Background: This meta-analysis systematically evaluates the effects of Chinese herbal additives on production performance, immune function and meat quality in sheep to support their application in ruminant nutrition. Methods: A total of 13 studies, comprising 37 controlled trials, were included in the analysis. The overall effect size was assessed by forest plots and meta-analysis was conducted to identify sources of heterogeneity, perform sensitivity analysis and evaluate publication bias by funnel plots. Result: Dietary supplementation with Chinese herbal additives significantly increased average daily gain (ADG) and average daily feed intake (ADFI) (P less than 0.05) and reduced the feed-to-gain ratio (F/G) (P less than 0.05). Immunological analysis showed that serum IgA and IgM levels were elevated (P less than 0.05). For meat quality parameters, the additives increased cooking yield and pH (P less than 0.05) and decreased shear force (P less than 0.05) with no significant effect on drip loss (P greater than 0.05). Funnel plot analysis revealed minimal publication bias and sensitivity analysis confirmed the robustness and reliability of the results. These findings suggested that Chinese herbal additives contributed to enhanced production performance, immune function and meat quality in sheep. Further research should validate these findings through more controlled feeding trials, while exploring the active ingredients and mechanisms of action of Chinese herbal additives.

KRTAP24-1 belongs to the high-sulphur KAP family and has been associated with cashmere fibre diameter in goats, but its role in ovine wool traits remains unclear. This study assessed KRTAP24-1 tissue expression by RT-qPCR and investigated genetic variation and associations with wool traits in 277 Tibetan sheep. Polymorphisms in the coding region were identified by PCR amplification and Sanger sequencing, and genotyping was performed using PARMS. A linear mixed model (LMM) incorporating a genomic relationship matrix (GRM) was used to evaluate associations between SNPs, haplotypes, and 12 wool traits. Bioinformatic analyses were restricted to the five haplotypes observed in the study population and were used as preliminary in silico assessments. Three missense SNPs were identified: c.191C>T (p.L64P), c.527G>A (p.G176D), and c.656C>T (p.A219V). The c.191C>T variant was associated with mean fibre length (MFL), single fibre tenacity (SFT), and scoured yield (SY), whereas c.656C>T was associated with lock length (LL) and clean fleece yield (CFY). Several haplotype combinations were also associated with LL, elongation at break (EB), and CFY. KRTAP24-1 showed high expression in skin. The observed haplotypes showed only minor differences in predicted mRNA secondary structure and mainly local changes in predicted protein features. These findings suggest that KRTAP24-1 may provide a preliminary basis for marker-assisted selection in Tibetan sheep breeding, but its functional role requires further validation in independent populations and experimental systems.

Background: Many genomic imprinting left during long-term selective evolution may drive the formation of important economical traits of introduced and indigenous sheep breeds. Methods: In this study, OvineSNP50 BeadChip data of the introduced breeds GMM and DOR and the indigenous breed Sunit were downloaded from public databases. Selective sweep base on Pi and Fst strategy initially screened for a number of candidate genes that could explain the genetic mechanism elucidated the genetic-molecular mechanisms underlying the differentiation of growth development and reproductive traits between introduced and indigenous breeds. Result: In the DOR_VS_GMM group, 32 genes were identified. In the DOR_VS_SUN group, 26 genes were identified. In the GMM_VS_SUN group, 25 genes were identified. GO, KEGG enrichment analysis showed that these genes are mainly involved in the pathways of muscle development and reproductive regulation. We speculate that EHBP1, CSRP1, TNNI1, MBNL1, AADACL3, RDH13, TNNI3, BMP2, Wfdc8, PPP1CC2 and MOV10L1 may have left deep marks on the genome during long-term domestication and evolution and may be responsible for the productive and reproductive performance in the Merino and Sunit sheep. These genes have played an important role in the evolution of selection in the three breeds. It is expected that the selected candidate genes will provide some insights for future sheep germplasm mining and foreign introductions.

Testis size is important for identifying breeding animals with adequate sperm production. The aim of this study was to survey the expression profile of mRNA and miRNA in testis tissue from rams carrying different FecB genotypes, including the wild-type and heterozygous genotypes in Tibetan sheep. Comparative transcriptome profiles for ovine testes were established for wild-type and heterozygote Tibetan sheep by next-generation sequencing. RNA-seq results identified 3,910 (2,034 up- and 1,876 downregulated) differentially expressed (DE) genes and 243 (158 up- and 85 downregulated) DE microRNAs (miRNAs) in wild-type vs heterozygote sheep, respectively. Combined analysis of mRNA-seq and miRNA-seq revealed that 20 miRNAs interacted with 48 true DE target genes in wild-type testes compared to heterozygous genotype testes. These results provide evidence for a functional series of genes operating in Tibetan sheep testis. In addition, quantitative real-time PCR analysis showed that the expression trends of randomly selected DE genes in testis tissues from different genotypes were consistent with high-throughput sequencing results.

This study represents one of the first investigations of circular RNAs (circRNAs) in the ovaries of Tibetan sheep, with a focus on their potential role in reproductive performance. The aim was to identify circRNAs involved in ovarian development and fertility regulation. High-throughput sequencing was applied to analyze ovarian tissue samples from 20 Tibetan sheep, leading to the identification of 82 differentially expressed circRNAs between the single multiparous (SL) and multiple multiparous (ML) groups, with 35 upregulated and 47 downregulated circRNAs. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses revealed significant associations with pathways involved in cell growth, cell cycle progression, energy metabolism, hormone regulation, and cellular transport. Protein-protein interaction (PPI) analysis identified key target genes, including EP300 , CUL1 , and oar-miR-654-5p . A comprehensive quaternary regulatory network, integrating circRNA, miRNA, mRNA, and related pathways, was constructed. This study provides novel insights into the molecular mechanisms underlying fertility in Tibetan sheep and identifies potential molecular targets for improving reproductive biotechnology. These findings lay the foundation for future molecular breeding programs aimed at enhancing fertility in Tibetan sheep.

Background: Tibetan sheep meat plays a pivotal role in the husbandry sector of the Qinghai-Tibet Plateau. Methods: We adopted a detailed sequencing and analysis strategy to verify the molecular mechanism of tenderness variation in different Tibetan sheep meat. Result: Transcriptomic analysis revealed 824 differentially expressed genes in Tibetan sheep muscle tissues of varying tenderness, encompassing 241 upregulated and 583 downregulated genes. Genes including MyoD, PAK6, PDGFRA, Myf5, IGF, GH, FGF and GDF8 were implicated, involving critical processes such as muscle development, growth and metabolism. GO and KEGG enrichment analyses unveiled significant enrichment phenomena pertaining to biological processes, cellular components and molecular functions. Validation via qRT-PCR confirmed the differential expression of eight candidate genes. These findings offer theoretical and practical insights for enhancing Tibetan sheep meat quality through genetic regulation.