Effects of Dietary Oregano Essential Oil on Cecal Microorganisms and Muscle Fatty Acids of Luhua Chickens

Effects of yeast cultures on meat quality, flavor composition and rumen microbiota in lambs

Since the banning of antibiotics, the use of feed additives to improve meat quality to satisfy people's pursuit of high quality has become a research hotspot. Yeast culture (YC) is rich in proteins, mannan oligosaccharides, peptides, and yeast cell metabolites, etc., and its use as a feed additive has a positive impact on improving meat quality. So the study aimed to provide a theoretical basis for YC improving mutton flavor and quality by detecting and analyzing the effects of YC on muscle physicochemical properties, amino acids, fatty acids, flavor composition, expression of related genes, and rumen microbiota of lambs. A total of 20 crossbred F1 weaned lambs (Australian white sheep♂ × Hu sheep♀; average 23.38 ± 1.17 kg) were randomly assigned to 2 groups, the control group (CON) and the 1.0% YC supplemented group (YC) (n = 10), and were reared in separate pens. The experiment had a pre-feeding period of 10 d and a treatment period of 60 d. After the experiment, 6 lambs in each group were randomly selected for slaughtering. The results showed that dietary YC supplementation increased rumen total VFA and acetate concentrations (p < 0.05), and muscle carcass fat (GR), a∗ value, intramuscular fat (IMF), lysine (Lys), arginine (Arg), nonessential amino acid (NEAA), oleic acid (C18:1n9c), and eicosanoic acid (C20:1) contents were significantly increased (p < 0.05), while cooking loss and γ-linolenic acid (C18: 3n6) were decreased (p < 0.05). Furthermore, we found that dietary YC improved the types of flavor compounds, and the key flavor substances such as hexanal, nonanal, styrene, benzaldehyde, p-xylene, and 1-octen-3-ol contents were changed (p < 0.05). Additionally, the expression of fat metabolism related genes PPARγ, FASN, and FABP4 were increased. Adding 1% YC to lamb diets increased profits by 47.70 CNY per sheep after 60 d of fattening. All of which indicated that YC could improve meat quality, especially flavor, which may be related to the regulation of the relative abundance of rumen microorganisms Bacteroidota, Prevotella_7, Succiniclasticum and Lachnospiraceae_NK3A20_group.

Study of the Interactions between Muscle Fatty Acid Composition, Meat Quality-Related Genes and the Ileum Microbiota in Tibetan Sheep at Different Ages

The intestinal microbiota of ruminants is an important factor affecting animal production and health. Research on the association mechanism between the intestinal microbiota and meat quality of ruminants will play a positive role in understanding the formation mechanism of meat quality in ruminants and improving production efficiency. In this study, the fatty acid composition and content, expression of related genes, and structural characteristics of the ileum microbiota of ewes of Tibetan sheep at different ages (4 months, 1.5 years, 3.5 years, and 6 years) were detected and analyzed. The results revealed significant differences in fatty acid composition and content in the muscle of Tibetan sheep at different ages (p < 0.05); in addition, the content of MUFAs in the longissimus dorsi muscle and leg muscle was higher. Similarly, the expressions of muscle-related genes differed among the different age groups, and the expression of the LPL, SCD, and FABP4 genes was higher in the 1.5-year-old group. The ileum microbiota diversity was higher in the 1.5-year-old group, the Romboutsia abundance ratio was significantly higher in the 1.5-year-old group (p < 0.05), and there was a significant positive correlation with oleic acid (C18:1n9c) (p < 0.05). In conclusion, the content of beneficial fatty acids in the longissimus dorsi muscle and leg muscle of Tibetan sheep was higher at 1.5 years of age, and the best slaughter age was 1.5 years. This study provides a reference for in-depth research on the mechanism of the influence of the gut microbiota on meat quality and related regulation.

