Effects Of Feeding Regimens On Lipids Metabolism And Meat Quality Of Sunit Sheep

In order to explore the effects of different feeding methods on the lipid metabolism and meat quality of Sunit sheep,this study took Sunit sheep as the research object,using gas chromatography-mass spectrometry(GC-MS)combined technology,real-time fluorescence quantitative polymerase chain reaction,enzyme-linked immunosorbent assay and other technologies to the differences in lipid metabolism-related gene expression and enzyme content of Sunit sheep under two different feeding methods,and establish the connection of fat metabolism and meat quality.the sheep fed in the shed were used to as a control group.By artificial driving,the amount of exercise of the sheep fed in the shed was increased.The study explored the mechanism of the influence of exercise on fat metabolism and meat quality to provide a theoretical basis for improving the growth performance and quality of the sheep by increasing the amount of exercise of the sheep in the shed in the future.After studying the effects of different feeding methods on Sunit's growth performance,slaughter performance,meat quality and lipid metabolism,it was found that the live length of grazing sheep was significantly higher than that of control sheep(P<0.05),and the carcass weight,carcass height,bone-to-body ratio and the slaughter rate was significantly lower than that of the control group(P<0.05).From the perspective of meat quality indicators,the p H₀and p H₂₄values of the longissimus dorsi of Sunit sheep in the control group were significantly lower than those in the pasture group(P<0.05).The redness value(a*)of the biceps femoris of the control group was significantly higher than that of the grazing group(P<0.05),and the shear force was significantly lower than that of the grazing group(P<0.05).Compared with the control group,the grazing group cooking loss rate of special sheep was significantly reduced(P<0.05),and the content of saturated fatty acids in the longissimus dorsi muscle was significantly reduced(P<0.05),and the content of?-linolenic acid and?-linolenic acid was significantly increased(P<0.05).The contents of TC and TG in the plasma of sheep in the grazing group were significantly lower than those in the control group(P<0.05).After measuring the fat metabolism-related enzyme content and gene expression,it was found that the FASN content in the longissimus dorsi muscle of the control group was significantly lower than that of the grazing group(P<0.05).The expression of FASN,HSL,PGC-1?,PRDM16 and UCP-1 genes in the longissimus dorsi muscle of the grazing group significantly increased(P<0.05).The above results indicate that the color and tenderness of lamb in the control group are better,and the nutritional quality of sunit lamb in the grazing group is higher,and its fat metabolism level is higher.The study of the quality changes and fat metabolism mechanism of sunit sheep by increasing the amount of exercise in the shed found that the exercise group has a higher live body,slaughter rate and meat-to-bone ratio significantly higher than that of the control group(P<0.05),and the backfat thickness is significantly lower than that Group(P<0.05).The shear force,brightness value(L*),redness value(a*)and yellowness value(b*)of the longissimus dorsi of sunit sheep in the control group were significantly higher than those in the exercise group(P<0.05).By exercising the deposition of saturated fatty acids in the longissimus dorsi muscle was increased,and significantly reduced the deposition of n-3series of polyunsaturated fatty acids was significantly reduced(P<0.05).The content of TC and TG in the blood of the exercise group decreased significantly(P<0.05),and the content of lipometabolizing enzymes(ATGL,HSL and FASN)in intramuscular fat and extramuscular fat increased significantly(P<0.05).The expression of PPAR?in the muscles of sunit sheep in the exercise group was significantly reduced(P<0.05),and the expression of FASN and HSL genes in the longissimus dorsi muscle was significantly increased(P<0.05),which indicated that exercise promotes body fat metabolism Level.The expression of PRDM16,UCP-1 and PGC-1?genes in the muscle and fat parts of sunit sheep in the exercise group were significantly increased(P<0.05),which indicating that exercise can promote the"browning"of some white fat and increased the body's overall energy metabolism.Therefore,exercise can affect fat deposition and fatty acid composition by increasing the level of fat metabolism.The possible reason is that it increases the body fat metabolism regulating gene and enzyme content,while promoting the"browning"of some white fat,increasing the level of mitochondrial biogenesis and body energy metabolism,resulting in extramuscular fat.The deposition is reduced,the content of unsaturated fatty acids is reduced,and the quality of mutton is degraded to a certain extent.