Ting Liu

Objective: Sodium butyrate (SB) is a potentially useful feed additive; however, its effects on lipid metabolism in adipose and liver tissues of lambs are still not fully explored. This study systematically examined the effects and underlying mechanisms of dietary SB supplementation on lipid metabolism in lamb adipose and liver tissues from an adipose-blood-liver perspective.Methods: Twelve 3-month-old male lambs (22.37±2.05 kg) were randomly divided into a control group and an SB group. We measured the adipose tissue cellular morphology and lipid metabolism-related indices in both adipose and liver tissues.Results: The results indicated that SB significantly reduces abdominal and perirenal adipose tissue mass, as well as the average area and diameter of adipocytes (p<0.05). Dietary supplementation with SB activated adenosine 5’-monophosphate-activated protein kinase α1 (AMPKα1) in lamb adipose tissue, resulting in upregulated mRNA expression of hormone-sensitive triglyceride lipase (HSL) and downregulated mRNA expression of sterol regulatory element-binding protein 1 and fatty acid synthase (p<0.05). Simultaneously, adiponectin secretion and receptor expression in adipose tissue, as well as serum adiponectin levels, were significantly elevated (p<0.05). Moreover, dietary supplementation with SB increased the levels of tricarboxylic acid cycle metabolites in lamb liver, including oxaloacetate, citrate, cis-aconitate, and succinate (p<0.05), while simultaneously activating the liver AMPKα1 signaling pathway. These changes led to upregulated HSL, platelet glycoprotein 4, and long-chain acyl-CoA synthetase mRNA expression (p<0.05), thereby enhancing liver fatty acid metabolism.Conclusion: In summary, dietary supplementation with SB alters adiponectin levels in lambs, activates the AMPK signaling pathway, promotes adipose tissue lipolysis, and regulates liver lipid metabolism. The findings provide valuable insights into the use of SB for managing lamb body fat reserves and offer a robust basis for further research in animal bioscience.

In this study, the safety of fermented lamb sausage was examined. The aim was to investigate the effect of Lactiplantibacillus plantarum X22-2 (LP X22-2) on the quality of, and biogenic amine (BA) formation in, fermented lamb sausages during fermentation, maturation, and storage. The results showed that LP X-22 was effective in increasing the number of lactic acid bacteria (LAB) and in significantly inhibiting the formation of putrescine, histamine, cadaverine, and tyramine in fermented lamb sausage (p < 0.05). The total volatile basic nitrogen (TVB-N) content, peroxide value (POV) of fat, pH, water activity (AW), and viscosity were lower in the LF group compared to other groups (commercial starter group—CF, and natural fermentation group—NF) (p < 0.05). Furthermore, sensory evaluation and texture profile analysis (TPA) indicated that LP X-22 significantly increased the a* value, chewiness, and hardness of the sausages (p < 0.05). Therefore, LP X-22 is recommended as a natural and safe protective culture for preserving fermented lamb sausage and maintaining the color of the sausages while improving their sensory quality and inhibiting the accumulation of BAs.

Sheep bones are a rich resource in China, but their deep processing is limited by outdated technology. Sausages are popular among various consumer groups due to their unique flavor. The purpose of this study was to optimize the preparation process of fermented-enzymatic sheep bone powder and develop calcium-fortified functional sausages with an excellent flavor, aroma, and taste. In this experiment, the fermented-enzymatic sheep bone powder was prepared by optimizing the two-bacterial fermentation process of Lactobacillus Plantarum BNCC336421 and Pediococcus Pentosaceus BNCC193259. The nutritional indexes and micro-structure were analyzed. Additionally, different ratios of fermented sheep bone powder were added into the sausages to investigate their effects on the nutritional indexes, physicochemical properties, and organoleptic quality of the sausages. The results showed that the optimal process conditions for the fermented sheep bone sludge were as follows: a strain inoculation of 3%; a compounding ratio of 1:1; a bone sludge concentration of 1:20; and fermentation time of 24 h. Under these conditions, the Ca²⁺ content and protein hydrolysis degree of the sheep bone were 2441.31 mg/100 mL and 23.78%, respectively. The fermented sheep bone powder analyzed using SEM, and the particle size analysis showed it was loose and porous with a small particle size. The addition of fermented sheep bone powder to the sausage increased its amino acid and calcium ion contents, improved the texture indexes such as cohesion, and enhanced both the L* value and sensory scores. The best result was observed in the 1% group (p < 0.05). It serves as a data source for developing fermented sheep bone powder and its application in sausage, offering a fresh idea and approach to achieving the high-value utilization of sheep bone.

