Calcium and phosphorus are essential for skeletal mineralisation and metabolism in mammals including pigs. Endogenous regulatory processes ensure a balance in mineral absorption, utilisation, retention, and excretion. Mineral homeostasis is maintained through a network of hormones and responsive loci that interact via direct effects and feedback regulation at both systemic and tissue-specific levels. The regulation of important endocrine factors such as parathyroid hormone (PTH) and vitamin D metabolites, as well as other regulators like fibroblast growth factor 23 (FGF23), is also significant in pigs. This review presents physiological and genetic findings on mineral homeostasis in pigs and contributes to a comprehensive understanding of mineral biology in monogastric animals by highlighting the current state of knowledge and functional targets. It examines molecular processes related to (i) the regulation of PTH within the parathyroid glands and (ii) the physiological, tissue-specific activation of the vitamin D system. Investigations of (iii) the natural genetic variability of mineral balance in pigs complement findings on physiology and on responses to exogenous factors, such as dietary mineral supply and exposure to UV-B radiation. The endogenous activation of the vitamin D system is considered of particular value to promote mineral utilisation, bone health, and immunity across divergent management types in pig husbandry. Overall, the review highlights how research on PTH and the vitamin D system can contribute to maintaining pig health and supporting the sustainable use of mineral phosphorus resources in the long-term.

Optimizing dietary phosphorus (P) levels is crucial for sustainable egg production, hen welfare, productivity, and reducing excessive P excretion. Dietary P influences systemic physiological responses, including gene expression dynamics and epigenetic regulation, particularly in the gut. Epigenetic modifications, including chromatin accessibility, play a crucial role in gene regulation by integrating genetic and environmental signals. It is hypothesized that age, strain, and mineral P levels together influence the epigenetic and transcriptional landscape in the jejunum during the transition to egg-laying. Using the domestic chicken (Gallus gallus domesticus), two commercial laying-hen strains, Lohmann Brown (LB) and Lohmann Selected Leghorn (LSL) were studied. The experiment followed a 2 × 2 × 2 factorial design including two strains (LB vs. LSL), two production periods (transition before the onset of egg laying vs. onset of laying), and two dietary P levels (without supplemental mineral P [P-] or with 1 g/kg supplemental P from monocalcium phosphate [P+]). A total of 80 hens were used, 10 per strain × period × diet combination, in a randomised complete block design. In each period, hens were housed individually in metabolic units for 4 weeks, beginning either before the onset of egg-laying (transition; placed at 15 weeks of age, sampled at week 19) or after the onset of egg-laying (onset of laying; placed at 20 weeks of age, sampled at week 24). At placement, mean initial body weight was 1228 ± 134 g (LB) and 1036 ± 70 g (LSL) in the transition period, and 1552 ± 93 g (LB) and 1244 ± 64 g (LSL) in the onset-of-laying period. Chromatin accessibility was assessed using an assay for transposase-accessible chromatin with sequencing (ATAC-Seq). The analysis revealed distinct strain-specific chromatin accessibility profiles, identifying 6610 differentially accessible regions (DAR) (adjusted P < 0.01). The LSL strain genome exhibited more regions with reduced accessibility (3603 DAR) compared to the LB strain (adjusted P < 0.01). Extensive chromatin remodelling was observed during the transition to laying onset (7884 DARs), with greater loss of accessibility at 24 weeks (4193 DARs). Dietary P had subtler effects (1671 DARs; P < 0.01), including increased accessibility at loci such as CALB1 under the P- diet. Enrichment analysis of transcripts nearest these DARs revealed pathways related to lipid transport, fatty acid metabolism, Wnt signalling, transforming growth factor-β (TGF-β) signalling, and calcium signalling. Additionally, ANalysis Algorithm for Networks Specified by Enhancers (ANANSE) integrates predicted transcription factor (TF) binding in accessible chromatin with RNA-Seq expression to weight gene regulatory networks (GRN) edges and rank TF influence (P+ vs. P-), highlighting regulators linked to bone/cartilage remodelling (RUNX2, STAT3, and CLOCK) and stress signalling (ATF3 and JUND). This study elucidated the complex interplay between sexual maturation period, genetic background, and nutritional mineral status in shaping the regulatory architecture of the jejunum, a key site for P absorption.

