Search Results (643)

Telomerase reverse transcriptase (TERT) plays a regulatory role in the induction, activation, and hair growth of human and mouse hair follicles. However, the effects of mutations in this gene on sheep hair follicle development and wool traits remain unclear. In this study, the TERT gene (TERT) was investigated using Kompetitive Allele-Specific PCR (KASP) technology and in situ hybridization. The results revealed six single nucleotide polymorphisms (SNPs) across the four exons of TERT, two of which were non-synonymous. The TERT mRNA showed weak positive expression in the stratum corneum, inner root sheath, hair follicle medulla, and sebaceous glands; moderate positive expression in the outer root sheath; and strong positive expression in the dermal papilla. An association analysis between wool trait variation and the SNPs revealed that the two non-synonymous changes were associated with mean wool staple strength (MSS), thus TERT could potentially serve as a candidate gene for this trait. Full article

Birth weight is a key early-life trait in sheep that influences neonatal survival and subsequent growth, but its genetic basis remains incompletely understood. Here, we used low-coverage whole-genome sequencing (lcWGS)-based genotyping and genome-wide association analysis (GWAS) to investigate birth weight in 671 East Friesian × Hu crossbred lambs, achieving high imputation accuracy (98.5% allelic concordance). A total of 148 SNPs reached the suggestive significance threshold, of which 20 reached genome-wide significance. Among these signals, the chromosome 7 locus contained 69 suggestive variants spanning an approximately 6 kb interval within the SPATA7 region, including 14 genome-wide significant SNPs. Notably, 13 of these suggestive variants overlapped annotated enhancer intervals, of which 3 reached genome-wide significance. Portions of the associated interval also coincided with pituitary ATAC-seq and liver H3K4me1 ChIP-seq signals. Chr7:98,178,889 A > G, the most strongly associated SNP in this region, showed birth-weight differences among genotypes. Lambs carrying the AG genotype had significantly higher adjusted least-squares mean birth weight than AA lambs (3.81 vs. 3.56 kg; Δ = 0.25 kg, +7.0%). These findings prioritize the SPATA7 region as a candidate regulatory locus for birth-weight variation and provide a basis for future fine-mapping and functional validation. Full article

The Wadi sheep (WAD) is a unique Chinese indigenous breed previously reported to show adaptation to humid and saline–alkali lowlands, disease resistance, high fecundity, and favorable meat quality. However, the recent widespread introduction of commercial sheep breeds has led to a sharp decline in the purebred WAD population, posing serious threats to the preservation of its unique genetic resources. Therefore, there is an urgent need to assess the current population structure and genetic diversity of WAD to support its conservation and sustainable utilization. In this study, we systematically analyzed genomic variation, population structure, and selection signatures using whole-genome resequencing data from 30 WAD sheep and 80 publicly available genomes representing five other breeds obtained from the NCBI database. Population genomic analyses revealed that WAD retains substantial genetic diversity and exhibits a distinct population structure, shaped by its unique breeding history. Selection signature analyses using F_ST, π ratio, and XP-EHH identified 457 candidate genes under positive selection, which are associated with key biological processes including environmental adaptation, immune defense, muscle traits, growth, and reproduction. These findings identify genomic regions potentially related to reported WAD traits and provide a theoretical basis for its conservation, molecular breeding, and sustainable utilization in lowland environments. Full article

Improvement in the in vitro maturation (IVM) of oocyte quality is a gateway to enhancing the efficiency of in vitro embryo production. The anti-Müllerian hormone (AMH) is a crucial hormone secreted by granulosa cells that effectively suppresses primordial follicle recruitment and regulates follicular growth and development. This study was designed to investigate the role of AMH on the IVM of sheep oocytes. In this current study, oocytes in vitro were cultured in media supplemented with AMH. We comprehensively analyzed the impact of AMH on various developmental parameters of sheep oocytes, such as cellular activity, cortical granules (CGs) migration, cytoskeleton and mitochondrial function of oocytes. Furthermore, Smart-seq2 single-cell RNA sequencing (scRNA-seq) was employed to elucidate the oocytes’ development. The results showed that treatment with 100 ng/mL improved the maturation rate of the oocytes, the normal distribution rate of cortical granules and mitochondrial function, while reducing the rate of spindle abnormalities in oocytes. A total of 741 differentially expressed genes (DEGs) were observed between the FSH_12 h and AMH_12 h groups, and 746 DEGs were observed between the FSH_24 h and A+F groups. KEGG pathway analysis revealed that the FSH_12 h and AMH_12 h groups significant enrichment in DEGs were associated with p53, MAPK, PI3K-Akt and TGF-beta signaling pathways, and the FSH_12 h and AMH_24 h groups significant enrichment in DEGs were associated with cAMP, AMPK, Hedgehog and estrogen signaling pathways. These findings suggest that AMH may regulates oocytes IVM via several candidate signaling pathways. Our results provide preliminary clues for exploring the regulatory mechanism of sheep oocyte maturation and optimizing relevant culture systems. Full article

