introduction: Heat stress poses a significant challenge to the dairy sector, leading to substantial losses due to its detrimental effects on both milk production and reproductive performance. In response to high temperatures, cows have developed various protective mechanisms to mitigate the adverse consequences of heat stress. Some cows maintain their productive and reproductive capabilities during hot summer conditions and are considered thermotolerant, making them potential candidates for selective breeding programs aimed at enhancing heat resilience. Methods: In the present study, we conducted a comprehensive analysis by collecting samples from both thermotolerant and thermosensitive cows, employing a whole-genome sequencing approach to elucidate the unique genetic variants that distinguish the two groups. After identifying group-specific variants, we focused on variants within miRNA genes using miRNASNP v4. Results: We successfully identified 15 variants in thermotolerant cows, including 1 novel variant, across 15 distinct miRNAs. Five of these variants were located in mature miRNAs, potentially disrupting their structure and functionality. Subsequent analyses (Gene Ontology and KEGG) indicated that several of these variants could also influence miRNA-mRNA interactions, thereby impacting various molecular pathways, including metabolic pathways, the MAPK signaling pathway, the Ras signaling pathway, and mitophagy. Conclusions: This research provides valuable insights into the underlying mechanisms associated with thermotolerance in dairy cattle. Understanding the role of these miRNA variants may lead to innovative approaches in livestock management, ultimately contributing to improved animal welfare and productivity under changing climatic conditions.

Sparicotyle chrysophrii (Van Beneden & Hesse, 1863) Mamaev, 1984 is a monogenean ectoparasite that specifically infects Sparus aurata Linnaeus, 1758. This parasite can cause parasitic diseases, leading to significant mortality, especially in aquaculture. The examination of the morpho-anatomical characteristics of ectoparasites infesting S. aurata across seven Tunisian sites confirmed the presence of S. chrysophrii. However, few molecular studies have been conducted on this monogenean, and its genetic variability remains poorly understood. This work provides the first molecular characterisation and phylogenetic analysis of S. chrysophrii from the Tunisian coasts, examining both wild and cage-reared hosts using two molecular markers: the large subunit ribosomal RNA (28S) and mitochondrial COI genes. The analysis of nuclear ribosomal 28S sequences revealed no intraspecific genetic variation, resulting in a strongly supported monophyletic group. The COI sequences were grouped into a monophyletic clade clustering specimens from both the northern Mediterranean (France, Adriatic Sea, Italian and Spanish coasts) and the southern Mediterranean (Algeria), showing no significant phylogenetic ramification. The haplotype network showed no distinct haplogroups, implying strong genetic flow between farmed and wild fish populations, as reflected by low nucleotide diversity (0.00445) relative to high haplotype diversity (0.821). Shared haplotypes indicated the potential for pathogen transmission between wild and cultured hosts along the Tunisian coasts. The AMOVA across the three regions (north, central, and south of Tunisia) showed that 0% of the total variation was attributed to differences among the groups, 7.62% to differences among populations within groups, and 92.77% to differences within populations. These findings indicate the absence of genetic structuring within the S. chrysophrii population. This study demonstrates that the species disperses homogenously and does not face significant barriers, likely due to the high gene flow occurring among parasite populations, facilitated by the dispersion potential of the host.

