Although it has been demonstrated that gastrointestinal microorganisms greatly influence livestock performance, the effect of gastrointestinal microorganisms on the growth performance of crossbred cattle remains unclear. Due to their superior production characteristics, understanding the impact of gastrointestinal microorganisms on the growth performance of crossbred beef cattle is of significant importance for improving farming efficiency. In this study, healthy Simmental with similar birth date and weight were selected as dams, Simmental (Combination I), Belgian Blue (Combination II) and Red Angus (Combination III) were used as parents for crossbreeding. The progeny of the three combination crosses were measured for growth performance under identical conditions from birth rearing to 18 months of age (n = 30). Rumen fluid and plasma were collected for macro-genomic and non-targeted metabolomic analysis (n = 8). The results showed that Combination II was superior to Combination I and Combination III in body weight (BW) and body height (BH) (P < 0.05). Mycoplasma, Succinivibrio, Anaerostipes, Methanosphaera, Aspergillus, and Acidomyces were significantly increased in the rumen of Combination II (P < 0.05), whereas differentially expressed metabolites (DEMs) 9,10,13-Trihome (11), 9,12,13-Trihome and 9(10)-Epome, and 9(S)-Hpode were reduced in abundance. In addition, plasma DEM PC (14:0/P-18:1(11Z)), PC (16:0/0:0), and PC (17:0/0:0) were down-regulated in combination II. Correlation analysis revealed that Anaerostipes, Methanosphaera, and Succinivibrio were associated with PC (14:0/P-18:1(11Z)), 9(10)-Epome, 9,10,13-Trihome (11), 9(S)-Hpode, 9,10,13-Trihome, PC (17:0/0:0), and PC (16:0/0:0). Growth traits were significantly positively correlated with the three dominant genera, Anaerostipes, Methanosphaera, and Succinivibrio, while significantly negatively correlated with key rumen metabolites and plasma metabolites (P < 0.05). Our study reveals the role of rumen microorganisms and its metabolites with host metabolism in the regulation of growth performance of crossbred cattle, which will contribute to the development of modern cattle breeding.

The Chinese Tan sheep is a unique breed of sheep that is typical throughout China, mainly used for fur and meat production. They are widely distributed in northwestern China and are famous for their lambskin and shiny white curly wool. In this study, the phenotypic traits of wool length, birth weight, and head coat color were evaluated in 256 Chinese Tan sheep breeds. Whole genome sequencing generated 23.67 million high-quality SNPs for genome-wide association studies (GWAS). We identified 208 significant SNPs associated with birth wool length, implicating RAD50, MACROD2, SAMD5, SASH1, and SPTLC3 as potential candidate genes for this trait. For birth weight, 1056 significant SNPs, with 76.89% of them located on chromosome 2, were identified by GWAS, and XPA, INVS, LOC121818504, GABBR2, LOC101114941, and LOC106990096 were identified as potential candidate genes for birth weight. The GWAS for head coat color identified 1424 significant SNPs across three chromosomes, with 99.65% on chromosome 14, and SPIRE2, TCF25, and MC1R as candidate genes were found to be possibly involved in the development of the black-headed coat color in sheep. Furthermore, we selected head coat color as a representative trait and performed an independent test of our GWAS findings through multiplex PCR SNP genotyping. The findings validated five mutation sites in chromosome 14 (14,251,947 T>A, 14,252,090 G>A, 14,252,158 C>T, 14,252,329 T>G, and 14,252,464 C>T) within the exon1 of the MC1R gene (517 bp), as identified by GWAS in an additional 102 Tan sheep individuals, and revealed that black-headed sheep predominantly exhibited heterozygous genotypes, possibly contributing to their color change. Our results provide a valuable foundation for further study of these three economically important traits, and enhance our understanding of genetic structure and variation in Chinese Tan sheep.

