搜索结果：Animal reproduction science

Understanding how organisms allocate energy across competing physiological demands is central to predicting responses to environmental variation. In seasonal environments, shifts in resource availability and activity impose dynamic constraints on energy storage, maintenance and reproduction. Here, we investigated seasonal changes in body composition in the tegu lizard Salvator merianae using the minimally invasive dual-energy X-ray absorptiometry (DEXA) technique. After DEXA validation against direct chemical analysis for this species, male and female individuals were repeatedly scanned across key phases of the annual cycle, including hibernation, reproduction and transition phases between them. Body composition remained largely unchanged during prolonged dormancy, despite fasting and inactivity, with lean and mineral compartments comparatively maintained in both sexes. In contrast, reproduction was associated with the most pronounced seasonal shifts, including reductions in fat reserves and increases in protein- and water-related compartments in both sexes, together with mineral remodeling that was more evident in females. In subsequent months, several of these components shifted back toward pre-reproductive values. These patterns indicate a coordinated reorganization of energy and body resources across seasons, with fat reserves mobilized during reproduction while lean and mineral compartments followed distinct, phase-dependent trajectories. Our results suggest a partial decoupling between energy storage and structural maintenance, consistent with the idea that key functional compartments may be differentially buffered against seasonal constraints. By linking within-individual variation in energy reserves to shifts in physiological demands, this study provides an integrative physiological perspective on how life-history trade-offs are expressed in seasonal environments. More broadly, these findings contribute to understanding how physiological flexibility may influence organismal performance under changing environmental conditions. SUMMARY STATEMENT: Validated DEXA measurements revealed broad maintenance of lean and mineral compartments during dormancy in both sexes, followed by fat mobilization during reproduction and sex-specific mineral remodeling, particularly in females.

Plant extracts rich in bioactive compounds, particularly polyphenols, have gained increasing attention in poultry breeder nutrition owing to their antioxidant and anti-inflammatory properties. These properties help preserve intestinal integrity and support improvements in gamete quality and embryonic viability. Commercial feed products, such as Elife®, have been developed to incorporate additives, including flavonoids, proanthocyanidins, and phenolic acids, delivering polyphenols in highly bioavailable forms and ensuring effective antioxidant activity. This study evaluated the effects of dietary supplementation with Elife® in brown egg-layer breeders (males and females) on productive and reproductive performance, egg quality, incubation traits, and progeny outcomes. Two experiments were conducted with birds aged from 54 to 70 weeks. In Experiment 1, 30 Rhode Island Red roosters were allocated to the following treatment groups: basal diet without additives (CON); basal diet + 0.5 kg of Elife®/t of feed (E500); and basal diet + 1 kg of Elife®/t of feed (E1000). Body weight, feed intake, and sperm quality were measured in each rooster every 28 days. For Experiment 2, 210 White Plymouth Rock brown egg-layer hens were assigned to the same three treatments as in Experiment 1. Body weight, feed intake, laying rate, egg quality, and incubation parameters were recorded every 28 days. Roosters receiving E1000 showed significantly improved sperm motility and an increased proportion of morphologically normal sperm without affecting feed intake, body weight, or sperm vigor. Hens under E1000 had lower feed intake than controls while maintaining egg quality (P > 0.05). Furthermore, combined parental supplementation with Elife® improved egg hatchability, reduced early embryonic mortality, and increased day-old chick weight. Overall, combined parental supplementation with Elife® demonstrated an effective nutritional strategy for improving fertility, embryonic viability, and chick quality in brown egg-layer breeders.