Single-cell omics technologies have transformed the study of cellular heterogeneity, enabling high-resolution analysis of tissue development and complex traits. In sheep and goats, these approaches have been applied to skin, hair follicles, reproductive organs, metabolic tissues, and adipose tissue, revealing cell type-specific regulatory programs underlying traits such as wool quality, fertility, growth, and fat deposition. However, most studies rely on single-cell RNA sequencing (scRNA-seq) and are limited by incomplete genome annotation, insufficient coverage of production traits, and weak integration with population genetics, restricting their application in molecular breeding. This review summarizes advances in single-cell omics in sheep and goats, focusing on tissue development and trait formation. We further discuss emerging strategies that integrate single-cell multi-omics, spatial transcriptomics, and population genetics to resolve regulatory mechanisms in a cell type-specific and spatially informed context. Finally, we discuss CRISPR/Cas9-based validation to link genotype and phenotype, accelerating gene discovery and precision breeding in small ruminants. Full article

Myostatin (MSTN) is a well-established negative regulator of skeletal muscle growth; however, its role in bone metabolism and osteogenic differentiation remains incompletely understood. In this study, untargeted and targeted metabolomic analyses were performed to investigate the metabolic effects of the MSTN^Del73C mutation during osteogenic differentiation of sheep bone marrow mesenchymal stem cells (BMSCs). Metabolomic profiles were analyzed in wild-type and MSTN^Del73C mutant BMSCs at 0, 7, and 14 days of osteogenic induction. During normal osteogenic differentiation, metabolites related to glycerophospholipid metabolism were repeatedly detected among significantly altered features, accompanied by marked increases in multiple lysophospholipid subclasses, including lysophosphatidylcholine (LPC), lysophosphatidylserine (LPS), and lysophosphatidylinositol (LPI). In contrast, MSTN^Del73C mutation was associated with significant reductions in several LPC and LPI species (p < 0.01 or p < 0.001), suggesting altered lipid metabolic profiles during differentiation. Targeted metabolomic validation further confirmed the altered abundance pattern of LPC 18:2. Collectively, these findings suggest that MSTN mutation is closely associated with metabolic remodeling during osteogenic differentiation and suggest potential involvement of glycerophospholipid-related metabolites involved in MSTN-related regulation of sheep BMSC osteogenesis. Full article

Leucine, an essential branched-chain amino acid, serves not only as a substrate for protein synthesis but also as a key regulator of placental function and fetal development. This study investigated the effects of dietary supplementation with RP-Leu during late gestation on placental development and offspring performance in Hu sheep. Sixty twin-pregnant ewes at day 80 of pregnancy were randomly assigned to either a control group (fed a basal diet) or an RP-Leu group (fed a basal diet supplemented with 19 g/day RP-Leu). The feeding trial lasted for 60 d. The ewes were slaughtered at day 140 of gestation. Maternal slaughter traits and fetal organ weights were recorded. Blood and milk samples were collected for milk composition analysis and targeted metabolomic profiling. Leucine supplementation significantly increased the percentage of milk fat content, total solid content, and the birth weight of lambs (p < 0.05). Improvements in placental morphology and antioxidant capacity were observed, including a significant increase in cotyledon density and a significant enhancement of catalase (CAT) activity (p < 0.05). Gene expression analysis indicated that the NOS3, SLC38A1 and FABP4 genes in the placental cotyledons (p < 0.05), and the VEGFA, NOS3, SLC27A1 and FABP4 genes were significantly upregulated in the maternal caruncles (p < 0.05). Plasma metabolomic profiling revealed increased L-glutamic acid levels and alterations in several amino acids, with pathway enrichment indicating involvement in amino acid metabolism and membrane transport processes. Transcriptomic analysis identified 739 differentially expressed genes, which were mainly enriched in the PI3K/Akt signaling pathway, ECM–receptor interaction pathway, and cytokine–cytokine receptor interaction pathway. Collectively, these findings suggest that RP-Leu supplementation during late gestation may enhance offspring growth by modulating amino acid metabolism, promoting placental development, and improving placental nutrient transport capacity, thereby supporting fetal growth and development. Full article