The development of animal husbandry is closely related to the meat quality of small ruminants. Intestinal metabolites and the muscle fiber types of lambs are important factors that affect their meat quality, but few studies have examined the regulation of the "intestinal muscle axis" by probiotics. In this study, 12 Sunit lambs were divided into a control group (C) and a probiotics group (P). The gene expressions of the myosin heavy chain, metabolic enzyme activity, and short-chain fatty acids in the intestines were analyzed using gas chromatography-mass spectrometry (GC-MS) and quantitative real-time PCR. The results showed that levels of propionic acid and butyric acid in the intestines of group P were significantly higher than in group C (p < 0.05). In addition, probiotics increased the number and area ratio of type I muscle fibers. They also increased the mRNA expression of MyHC IIA and the activity of malate dehydrogenase (MDH) and succinate dehydrogenase (SDH). Propionic acid was negatively correlated with the number ratio of type IIB muscle fibers. Butyric acid was found to be significantly positively correlated with the number ratio of type IIA muscle fibers. Cooking loss, pH_24h, and shear force decreased significantly in group P. In conclusion, intestinal metabolites (SCFAs) altered the activity of oxidative-myofibril-metabolizing enzymes and the expression of myosin heavy-chain type IIA, reduced the meat shear values, and improved meat tenderness. This study provides a new basis for improving the production and meat quality of small ruminants.

To improve the meat quality of Nei Mongol mutton and the benefits for farmers, we selected Australian salmon hybrid lambs as experimental subjects to investigate the effects of Allium mongolicum Regel powder (AMR) and yeast-fermented distiller’s grains (DGS) on their production performance and economic efficiency. The results showed that the DGS group had higher kidney index, the AMR group had better meat quality, and the economic efficiency ratio of DGS and AMR was 2.08. In conclusion, both feeds had no adverse effects on the production performance of lambs, and the DGS group had greater potential for promotion.

The probiotic fermentation of lamb liver paste is a new method with which to utilize sheep by-products and address the issue of waste. In this study, a pH meter, chromaticity meter, texture analyzer, and gas chromatograph–mass spectrometer (GC–MS) were used to determine various indicators. The objective was to investigate the effect of fermentation on the physical properties and aroma of lamb liver paste. The results showed that the L* (brightness), a* (redness), and b* (yellowness) of the samples were significantly higher in the starter fermentation group than in the other two groups after storage for 0, 1, 7, 14, 21, and 28 days (p < 0.05). In addition, cohesiveness, adhesion, and chewiness were lower in the starter fermentation group after 7 days (p < 0.05). TVB-N and fat were lower in the starter fermentation group compared to the sterilization group at 28 days. pH was significantly lower in the starter fermentation group at the beginning of storage, and lactic acid bacteria numbers were significantly higher than in the sterilization groups (p < 0.05). Important aroma compounds, such as 2-undecenal, 1-octen-3-ol, and anethole, were significantly higher in the starter fermentation group than in the sterilization group (p < 0.05). Fermented lamb liver paste is a new by-product that exhibits a high degree of freshness and a low degree of fat oxidation during storage. This study provides a theoretical basis for future industrial production.

Sheep crude tail fat has unique nutritional values and is used as a raw material for high-quality natural oil. The purpose of this study was to investigate the effects of probiotics on the metabolites and flavor of sheep crude tail fat. In this study, 12 Sunit sheep were randomly divided into an experimental group (LTF, basal feed + Lactiplantibacillusplantarum powder) and a control group (CTF, basal feed). The results of sheep crude tail fat analysis showed that blood lipid parameters were significantly lower and the expression of fatty acid synthase and stearoyl-CoA desaturase genes higher in the LTF group than in the CTF group (p < 0.05). Metabolomic analysis via liquid chromatography–mass spectrometry showed that the contents of metabolites such as eicosapentaenoic acid, 16-hydroxypalmitic acid, and L-citrulline were higher in the LTF group (p < 0.01). Gas chromatography–mass spectrometry detection of volatile flavor compounds in the tail fat showed that nonanal, decanal, and 1-hexanol were more abundant in the LTF group (p < 0.05). Therefore, Lactiplantibacillus plantarum feeding affected blood lipid parameters, expression of lipid metabolism-related genes, tail fat metabolites, and volatile flavor compounds in Sunit sheep. In this study, probiotics feeding was demonstrated to support high-value sheep crude tail fat production.