Effect of different levels of Lactobacillus added to diets on fat deposition and meat quality of Sunit lambs.

In this study, we examined the impact of adding Lactobacillus to the diet on fat distribution and meat quality of Sunit lambs. For 90 days, twenty-four lambs (19.31 ± 0.47 kg) were fed diets that contained 0 (NP), 6 (P1), 12 (P2), or 24 (P3) g of Lactobacillus casei/d. The results suggested that dietary supplementation with Lactobacillus decreased serum triglyceride in Sunit lambs (P < 0.001). The loin muscle area displayed notable increases in the P1 group (P < 0.05). Meanwhile, tail and visceral fat deposition of lambs were reduced when Lactobacillus was added to the diet (P < 0.05). Compared with the NP group, the values of shear force and cooking loss of in the P1 group exhibited a significant reduction, and intramuscular fat content increased significantly (P < 0.05). Additionally, the P1 group showed an increase in polyunsaturated fatty acids and a decrease in saturated fatty acids in the longissimus thoracis and biceps femoris muscles (P < 0.05). The P1 group showed downregulation of protein kinase AMP-activated catalytic subunit alpha 2 (AMPKα2) and carnitine palmitoyltransferase 1B expression in the longissimus thoracis muscle (P < 0.05). However, there was an upregulation of acetyl-CoA carboxylase (ACC), sterol regulatory element binding transcription factor 1 (SREBF1), and fatty acid synthase (FASN) expression (P < 0.05). In conclusion, feeding Sunit lambs 6 g/d of Lactobacillus as a dietary supplement may be a valuable way to improve fat distribution and meat quality. The AMPK/ACC and AMPK/SREBF1/FASN signaling pathways may be involved in this outcome.

Lipid transformation during postmortem chilled aging in Mongolian sheep using lipidomics.

This present study aimed to investigate the effects of postmortem chilled aging on lipid and molecular transformation mechanisms in Mongolian sheep. UPLC-ESI-MS/MS was used to identify 812 lipids in Mongolian sheep within four days of chilled aging. Using multivariate analysis, 95 significant differential lipids were identified. The levels of phosphatidylcholine, phosphatidylinositol, and certain free fatty acids were observed to rise significantly, while other phospholipids and acylcarnitines showed a downward trend. In addition, levels of most of the lysophospholipids increased significantly in the early postmortem period; however, their levels did not alter significantly after 48 h. The Kyoto encyclopedia of genes and genomes pathway analysis revealed that these differential lipids are primarily involved in glycerophospholipid metabolism, linoleic acid metabolism, arachidonic acid metabolism, and thermogenesis. Our results have important implications in terms of understanding lipid transformation and changes in meat quality during postmortem chilled aging in Mongolian sheep.

Probiotics Increase Intramuscular Fat and Improve the Composition of Fatty Acids in Sunit Sheep through the Adenosine 5'-Monophosphate-Activated Protein Kinase (AMPK) Signaling Pathway.

This experiment aims to investigate the impact of probiotic feed on growth performance, carcass traits, plasma lipid biochemical parameters, intramuscular fat and triglyceride content, fatty acid composition, mRNA expression levels of genes related to lipid metabolism, and the activity of the enzyme in Sunit sheep. In this experiment, 12 of 96 randomly selected Sunit sheep were assigned to receive the basic diet or the basic diet supplemented with probiotics. The results showed that supplementation with probiotics significantly increased the loin eye area, and decreased plasma triglycerides and free fatty acids, increasing the content of intramuscular fat and triglycerides in the muscle and improving the composition of the fatty acids. The inclusion of probiotics in the diet reduced the expression of adenosine 5'-monophosphate-activated protein kinase alpha 2 (AMPKα2) mRNA and carnitine palmitoyltransferase 1B (CPT1B) mRNA, while increasing the expression of acetyl-CoA carboxylase alpha (ACCα) mRNA, sterol regulatory element-binding protein-1c (SREBP-1c) mRNA, fatty acid synthase mRNA, and stearoyl-CoA desaturase 1 mRNA. The results of this study indicate that supplementation with probiotics can regulate fat deposition and improves the composition of fatty acids in Sunit sheep through the signaling pathways AMPK-ACC-CPT1B and AMPK-SREBP-1c. This regulatory mechanism leads to an increase in intramuscular fat content, a restructuring of muscle composition of the fatty acids, and an enhancement of the nutritional value of meat. These findings contribute to a better understanding of the food science of animal resources and provide valuable references for the production of meat of higher nutritional value.