Newcastle disease in its most virulent form affects the poultry population of all ages. Such an infection causes a huge economic loss to the poultry industry. A study was conducted in the Selesih, Melthum, and Zemabawk districts in Mizoram this year in which phylogenetic analysis was carried out to determine the circulating strains in Mizoram. Detailed necropsy was conducted on the poultry carcasses collected from the above farms. Gross and histopathological changes were observed in all vital organs which were suggestive of Newcastle disease, and suspensions from the suspected tissue samples were inoculated in 9-10-day-old embryonated eggs for isolation of the Newcastle disease virus. The isolates were tested by targeting and amplification of the full-length fusion glycoprotein of the Newcastle disease virus of 1662 bp in length by using reverse transcriptase-polymerase chain reaction. The full-length amplicons were sequenced and phylogenetic analysis was carried out using phylogenetic analysis tools like MEGA7. The analysis of the amino acid sequences present at the fusion cleavage site and phylogenetic tree suggested that the virus circulating in the remote districts of Mizoram belonged to a velogenic strain with sequences at the fusion cleavage site from positions 113-117 as RRQKR’F and belonged to a new genotype XXII as per the updated phylogenetic nomenclature system. The new genotype XXII was further classified into two subgenotypes under the updated classified nomenclature system as XXII.1 and XXII.2.

Short-term storage allows for the safe transportation and handling of gametes for short periods, ranging from hours to weeks. This method facilitates gamete storage, enables sperm selection for breeding programs, and contributes to creating gene banks. In this study, we evaluated the motility time and percentage of motile spermatozoa in grass carp (Ctenopharyngodon idella) at intervals of 0, 24, 48, 72, and 96 hours after storage at a chilled temperature of 4 °C. Semen from eight mature males, with a mean weight of 7837.5 ± 1132.5 g, was used for this purpose. For the sampling process, the fish were anesthetized using clove powder extract. Semen was then collected by applying gentle pressure to the abdominal region. Half a mL of each semen sample was placed in plastic tubes and stored under chilled conditions without dilution in a storage medium. The examination of these samples was conducted at various times after storage. The results indicate that 48 hours after chilled storage, there was a significant difference in the percentage of motile spermatozoa compared to the initial time (P < 0.05). Furthermore, there were significant differences in motility time from 72 hours after chilled storage compared to the initial time (P < 0.05). All semen samples remained active for up to 48 hours after being chilled. After 96 hours of storage, the mean activity in the three remaining samples was 20.0 ± 10.0%. According to the results, the best quality of the samples was observed within 24 hours of chilled storage. Therefore, storing grass carp semen in chilled conditions for up to 24 hours can facilitate the artificial insemination process in hatchery centers.

Introduction: Imidacloprid is a neonicotinoid designed to target the nicotinic acetylcholine receptors of invertebrate insects but may affect the development of vertebrates. Nicotine is known to alter vertebrate development. Avian species may also be of particular risk of exposure to neonicotinoids from environmental pesticides and ingestion of contaminated insects and freshwater species.

Methods: We evaluated the impact of environmental relevant imidacloprid (10 µg/mL) exposure on vertebrate embryo development using a chicken egg assay and compared that with the effects of saline or nicotine exposure (0, 10 and 100 µg/mL). Research grade, specific-pathogen-free (SPF) eggs were injected on day 0 and harvested on day 14 of development. Egg weight, embryo weight and body morphometrics were compared between the treatment groups.

Results: Eggs treated with nicotine had an overall (10 - 20%) lower survival rate (P < 0.05). Embryos exposed to 10 µg/mL nicotine that remained viable at 14 days did not differ significantly from controls. Embryos exposed to 100 µg/mL exhibited reductions in limb development (P < 0.01) and altered head circumference (P < 0.009). Reductions in limb length were noted in imidacloprid exposed embryos (P = 0.054). Embryo weight was significantly reduced in the imidacloprid exposed embryos relative to controls (P = 0.034). Tissues were harvested to determine histological changes as a result of imidacloprid.

Conclusions: Evaluating the developmental impact of nicotine and imidacloprid in the chicken embryo assay highlights the potential effects of environmental exposure in poultry and other vertebrates.