In this study, we investigated the dynamic changes in muscle lipid content (MLC) deposition in the breast muscle of Jingyuan chickens at different stages (42-, 126-, and 180- days old) using metabolomics. The pH_45min, a*, and L* were significantly increased in the breast muscle of 126-day-old chickens, and MLC and b* were significantly increased in the breast muscle of 180-day-old chickens. A total of 4643 differentially expressed metabolites (DEMs) were identified, of which 10 decreased and 29 increased with age. Key pathways associated with meat quality traits included oxidative phosphorylation, β-alanine metabolism, and glycerophospholipid metabolism. Combined transcriptomic and phenotypic correlation analyses revealed significant positive correlations of MLC, pH_45min, a*, and L* with LysoPC 20:4, CD3E, TARP, IL7R, ENSGALG00010025331, and RASSF5. In the 42- and 180-day-old chickens, MLC, pH_45min, a*, and L* were significantly and positively correlated with L-Anserine, Dihydroxyacetone phosphate, ENSGALG00010006904, and HSPB7. MLC, pH_45min, a*, and L* were significantly and positively correlated with beta-Nicotinamide adenine dinucleotide in the 126- and 180-day-old chickens. This study deepens our understanding of the differences in MLC deposition at different stages of Jingyuan chickens and its relationship with meat quality traits.

Background: Ye Mule Aries sheep is one of the most important sheep breeds in Xinjiang, China. This breed is well adapted to harsh environmental conditions and displays strong disease resistance, fast growth, and high cold tolerance. To analyze the clonal expression and immunogenicity of the Ye Mule Aries sheep inhibin gene, total RNA was extracted from sheep ovarian tissue and used as a template to generate a eukaryotic expression vector and study inhibin immunogenicity. Methods: Primers were designed to amplify the inhibin A gene via polymerase chain reaction and the amplified product was cloned between the ScalI and EcoRI restriction sites of the expression vector pEGFP-N1 to construct a recombinant plasmid, pEGFP-INHα. Following the validation of successful cloning, the pEGFP-INHα plasmid was transfected into BHK cells to verify expression in eukaryotes and subsequently utilized as an antigen in rabbits. Rabbits were tested for anti-inhibin antibodies and serum follicle-stimulating hormone (FSH) concentrations. Results: The analysis of the INHα gene sequence revealed that INHα is 1109 bp long and is translated to an approximately 40 KDa protein. Bioinformatics approach indicated that the INHα gene is highly conserved between organisms. Immunization with the eukaryotic expression vector, pEGFP-INHα, which expresses the INHα gene elicited immune response and generatigeneration on of anti-INHα antibody. The antibody had a significant regulatory effect on the serum concentration of FSH in rabbits and led to higher levels of FSH, indicating increased ovary function. Conclusions: The present work resulted in a successful construction of eukaryotic expression plasmid pEGFP-INHα and verified the immunogenicity of this highly conserved protein. Further, the expression of pEGFP-INHα was shown to have a significant impact on the secretion of FSH, indicating a potential regulatory role in ovarian function. In conclusion, our current findings can serve as a working model for studying the effect of INHα on the breeding performance of Ye Mule Aries sheep, providing a novel strategy to improve their reproduction rates.

TRNA fragments (tRFs) are small non-coding RNAs generated from cleaved tRNA molecules, playing key roles in gene regulation and cellular processes. Produced by ribonucleases like angiogenin and Dicer, tRFs vary in length and function in gene silencing and stress responses. They interact with Argonaute proteins and affect mRNA levels, and are emerging as potential diagnostic and therapeutic targets for diseases such as cancer and neurodegenerative disorders. Given that the skin is the largest organ in mammals, it serves as an ideal model for studying development and various diseases. Therefore, this study investigates tRF expression in sheep skin tissues to understand their regulatory roles during growth and development. This study analyzed skin tissue from five 1-month-old lambs and five 24-month-old adult Tan sheep using small RNA sequencing and proteomics. Raw sequencing data were filtered and aligned to identify various tsRNAs, while proteomic data were assessed for differential expression. Principal Component Analysis (PCA) revealed distinct separation between juvenile and adult samples based on tsRNA expression patterns, indicating intra-group similarity and inter-group differences. Differentially expressed tsRNAs were identified, with 19 highly expressed tsRNAs at 1 month of age. Proteomic screening identified 932 highly expressed and 835 lowly expressed proteins in the 1-month-old group, with functional enrichment highlighting immunity and inflammation pathways. Predictive analysis of tsRNA target genes intersected with 20 differentially expressed proteins involved in mitochondrial metabolism and stress response. This study reveals that tsRNAs significantly influence developmental and immune processes in sheep, with distinct expression patterns between juveniles and adults. Future research should validate these findings and further elucidate the functional mechanisms of tsRNA regulation.