What did our ancestors eat? Current understanding of diet in human evolution is predicated on abundant animal foods and mastery of fire, both unlikely for early hominins. Using multiple lines of evidence, including the metabolic requirements of an enlarging brain and reproduction, we model macronutrient distribution across 4 million years of evolution. Before cooking made starch easily digestible, the sugars in fruit and honey provided glucose, the brain's preferred fuel. Modeling suggests that sugars provided >25% of dietary energy, fulfilling obligatory glucose demand. Pounding and cooking released glucose specifically, not merely energy. The evolution of a bigger brain is therefore a story of carbohydrate foods as much as animal foods: from sweet sugars to cooked starch, from chewing to processing, and from wadging to advanced nutrient extraction.

Sea urchin grazing can drive kelp loss creating low productivity "barrens" with reduced biodiversity that may persist for decades. In these habitats, limited food driven by sea urchin herbivory reciprocally affects sea urchin physiology, yet the metabolic pathways enabling survival in the starvation conditions remain poorly understood. This study employed gas chromatography-mass spectrometry metabolomics to compare gonad metabolite profiles of purple sea urchins, Strongylocentrotus purpuratus, from barrens and adjacent kelp forest margins. Gonads from barren animals showed pronounced metabolic reallocations relative to kelp-margin animals, supporting energy production, redox balance, and membrane integrity. Carbohydrate metabolism was shifted towards increased glucose and gluconeogenesis with reduced alanine and glutamine as substrates for energy production. The pentose phosphate pathway fluxed towards energy production (supported by elevated sedoheptulose and mannoheptulose, and reduced glutamine and glutamate), rather than nucleotide synthesis and growth. Elevated amino acids (cysteine, cystine and lysine) reflected gonad protein catabolism, energy production and redox balance. Changes in lipid metabolism showed elevated monostearin from lipid breakdown, reduced heptanoic acid as energy substrate, and increased malonate supporting membrane integrity. This study reveals the specific metabolic adjustments purple sea urchins employ under food-limited conditions in barrens, diverting energy from reproduction to enhance long-term survival, potentially signaling challenges for kelp restoration.

Early nutritional programming can affect later development in birds, yet the carryover effects of dietary arginine in Japanese quail remain poorly understood. Arginine is an essential amino acid for birds, as they cannot synthesise it endogenously, and it plays a vital role in growth and metabolism. This study aimed to evaluate the effect of dietary arginine restriction or supplementation on body mass change, reproduction, and plasma biochemistry in Japanese quail after the dietary treatment was discontinued for two consecutive weeks. Birds were fed either a low-arginine diet (25% below recommendations), a control diet (recommendations), or a high-arginine diet (25% above recommendations) at the early reproductive stage and adult stage and were then subsequently returned to a standard diet for two weeks. Overall, in comparison with the immediate effects of dietary arginine, no significant residual effects of dietary arginine were observed on body mass change, average daily body mass gain, feed conversion ratio, and egg production after the withdrawal period. However, age-dependent responses were observed, and adult birds showed a significant decrease in body mass change as compared to early reproductive stage birds. In addition, cholesterol showed age-related differences, whereas alanine aminotransferase (ALT/GPT) and aspartate aminotransferase (AST/GOT) showed both age- and treatment related difference with adult birds exhibiting lower concentrations than early-reproductive-stage birds. These findings suggest that early-life dietary arginine manipulation has a limited influence on growth and reproduction after withdrawal but may induce age-dependent changes in selected biochemical parameters in Japanese quail.

Communication systems shape behavioral interactions that are crucial for recognition, territoriality, and reproduction across animals. In many anuran species, acoustic communication drives reproductive and defensive behaviors as males produce advertisement calls to establish territories and attract females. Understanding the temporal dynamics in vocalizations and their variation between and within males can provide crucial insight into the mechanisms that generate call patterning and communication. Here, we examine such dynamics in the call patterning of male Boana pulchella, a South American treefrog species that produces temporally-variant call series over time. Using rhythm analysis, we quantify the rhythmic structure of these vocalizations and characterize the variability in their temporal patterning between males. We find that rhythmic isochrony is timescale-dependent - call series are produced isochronously while the patterning of calls and notes within these series is non-isochronous yet periodic. The isochronous rhythm is maintained through an inverse relationship between series duration and the silence interval that follows it, such that longer series are followed by shorter silence intervals. Temporal features of calls and notes as well as their variation vary depending on within-series patterning dynamics and across timescales. Taken together, these results suggest that B. pulchella vocal timing is generated by hierarchically organized oscillators that produce isochronous vocalizations over a calling bout through flexible modulation at finer timescales.