Paternal influences on offspring development extend beyond Mendelian inheritance, but how sire genetics shape fetal transcription and cis-regulatory landscapes across tissues is unclear. Using a reciprocal backcross in pigs (F1×German Landrace vs. F1×Piétrain) and a haplotype-agnostic RNA-seq pipeline, we profiled six fetal tissues to test sire-breed effects. We identified paternal breed-driven transcriptional divergence, with 1,176 genes differentially expressed. Transcriptional divergence was most pronounced in metabolic tissues, revealing a tissue-specific trade-off: F1 × GL conceptuses prioritized metabolic and energy pathways, whereas F1 × Pi conceptuses upregulated developmental and cell cycle processes. Allele-specific expression analysis revealed extensive, tissue-dependent cis-regulatory divergence, and differential ASE highlighted candidate mediators, including SLC5A12 and IVD (kidney), BRD3 (brain), and CES1 (liver). These results indicate that paternal genetics programs fetal tissues via cis-regulatory variation, informing strategies to improve livestock traits. Notably, many loci overlapped known QTLs, suggesting that regulatory variants connect sire background to performance-related phenotypes and fetal programming.

BACKGROUND: Synovium derived mesenchymal stem cells (SMSCs) are considered promising for orthopedic application due to easy accessibility and strong differentiation potential. However, the transcription factors (TFs) that orchestrate the SMSCs osteogenic commitment, as well as the dynamic landscape of associated cis-regulatory elements, remain largely unclear. In addition, donor-specific epigenetic memory may lead to heterogeneous gene-regulatory profiles. RESULTS: In this study, we isolated porcine SMSCs from two pig breeds (German Saddleback, GS; German Landrace, GL) with distinct intrinsic metabolic characteristics and profiled their dynamic chromatin accessibility and transcriptomes during osteogenic induction. GO terms related to ossification and mesenchymal cell differentiation emerged earlier in the chromatin landscape (ATAC-seq, day 7) than at the transcriptional level (RNA-seq, day 21), indicating that chromatin accessibility captures lineage-specific programs prior to overt gene expression changes. Donor-specific differences in chromatin accessibility were minimal at baseline (day 0), became evident early after induction, and diminished over time. Footprinting analysis showed stronger binding affinity of C/EBP family members in osteogenic-induced SMSCs, whereas the FOS::JUN heterodimer exhibited greater occupancy in control cells. Interestingly, RUNX2 footprints displayed a slight decrease from day 0 to day 21 despite its established role in osteogenesis. De novo motif analysis further revealed TF-binding motif in differentially accessible regions, with RUNX2/RUNX motifs enriched in regions of reduced accessibility and CEBPs enriched in regions of increased accessibility. CONCLUSIONS: This study characterizes chromatin accessibility dynamics in SMSCs during osteogenic differentiation, driven mainly by differentiation state and time rather than donor metabolic differences. Integrated ATAC-seq/RNA-seq highlights key transcription factors and networks guiding osteogenic commitment, supporting porcine SMSCs as a translational model for bone regeneration.

In chickens, secondary myogenesis occurs during embryonic days (ED) 10-13, which is a critical developmental window sensitive to incubation temperature as a key environmental factor. This study investigates transcriptional profiles in leg muscle of broiler (Ross 308; Ross) and layer chickens (Lohmann Brown; LB) at hatch following transient ± 1 °C deviations from standard incubation temperature during ED 10-13. Eggs were incubated at 37.8 °C (CON), 36.8 °C (Low), or 38.8 °C (High) for 72 h between ED 10-13 before being returned to standard conditions until hatch (ED 21). Leg muscle samples from both sexes were analysed using RNA sequencing (n = 108). Hatch body weight and yolk-free body weight were higher in Ross compared to LB, but were unaffected by incubation temperature. Lowered incubation temperature in LB hatchlings was associated with altered mitochondrial and metabolic pathways, including the downregulation of genes involved in oxidative phosphorylation and reduced expression of myogenic regulators such as MYF5 and MYOG compared to CON birds. Increased incubation temperature involved enrichment of proteolytic processes and downregulation of genes associated with extracellular matrix organization (COL1A1, COL6A1) in LB hatchlings and myogenesis (MYOG) in Ross hatchlings compared to CON birds. Results suggest that deviations from standard incubation temperature during the critical window of secondary myogenesis modulate leg muscle development in a strain-specific manner.

