Animals最新文献

Sarcocystis is a genus of heteroxenous, globally distributed apicomplexan parasites found in reptiles, birds, and mammals. Typically, sarcocysts develop in muscles of intermediate hosts, and oocysts sporulate in intestines of definitive hosts. The parasite's life cycle is based on prey-predator relationships and usually involves two distinct host species. However, some Sarcocystis spp. can complete their full development within a single host species. Brown rats (Rattus norvegicus) are invasive, synanthropic, highly adaptable rodents that are true omnivores and opportunistic feeders. Therefore, it is possible that they can act as definitive hosts of Sarcocystis parasites. This study provides the first comprehensive assessment of Sarcocystis protists in brown rat intestinal samples under natural conditions, combining microscopy and molecular analyses. Of 27 brown rats investigated, 25.9% (7/27) of animals harbored oocysts/sporocysts of Sarcocystis spp. Based on nested PCR and sequencing of four genetic loci (18S rRNA, 28S rRNA, ITS1, and cox1), 59.3% of samples were positive for Sarcocystis spp. Parasites identified were genetically similar to Sarcocystis spp. using bird-bird, bird-Carnivora, rodent-Carnivora, or ungulate-Carnivora as their intermediate-definitive hosts. The present study suggests that synanthropic rodents may facilitate cross-ecosystem transmission of these parasites, increasing infection pressure on livestock, companion animals, and wildlife in human-dominated environments. Future molecular and dietary ecological studies are needed to assess the role of synanthropic and opportunistic hosts, such as the brown rat, in the transmission of Sarcocystis spp.

Micro-minerals are essential for fish, but traditional inorganic micro-minerals (IMM) have low bioavailability. This study evaluated coated inorganic micro-minerals (CIMM) in juvenile American eels under commercial recirculating aquaculture system (RAS) conditions. Three experimental groups (n = 3 tanks per group, stocking density: 138 fish/m³) were fed basal diets supplemented for 56 days with: 1000 mg/kg IMM (IMM group, providing Cu 7, Fe 200, Mn 30, Zn 70, I 1.6, Se 0.4, and Co 1.2 mg/kg diet), 1000 mg/kg CIMM (CIMM group I), or 500 mg/kg CIMM (CIMM group II). Compared to the IMM group, the CIMM group I demonstrated significantly enhanced growth performance, with the specific growth rate increasing by approximately 31.14%, higher whole-body content and retention of minerals (Ca, P, Cu, Fe, Mn, Zn), and superior intestinal health, as reflected by significantly increased activities of digestive enzymes (amylase and lipase), enhanced antioxidant capacity (elevated SOD and CAT, reduced MDA), and improved morphology (villi length and muscular thickness), an altered intestinal microbiota (increased relative abundance of Firmicutes and reduced relative abundance of Proteobacteria), and significant metabolomic alterations in purine metabolism and linoleic acid metabolism. The CIMM group II maintained growth performance, with no significant difference in WGR and SGR compared to the IMM group, while still showing significant improvements in feed intake and mineral retention (P, Cu, Fe, Zn), and antioxidant capacity. Collectively, this study not only confirms the efficacy of CIMM in commercial RAS but also reveals that the supplementation level previously shown to be effective in the laboratory (50% CIMM) is insufficient under commercial farming conditions, implying that the dietary micro-mineral requirements for juvenile American eels in commercial RAS may be higher than those established in laboratory settings.

Background/objectives: Apple pomace, a major by-product of juice production, represents both an environmental burden and an underutilized resource. This study aimed to enhance the nutritional value of apple pomace via solid-state fermentation (SSF) to develop a functional feed ingredient and systematically evaluate its effects on growth, metabolism, and intestinal health in weaned piglets.

Methods: Apple pomace was fermented using a multi-species consortium (Geotrichum candidum, Saccharomyces cerevisiae, Rhizopus oryzae, Bacillus subtilis, and Trichoderma viride). A total of 180 weaned piglets were fed iso-nitrogenous diets containing 0, 2, 4, 6, 8, or 10% fermented apple pomace for 35 days. Growth performance, serum biochemical and immuno-antioxidant indices, diarrhea incidence, jejunal morphology, and fecal microbiota were analyzed.

Results: Dietary fermented apple pomace supplementation showed dose-dependent effects. The 8% fermented apple pomace group exhibited optimal growth performance, with increased average daily gain and feed intake and reduced feed-to-gain ratio (p < 0.05). Serum analysis indicated enhanced protein synthesis, antioxidant capacity (T-AOC, SOD, GSH-Px), and immunoglobulin levels (IgA, IgG, IgM), along with reduced urea nitrogen and oxidative stress marker MDA. This group also had the lowest diarrhea rate, associated with improved jejunal villus morphology. Microbiota analysis revealed that 8% fermented apple pomace effectively increased α-diversity, promoted beneficial bacteria (e.g., lactic acid bacteria and butyrate-producing Clostridium sensu stricto_1), and suppressed pathogens (Escherichia coli, Salmonella, Streptococcus).