Information about on-farm goat productivity patterns is crucial for building resilient production systems in marginalised communities. Goat flock dynamics, management practices and production constraints in selected smallholder farming systems of Zimbabwe were explored. A multistage sampling approach was adopted to recruit a total of 200 participants. The effect of environment on productive indices and constraints was analysed using the Mann-Whitney U test and either Ordinal or Nominal logistic regression, respectively, in IBM SPSS version 26. Results highlight the importance of goats to rural communities. On average, 10.01 ± 5.14 goats were maintained per capita and the largest proportion was found in hot-humid environments (p > 0.05). However, reproductive performance in terms of average gestation length (4. 47 ± 0.59 months), age at first service (11.20 ± 2.24 months) and kidding (15.67 ± 2.30 months) was poorer in semi-arid environments than in the hot-humid areas (p > 0.05). Moreover, optimum productivity is hampered by a multitude of factors, including selection of breeding animals mainly based on personal appraisal (Index = 0.120), dependence of animals primarily on natural forages for feed (Index = 0.213), sub-optimal housing conditions like irregular cleaning (Index = 0.123) and disease preponderance (Index = 0.129). Ailments were mainly controlled using ethnoveterinary medicines (Index = 0.103). Taken together, our results underline the crucial role of goats to rural livelihoods, which could be elevated even more through community-based capacity building on proper animal husbandry practices in terms of breeding, nutrition, health and housing management.

This paper is a narrative review focusing on the association between environmental cadmium exposure and male reproductive dysfunction. The relationship between environmental pollutants encountered in daily life and the male reproductive system is attracting increasing attention. Humans are exposed to cadmium through inhalation, dietary intake (food) and other routes, leading to adverse health effects. This study systematically searched PubMed, Web of Science, and CNKI databases from January 1, 2020, to December 31, 2024, and included 40 eligible in vivo studies based on standardized selection criteria. This study reviewed and analyzed relevant animal experiments conducted in recent years. Based on the lowest observable adverse effect level (LOAEL, 10 μg/kg/d) for reproductive toxicity in rats from a chronic 90-day study (Ait Benbella et al., 2025), the minimum critical human equivalent dose (HED) of cadmium-induced male reproductive damage was calculated, All 40 studies in Table 1 were selected according to predefined inclusion/exclusion criteria (see Section 2). The Lowest-Observed-Adverse-Effect Level (LOAEL) was converted to HED using the following formula: H E D ( m g / k g ) = A n i m a l   L O A E L   ( m g / k g ) × k m   o f   a n i m a l   k m   o f   h u m a n (The LOAEL was derived from rat reproductive toxicity data (10 μg/kg/d) (Ait Benbella et al., 2025); km factors of 6 (rat) and 37 (human, 60kg) were applied. The calculated HED was 0.002 mg/kg/d.) Comparisons reveal that cadmium exposure levels in some regions approach or even exceed this threshold. The results suggest that cadmium may cause damage to the male reproductive system, potentially adversely affecting semen quality. Cadmium also induces renal dysfunction that indirectly exacerbates testicular injury via the renal-testis axis, further disrupting the hypothalamic-pituitary-testicular axis and amplifying reproductive toxicity. These findings highlight the integrated renal-reproductive toxicity of environmental cadmium exposure.