The use of agricultural by-products as feed is essential for sustainable animal husbandry. This study assessed the effects of substituting whole-plant corn silage with a mixed silage of cotton stalks and grape pomace on growth, serum biochemistry, and jejunal metabolomics in Suffolk rams. In this experiment, 135 rams (6-mo, 30.55 kg BW) were allocated to 0%, 50%, or 100% replacement (CG, EG50, EG100) and fed for 120 d after a 15-d adaptation. Compared with the CG, average daily gain improved by 27.3% and 17.5%, and feed conversion improved by 30.8% and 15.4% in EG50 and EG100 (p < 0.01). Compared with CG, the levels of BUN, TNF-α and IL-1β in serum of EG50 and EG100 were significantly decreased. The levels of IgG, IgM, IL-4, antioxidant enzymes and total antioxidant capacity were significantly increased (p < 0.05). Subsequently, the slaughter performance and jejunal content metabolome of CG and EG50 were further detected and analyzed. The results indicated that the live weight, eye area and muscle crude protein content of EG50 were extremely significantly higher than those of CG (p < 0.01). In jejunal contents, 31 differential metabolites (EG50 vs. CG) were enriched in ABC transporters, branched-chain amino acid biosynthesis, mineral absorption, purine and biotin metabolism, and glucagon signaling. In conclusion, substituting corn silage with the mixed silage promotes growth, improves antioxidant and immune status, reduces serum urea nitrogen, enhances muscle protein deposition (EG50), modulates intestinal nitrogen, purine, lipid, and carbohydrate metabolism (EG50), and supports sustainable meat sheep production. Full article

Salivary microbiota constitutes complex microbial assemblages and acts as a source of reliable non-invasive biomarkers for evaluating growth, metabolism, and health status of farm animals. This review explores the research value of saliva and its resident microbes in livestock health monitoring. We summarize saliva composition, physiological functions, and sampling protocols for pigs, cattle, sheep, and goats. Core microbial taxa of monogastric and ruminant species are outlined, together with their roles in digestion, rumen fermentation, growth, and stress responses. We also present classic salivary diagnostic indicators and the impacts of oral bacteria on common livestock diseases. Current research is limited by undefined causal relationships, low diagnostic specificity, and heterogeneous technical standards, and thus fails to support accurate diagnosis at the individual animal level. Future studies should elucidate microbial interaction mechanisms, standardize experimental protocols, and establish multi-index evaluation models. This review advances theoretical research and promotes the practical application of salivary microbiota in precision livestock farming. Full article