In female birds, the development of medullary bone within the cavities of long bones ensures a calcium reservoir used for eggshell formation. The transition from haematopoietic bone marrow in immature pullets to medullary bone in sexually mature female chickens is accompanied by pronounced structural and functional modifications. Phosphorus is interlinked via endocrine themes, which affect mineral utilization particularly under conditions of rapid daily calcium turnover. In this study, 80 laying hens of Lohmann Selected Leghorn (LSL) and Lohmann Brown (LB) strains were fed diets with either mineral phosphorus supplement (1 g/kg feed) or without mineral phosphorus supplement (0 g/kg feed) for periods of 4 weeks at two different time points, either immediately before the onset of egg laying (from 15 to 19 weeks of age) or shortly after onset of laying (from 20 to 24 weeks of age). Responses on plasma metabolites and gene expression of medullary bone material were evaluated (n = 10 per strain per week of age per diet). Deconvolution analysis of bulk mRNA sequencing data was performed to estimate cell compositions. Cells of the erythroid lineage made up 85% of all cells located within the medullary bone cavity, while mesenchymal cells including osteoblasts made up 0.33%. During the maturation process, it was estimated that hens developed their macrophage and lymphatic cell populations at the expense of erythroid cells. Results indicated a complete absence of osteoblasts in both hen strains at week 19, whereas at week 24, LSL were estimated to exhibit a higher osteoblast percentage than LB, indicating an advanced molecular adaptation in LSL compared to LB. There was no evidence of impaired development of immune cells or osteoblasts due to the transient lack of mineral phosphorus supply.

Background: Traditional pig breeds experience a renaissance in public perception to favor biodiversity and resilience to diseases. Moreover, the routine use of parturition induction with exogenous hormones is questioned, as it may compromise the welfare of both dams and piglets.Aims and Objectives: In this study, neonatal complete blood counts were analysed regarding the effects of genotype, i.e., traditional German Saddleback versus modern German Landrace, and the implementation or omission of parturition induction by hormonal intervention.Materials and Methods: Blood samples of n = 296 newborn piglets from 28 farrowings were taken within the first 6 h of life to study hematological traits.Results: The population showed 22% of neonates being anaemic with hemoglobin <11.0 g/dl (P < 0.01). The Saddleback piglets exhibited higher red blood cell count and lower mean corpuscular volume and mean corpuscular hemoglobin levels than Landrace piglets (P < 0.001). The Landrace piglets exhibited higher white blood cell count, neutrophil count, and neutrophil-to-lymphocyte ratio than Saddleback piglets (P < 0.001). The hormonal parturition induction revealed no effects for the analysed indices except for red cell distribution width-coefficient of variation with higher values in spontaneously born piglets compared with piglets that experienced an induced parturition (P < 0.001).Conclusion: The pronounced differences between Saddleback and Landrace neonates suggest a breed-specific setting of the hematological activity at birth, which might be partially modulated by hormone application due to labor induction in pigs.

Curcumin, the major polyphenolic constituent of Curcuma longa, has been widely investigated as a hepatoprotective adjunct due to its antioxidant and immunomodulatory properties. This review evaluates the relevance of curcumin for the prevention and management of liver dysfunction and hepatitis in pigs by synthesizing available porcine evidence and integrating mechanistic insights from translational liver injury models where pig-specific data remain limited. Across experimental hepatic injury contexts, curcumin administration is most consistently associated with reduced biochemical and structural indicators of hepatocellular damage, including decreased aminotransferase activity, attenuation of lipid peroxidation, and enhancement of endogenous antioxidant defenses. These effects are mechanistically linked to suppression of pro-inflammatory signaling pathways, particularly NF-κB-related transcriptional activity and inflammasome-associated responses, together with reduced expression of key cytokines such as TNF-α, IL-1β, and IL-6. Concurrent activation of Nrf2-centered cytoprotective pathways and induction of phase II antioxidant enzymes (including HO-1, GST, and NQO1) appear to constitute a conserved axis supporting hepatic oxidative stress resilience. In swine-relevant infectious settings, available data further support antiviral activity against selected porcine pathogens, including classical swine fever virus and porcine reproductive and respiratory syndrome virus, potentially mediated through interference with lipid-dependent stages of viral replication and modulation of Kupffer cell activation. Although combination strategies with established hepatoprotective approaches are conceptually attractive, current synergy evidence remains heterogeneous and largely extrapolated. Overall, curcumin represents a plausible adjunct candidate for supporting porcine liver health; however, translation into practice will depend on resolving formulation-dependent bioavailability constraints and strengthening the pig-specific evidence base.