Advanced methodologies for Botryllus schlosseri artificial seawater systems are needed to decrease dependency of large-scale culture on natural seawater and expand this important new model organism to more inland laboratories. We constructed two botryllid tunicate customized closed aquaculture systems, a static system consisting of aerated jars fed commercial filter feeder diet, and a recirculating aquaculture system (RAS) consisting of pertinent marine RAS components fed live microalgae and zooplankton diets. Initially, static tunicate culture yielded exponential growth in contrast to poor survival and negligible growth observed in RAS tunicates. RAS modifications were made to increase water treatment proficiency, which improved tunicate survival and growth. Experiments were performed isolating feed and water type as variables differentiating static and RAS and evaluating their specific effects. Live feed promoted five-fold greater growth relative to a commercial concentrate diet. Tunicates maintained in optimized RAS water achieved two-fold faster growth relative to animals in freshly prepared artificial seawater. Subsequent procedural modifications combined with the RAS revisions resulted in growth rates comparable to the static system. Both optimized systems are suitable for long-term husbandry of botryllid tunicate populations supporting both sexual and asexual modes of reproduction, with a current RAS residence time of over 24 months.

Leptin, discovered in 1994 in ob/ob and db/db mutant mice, is a key regulator of energy balance, appetite, and multiple physiological systems including immunity and reproduction. While its function in mammals is well-established, leptin's presence and role in birds remain controversial due to differences in gene sequence, tissue expression, and signaling mechanisms. Avian leptin exhibits a GC-rich sequence, predominates in autocrine and paracrine signaling, and maintains conserved receptor-binding residues, supporting functional activity despite low systemic levels. Experimental studies show leptin influences feed intake, immune function, and reproduction, though conflicting results have fueled ongoing debate. In this review, we discuss evidence supporting and questioning avian leptin function and highlight emerging gene-editing approaches, including CRISPR/Cas9-mediated manipulation of leptin and its receptor in poultry, as powerful tools to clarify its functional dynamics in vivo, resolve longstanding uncertainties, and potentially enhance poultry growth and production efficiency.

Untreated manure is commonly used as a biological soil amendment of animal origin in organic production but may introduce foodborne pathogens into the farm environment. In this multi-regional study, generic E. coli was used as an indicator of fecal contamination to identify factors associated with its in manure-amended soils. The analysis included samples from 19 certified organic farms in California, Maine, Minnesota, and Maryland collected over two growing seasons. A zero-inflated linear mixed model was used to assess the association between generic E. coli concentration in soil, farm-related practices, soil and environmental factors. Generic E. coli concentration in the soil rapidly declined in the first 60 days after manure application (β: -1.00, CI95: -1.17, -0.83) before a secondary increase through Day 180. Manure management practices, including use of different types of animal manure and manure application rates, were significantly associated with generic E. coli in soil. Soil nutrients (phosphorus (β: 0.22, CI95: 0.15, 0.30)) and micronutrients (zinc (β: 0.03, CI95: 0.01, 0.04) and manganese (β: 0.02, CI95: 0.01, 0.02)), elevated moisture content (β: 0.13, CI95: 0.07, 0.19), and Salmonella (β: 1.79, CI95: 1.31,2.23) or Listeria monocytogenes (β: 0.24, CI95: 0.03, 0.44) also showed positive association with generic E. coli in soil. Lower wind speed (β: -0.12, CI95: -0.19, -0.06), increased precipitation (β: 0.03, CI95: 0.01, 0.05), and increased UV index (β: 0.24, CI95: 0.15, 0.34) were found to be associated with higher E. coli concentration in manured soil. Overall, the persistence of generic E. coli in manure-amended soil was multifactorial. Effective microbial risk management should incorporate considerations for origin of manure, management, environmental and meteorological factors alongside current USDA National Organic Program standards (90-120 days) regarding the interval of application of raw manure to harvest of the edible portion of food crops.

