Concepta McManus

This study evaluated species-specific 96-SNP panels for parentage assignment in Brazilian sheep and goats using genotypes from 1481 animals, generated with the EMBRAPA Multispecies 65K Illumina Infinium 1 chip. Panels were selected under strict quality control (minor allele frequency ≥ 0.30) and compared with published panels and full species-specific datasets. Evaluation included confirmed trios (84 sheep, 95 goats) and independent simulation sets (357 sheep, 117 goats). Under the P2 parentage-exclusion scenario, in which the second parent’s genotype is unknown, the panels achieved a cumulative probability of exclusion (CPE) of 0.9999 using ≤70 SNPs in sheep and ≤72 in goats. They showed higher heterozygosity and polymorphic information content than random subsets and published reference panels (Holm-adjusted p < 0.0001), whereas differences from the full species-specific datasets varied. In empirical trio validation, observed parentage assignment success at the 95% confidence level was 96.43% in sheep and 95.80% in goats, comparable to larger panels. These findings support the potential utility of the panels for parentage assignment. As all markers are present on the multispecies BeadChip, they can be extracted from existing genotyping datasets, potentially reducing additional genotyping requirements and computational burden. Further validation across broader genetic backgrounds and complex pedigree scenarios is recommended before large-scale implementation.

Background/Objectives: Brazilian locally adapted sheep breeds represent valuable genetic resources. However, the commercial valorization of these breeds depends in part on genetic certification to support traceability and verify product origin. This study aimed to identify and evaluate a minimum set of highly informative SNPs for accurate and efficient breed assignment across five Brazilian locally adapted sheep breeds. Methods: A total of 677 samples were genotyped using the Embrapa Multispecies 65 K Illumina Infinium 1 chip, which contains 2926 markers for Ovis aries. The dataset was partitioned into training (n = 566) and independent testing (n = 111) sets. Markers were ranked according to genetic differentiation based on pairwise Wright’s fixation index (F_ST) using the Toolbox for Ranking and Evaluation of SNPs (TRES), generating three nested reduced panels of 288, 192, and 96 SNPs. Panel performance and preservation of population structure were evaluated using Random Forest classification, Principal Component Analysis (PCA), and ADMIXTURE. Results: The 96-SNP panel achieved classification accuracy comparable to that of the 2145-SNP post-QC baseline and the 192- and 288-SNP panels (Cochran’s Q test: Q = 6.00, df = 3, p = 0.112), with no statistically significant difference in classification performance despite the substantial reduction in marker number. PCA and ADMIXTURE analyses indicated that the 96-SNP panel preserved the major population structure observed with the full post-QC marker set. Conclusions: Although formal analytical validation of a dedicated low-density genotyping assay remains necessary before routine implementation, the in-silico marker selection and empirical validation performed here provide an evidence-based framework for translating high-density genomic information into accessible and cost-effective applications for breed assignment, traceability, and conservation of Brazilian locally adapted sheep genetic resources.

Background/Objectives: Hatching egg sanitization protocols are primarily developed to protect embryos during the embryonic stage from exposure to horizontally transmitted pathogenic bacteria, thereby ensuring their survival. This study aimed to evaluate the antibacterial efficacy of Cymbopogon nardus (L.) Rendle (Poaceae) essential oil, alone or combined with UV-C radiation, as a potential sanitization protocol for hatching eggs. Methods: Unwashed table eggs, used as an experimental model, were sprayed with C. nardus essential oil at two concentrations (0.625–1.25%) and exposed to UV-C radiation for different exposure times (0–10 min). Mesophilic bacterial load and the physical characteristics of the eggshell were subsequently evaluated. Results: A significant reduction in the mesophilic bacterial load on the eggshell surface was observed following the application of the treatments. C. nardus essential oil promoted reductions greater than 2 log₁₀ CFU/mL, demonstrating strong antimicrobial activity. The application of UV-C radiation alone resulted in a progressive decrease in the bacterial population, reaching approximately 2 log₁₀ CFU/mL after 10 min of exposure. However, the combination of the essential oil and UV-C radiation showed the highest antibacterial efficacy, reducing bacterial counts to below 1 log₁₀ CFU/mL, indicating that the combination of the two technologies was more effective than either treatment applied alone. No significant macroscopic changes were observed in the physical characteristics of the eggshells. Conclusions: The combined application of C. nardus essential oil and UV-C radiation on the eggshell surface may represent a promising sanitization protocol with potential application for hatching eggs.

Background/Objectives : Brazilian locally adapted sheep breeds represent valuable genetic resources. However, market appreciation of these breeds depends on genetic certification that ensures traceability, thereby qualifying their products as originating from sustainable production models. This study aimed to identify and evaluate the minimum set of highly informative SNPs for accurate and efficient breed assignment across five Brazilian sheep breeds. Methods: A total of 677 animal samples were used, the SNPs were selected from the Embrapa Multispecies 65K Illumina Infinium 1 chip, which contains 2,926 markers for Ovis aries. The dataset was randomly partitioned into training (80%) and testing (20%) sets. Markers were prioritized based on genetic differentiation using Pairwise Wright's fixation index (F_ST), implemented in the Toolbox for Ranking and Evaluation of SNPs (TRES), generating three nested reduced panels of 288, 192, and 96 SNPs. Finally, panel performance and preservation of population structure were evaluated using Random Forest classification, Principal Component Analysis (PCA), and ADMIXTURE. Results: The 96-SNP panel maintained high classification accuracy, comparable to larger subsets. This indicates that targeted marker selection is more effective than simply increasing marker density for breed assignment. Conclusions: While the development and analytical validation of a dedicated low-density genotyping assay remain necessary before routine implementation, the 96-SNP panel identified here provides a solid foundation for an efficient, cost-effective genomic tool. This panel will support breed certification, traceability, and the conservation of Brazilian locally adapted sheep genetic resources.