BACKGROUND:Phosphorus (P) utilization is a complex trait influenced by numerous genetic variants. The jejunum is the primary site of P absorption in poultry. Therefore, identifying the genetics that regulate transcription in jejunum may help uncover key regulators of P homeostasis. We performed a genome-wide association study using the expression of jejunal mucosa transcripts (88 miRNAs, 65 mRNAs). These transcripts were selected from our previous studies due to their association with P utilization and related pathways. In total, the trial comprised 400 laying hens from two high-yielding strains, Lohmann Brown (LB) and Lohmann Selected Leghorn (LSL), fed a diet lacking mineral P supplements and exogenous microbial phytase to stimulate adaptive mechanisms. RESULTS:In total, 114 miR-eQTLs (microRNA expression quantitative trait loci) were detected at a false discovery rate (FDR) of less than 5%, including 56 miR-eQTLs in the LB strain and 58 miR-eQTLs in the LSL strain. Lohmann Brown contained 23 cis and 35 trans loci, with the most significant cis-eQTL targeting miR-146b. In the LSL strain, a cis-eQTL cluster for miR-203a was present on chromosome 5. Similarly, 123 mRNA-eQTLs (94 in LB and 29 in LSL) were identified at the 5% FDR threshold. The genetic regulation of key genes involved in mineral binding and mineral transport, including CALB1 and SLC34A2, in LB hens was predominantly driven by strong cis-eQTL. In contrast, gene expression in LSL hens was largely modulated by trans-eQTLs, with CALM1 being the only gene under significant cis-regulation. Furthermore, correlation analysis with the gut microbiome revealed that the expression of cis-regulated CALB1 is significantly positively associated with the abundance of Lactobacillus species. CONCLUSIONS:Our findings reveal that LB and LSL hens exhibit distinct genetic architectures contributing to maintain mineral homeostasis. Genetic differences between the two strains influence the transcriptional response of key mineral transporter genes and miRNAs under a low-P diet. These divergent host genetic strategies are also associated with distinct gut microbiota profiles, highlighting interactions between host genetics, gene expression, and the microbiome in P utilization.

Aflatoxin B1 (AFB1) contamination in animal feed poses a serious risk to livestock health due to its hepatotoxic effects. Many medicinal herbs which may be used as feed additives exhibit antioxidant and anti-inflammatory properties with potential hepatoprotective outcomes. We investigated effects of AFB1 in three concentrations (30 µg/kg BW, 60 µg/kg BW, 120 µg/kg BW) as well as three medicinal herbs, i.e., kalmegh (Andrographis paniculata), milk thistle (Silybum marianum), and turmeric (Curcuma longa) in pigs. Hepatic expression of genes involved in biotransformation, detoxification, antioxidation, energy homeostasis, and immunity were evaluated by high-throughput real-time PCR. We found that AFB1 significantly suppressed genes involved in biotransformation (CYP2U1, CYP4V2, CYP7B1, CYP26A1, CYP51A1), detoxification (GSS, ABCC2, SULT1E1), redox balance (GPX1, PRDX4), lipid homeostasis (ACOX1), and immune regulation (CP, CRP). Kalmegh and, to a lesser extent, milk thistle supplementation provided a comprehensive upregulation of genes involved in key hepatic pathways maintaining liver integrity. Under the specific experimental conditions, the applied dietary turmeric supplement did not induce consistent effects on the analyzed target genes. The results indicate that certain medicinal herbs could counteract AFB1-induced gene expression responses in liver. Their application as dietary supplements to reduce potentially harmful effects caused by AFB1 toxicity in farm animals might be an effective tool in improving animal health, productivity and food safety.

