenic differentiation markers (p < 0.05). Conclusions This study identified breed-specific DEGs and key gene modules in porcine skeletal muscle and verified that CCND2 promotes myogenic differentiation. These findings provide a genetic theoretical basis for further investigations into skeletal muscle growth and development. Keywords pig, skeletal muscle, transcriptome, WGCNA, CCND2

Background: The yak (Bos grunniens) is an essential livestock species in high-altitude alpine ecosystems, serving key roles in meat, milk, and wool production as well as ecological maintenance. However, traditional yak breeding systems face several limitations, including fragmented herd data management, inefficient phenotypic collection, missing pedigree records, and high technical barriers to applying genomic technologies. These factors constrain the widespread application of modern genetic evaluation methods in yak breeding programs. Description: We developed the Yak Genomic Evaluation Platform (YGEP, https://yakbreeding.swun.edu.cn/en/), an integrated digital system for yak genetic selection and herd management. YGEP integrates three core analytical modules: pedigree reconstruction, genotype imputation and genomic breeding value estimation. Benchmarking on 706 yaks showed that GBLUP achieved a prediction accuracy of r = 0.96 for cannon bone circumference (CCB), and KBeagle reached 84.0% imputation accuracy with the combined reference panel. Conclusion: YGEP bridges the gap between advanced genomic analytics and practical yak breeding. By integrating pedigree reconstruction, genotype imputation, and GEBV estimation into a user-friendly cloud platform, YGEP effectively eliminates technical and data bottlenecks. Overall, it provides an accessible, scalable, and standardized solution to advance digital herd management and precision genetic improvement in alpine livestock.

In this work, we investigate the homogeneity of performance in binary classification between the Rotterdam phenotypes and phenotype prediction. For this purpose, a multi-task neural network architecture is designed to improve the prediction accuracy of phenotypes while maintaining the accuracy of binary classification. Using a clinical PCOS dataset which contains unlabeled samples of patients that cannot be attributed to any of the known phenotypes, three models are evaluated: optimized binary Random Forest (RF), six-class weighted class RF, and multi-task neural network (with a common hidden layer and two heads for binary and six-class classifications) optimized by a genetic algorithm. Techniques used for evaluation include ten-fold out-of-fold predictions, paired McNemar tests, bootstrap tests, ablation study, and clustering (Adjusted Rand Index, ARI). Binary RF model reached 90.2% accuracy; however, recall of different phenotypes was significantly unbalanced - from 75.0% of phenotype B to 97.8% of phenotype A. This difference of 22.8 % points was observed (23.3 points) even after excluding phenotype-specific features. While direct phenotype prediction improved recall for common phenotypes, it decreased recall for phenotype B to 43.8% and unclassified cases to 31.5%. Our multi-task model preserved 90.2% binary accuracy and significantly recovered phenotype B recall to 87.5% and unclassified cases to 79.6% (p<0.05). The cluster analysis confirmed the weak correlation between the results and labels (ARI=0.045). The ablation analysis demonstrates that feature selection and class weighting drive this improvement, isolating the specific components responsible for performance gains. We establish that aggregate binary accuracy does not reflect the heterogeneous detection of PCOS phenotypes. Direct phenotype prediction alone redistributes the classification errors, but the multi-task architecture successfully improves the detection of rare phenotypes without compromising binary accuracy. Phenotype-disaggregated evaluations, supported by significance testing and ablation, are essential for clinical classifier research.

The maned wolf (Chrysocyon brachyurus) is a near-threatened canid species that suffers from gastrointestinal (GI) disease under human care. While the cause remains poorly understood, recent studies report that altered gut microbiota is linked to GI disease in the domestic dog. The goal of this study was to describe the relationship between gut bacteria and environmental factors, GI health, short chain fatty acid (SCFA) peaks, and genetic relatedness in maned wolves. Fresh fecal samples were collected twice from wolves (first collection n = 29; second collection n = 25) housed in six facilities in the United States. Fecal alpha-1 proteinase inhibitor (FA1PI), a biomarker for GI health in canids, and SCFA peaks were quantified. Information on diet, housing group and history of GI disease or inflammation was provided by the zoological facility for each wolf. We characterized gut microbiota using 16S rRNA gene amplicon sequencing with qPCR abundance corrections. We found that dietary fiber gross energy (GE), protein GE, and number of daily produce items influenced gut microbiota. Additionally, there was a negative relationship between dietary fiber GE and Fusobacterium sp. abundance, corroborating previous findings linking fiber to altered gut microbiome composition in canids. Lastly, fiber GE was negatively correlated with FA1PI, connecting fiber to GI health in the maned wolf. Findings from this study suggest that increasing dietary fiber GE changes the gut microbiome and may improve GI health in the maned wolf, highlighting important management decisions that can be considered to maintain a healthy zoo-managed maned wolf population. IMPORTANCEFindings from this study are important because gastrointestinal disease is a common health concern for maned wolves under human care, and the causes are not well understood. The current study found that diet, especially the amount of fiber gross energy, can affect gut bacteria and may support better gastrointestinal health. Diet alterations could be a practical tool for zoos to support management of gastrointestinal health issues in maned wolves. These findings also show the importance of carefully managing diets for a near-threatened species, since better gastrointestinal health may improve overall health and well-being and support reproduction. More research is needed to determine the best amount and type of fiber, but our results provide foundational information for improving care and supporting healthy zoo-managed maned wolf populations.