Impact of dietary Lactobacillus supplementation on intramuscular fat deposition and meat quality of Sunit sheep.

To investigate the impacts of dietary Lactobacillus supplementation on meat quality such as edible quality and nutritional value of Sunit sheep, a 90-day feeding experiment (Lactobacillus dietary group, R group; non-Lactobacillus dietary group, C group) using twelve 3-month-old Sunit sheep was conducted. The deposition of intramuscular fat (IMF) was increased (p < .05) while the share force and cooking loss were decreased (p < .05) in the R group compared with the C group. The proportions of seven kinds of fatty acids (FAs) have changed significantly (p < .05), especially with higher functional FAs and lower trans-FA in the R group. Metabonomics analysis showed that the metabolites and pathway-related lipid syntheses, such as carnitine cycle, tricarboxylic acid cycle, and glycerophosphocholine metabolic pathway, have significantly changed in the R group. The Lactobacillus dietary supplements impacted the variation of IMF deposition and FAs composition by altering the lipid metabolism pathways of Sunit sheep and then changed the edible quality and nutritional value. PRACTICAL APPLICATIONS: It is well known that the intramuscular fat (IMF) and fatty acids composition in livestock is positively correlated with various aspects of meat quality such as edible quality and nutritional value, which are related to consumer preference. The present study analyzed the effects of Lactobacillus supplement on the intramuscular fat deposition and meat quality of Sunit sheep, which resulted in the increase of IMF, and the differences of fatty acids composition, especially the functional fatty acids. It was explored the mechanism of Lactobacillus affect the variation of lipid metabolism pathways and key metabolites in sheep, which suggested that altering the feeding regimen could improve the meat quality of agri-animals.

Transcriptome analysis reveals the molecular regulatory network of muscle development and meat quality in Sunit lamb supplemented with dietary probiotic.

Supplementing animal feed with probiotic additives can promote muscle production and improve meat quality. The study aimed to explore the effects of dietary probiotics supplementation on the performance, meat quality and muscle transcriptome profile in Sunit lamb. Overall, feeding probiotics significantly increased the body length, LT area, pH24h and intramuscular fat (IMF) content, but decreased cooking loss and meat shear force compared to the control group (P < .05). A total of 651 differentially expressed genes (DEGs) were found in probiotic supplemented lambs. Pathway analysis revealed that DEGs were involved in multiple pathways related to muscle development and fat deposition, such as the ECM-receptor interactions, the MAPK signaling pathway and the FoxO signaling pathway. Therefore, dietary probiotic supplementation can improve muscle development and final meat quality in Sunit lambs by altering gene expression profiles associated with key pathways, providing unique insights into the molecular mechanisms by which dietary probiotics regulate muscle development in the lamb industry.

Effects of physical exercise on muscle metabolism and meat quality characteristics of Mongolian sheep.

