Animal Biotechnology最新文献

Cold ambient temperatures decrease semen quality. However, the effects of dietary energy sources on semen quality under cold stress conditions remain unclear. In the present study, purebred Yorkshire boars (572 days old) were fed diets supplemented with either fat (FAT), amino acid complex (AA), or dietary fiber beet pulp (BP) during the winter. The experiment was conducted for 84 days. Results showed that BP supplementation increased semen volume, sperm count, plasma immunoglobulin M level and the relative abundance of fecal norank_f_Erysipelotrichaceae (positively correlated with sperm viability), while decreasing the levels of interleukin-1β and lipopolysaccharide-binding protein (p < 0.05). AA supplementation increased sperm density, progressive motility, and sperm velocity during weeks 7-12 (p < 0.05), while no significant effect was observed during weeks 1-6. The relative abundance of fecal Lachnospiraceae_UCG-006 (positively correlated with sperm velocity) also was increased in the AA group. FAT supplementation had a minor effect on sperm progressive motility and average curvilinear velocity, which may be related to the increased relative abundance of fecal T2WK15B57 (negatively correlated with semen quality). In summary, daily supplementation with BP and AA improves sperm quality under cold stress conditions, likely through improvements in inflammation, immunity and intestinal microflora.

The natural flavonoid quercetin, which exhibits a range of biological activities, has been implicated in liver disease resistance in recent research. In vivo study attesting to quercetin's protective effect against metabolic-associated fatty liver disease (MAFLD) is inadequate, however. Here, our investigation explored the potential benefits of quercetin in preventing MAFLD in C57BL/6 mice fed a high-fat diet (HFD). The results revealed that quercetin ameliorated the aberrant enhancement of body and liver weight. The hepatic histological anomalie induced by MAFLD were also mitigated by quercetin. HFD-induced imbalance in serum LDL, HDL, AST, ALT, TG, and LDH was mitigated by quercetin. Mechanically, we found that quercetin improved lipid metabolism by reducing lipogenesis proteins including ACC, FASN, and SREBP-1c and enhancing β-oxidation proteins including PPARα and CPT1A. In vitro study demonstrated that quercetin regulated hepatic lipid metabolism by targeting SREBP-1c and PPARα. Additionally, quercetin enhanced the antioxidant capacity in HFD-treated mice by downregulating Nrf2 and HO-1 expressions and upregulating SOD and GPX1 expressions. The hyper-activation of inflammation was also restored by quercetin via eliminating the phosphorylation of IκBα and NF-κB p65. Collectively, our observations highlight that quercetin exerts hepatoprotective properties in MAFLD mice by regulating hepatic lipid metabolism, oxidative stress and inflammatory response.

Fistulated animals and rumen simulation systems are essential for evaluating the effects of ingredients like probiotics, proposed as sustainable alternatives to growth-promoting antibiotics in ruminant nutrition. This study assessed the impact of microencapsulated probiotics on the structure and functionality of an initial ruminal microbial community using in vivo (IVV) and in vitro (IVT) systems. The IVT system was inoculated with rumen fluid obtained from the cattle animal used as IVV system. Over time, both systems were analysed for short-chain fatty acid (SCFA) production, microbial composition and functionality using next-generation sequencing. Physicochemical parameters were consistent across both systems and the inoculum, with an increase in propionate concentration observed. Although the microbial composition of IVV and IVT systems was highly similar (Pearson correlation of 0.869), significant differences in B-diversity were noted (p value = 0.023). The systems also exhibited high similarity in enzymatic profiles (correlation: 0.971) and metabolic pathways (correlation: 0.938), despite differences in functional B-diversity. Both systems showed increased production of fibrolytic enzymes, enhancing feed efficiency. The use of microencapsulated probiotics induced both taxonomic and functional changes in the initial microbial community of the IVT and IVV systems, which can be linked to the zootechnical effects of using probiotics as additives in ruminal animal nutrition.