The objective of the current study was to evaluate the plasma endocrine profiles and ovarian follicular dynamics resulting from a single, random injection of PGF2α given to Barbari goats during the breeding season. B mode ultrasonography was used to monitor ovarian dynamics every 12 hours, while bucks with aprons were employed to identify standing estrus every 6 hours. Additionally, blood samples were collected every 12 hours for hormonal analysis, which included measurements of progesterone and estradiol 17β. The goats were classified into three groups: early responders (n = 7), intermediate responders (n = 6), and late responders (n = 6), with significant differences observed (p < 0.05) in the initiation of standing estrus and ovulation in conjunction with PGF2α administration. Remarkably, the peak plasma concentration of estradiol 17β was observed twelve hours prior to ovulation. While the average size of the ovulatory follicle and the duration of standing estrus were comparable across groups (p > 0.05), early responders showed a quicker degeneration of the corpus luteum compared to their intermediate and late counterparts (p < 0.05). Variability in estradiol 17β levels and dominant follicle diameter was significantly different among the groups (p < 0.05), whereas progesterone concentrations remained stable (p = 0.065). Furthermore, fluctuations in progesterone levels over time were significant (p < 0.05), suggesting that the interplay of hormonal and follicular dynamics during the luteal phase affects both the timing and duration of estrus and ovulation in Barbari goats after PGF2α treatment.

Exposing broiler chicken eggs to light during incubation can influence hatchability, stress levels, and overall chick welfare after hatching. Therefore, this study aimed to determine the effect of different-colored lights applied during incubation on serotonin and corticosterone hormone concentrations related to post-hatch chicken welfare. Gerze Turkish Indigenous chicken eggs were incubated under no light (dark; n: 108), green light (n: 114), red light (n: 114), and white (n: 114) light for 18 days. All chicks from each treatment group were fed for 120 days. Plasma corticosterone levels were evaluated using a commercially available ELISA kit (detection range 0.1-40 ng/mL, Chicken Corticosterone ELISA ^{BT LAB}). Plasma 5-HT levels were also measured using a commercially available ELISA kit (analytic range 0.5-150ng/mL, 5-HT BT LAB Chicken Serotonin ELISA Kit), following the standard procedures. Red-light-incubated chicks had the lowest (P<0.05) plasma corticosterone. Dark-incubated chicks had higher (P<0.05) plasma serotonin concentrations than green- and white-incubated chicks. However, green-incubated chicks had lower (P<0.05) plasma serotonin concentrations than red- and dark-incubated chicks. These results indicate that different-colored light applications during incubation altered post-hatch serotonin and corticosterone concentrations. This work was supported by the Ondokuz Mayis University (Project no: BAP04-A-2024-4803) Scientific Research Coordination Unit.

Antibiotic and pesticide usage in poultry requires careful monitoring to prevent residues while maintaining bird health and productivity. Mechanistic modelling approaches provide sophisticated tools for understanding and optimizing bird health and production systems. This study presents integrated frameworks for analysing chemical toxicity in laying hens through the modelling of hormonal balance and physiological responses.

We adapted and extended mathematical models initially designed for chemical toxicity risk assessment in avian species. To model physiological processes in pharmacokinetics (PK—what the body does to the drug) and pharmacodynamics (PD—what the drug does to the body), we employed ordinary differential equations to describe the evolution of drug concentrations and their effects over time. To elucidate the interaction between PK and PD in laying hens upon exposure to hypothetical endocrine-disrupting chemicals, our modeling incorporated endocrine dynamics on the ovulation cycle over weeks.

The developed model could predict organ-specific compound distribution and temporal dose–response patterns of hormonal homeostasis disruption. Our simulations demonstrate how altered hormonal levels influence egg production, including scenarios of 50% reduced productivity. This study further revealed how disrupted ovulation cycles affect pesticide pharmacokinetics in laying hens' eggs. Our PKPD modelling predictions provide quantitative metrics applicable to food safety evaluation for human health. The adverse outcome pathway framework was utilized to illustrate processes and enhance understanding of animal health in a harmonized and transparent manner.

Our systems modelling approach provides a mechanism-based framework incorporating biological processes to elucidate the production dynamics of hens upon exposure to chemicals. Future work will focus on integrating in vitro as well as legacy in vivo data to calibrate models for different avian species. Overall, the integrative modelling effort can advance the One Health vision of protecting human, animal, and environmental health in a sustainable way.