Sanitizing hatching eggs has become increasingly recommended as a strategy to reduce infections, limit the spread of bacteria, and promote healthier conditions for developing embryos. The absence of this procedure can contribute to lower hatchability rates in commercial hatcheries. Therefore, investigating different sanitizers applied to hatching eggs is essential. This review synthesized evidence from Google Scholar up to June 2026, examining the effects of ultraviolet light (UV), hydrogen peroxide (H₂O₂), peracetic acid (PAA), and ozone (O₃) on eggshell bacterial load, eggshell structural integrity, and hatchability. The findings reveal that these sanitizers have the potential to reduce eggshell bacterial load without apparently causing significant structural alterations or compromising hatchability. However, it also became clear that outcomes depend strongly on the protocol configuration, as adverse effects may occur under different conditions, such as concentration, exposure time, or application method. Overall, UV, H₂O₂, PAA, and O₃ can be used to sanitize hatching eggs, if protocols prioritize microbiological safety without impairing embryonic performance, thereby avoiding negative impacts on hatchability rates.

Sanitization constitutes a pillar of modern bacterial control in the management of hatching eggs. When improperly performed, eggshell contamination may increase, thereby increasing embryo susceptibility to bacterial pathogens and negatively affecting their viability and development. Sanitizing agents based on quaternary ammonium compounds (QACs) and sodium hypochlorite (NaClO) have been considered potential treatments to mitigate bacterial problems in poultry production. Therefore, this review aims to analyze the antibacterial potential of QACs and NaClO as sanitizers for bacterial control on hatching eggshells. In summary, both evaluated compounds proved effective in reducing bacterial contamination on eggshell surfaces, as evidenced by the significant antibacterial activity observed. However, their use should be rational, respecting the specific characteristics and recommendations of each compound, and guided by manufacturers’ guidelines and scientific evidence.

Prolificacy and coat color are key economic traits influencing sheep production. This study evaluated a reduced panel of 48 SNPs previously associated with these traits and assessed its applicability to locally adapted Brazilian sheep breeds. A total of 1152 samples from 15 breeds, conserved in situ at conservation nuclei and ex situ in the Brazilian Animal Germplasm Bank, were genotyped. Allelic, genotypic, and haplotypic frequencies were estimated to compare genetic variability between in situ and ex situ populations. Additionally, linkage disequilibrium (LD) among SNPs within GDF9, a key gene associated with prolificacy, was evaluated across local breeds, revealing strong LD among specific markers. The results highlight the importance of the FecG^E (GDF9) variant for prolificacy in hair sheep, confirming the presence of mutant allele E in prolific breeds, such as Santa Inês and Morada Nova, and identifying, for the first time, a high frequency of such allele in the Brazilian Blackbelly, which provides new insights into the genetic basis of this prolific hair breed. Other prolificacy-related genes, BMP15 and BMPR1B, appear to have no functional role in locally adapted breeds, as initially hypothesized, considering genetic differences among European and tropical sheep. Allelic and genotypic variation in ASIP, MC1R, TYRP1, and MITF genes reflected differences between wool and hair sheep and between local and commercial breeds. Overall, the results indicate that the germplasm bank effectively preserves in situ diversity. In conclusion, the reduced SNP panel efficiently genotyped Brazilian sheep for prolificacy and coat color SNPs, confirming which markers are present and segregating in these breeds. However, its utility could be improved by removing markers of limited relevance in the targeted breeds.

Climate change is a major driver of transformation in livestock systems; however, existing reviews remain fragmented, often addressing environmental impacts or adaptation strategies in isolation, without systematically integrating the structure, evolution, and knowledge gaps of the field. This study addresses this limitation through a comprehensive bibliometric-scientometric analysis of global research on climate change and animal production. A total of 1,694 peer-reviewed articles and reviews indexed in Scopus (1974-2025) were retrieved using a structured search applied to titles, abstracts, and keywords. Data were processed through duplicate removal and keyword harmonization, and analyzed using Bibliometrix (R) and VOSviewer to perform co-occurrence network analysis, thematic clustering, and temporal trend evaluation. Results indicate a sustained annual growth rate of 9.47% and increasing international collaboration (35.71%), reflecting the rapid expansion of the field. The co-occurrence network reveals a highly interconnected structure, with "climate change" acting as the central organizing concept linking environmental, physiological, genetic, and production-related domains. Thematic analysis shows that research on greenhouse gas emissions and environmental impacts is well established, whereas emerging areas-such as climate-smart agriculture, One Health, and integrated sustainability frameworks-remain less connected to applied and policy-oriented research. Temporal trends highlight a shift, particularly after 2015, from impact-oriented studies toward more integrated approaches incorporating sustainability, animal welfare, resilience, and adaptive management, alongside increasing use of digital tools such as modeling and machine learning. In addition, life cycle modeling further indicates that the field remains in an early expansion stage, having reached approximately 11.6% of its estimated saturation level, with continued growth expected over the coming decades. Despite this progress, important gaps persist, particularly regarding the translation of scientific knowledge into practice and the uneven geographic distribution of research efforts. Strengthening region-specific and socially inclusive research, enhancing the integration between technological innovation and field-level application, and advancing interdisciplinary frameworks are key priorities to improve the adaptive capacity of livestock systems. By mapping the structure, evolution, and gaps of the field, this study provides a robust basis to inform future research agendas and support the transition toward more resilient and sustainable livestock systems under climate change.