Kalmyk cattle are an important meat breed in Kazakhstan, valued for their strong physique, genetic stability, and adaptability. In this study, we investigated the mRNA expression of ELOVL fatty acid elongase 6 (ELOVL6) and CREB-regulated transcription coactivator 2 (CRTC2) across multiple tissues, and further examined their genetic variations and associations with growth and carcass traits in 200 Kalmyk cattle. Expression analysis showed that CRTC2 was most highly expressed in the heart and liver, whereas ELOVL6 was predominantly expressed in the spleen and large intestine, highlighting their tissue-specific expression patterns. In addition, we identified a polymorphic SNP (g.16511290A > G) in the 3'UTR of ELOVL6, with three genotypes (AA, AG, GG) and the G allele being dominant (0.520). Polymorphism information content (PIC) analysis indicated high genetic diversity at this locus. Importantly, this SNP was significantly associated with live weight and body oblique length (p < 0.05), and individuals carrying heterozygous AG genotype showed higher body weight and length. Collectively, these findings suggest that g.16511290A > G within ELOVL6 may serve as useful molecular markers for body measurements and meat traits, providing valuable resources for marker-assisted selection in beef cattle breeding programs.

This study aimed to explore the diversity and functions of rumen mycobiota in 14‑ (PLf) and 15‑rib (DLf) Jiani yaks using ITS sequencing. A total of 1,079,105 and 1,086,799 filtered sequences were obtained for the PLf and DLf groups, respectively, with 491 ASVs common to both. No significant difference regarding the α‑diversity of mycobiota within the two groups was observed. While β‑diversity analysis indicated that the abundance of fifteen (15) genera in the PLf group and two (2) genera in the DLf group was found to be significantly different (p < 0.05). 16S rRNA sequencing results indicated that at the phylum level, in 14 ribs yaks Ascomycota, Basidiomycota, and Olpidiomycota, while in 15 rib yaks, Neocallimastigomycota, Mortierellomycota, and Rozellomycota were found to be significantly different (p < 0.05). At the genus level, Rhodotorula, Kluyveromyces, Comoclathris, Arthrinium, Cladophialophora, Seimatosporium, Lambertella, and Sphacelotheca in 14 rib yaks, and Orpinomyces, Ustilago, Fusarium, Aspergillus, Caecomyces, Alternaria, Trichoderma and Acremonium in 15 rib yaks were found to be significantly (p < 0.05) different. Predictive functional analysis based on ruminal fungal DNA sequences from 15‑rib yaks (DLf) demonstrated that genes involved in energy metabolism were upregulated. This study sheds novel insights into how genetic variations influence gut mycobiota in Jiani yak.

The study investigates the relationship between biofilm formation and antibiotic resistance in Escherichia coli (E. coli) isolated from calves. Using biochemical and molecular methods, we identified the isolates and assessed their biofilm-forming ability through an improved crystal violet staining method. The minimum inhibitory concentrations (MICs) of 18 antibiotics against the isolates were determined using the broth microdilution method. The impact of cefoxitin on biofilm formation was analyzed using laser scanning confocal microscopy (LSCM). Additionally, qRT-PCR was employed to evaluate the expression levels of biofilm-related genes (luxS, motA, fliA, pfs, and csgD) in response to varying cefoxitin concentrations. Results indicated a significant correlation between antimicrobial resistance (AMR) and biofilm formation ability. Cefoxitin effectively reduced biofilm formation of multidrug-resistant E. coli isolates at 1/2 and 1 MIC, with enhanced inhibition at higher concentrations. The QS-related genes luxS, pfs, motA, and fliA were downregulated, leading to decreased csgD expression. At 1/2 MIC, csgD expression was significantly reduced. In conclusion, cefoxitin inhibits biofilm formation in multidrug-resistant E. coli by down-regulating key genes, offering a potential strategy to mitigate resistance and control infections in calves caused by biofilm-positive E. coli isolates.

This study investigates the role of Perilipin1 (PLIN1) in milk fat synthesis in bovine mammary epithelial cells (BMECs) and its regulatory mechanisms, aiming to provide a foundation for improving milk fat content through molecular breeding. BMECs were used as a model to analyze the effects of PLIN1 overexpression (OE-PLIN1) and interference (si-PLIN1) on milk fat synthesis and lipid-related gene expression using RT-qPCR, Western blot, and Oil Red O staining. Results show that OE-PLIN1 significantly enhances triglyceride (TAG) accumulation in BMECs (P < 0.01), upregulates lipid synthesis-related genes (such as PPARγ, C/EBPα, C/EBPβ, FABP4, FASN) (P < 0.05), and downregulates the mRNA expression of lipid breakdown-related genes (HSL, ATGL) (P < 0.05). Conversely, si-PLIN1 significantly reduces TAG accumulation (P < 0.05) and lowers the expression of lipid synthesis and breakdown genes (P < 0.05). Additionally, OE-PLIN1 combined with SREBP1 siRNA interference (si-SREBP1) did not have a significant impact on the mRNA and protein levels of SREBP1, but it significantly altered SREBP1's phosphorylation, indicating that SREBP1 interference inhibits PLIN1's effect on milk fat synthesis. This study suggests that PLIN1 promotes milk fat synthesis in BMECs via regulating SREBP1 activity, offering a new strategy for enhancing milk fat content in dairy cattle.