Considering physiological and reproductive differences between European (Apis mellifera) and Africanized (Apis mellifera L.) honeybees, understanding sperm characteristics is essential for the application of assisted reproductive techniques. This work aimed to compare the morphological, morphometric and ultrastructural characteristics of spermatozoa from European and Africanized honeybee drones in the Caatinga biome. The experiment was conducted at the Laboratory of Animal Germplasm Conservation, Federal Rural University of the Semi-Arid Region (UFERSA), in Mossoró, RN, Brazil (5°03′37′′S;37°23′50′′W), in July-August/2024. Semen was collected from 9 European and 16 Africanized mature honeybee drones using the endophallus eversion technique. Samples were stained with rose Bengal solution to assess the percentage of normal spermatozoa under a light microscope and to measure the head, flagellum and total length using digital analysis software. Scanning electron microscopy was used to analyze sperm ultrastructure. Data were expressed as the mean ± standard error and compared by Student’s t-test for sperm morphology and the Mann–Whitney test for morphometric parameters (P<0,05). The percentages of normal spermatozoa in the Africanized and European drones were 12.06±1.01% and 10.89±1.66%, respectively, with no statistical difference; curled tail was the most prevalent defect observed. Morphometric measurements revealed significantly longer sperm heads in European drones (10.04±0.03µm) compared to Africanized drones (9.33±0.04µm; P < 0.05), although the flagellum and total length did not show significant differences, with a total length of approximately 260µm in both groups, aligning with the literature values. Ultrastructural evaluation allowed for a detailed identification of the conical acrosomal vesicle and the defined nucleus surface, which was not easily possible with conventional rose Bengal staining. In the head–flagellum coupling, the major mitochondrial derivative and the axoneme were visualized in parallel, but no differences were identified between groups. Although there is a morphometric difference in spermatozoa between European and Africanized drones, particularly in terms of head length, the overall morphological and ultrastructural characteristics are similar, suggesting a comparable basis for future applications in reproductive biotechnologies.

Bees play an essential role in pollination, as well as producing honey and other bee products. With over 20,000 known species, bees differ morphologically and physiologically, which emphasizes the need for knowledge about the biology and reproductive parameters of different species to promote management adjustments. Therefore, the objective was to compare the semen quality of European (Apis mellifera) with that of Africanized honeybee drones (Apis mellifera L.) raised in the Caatinga biome. This study was conducted at the Experimental Station (5º03‟37” S; 37º23‟50” W) of the Federal Rural University of the Semiarid Region (UFERSA) in Mossoró, RN, Brazil. Nine European bee drones and 16 Africanized bee drones, approximately 25 days old, were used. Semen collection was performed using the endophallus eversion technique, manually stimulated by abdominal pressure. The parameters analyzed included motility (light microscopy), membrane integrity (fluorescent probes: Hoechst 342 and propidium iodide), and functional integrity of the plasma membrane (hypo-osmotic test, 0 mOsm/L). Data, expressed as the mean ± standard error of the mean, were compared using the Mann–Whitney test (hypo-osmotic test) and Student's t-test (for other parameters), using GraphPad Prism® software version 9.3 (GraphPad Software Inc., San Diego, CA, USA), at 5% significance. Both species presented a sperm motility around 90%, with a membrane integrity of 82.4 ± 2.5% for European drones and 81.1 ± 2.4% for Africanized drones. In European drones, the functional integrity of the plasma membrane was 93.4% ± 1.8%, while for Africanized drones, it was 91.6 ± 1.5%. For none of the parameters was there a statistical difference between the species (P > 0.05), which presented excellent sperm quality. In conclusion, it was demonstrated that there is a similarity between the sperm parameters of European and Africanized bees, which indicates the possibility of applying similar reproductive managements.