Phosphate homeostasis is controlled by fibroblast growth factor 23 (FGF23) produced by bone cells in mammals and primarily acting in the kidney. For its phosphaturic effect and for suppression of production of active vitamin D, it requires αKlotho as a co-receptor. FGF23 and αKlotho have emerged as disease biomarkers. Relatively little is known about their significance in laying hens that are in particular need of balanced mineral homeostasis for eggshell formation. Dietary myo-inositol (MI) and phosphate metabolism are interdependent, and this study aimed to explore FGF23 and αKlotho expression in two commercial hen strains fed different amounts of MI. Forty Lohmann Brown Classic (LB) and Lohmann LSL-Classic (LSL) 26-week-old hens received standard diets with 0, 1, 2, or 3 g supplemental MI per kg feed for four weeks, and gene expression of FGF23 and αKlotho was measured by quantitative real-time PCR in different organs. Statistical analysis was performed with the MIXED procedure, and correlation analysis with markers of phosphate homeostasis and hepatic inflammation applying Pearson's correlation coefficient or Spearman's Rho. Three g supplemental MI per kg feed resulted in lower hepatic FGF23 expression only in LB hens. Regardless of MI supplementation, tibial FGF23 expression tended to be lower in LSL than LB hens. Moreover, supplemental MI did not significantly impact αKlotho expression, but hepatic αKlotho expression was higher in LSL than LB hens without MI supplementation and tibial and renal αKlotho expression was significantly higher in LB than in LSL hens, regardless of dietary MI. To summarize, MI supplements at 3 g/kg reduced hepatic FGF23 expression in LB, but not in LSL hens at the peak of egg-laying. Further studies might be needed to elucidate the effect before sexual maturity.

Haematological parameters are important indicators of health, physiological status and resilience. In pigs, these parameters are influenced by both exogenous factors, such as feeding, housing and weaning age and intrinsic factors, including physiological maturity and genetic background. In this study, complete blood counts from 512 German Landrace (GL) and German Saddleback (GS) piglets kept in conventional (CON) and organic (ORG) housing systems were analysed throughout four developmental stages until day 70 of life. The GS consistently showed significantly higher counts of red and white blood cells, alongside higher counts of leukocyte subsets such as lymphocytes and monocytes, indicating a potentially efficient immune profile compared to GL. In contrast, GL exhibited larger erythrocytes with higher haemoglobin content as reflected via higher MCV and MCH levels, potentially endowing GL pigs to cope with the high metabolic demands for growth and performance. Housing effects were observed at day 70, where pigs kept in ORG showed reduced HCT and MCV, but higher MCHC levels, which might be attributed to feed components in ORG husbandry, potentially reflecting dietary limitations in methionine. Notably, platelet counts were higher in GL compared to GS piglets under ORG conditions, implying a breed-dependent haematopoietic response. In summary, these findings indicate a trade-off between erythrocyte quantity and haemoglobin-loading capacity, with potential implications for breed-specific myoglobin characteristics. The leukocytes profile further suggests breed-related differences in immune resilience which need to be validated by functional analyses to inform housing and management strategies for weaning in both modern and indigenous pig breeds.

Phosphorus (P) and calcium (Ca) are essential minerals for laying hens. Phosphorus in plant feeds is mainly stored as phytate and needs to be released by the enzyme phytase. Due to the high requirement of Ca, laying hens exhibit limited endogenous phytate degradation and thus plant-P is available to a limited extent. Mineral P supplemented to laying hen feed reduces phytate degradation further and decreases myo-inositol release in the intestinal tract, which is known to have many functions in poultry metabolism. The focus of this study was the investigation of P and Ca metabolism in the peak period of egg production in commercial hybrid laying hens from Lohmann Selected Leghorn (LSL; n = 200) and Lohmann Brown (LB; n = 200) strains at the phenotypic and quantitative genetic level using data referring to blood plasma, ileal digesta, excreta, and eggs. Population genetic analyses revealed larger genetic diversity in LB than LSL and substantial differentiation between the strains. The majority of Ca and P metabolism traits differed significantly in trait mean or variance between the two strains. The LB strain showed more trait variation at the phenotypic and quantitative genetic levels. Moderate to high and significant heritabilities were estimated for myo-inositol in the plasma ( h^2 = 0.43 for LSL and h^2 = 0.36 for LB), ileum digesta ( h^2 = 0.60 for LB; not estimable for LSL) and egg ( h^2 = 0.69 for LSL and h^2 = 0.55 for LB), and for the Ca concentration in the plasma ( h^2 = 0.27 for LB; not estimable for LSL). Noticeably significant phenotypic correlations between the traits of P and Ca metabolism measured in excreta, plasma, and ileal digesta were present in both strains. The study provided a comprehensive insight into P and Ca metabolism under standardized conditions in the two commercial laying hen strains LSL and LB during egg laying. Differences between the strains were present at the phenotypic and quantitative genetic level. Thereby, the hens’ genetics appeared to be a relevant driver of P and Ca metabolism, with LB showing more variability. The study confirmed population genetic differences between the strains. Despite the detected strain differences, significant correlations among the traits of P and Ca metabolism indicate that the general relationships between traits are comparable in both strains.