Maize, as a major cereal crop in China, is vital for national food security, and appropriate nitrogen fertilization is essential for its growth and yield. Avoiding excessive nitrogen fertilizer application while maintaining productivity remains a critical challenge for sustainable agriculture. Although straw returning is widely adopted to reduce chemical fertilizer inputs, its effectiveness is often regionally constrained. In the West Liaohe Plain, low temperature and spring drought limit straw decomposition and nutrient release, making it difficult to reduce nitrogen fertilizer input and improve fertilizer use efficiency. Therefore, this study examined the effects of different nitrogen management modes on straw decomposition, nutrient release, mineral fertilizer substitution potential, soil available nutrients, and maize yield under shallow buried drip irrigation with integrated water and fertilizer management. A field experiment was conducted with five nitrogen (N) fertilizer management treatments: a conventional fertilization treatment (CK), in which 15% of total N was applied as starter fertilizer; two increased starter N treatments, in which 30% (30%N) and 45% (45%N) of total N were applied as starter fertilizer; and two organic substitution treatments, in which 30% (30%ON) and 45% (45%ON) of mineral N fertilizer were substituted with decomposed sheep manure based on equivalent total N input. Straw decomposition and nutrient release were measured using the nylon mesh bag method and fitted with an exponential decay model. The mineral fertilizer substitution potential was estimated based on straw nutrient release, while soil available nutrient dynamics in the 0–40 cm soil layer were analyzed, and the Mantel test and PCA were used to assess their relationships. Organic substitution promoted straw decomposition. The 30%ON treatment showed the highest rate at 70.91%, which was 19.2% higher than that of CK, and it exhibited a higher theoretical maximum decomposition rate (a), higher decomposition rate constant (k), and a shorter half-life. All treatments increased nutrient release and soil available nutrients, and organic substitution demonstrated stronger temporal persistence and more uniform vertical distribution among soil layers. The 30%ON treatment increased straw nutrient release by 4.8% to 18.2% and enhanced mineral fertilizer substitution potential. Although the 30%ON treatment did not increase yield in the first experimental year, it showed a significant yield advantage in the second year, which coincided with greater straw nutrient release and higher soil available nutrient levels under this treatment. Substituting 30% of mineral N fertilizer with organic fertilizer under shallow buried drip irrigation (300 kg N ha⁻¹) optimized the C/N balance of the input system and facilitated straw decomposition and nutrient release. The continuous accumulation of soil available nutrients under this treatment, together with sustained straw nutrient release, was associated with a significant yield advantage in the second experimental year. Therefore, the 30%ON treatment may represent an appropriate management strategy for coordinating straw resource utilization, soil fertility maintenance, and stable maize production in the West Liaohe Plain. Full article

Background/Objectives: Seasonal crude protein (CP) and phosphorus (P) deficiency in northern Australian pastures reduces feed intake and growth of grazing ruminants, but the hepatic mitochondrial mechanisms underlying this response remain unclear. We characterized the hepatic mitochondrial transcriptome of sheep exposed to CP-P deficiency or matched-intake feed restriction. Methods: Merino wethers were assigned for 63 d to one of three treatments (n = 8/group): High CP-P, Low CP-P, or Restricted, in which High CP-P feed was offered at the same energy intake as the Low CP-P group. Liver RNA was sequenced, and transcripts encoding mitochondrial proteins were identified using MitoCarta 3.0. Differentially expressed genes (DEGs) were defined as adjusted p < 0.05 and |log2FC| ≥ 0.585. Results: Of 804 mitochondrial genes detected, 83 were differentially expressed in at least one pairwise comparison. The greatest transcriptional response occurred in contrasts against High CP-P (Low CP-P vs. High CP-P: 38 DEGs in 8 enriched pathways; Restricted vs. High CP-P: 37 DEGs in 10 enriched pathways). In both low-intake treatments, ALDH1L2, ALDH1L1, SHMT2, and DMGDH were upregulated, suggesting altered folate-mediated one-carbon metabolism. Restricted sheep also showed higher expression of several SLC25A transporters (SLC25A4, SLC25A28, SLC25A29, SLC25A33, and SLC25A34), indicative of enhanced mitochondrial nucleotide and metabolite exchange under CP-P adequate energy restriction. In contrast, Low CP-P sheep showed higher expression of SLC25A15 and SLC25A25 relative to either High CP-P or Restricted sheep, a nutrient-deficiency specific transporter response. CKMT2 expression was also higher in Restricted sheep than in both other groups. Conclusions: These findings suggest that reduced metabolizable energy intake was associated with the bulk of the hepatic mitochondrial transcriptional response, particularly in folate-mediated one-carbon metabolism, whereas CP-P deficiency was associated with a smaller but distinct transporter signature. The liver mitochondrial transcriptome may provide mechanistic insight into nutritional adaptation under CP and P deficiency in grazing sheep. Full article