Conclusions: Multi-species SSF successively enhanced the nutritional profile of apple pomace. Inclusion at 8% showed the most favorable response in terms of growth performance, metabolic profile, and immune-antioxidant status in weaned piglets, mediated through improved intestinal morphology and targeted modulation of the gut microbiota toward a more diverse and beneficial ecosystem. These findings support the high-value, functional utilization of apple pomace as a feed additive in swine nutrition.

Sexual dimorphism (SD) is a widespread phenomenon among animals and has attracted considerable interest in evolutionary biology. Most studies on SD have been limited to a single population, and few have focused on multiple populations. In this study, size and shape SD were evaluated in three populations of Batrachuperus karlschmidti, a hynobiid species endemic to China. SD was not found in body size, but was observed in body shape. Males had larger relative dimensions in head length, head width, forelimb length, forelimb width, hindlimb length, hindlimb width, and tail length. Conversely, females were larger in the relative dimension of interlimb distance. Sexual selection can account for SD in head and limbs, thereby enhancing male reproductive success. Conversely, fecundity selection drives SD in limbs, tail length, and interlimb distance, ultimately improving the reproductive ability of both sexes. Differences in sexual shape dimorphism (SShD) traits were also found among populations, which may be caused by dissimilar levels of selection forces in the environment. This study provides insight into identifying the causes that promote sexual dimorphism, as well as the degree of difference in SShD traits among populations.

Background: Urinary proteins may reflect physiological changes occurring during the periparturient period, but reference data for goats are still lacking. This study investigated urinary protein patterns around parturition to help fill this gap and generate baseline information.

Methods: Ten pregnant Alpine goats were sampled by spontaneous voiding 22 ± 3 days before delivery (T0), 7 days postpartum (T7), and 30 days postpartum (T30). Physical and chemical urine analyses were performed, and urinary proteins were separated using one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Statistical tests (Shapiro-Wilk, repeated-measures ANOVA, or Friedman) were applied to evaluate differences among time points.

Results: Significant temporal changes were observed: urine pH decreased at T30, the urine protein-to-creatinine ratio increased at T7 and T30, and urinary creatinine concentration was highest at T0. Most samples showed common protein bands at approximately 80, 70, 62, 50, 37, 29, 25, 22, and below 13 kDa, with the 62, 50, and <13 kDa bands present in all samples. Bands between 18 and 64 kDa and above 60 kDa appeared only in some samples. Protein bands between 23 and 42 kDa were more frequent at T0, suggesting immune-related variations associated with pregnancy.

Conclusions: This study provides the first description of urinary protein electrophoretic profiles in goats during the periparturient period and highlights measurable changes across time. These findings offer a starting point for developing future research and may contribute to establishing reference parameters for clinical and physiological monitoring in goats.

Dendrobium officinale Kimura et Migo (D. officinale) is a traditional Chinese medicinal herb with recognized anti-inflammatory, antioxidant, and immunomodulatory properties. This study evaluated whether dietary supplementation with D. officinale leaf powder could influence bone mass, mechanical strength, and molecular markers of bone metabolism in caged laying hens. A total of 192 healthy 19-week-old Jinghong No. 1 hens were randomly assigned to three dietary groups: a control group fed a basal diet and two treatment groups supplemented with 1200 or 3600 mg/kg of D. officinale leaf powder for 16 weeks. Tibial and femoral bone strength and mineral density did not differ significantly among treatments (p > 0.05). However, tibial breaking strength displayed upward trends in both supplemented groups (p = 0.08), and similar tendencies were observed for femoral bone mineral content and bone density (p = 0.08). At the molecular level, dietary supplementation produced selective changes in gene expression. The low-dose diet significantly increased VEGFA expression (p < 0.05), whereas the high-dose diet resulted in significantly higher TGF-β1 expression (p < 0.05). Several other genes related to bone formation, bone resorption, or cytokine signaling exhibited numerical increases but did not reach statistical significance. These findings indicate that D. officinale leaf powder may modulate bone metabolic processes at the transcriptional level, although these molecular alterations were not accompanied by significant improvements in bone mass.

The objective of this study was to evaluate the persistence and environmental dissemination of enrofloxacin (EFX) and its metabolite ciprofloxacin (CFX) residues in poultry systems, as well as their effect on antimicrobial resistance in Escherichia coli. The experimental design included three groups: one treated group (A) and two untreated groups (B.1 and B.2), located in pens adjacent to or within 30 cm of group A to assess residue transfer. Birds in group A received EFX orally (10 mg·kg^-1 every 24 h for 5 days) via orogastric tube. EFX and CFX residues persisted in litter and excreta for up to 18 days post-treatment, reaching initial concentrations of 20,968 µg·kg^-1 in litter and 884.8 µg·kg^-1 in droppings in group A. Significant differences were detected between groups (Kruskal-Wallis, p < 0.05), confirming greater accumulation in the treated group and environmental dissemination. E. coli isolates obtained from litter and droppings from group A showed 73% resistance after treatment and correlated positively with residue concentration (ρ = 0.53). While the untreated groups B.1 and B.2 showed resistance rates of 24% and 13%, respectively, the control group exhibited a resistance rate of 3.3%. This study shows the detection of low levels of EXF and CFX residues in the litter of untreated groups, indicating limited dispersion. These findings highlight the importance of proper byproduct management and targeted environmental monitoring within the One Health framework, as continuous environmental exposure over time, combined with the persistence of this compound, may contribute to the selection of resistant bacteria.