Medullary bone is deposited in the cavities of avian long bones and serves as a calcium reservoir for successful eggshell mineralization in sexually mature female chicken. Osteoblasts and osteoclasts located in medullary bone respond to endocrine changes, including high estrogen levels at sexual maturation, and represent important targets for improving mineral turn-over in laying hens. In this study, weekly samples of blood and femur to extract medullary bone material were taken from Lohmann Brown (LB, n = 54) and Lohmann Selected Leghorn (LSL, n = 54) hens from pullet stage (week 16 of age) until onset of oviposition (week 24). Blood beta CTX-1 (C-terminal telopeptides of type I collagen) levels increased in week 17 (LSL) and week 18 (LB) until week 21, indicating organic matrix breakdown for initial bone remodelling. Estradiol increased not before week 20 (LSL) and week 21 (LB). Subsequently, medullary bone calcium content increased in week 23 (LB, LSL), whereas the phosphorus content increased in week 22 (LSL) and week 23 (LB). The longitudinal gene expression patterns of medullary bone material across the maturation period showed pronounced synergistic activities to ensure vascularisation, energy metabolism, and ossification. These analyses identified key genes and pathways involved in successful medullary bone formation in both LB and LSL strains, offering potential targets for genetic or nutritional interventions aimed at maintaining efficient mineral turn-over throughout the laying period. Taken together, the cascade-like sequence of bone remodelling, which controls the differentiation and activity of osteoblasts and osteoclasts and ultimately drives the transition from haematopoietic bone marrow in pullets to medullary bone in mature female birds, is initiated earlier in LSL than in LB hens.

Metabolic processes in fetuses can significantly influence piglet weight at birth. Understanding the genetic determinants of systemic metabolism is crucial for uncovering how genetic and molecular pathways impact biological mechanisms, particularly during the fetal phase. We present data on 1112 plasma metabolites using untargeted ultra-high performance liquid chromatography-tandem mass spectrometry methods, of 260 backcross (BC) fetuses from two sires’ breeds at 63 days post-conception. Eight chemical superclasses have been identified, with lipids accounting for the majority of metabolites. Genomic heritability (h²) was estimated for each metabolite, revealing that 50% had h² values below 0.2, with a higher average in the amino acid class compared with the lipid. We annotated 448 significant metabolite quantitative trait loci associated with 10 metabolites, primarily lipids, indicating strong genetic regulation. Additionally, metabolite associations with sex, fetal weight and sire’s breed were explored, revealing significant associations for 354 metabolites. Fetal weight influenced the largest number of metabolites, particularly glycerophospholipids and sphingolipids, emphasizing the genetic and metabolic complexity underlying fetal development. These findings enhance our understanding of the genetic regulation of metabolite levels and their associations with key phenotypic traits in fetuses, providing insights into metabolic pathways, potential biomarkers and serving as a baseline dataset for metabolomics studies of fetuses.