During long-term artificial selection, China has developed indigenous dairy goat populations with breed-specific traits and environmental adaptability. However, the genetic relationships and genomic characteristics of these populations remain insufficiently studied. We analyzed 270 whole-genome sequences from 16 goat breeds, including eight Chinese dairy breeds, four introduced dairy breeds, and four other breeds. Population structure analysis revealed significant genetic differentiation among Chinese, European, and African dairy goats. Different dairy goat breeds in China formed geographically distinct subclusters, and multiple gene flow events with introduced breeds were detected. Compared with European and African populations, Chinese dairy goats exhibited higher genetic diversity, lower genomic inbreeding levels, and faster linkage disequilibrium decay. Among five machine learning algorithms evaluated across 10 repeated validations, k-nearest neighbors (KNN) showed the best performance (accuracy = 0.981, AUC = 0.991), and a minimal 134-SNP panel was selected for accurate classification of Chinese dairy goat breeds. Genome-environment association analyses identified candidate genes associated with energy and lipid metabolism, stress response, reproduction, and immune function, with a missense variant in HDAC10 (chr5:118557145 A > G) showing significant differentiation among Chinese dairy goat populations from different regions. Selection signature and genome-wide association analyses identified candidate genes associated with horn type and coat color, including two missense mutations in ERG (chr1:149921788 C > G) and MITF (chr22:31686241 T > C). These findings systematically reveal the genetic structure and genomic characteristics of Chinese dairy goats, providing an important scientific basis for genetic improvement, breed identification, and the conservation of dairy goat genetic resources.

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants with potential reproductive toxicity, yet their profiles in follicular fluid and impacts on human fertility remain unclear. Given the importance of diet as an exposure pathway, we aimed to characterize PFAS in follicular fluid, examine associations with reproductive outcomes, and explore dietary contributors across regions in China. In this multicenter study involving 1301 women undergoing assisted reproductive technology in eight administrative divisions, 20 PFAS were quantified in follicular fluid. Reproductive outcomes included live birth, pregnancy loss, and early measures of ovarian hormones, endometrial thickness, and oocyte or embryo development. Associations were estimated using center-specific regression models combined by meta-analysis, with false discovery rate (FDR) correction. Both legacy and emerging PFAS were detected, with perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid contributing 19%-40% and 23%-37% of total concentrations, respectively, and 6:2 chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFESA) 11%-19%. Concentrations were higher in eastern and southern centers. Higher PFOS concentrations were significantly associated with an increased risk of biochemical pregnancy loss after FDR correction (RR per natural-log-unit increase: 2.10; 95% CI: 1.28, 3.45). Several legacy PFAS were linked to lower luteinizing hormone, elevated progesterone, and thinner endometrium on the day of human chorionic gonadotropin. Comparable associations were observed for emerging PFAS. Dietary intake of aquatic food and other animal-derived foods correlated positively with PFAS concentrations. These findings highlight PFAS accumulation in the ovarian microenvironment and potential disruption of early reproductive processes, underscoring the need for exposure mitigation through modifiable dietary pathways.

The symbiotic bacterium Photorhabdus is a rich source of bioactive secondary metabolites that mediate tripartite interactions with nematodes and insect hosts. However, natural products of ribosomal origin remain largely underexplored within this ecological niche. Here, we report the identification of aphotorhaptin A, a darobactin-like peptide (daropeptide) natural product from Photorhabdus asymbiotica, which structurally features an ether crosslink and an N-terminal acetyl unit. Biosynthetic investigation uncovers aphotorhaptin A is matured via an unexpected leader cleavage step, and the subsequent N-terminal acetylation confers metabolic stability that maintains the hexapeptide scaffold integrity. Biochemical and structural studies demonstrate the acetyltransferase PasC exhibits remarkable substrate promiscuity, facilitated by an expansive active-site cavity that accommodates diverse acyl-CoA donors and peptide substrates. Unlike the antimicrobial darobactin, aphotorhaptin A appears to lack antibacterial activity but modulates nematode development, and this activity requires the ether crosslink and the N-terminal acetyl group in the hexapeptide scaffold. These findings expand the chemical and biosynthetic space of ribosomal peptide family and establish its link with nematode development and reproduction.