Background: Dietary crude protein (CP) acts as a key nutritional factor that affects the growth performance and liver metabolism of fattening Hu sheep, with metabolizable energy (ME) representing a major confounding factor in CP-related responses. To isolate the specific effects of CP on liver metabolism and minimize energy–protein interactions, we standardized dietary ME at 9.4 MJ/kg dry matter. Methods: We then established three isoenergetic CP concentrations: 11.07%, 13.07%, and 15.11%. A total of ninety 4-month-old male Hu sheep (with an initial body weight of 27.09 ± 1.83 kg) were allocated at random to three dietary treatment groups, each containing 30 animals distributed across three replicate pens, and fed pelleted total mixed rations (PTMRs) for 75 days under pen conditions in southern Xinjiang. Exploratory combined transcriptomic and metabolomic profiling of liver tissue was conducted to characterize how graded CP levels modulate growth traits and hepatic metabolic pathways, thereby identifying the appropriate dietary CP level for efficient and sustainable fattening of Hu sheep in this region. Result: Results indicated that animals fed the 15.11% CP diet showed a significantly higher average daily gain (ADG) and cumulative weight gain compared with those fed 11.07% or 13.07% CP (p < 0.05). Exploratory multi-omics enrichment analysis demonstrated significant overrepresentation (p < 0.05) of differentially expressed genes and metabolites in key biological pathways—including bile secretion, AMP-activated protein kinase (AMPK) signaling, steroid biosynthesis, peroxisome proliferator-activated receptor (PPAR) signaling, and oxidative stress-related and oxidative phosphorylation. Correlation analyses characterized two hub genes—ATP6AP1 and LOC101119853—that were significantly and negatively correlated with ADG (p < 0.05), whereas two metabolites—calcidiol and ADP—displayed significant positive relationships with ADG (p < 0.05). Pathway-level comparisons further demonstrated that both the 13.07% vs. 15.11% CP and the 11.07% vs. 15.11% CP contrasts yielded significant enrichment in AMPK signaling and steroid biosynthesis. Notably, calcidiol and ADP both declined numerically in the 13.07% vs. 15.11% CP comparison, whereas only ADP reached statistical significance in the 11.07% vs. 15.11% CP contrast. Conclusions: Collectively, under an ME level of 9.4 MJ/kg, a dietary CP concentration of 15.11% contributes to favorable growth of 4-month-old fattening Hu sheep housed in pens in southern Xinjiang. This level is associated with improved growth performance and coordinated regulation of central hepatic regulatory networks—particularly those involved in energy homeostasis and steroidogenesis—thereby supporting metabolic stability without compromising animal health or production efficiency. These findings provide a preliminary molecular basis for precision protein nutrition in Hu sheep feeding systems and offer translational insights for optimizing ruminant nutrition under arid and semi-arid environmental constraints. All correlations indicate potential associations, not causal relationships. Full article

During the early growth stage, lambs are highly susceptible to pathogenic microbial invasion due to an underdeveloped intestinal structure, unstable microbial colonization, and immature mucosal immune function, leading to diarrhea, growth retardation, and elevated mortality factors that severely constrain the production efficiency and economic viability of the sheep industry. This study aimed to compare the regulatory effects of compound yeast culture (CYC) and yeast polysaccharides (YPs) on intestinal barrier function in Mongolian male lambs and clarify their underlying molecular mechanisms. Eighteen lambs were randomly assigned to three groups (n = 6/group): control group (basal diet), CYC group (40 g/kg), and YP group (3 g/kg). After a 30-day feeding trial, intestinal histomorphology, tight junction proteins, immune signaling pathways, and gut microbiota were analyzed. The results showed that both additives improved intestinal villus morphology, and CYC markedly increased the villus height/crypt depth ratio (p < 0.05). At the mechanical barrier level, CYC upregulated the protein expression of occludin, claudin-1, and ZO-1, whereas YPs increased occludin and ZO-1 expression (p < 0.05). Immunologically, CYC inhibited intestinal inflammation via the TLR4/TRAF6/MyD88/NF-κB pathway, increasing interleukin-10 (IL-10) and secretory immunoglobulin A (sIgA) while decreasing pro-inflammatory cytokines. YPs exerted similar anti-inflammatory effects through the TLR2/MyD88 pathway. Microbial analysis indicated that both additives increased the relative abundance of beneficial bacteria including Eubacterium, Bacillus, and Succinivibrio, while reducing the potential pathogen Mogibacterium. Spearman correlation analysis revealed that Mogibacterium was positively correlated with TNF-α and negatively correlated with occludin expression. In conclusion, CYC and YPs effectively enhance intestinal mechanical, immune, and biological barriers via different TLR-mediated pathways and microbial modulation. Both natural additives have great application potential for improving lamb health, reducing antibiotic dependence, and promoting sustainable green animal husbandry. Full article