BackgroundThere is an emerging body of evidence that current poultry feed is formulated in excess for phosphorus (P), which results in unnecessarily high P excretions. Sustainable concepts for agricultural P flows should trigger animal-intrinsic mechanisms for efficient P utilization. In the current study, Lohmann Brown (LB) and Lohmann Selected Leghorn (LSL) laying hens were fed either a high P diet (P+) with 1 g/kg mineral P supplement or a low P diet (P-) with 0 g/kg mineral P supplement for a period of 4 weeks prior to sampling. Before and after onset of laying, i.e., at 19 and 24 weeks of life, kidney and plasma samples were collected to investigate the endogenous P utilization in response to restricted dietary P, laying hen strain, and sexual maturation.ResultsPlasma analyses of minerals and metabolites confirmed the response to a low P diet, which was characterized by a significant reduction in plasma P levels at week 19 in both strains. The plasma calcium (Ca) levels were tightly regulated throughout the entire experimental period. Notably, there was a numerical trend of increased plasma calcitriol levels in P- fed birds of both strains compared to the P + group, which might have mediated a substantial role regarding the adaptive responses to low P supply. At week 19, RNA sequencing of kidney identified 1,114 and 556 differentially expressed genes (DEGs) unique to the LB and LSL strains, respectively. The number of DEGs declined with increasing maturity of the hens culminating in 90 and 146 DEGs for LB and LSL strains at week 24. Analyses revealed an enrichment of pathways related to energy metabolism and cell cycle, particularly at week 19 in both strains. The diet-specific expression of target genes involved in P homeostasis highlighted transcripts related to active (SLC34A1, SLC20A2) and passive mineral transport (CLDN14, CLDN16), Ca utilization (STC1, CALB1), and acid-base balance (CA2, SLC4A1).ConclusionsResults suggest that both laying hen strains adapted to the lack of mineral P supplements and achieved a physiological Ca: P-ratio in body compartments through endogenous regulation as evidenced via the endocrine profile.

Aim was to characterize birth-relevant hormone profiles of reproductively productive hybrid sows in the peripartum period. It was examined whether there are deviations in the hormone profile depending on the birth process (eutocia:dystocia) and the type of housing (box stall BS vs. farrowing pen FP vs. group housing GH).A total of 40 healthy, heavily pregnant hybrid sows (German Landrace x Large White) with a gestation number≥ 2 were available. The distribution between the housing types was: BS n=18, FP n=15, GH n=7. All births occurred after the biologically completed gestation period. Blood samples were taken via indwelling catheters (113th day ante partum to 4th day post partum). Progesterone (P4), oestradiol (E2), prostaglandin F2α and its metabolites (PGFM), relaxin, oxytocin, cortisol, adrenaline and noradrenaline were determined.The ratio of eutocia:dystocia was 15:25. Dystocia occurred regardless of type of housing. The only reason for dystocia was a weak labor (>60 min). The litter size was 17.73± 3.85 piglets. Differences in the hormone profiles between eutocia and dystocia were as follows: P4 tended to be higher in dystocia p=0.0776; oxytocin higher in eutocia (not significant), 12.5% of sows permanently with hypoxytocinemia; cortisol p=0.0503; noradrenaline p=0.0098. The type of housing had the following influence on the hormone profile: P4 p=0.046; E2 p=0.0009; PGFM p=0.0108; relaxin p=0.0022; noradrenaline p=0.0078.The parturition-relevant hormones are related to the parturition and to the type of housing during birth. The hormone profiles obtained could be of use in the discussion about the animal welfare-oriented housing system in the peripartum phase in pigs. The proportion of sows of the hyperproliferative line studied with permanent hypoxytocinaemia in stage II of parturition is remarkable. The ratio of eutocia:dystocia is unevenly distributed. Dystocia occurred regardless of the type of housing.

The cognitive and regulatory processes within higher-order brain structures that regulate the hypothalamic–pituitary–adrenal (HPA) axis and the limbic system orchestrate a complex stress response system. In order to address this, we collected 48 tissue samples from the amygdala (Amy), hippocampus (Hip), thalamus (Tal), hypothalamus (HT), pituitary gland (PG) and adrenal gland (AG). We applied ATAC-seq, a method for profiling accessible chromatin, to map the epigenetic landscape of these brain and endocrine tissues in pigs and generate foundational baseline chromatin accessibility datasets that can serve as a reference for future studies. A total of 321,584 consensus peaks, representing open chromatin regions across various samples and tissues in the pig genome, were identified. Screening for transcription factor binding motifs within these chromatin-accessible regions revealed 377 significantly enriched motifs in at least one tissue ( p ≤ 0.001). Among the 93 motifs enriched in only one tissue, some showed concordant expression of their corresponding transcription factors, including GRHL2 and KLF5 in the PG, and GATA4/6 , and HAND2 in the AG. Differentially accessible regions (DARs), particularly in promoter regions, between brain and endocrine tissues were identified, with functional specificities in the AG, including cortisol synthesis and secretion, as well as tyrosine metabolism. The cytokine-cytokine receptor interaction and neuroactive ligand-receptor interaction pathways showed greater enrichment and open chromatin accessibility in brain regions compared to endocrine tissues (PG or AG). This study provides valuable insights into brain transcriptional regulation and adds a novel layer of information for future research on genetic improvement and animal welfare.