The Peruvian Paso horse, a breed of national significance in Peru known for its unique gait, has been selectively bred for nearly 500 years and now faces potential risks due to reduced genetic diversity. To investigate the potential of somatic cell nuclear transfer to enhance genetic conservation strategies, a program was initiated to produce cloned Peruvian Paso foals. Skin biopsies from a highly awarded stallion with exceptional breed-defining traits were used as the source of donor somatic cells. Of the 15 cloned embryos reconstructed, seven blastocysts were produced, and five were transferred to five recipient mares. Three pregnancies ensued, two of which resulted in the birth of healthy foals at 333 and 347 days of gestation. Cloned foals were genetically and phenotypically identical to the donor animal, demonstrating the successful application of this approach to support genetic conservation in a protected horse breed.

Reconstructing ancestral reproductive systems is crucial for understanding the evolution of bilaterian body plans. Yet, despite extensive research on some organ systems of the last common bilaterian ancestor, the evolution and development of reproductive systems remain poorly understood. To address this gap, we investigated postembryonic sexual development in the xenacoelomorph Hofstenia atroviridis, a basal acoel species belonging to the infraorder Prosopharyngida. We reared H. atroviridis from eggs to adults and described the ontogeny of its reproductive organs using histology and immunohistochemistry with muscle and neural markers, along with observations of mating behaviors in each size class. Hofstenia atroviridis is a protandrous simultaneous hermaphrodite whose sexual maturity correlates with body size rather than age, as observed in Hofstenia miamia. The male copulatory system comprises a seminal vesicle, granular vesicle, penis, and a single copulatory stylet, surrounded by regionally specialized musculature and innervation. In contrast, the female system consists of paired, asaccate ovaries with large, follicle cell-bound oocytes, lacking a discrete gonopore or copulatory organ. Fertilization occurs internally through traumatic insemination, and eggs are likely released through the mouth. Our findings reveal that the male reproductive system of H. atroviridis exhibits unexpected complexity and structural differentiation despite the organism's overall simplicity. We propose that sexual selection acting on a hermaphroditic reproductive system may have driven the evolution of a multifunctional copulatory organ in the Urbilateria. This study establishes H. atroviridis as a promising and comparative model for exploring the evolutionary origins of animal reproductive systems.

The Boer goat, a key global meat breed originating from South Africa, has been exported for breeding in over 70 countries, leading to diverse selection pressures and environmental adaptations. In this context, the main objectives of this study were to quantify genome-wide diversity, breed structure, and selection signatures in Boer goats from nine countries to identify shared and population-specific adaptation and production-related signals. Genomic information of 321 Boer goats from nine populations worldwide was analysed: Australia (AUS), Canada (CAN), New Zealand (NZL), South Africa (ZAF), Switzerland (CHE), Tanzania (TZA), Uganda (UGA), United States (USA), and Zimbabwe (ZWE). Genetic diversity varied markedly among populations. The ZAF population exhibited the lowest observed heterozygosity (0.360) and the highest fraction of the genome in runs of homozygosity, suggesting recent inbreeding or strong selection. Population structure analyses, including principal component analysis and ADMIXTURE (optimal K = 8), revealed clear genetic differentiation. AUS Boer goats were the most divergent, while others formed clusters indicating shared ancestry. Four complementary selection signature methods, Fixation index, Divergence index, integrated haplotype score, and cross-population extended haplotype homozygosity, identified 4 706 unique genes under putative selection. No identified genes were common to all populations, indicating strong local adaptation, but 35 candidate genes were identified across five to six populations, highlighting shared selection for core production traits like growth, metabolism, and reproduction. Key shared genes regulating metabolism, including PPP2R2B, SCP2, and PRELID2, were detected in six populations. Regulatory hub genes such as MAPK3, HIF1A, PRKACA, and CREB1 were also detected, playing crucial roles in coordinating important biological processes. Population-specific adaptations included heat tolerance genes in AUS, cold adaptation and reproductive performance genes in CAN, and disease resistance genes in ZAF. These results underscore the need to monitor local genetic diversity while improving production traits in Boer goat breeding worldwide.