The objective of this study was to investigate the effects of exercise training on muscle metabolism, fatty acid composition, carcass traits, and meat quality characteristics of Mongolian sheep. Fourteen Mongolian sheep were randomly divided into two groups (7 sheep in each) and placed in two adjacent livestock pens. One group of sheep was kept in the pen (Control [C] group) and the other group of sheep (Training [T] group) were driven away in a field to walk twice a day. The results showed a reduction in pH measured 45 min post mortem, L*, a*, and b* value, intramuscular fat, and carcass length, and an increase in the ultimate pH value and shear force in the meat of T group in comparison with that of C group (p < .050). Also, exercise training moderately affected the fatty acid composition of LT muscle. Compared with C group, the concentrations of myristoleic acid (C14:1) and stearic acid (C18:0) were increased (p < .050), while the concentrations of C20:3 n-6, neurolic acid (C24:1), and n-3 polyunsaturated fatty acid (PUFA) were decreased in T group (p < .050). Transcriptome analysis highlighted 621 genes differentially expressed in two groups, including 385 were up-regulated (e.g., GLUT4 and PGC-1α) and 236 were down-regulated (e.g., PLIN1 and ACSL3) in T with respect to C group. Besides, considering these genes, a number of enrichment pathways related to muscle metabolic processes, involving carbohydrate metabolism, lipid metabolism, oxidation reduction process, and muscle tissue development, were highlighted. In conclusion, these results contributed to a better understanding of the possible biological and molecular processes underlying the effects of exercise training on muscle metabolism and meat quality in Mongolian sheep, and provide useful information for contributing to understand the phenotypic and functional differences in meat quality of sheep.

Enhancement of thermal and mechanical properties of silicone rubber with γ-ray irradiation-induced polysilane-modified graphene oxide/carbon nanotube hybrid fillers.

In this study, a polysilane-modified graphene oxide (GO) and carbon nanotube (CNT) nanocomposite (GO/CNTs-Si) was prepared as a thermal conductive nanofiller to enhance the thermal and mechanical properties of silicone rubber composites. By γ-ray-radiation 3-methacryloxypropyltrimethoxy silane (MPTMS) was polymerized on the surface of GO and CNTs to improve the interfacial interaction between the GO/CNTs-Si and SR matrix. FTIR characterization results demonstrated that polysilane modified the GO/CNTs successfully. The pristine GO/CNTs and resultant GO/CNTs-Si were individually incorporated into α,ω-dihydroxypolydimethylsiloxane to vulcanize SR composites. Compared with SR-GO/CNTs, SR-GO/CNT-Si exhibited better mechanical and thermal performance. Moreover, the time-dependent complex modulus of SR-GO/CNTs-Si was much higher than that of SR-GO/CNTs, which indicates longer service time and more stable performance. In terms of electronic packaging, SR-GO/CNTs exhibited better performance than the 1180B counterpart. The low value of warpage of chip packaged by SR-GO/CNTs implied that SR-GO/CNTs-Si could have potential application as the thermal interface electronic packaging material.

Anti-nociceptive effect of patchouli alcohol: Involving attenuation of cyclooxygenase 2 and modulation of mu-opioid receptor.

OBJECTIVE: To explore the anti-nociceptive effect of patchouli alcohol (PA), the essential oil isolated from Pogostemon cablin (Blanco) Bent, and determine the mechanism in molecular levels. METHODS: The acetic acid-induced writhing test and formalin-induced plantar injection test in mice were employed to confirm the effect in vivo. Intracellular calcium ion was imaged to verify PA on mu-opioid receptor (MOR). Cyclooxygenase 2 (COX2) and MOR of mouse brain were expressed for determination of PA's target. Cellular experiments were carried out to find out COX2 and MOR expression induced by PA. RESULTS: PA significantly reduced latency period of visceral pain and writhing induced by acetic acid saline solution (P<0.01) and allodynia after intra-plantar formalin (P<0.01) in mice. PA also up-regulated COX2 mRNA and protein (P<0.05) with a down-regulation of MOR (P<0.05) both in in vivo and in vitro experiments, which devote to the analgesic effect of PA. A decrease in the intracellular calcium level (P<0.05) induced by PA may play an important role in its anti-nociceptive effect. PA showed the characters of enhancing the MOR expression and reducing the intracellular calcium ion similar to opioid effect. CONCLUSIONS: Both COX2 and MOR are involved in the mechanism of PA's anti-nociceptive effect, and the up-regulation of the receptor expression and the inhibition of intracellular calcium are a new perspective to PA's effect on MOR.