This study evaluated the effects of dietary PUFA supplementation on growth performance, serum biochemical indices, rumen morphology, ruminal fermentation, and rumen microbial communities in Hu sheep. Thirty healthy male Hu sheep (80 days old; 18.70 ± 0.72 kg) were randomly assigned to three groups (n = 10/group) and fed a basal diet supplemented with 4% rumen-bypass palmitic acid fat powder (POS), 4% linseed oil (LO; rich in ω-3 PUFA), or 4% sunflower oil (SO; rich in ω-6 PUFA). PUFA supplementation did not affect average daily gain or rumen tissue morphology (p > 0.05), but it significantly reduced serum creatinine, uric acid, and high-density lipoprotein concentrations (p < 0.05). Orthogonal comparative analysis showed that supplementing with PUFA significantly reduced acetate and propionate, while increasing isobutyrate, butyrate, isovalerate, and TVFAs (p < 0.05). The levels of propionate, butyrate and TVFAs in the SO group were higher than those in the LO group (p < 0.05), and the ratio of acetate to propionate was lower (p < 0.05). Supplementing with PUFA reshaped the rumen microbiota, increasing the relative abundances of Bacteroidota, Firmicutes, Euryarchaeota, Cyanobacteria, and Actinobacteriota, while decreasing Proteobacteria and Desulfobacterota (p < 0.05). At the genus level, Prevotella and Rikenellaceae_RC9_gut_group were enriched in both groups with added PUFA, while Prevotellace-UCG-001 was specifically enriched in the LO group; in contrast, Prevotella_7, Succinivibriaceae_UCG-001, Prevotella_9, and Dialist all showed a decrease (p < 0.05). The alpha diversity increased, while the beta diversity showed significant differences between the group with added PUFA and the control group. Functionally, LO enriches carbohydrate and energy metabolism, while SO enriches nucleotide metabolism. In summary, linseed oil and sunflower oil improved serum indices and ruminal fermentation without impairing growth, but through distinct microbial and functional pathways. Full article

As a dual-purpose (meat and fat) coarse-wool sheep breed in Xinjiang, the Pishan Red sheep exhibits year-round estrus and excellent reproductive performance. The aim of this study was to systematically estimate the genetic parameters of growth traits in Pishan Red sheep at each stage from 0 to 12 months of age, and to provide a scientific basis for optimizing early selection indices for this breed. Year of birth, type of birth, and sex were included as fixed effects, while maternal genetic effects and individual additive genetic effects were treated as random effects. A multi-trait animal model was constructed using DMU software to analyze the genetic parameters. The results showed that for growth traits at 0 months of age, heritability ranged from 0.09 to 0.64, genetic correlations from –0.03 to 0.84, and phenotypic correlations from 8.2 × 10⁻³ to 0.32. Among these, the direct heritability of body weight was 0.18, and the maternal heritability was 0.21, while cannon circumference was identified as a high-heritability trait. At 2 months of age, heritability ranged from 0.04 to 0.69, genetic correlations from −0.78 to 0.96, and phenotypic correlations from 0.036 to 0.44. Body weight, body length, and cannon circumference were high-heritability traits. At 6 months of age, heritability ranged from 0.04 to 0.71, genetic correlations from −0.32 to 0.70, and phenotypic correlations from −0.13 to 0.54. Body weight was a medium-heritability trait, while chest width and cannon circumference were high-heritability traits. At 12 months of age, heritability ranged from 0.07 to 0.48, genetic correlations from −0.04 to 0.87, and phenotypic correlations from 0.28 to 0.72. Body weight was a medium-heritability trait, whereas body height, body length, cannon circumference, and heart girth were high-heritability traits. Both body weight and cannon circumference exhibited high heritability throughout the 0–12 month period and can therefore serve as key selection indices for early breeding in this breed. The findings of this study provide essential local baseline data for the genetic improvement, breeding program design, and genetic evaluation of Pishan Red sheep. Full article