Effects of feeding patterns on production performance, lipo-nutritional quality and gut microbiota of Sunit sheep.

This study aimed to investigate the impact of feeding patterns on the production performance, lipo-nutritional quality, and gut microbiota of Sunit sheep. A total of 24 sheep were assigned to two groups: confinement feeding (CF) and pasture feeding (PF) groups. After 90 days, the CF group exhibited significantly increased average daily gain, carcass weight, backfat thickness, and intramuscular fat content of the sheep, whereas the PF group showed significantly increased pH24h and decreased L∗ value and cooking loss of the longissimus lumborum (LL) muscle (P < 0.05). In the PF group, the contents of linoleic, α-linolenic, and docosahexaenoic acids were considerably higher and the n-6/n-3 polyunsaturated fatty acid ratio was significantly lower (P < 0.05). Furthermore, the triglyceride, cholesterol, and nonesterified fatty acid levels in the serum of the CF group significantly increased, whereas the enzyme contents of fatty acid synthase (FASN) and hormone-sensitive lipase (HSL) in the LL muscle of the PF group were markedly elevated (P < 0.05). The PF group also showed altered expression of lipid metabolism-related genes, including upregulated FASN, HSL, fatty acid binding protein 4 (FABP4), and peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) (P < 0.05). Meanwhile, differences were observed in the abundance of key bacteria and microbiota functions between the groups. Correlation analysis revealed that production performance and lipid metabolism may be related to the differential effects of bacteria. In conclusion, the transition in the feeding patterns of Sunit sheep caused changes in the gut microbial community and lipid metabolism level in the muscle as well as differences in fat deposition and meat quality.

Effects of Probiotics Supplementation on the Intestinal Metabolites, Muscle Fiber Properties, and Meat Quality of Sunit Lamb.

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, pH24h, 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.

Impact of Feeding Probiotics on Blood Parameters, Tail Fat Metabolites, and Volatile Flavor Components of Sunit Sheep.

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.