Multi-omics analysis reveals the molecular regulatory network underlying the prevention of Lactiplantibacillus plantarum against LPS-induced salpingitis in laying hens

BACKGROUND

Salpingitis is one of the common diseases in laying hen production, which greatly decreases the economic outcome of laying hen farming. Lactiplantibacillus plantarum was effective in preventing local or systemic inflammation, however rare studies were reported on its prevention against salpingitis. This study aimed to investigate the preventive molecular regulatory network of microencapsulated Lactiplantibacillus plantarum (MLP) against salpingitis through multi-omics analysis, including microbiome, transcriptome and metabolome analyses.

RESULTS

The results revealed that supplementation of MLP in diet significantly alleviated the inflammation and atrophy of uterus caused by lipopolysaccharide (LPS) in hens (P < 0.05). The concentrations of plasma IL-2 and IL-10 in hens of MLP-LPS group were higher than those in hens of LPS-stimulation group (CN-LPS group) (P < 0.05). The expression levels of TLR2, MYD88, NF-κB, COX2, and TNF-α were significantly decreased in the hens fed diet supplemented with MLP and suffered with LPS stimulation (MLP-LPS group) compared with those in the hens of CN-LPS group (P < 0.05). Differentially expressed genes (DEGs) induced by  MLP were involved in inflammation, reproduction, and calcium ion transport. At the genus level, the MLP supplementation significantly increased  the abundance of Phascolarctobacterium, whereas decreased the abundance of Candidatus_Saccharimonas in LPS challenged hens (P < 0.05). The metabolites altered by dietary supplementation with MLP were mainly involved in galactose, uronic acid, histidine, pyruvate and primary bile acid metabolism. Dietary supplementation with MLP inversely regulates LPS-induced differential metabolites such as LysoPA (24:0/0:0) (P < 0.05).

CONCLUSIONS

In summary, dietary supplementation with microencapsulated Lactiplantibacillus plantarum prevented salpingitis by modulating the abundances of Candidatus_Saccharimonas, Phascolarctobacterium, Ruminococcus_torques_group and Eubacterium_hallii_group while downregulating the levels of plasma metabolites, p-tolyl sulfate, o-cresol and N-acetylhistamine and upregulating S-lactoylglutathione, simultaneously increasing the expressions of CPNE4, CNTN3 and ACAN genes in the uterus, and ultimately inhibiting oviducal inflammation.

Interactions of rumen microbiota and metabolites with meat quality-related genes to regulate meat quality and flavor of Tibetan sheep under nutrient stress in the cold season

AIM

The meat of Tibetan sheep has a unique flavor, delicious taste, and superior nutritional value. However, the change of grass will lead to a change in meat quality. This study aimed to explore the potential regulatory mechanisms of microbial metabolites with respect to meat quality traits of Tibetan sheep under nutrient stress in the cold season.

METHODS AND RESULTS

We determined and analyzed the longissimus dorsi quality, fatty acid composition, expression of genes, and rumen microbial metabolites of Tibetan sheep in cold and warm seasons. The shear force was decreased (P < .05), the meat color a*24 h value was increased (P < .05), and the contents of crude fat (EE) and protein (CP) were decreased in the cold season. Polyunsaturated fatty acids (PUFAs)-linoleic acid and docosahexaenoic acid increased significantly in the cold season (P < .05). The expressions of meat quality genes MC4R, CAPN1, H-FABP, and LPL were significantly higher in the warm season (P < .05), and the CAST gene was significantly expressed in the cold season (P < .01). The different microbial metabolites of Tibetan sheep in the cold and warm seasons were mainly involved in amino acid metabolism, lipid metabolism, and digestive system pathway, and there was some correlation between microbiota and meat quality traits. There are similarities between microbial metabolites enriched in the lipid metabolism pathway and muscle metabolites.

CONCLUSION

Under nutritional stress in the cold season, the muscle tenderness of Tibetan sheep was improved, and the fat deposition capacity was weakened, but the levels of beneficial fatty acids were higher than those in the warm season, which was more conducive to healthy eating.