Thamnaconus septentrionalis is an emerging commercially important aquaculture species in China, distributed extensively in the Indo-West Pacific Ocean. Recently, because of the seriously declining population and considerable economic potential of this aquaculture fish, increasing attention has been paid to the conservation and development of T. septentrionalis. Artificial fish breeding is essential and has become progressively implemented on local farms in China, which benefits the protection of T. septentrionalis resources and facilitates the development of its fishery industry. Previous studies have demonstrated that temperature could significantly influence ovary development in T. septentrionalis. However, the potential molecular mechanisms underlying the influence of temperature on testis development in T. septentrionalis have been scarcely studied. Thus, this study comprehensively explores the effects of temperature on testis development in T. septentrionalis using histological observation and transcriptomic techniques. Histological and transmission electron microscopy analyses indicated that T. septentrionalis testes, undergoing a rise in temperature, developed from phase III to IV. Transcriptomic analysis identified 315 differentially expressed genes, including 200 upregulated and 115 downregulated genes. Moreover, rising temperatures may enhance testis development by regulating steroid hormone biosynthesis, cellular senescence, and nucleotide metabolism. The upregulation of four genes (hsd11b2, cyp11b, cyp11a, and hsd17b3) involved in the steroid hormone biosynthesis process may significantly contribute to the increased level of testosterone and 11-keto-testosterone. This study is the first to elucidate the potential molecular mechanism involved in T. septentrionalis testis development induced by temperature, offering valuable and novel insights for its artificial breeding and fishery resources conservation.

This study investigated the effects of dietary probiotic supplementation and stocking density on the growth performance, carcass traits, immunity, blood biochemical parameters, and ileal histomorphology of broiler chickens. A total of five hundred ten 1-day-old unsexed broiler chicks (Cobb 39) were allocated to three probiotic levels (0%, 0.1%, 0.2%) and two stocking densities (low vs. high). Results indicated that stocking density significantly influenced body weight from the third week onward, with birds reared under low density showing higher weight and better feed-to-gain ratio. Probiotic supplementation did not significantly affect weekly body weight, feed intake, or mortality, although mortality tended to be lower in probiotic-fed groups. Carcass traits and lymphoid organ indices were largely unaffected by treatments, except for a higher heart percentage in low-density birds. Cell-mediated immunity was enhanced under low stocking density, and probiotic supplementation at 0.2% increased the immune response at 48 h post-challenge. Blood biochemical analysis revealed significant effects of stocking density on total protein, globulin, and triglycerides, while probiotics reduced total lipid and LDL levels. Ileal histomorphology was significantly improved by probiotics, with increased villus height, crypt depth, and villus-to-crypt ratio. Similarly, low stocking density further enhanced these parameters. Overall, probiotic supplementation, particularly at 0.1%, combined with low stocking density, positively influenced gut morphology and immune responses, contributing to improved broiler health and performance.

Research has demonstrated that incorporating nitrate into animal feed can effectively decrease methane production in ruminants, though its impact on carcass characteristics and meat attributes in Hu sheep requires further investigation. This experiment examined how a dietary inclusion of 3% calcium nitrate (CN) influenced slaughter parameters, meat properties, gut microbial populations, and host gene regulation in Hu sheep. The study involved sixty healthy male Hu sheep aged 120 days with comparable body weights (31.11 ± 3.39 kg), randomly allocated into two groups: a control group receiving standard feed (CON) and a CN-supplemented group. The trial lasted 60 days, including a 15-day adaptation period and a 45-day formal trial period. They were housed individually and fed twice daily (at 8:00 and 18:00). The findings revealed that CN supplementation notably reduced the water loss rate in the longissimus dorsi muscle (LD), elevated meat color brightness, and enhanced the proportion of polyunsaturated fatty acids (PUFA), particularly n-6 PUFA, along with the n-3/n-6 PUFA ratio. Conversely, it reduced the levels of saturated fatty acids such as myristic acid (C14:0) and oleic acid (C18:1n9t). Additionally, the treatment boosted ruminal Ammoniacal nitrogen content and total short-chain fatty acid production, thereby contributing to energy metabolism in the animals. Microbiological examination demonstrated that CN supplementation led to a decrease in Fibrobacterota and Methanobrevibacter populations within the ruminal environment, while promoting the growth of Proteobacteria in the duodenal region. The gene expression profiling of digestive tract tissues showed an increased activity in nitrogen processing genes (including CA4) and oxidative phosphorylation pathways (such as ATP6), indicating an improved metabolic efficiency and acid-base homeostasis in the host animals. These findings demonstrate that CN-enriched diets enhance the carcass characteristics of Hu sheep by modifying intramuscular lipid profiles through gastrointestinal microbial community restructuring and metabolic pathway adjustments. Such modifications affect energy utilization and acid-base equilibrium, ultimately impacting muscle characteristics and adipose tissue distribution, presenting viable approaches for eco-friendly livestock farming practices.