Genomics offers a promising solution by enabling precise cattle selection and breeding to boost productivity and sustainability. In Peru, livestock plays a crucial role in the economy and food security. Despite its importance, the sector faces significant challenges, including poor pasture quality, limited conservation practices, a shortage of trained professionals, minimal use of genomic tools, and an incomplete understanding of the genetic potential of both native and introduced breeds. Since the 1940s, Peru has advanced in genetic improvement through artificial insemination, improved semen preservation, the establishment of a National Semen Bank, and the introduction of new breeds. Key developments have included embryo transfer, in vitro fertilization, and pioneering cloning efforts. Future perspectives for livestock genomics in Peru involve expanding bioinformatics capacity, improving genomic infrastructure, and integrating genomic selection into national breeding strategies. This review discusses the history, current status, challenges, and future perspectives of livestock genomics in Peru.

In this study, we evaluated the copy number variation in the genomes of two groups of Beichuan-white goat populations with large differences in litter size by F_ST method, and identified 1739 genes and 485 missense mutations in the genes subject to positive selection. Through functional enrichment, ITGAV, LRP4, CDH23, TPRN, RYR2 and CELSR1 genes, involved in embryonic morphogenesis, were essential for litter size trait, which received intensive attention. In addition, some mutation sites of these genes have been proposed (ITGAV: c.38C > T; TPRN: c.133A > T, c.1192A > G, c.1250A > C; CELSR1: c.7640T > C), whose allele frequencies were significantly changed in the high fecundity goat group. Besides, we found that new mutations at these sites altered the hydrophilicity and 3D structure of the protein. Candidate genes related to litter size in this study and their missense mutation sites were identified. These candidate genes are helpful to understand the genetic mechanism of fecundity in Beichuan white goat, and have important significance for future goat breeding.

Bodyweight loss and rumen microbial dysfunction of grazing sheep was a challenge for the sheep production industry during cold season, which were considered to correlated with under-roughage-feeding. Alfalfa is a good roughage supplementary for ruminants, which can improve grazing sheep bodyweight-loss and rumen microbial dysfunction during grass-withering period. This study evaluated the effects of alfalfa hay supplementary change dietary non-fibrous carbohydrate/neutral detergent fiber (NFC/NDF) ratios on rumen fermentation and microbial function of Gansu alpine fine wool sheep during extreme cold season. 120 ewes (3-4 yrs) with an average body weight of 28.71 ± 1.22 kg were allocated randomly into three treatments, and fed NFC/NDF of 1.92 (H group), 1.11 (M group), and 0.68 (L group), respectively. This study was conducted for 107 d, including 7 d of adaption to the diets. The rumen fermentation parameters and microbial characteristics were measured after the end of feeding trials. The results showed that the concentrations of sheep body weight, nitrogen components (Total-N, Soluble protein-N and Ammonia-N), blood biochemical indices (LDH, BUN and CHO) and ruminal volatile fatty acids (TVFA and propionate) significantly increased with an increase in the proportion of NFC/NDF ratios (p < .05), and the acetate and acetate/propionat ratio presented a contrary decreasing trend (p < .05). A total of 1018 OTUs were obtained with 97% consistency. Ruminococcus, Ruminococcaceae and Prevotella were observed as the predominant phyla in ruminal fluid microbiota. Higher NFC/NDF ratios with Alfalfa supplementary increased the richness and diversity of ruminal fluid microbiota, and decreased ruminal fluid microbiota beta-diversity. Using clusters of orthologous groups (COG), the ruminal fluid microbiota of alfalfa supplementary feeding showed low immune pathway and high carbohydrate metabolism pathway. In summary, the study suggested that there was an increasing tendency in dietary NFC/NDF ratio of 1.92 in body weight, ruminal fermentation, microbial community composition and fermentation characteristics through developing alfalfa supplementary system.