IntroductionStress involves complex interactions between the brain and endocrine systems, but the gene-level processes and genetic factors mediating these responses remain unclear. This study investigates gene expression patterns and allele-specific expression (ASE) in key limbic, diencephalon and endocrine tissues to better understand stress adaptation at the molecular level.MethodsWe performed RNA sequencing on 48 samples from six distinct tissues: amygdala, hippocampus, thalamus, hypothalamus, pituitary gland, and adrenal gland. These tissues were categorized into three functionally and anatomically distinct groups: limbic (amygdala, hippocampus), diencephalon (thalamus, hypothalamus), and endocrine (pituitary, adrenal). Differential expression analyses were conducted both between individual tissues and across these tissue groups. Weighted Gene Co-expression Network Analysis (WGCNA) was applied exclusively at the tissue group level to identify group-specific gene networks. Allele-specific expression (ASE) was analyzed at the individual tissue level to capture cis-regulatory variation with high resolution.ResultsThirty-three candidate genes were differentially expressed across all tissues, indicating a core set involved in stress responses. Weighted Gene Co-expression Network Analysis revealed limbic and diencephalon modules enriched in neural signaling pathways such as neuroactive ligand-receptor interaction and synaptic functions, while endocrine modules were enriched for hormone biosynthesis and secretion, including thyroid and growth hormone pathways. Over 1,000 genes per tissue showed ASE, with 37 genes consistently colocalized. Ten of these displayed differences in allelic ratios, with seven (PINK1, TTLL1, SLA-DRB1, HEBP1, ANKRD10, LCMT1, and SDF2) identified as eQTLs in pig brain tissue within the FarmGTEx database.ConclusionThe findings reveal significant genetic regulation differences between brain and endocrine tissues, emphasizing the complexity of stress adaptation. By identifying key genes and pathways, this study provides insights that could aid in enhancing animal welfare and productivity through targeted modulation of stress-related molecular pathways.

Since genomic selection has been established in animal breeding, attention has turned towards other omics layers that are seen as promising to improve prediction accuracy. Transcriptomic data provide insights into gene expression patterns, which are shaped by both genetic and environmental factors, offering a more comprehensive understanding of the expression of phenotypes. This study utilized various statistical methods to assess the applicability of transcriptomic data derived from intestinal tissue to the prediction of efficiency-related phenotypes. The focus was on formal derivation of the previously described GTCBLUP model, which was adapted to create GTCBLUPi and compared with other BLUP models. The GTCBLUPi model addresses redundant information between genomic and transcriptomic information. We compared estimated variance components and accuracies of prediction of phenotypes for efficiency-related traits in an F2 cross of 480 Japanese quail using different models. Additionally, we estimated transcriptomic correlations between the traits using animal effects based on transcriptomic similarity, and the effects of individual transcript abundances on the phenotypes. This study showed that transcript abundances from the ileum explain a larger portion of the phenotypic variance of the traits than host genetics. Models incorporating both genetic and transcriptomic information outperformed those using only one type of information, with regard to the phenotypic variances explained. The combination of both data types resulted in higher trait prediction accuracies, confirming that transcriptomic information complements genetic data effectively. The derived GTCBLUPi model proved to be a suitable framework for integrating both information types. Additionally, polygenic backgrounds were identified for the traits studied based on transcriptomic profiles, along with high transcriptomic correlations between the traits. Transcriptomic data account for a high portion of phenotypic expression for all phenotypes and incorporating them enables more accurate predictions of phenotypes for efficiency and performance traits. Models that integrate both genetic and transcriptomic information are the most effective, offering valuable insights for improving phenotype prediction accuracy and insights in biological mechanisms underlying phenotypic variation of traits.