Toxoplasmosis remains a major global health concern, particularly in immunocompromised individuals and pregnant women, while currently available therapies are associated with significant toxicity and limited efficacy against chronic infection. Drug repurposing represents an attractive strategy for the identification of safer and more effective anti-Toxoplasma gondii agents. This study investigated the antiparasitic potential of loratadine, a second-generation antihistamine, using an integrated in silico, in vitro, and in vivo approach. The anti-T. gondii activity of loratadine was evaluated through β-galactosidase-based proliferation assays, reversibility assays, and experiments using pretreated tachyzoites. In vivo efficacy was assessed in murine models of acute and chronic toxoplasmosis. Disease progression, survival, parasite burden, and cerebral cyst formation were analyzed following treatment. Loratadine inhibited the intracellular proliferation of T. gondii tachyzoites in a concentration-dependent manner and induced partially irreversible effects on parasite viability after drug withdrawal. Pretreatment of extracellular tachyzoites produced limited effects, suggesting that loratadine predominantly acts during the intracellular stage of infection. In the acute toxoplasmosis model, loratadine treatment delayed disease progression, prolonged animal survival, and significantly reduced the number of tachyzoites recovered from the peritoneal cavity. In the chronic infection model, treatment significantly decreased both the number and size of cerebral cysts, although these findings do not demonstrate cyst eradication or direct bradyzoite killing. Despite its measurable biological activity, loratadine exhibited a relatively low in vitro selectivity index, highlighting the need for further optimization. These exploratory findings identify loratadine as a promising lead compound (hit) for further optimization rather than an immediately translatable therapeutic candidate. Additional medicinal chemistry, pharmacokinetic, mechanistic, and confirmatory preclinical studies will be required to determine its potential for anti-T. gondii drug development.

Gestational success in ruminants depends on the maintenance of a dynamic maternal-foetal microenvironment, resulting from complex interactions among the conceptus, extraembryonic membranes, maternal tissues, and gestational fluids. This study performed a comparative and longitudinal proteomic characterization of allantoic and amniotic fluids throughout pregnancy in sheep, aiming to elucidate the molecular mechanisms involved in maternal-foetal communication and embryonic development. Samples of allantoic and amniotic fluids aseptically collected from extraembryonic compartments after uterine opening following animal slaughter and allocated into three gestational groups according to foetal development: early gestation (0-50 days; n = 6), mid gestation (50-100 days; n = 3) and late gestation (100-150 days; n = 5). After centrifugation and protein quantification using the Bradford method, standardized aliquots were subjected to in-solution protein digestion and analysed by nano-LC-ESI-Q-TOF mass spectrometry. A total of 201 proteins were identified in the allantoic fluid and 159 proteins in the amniotic fluid, with five proteins showing significant differences across gestational stages. In the allantoic fluid, differentially abundant proteins included alpha-2-macroglobulin, gelsolin, basement membrane-specific heparan sulphate proteoglycan core protein and alpha-globin chain. In the amniotic fluid, changes were observed in peroxiredoxin-2, mucin-5 AC, fetuin-B, cystatin domain-containing protein and globin domain-containing protein. Multivariate analyses revealed progressive remodelling of the foetal extraembryonic microenvironment, associated with proteolytic control, tissue remodelling, redox homeostasis, epithelial protection and metabolic processes. Collectively, these findings reinforce the active role of foetal extraembryonic fluids in gestational physiology and highlight their potential as sources of biomarkers associated with reproductive success in sheep.