Effects Of Different Forms Of Linseed Oil On Growth Performance,Fatty Acid Content And Lipid Metabolism In Muscle Of Sheep

This experiment was to study the different forms of linseed oil?linseed oil,linseed oil microcapsules,flaxseed?have effect on the composition of fatty acid,key regulatory factors of lipid metabolism and gene expression of related enzymes in fattening sheep.From the different forms of linseed oil on sheep growth performance,slaughtering performance,meat quality,rumen fermentation index,blood biochemical parameters,the fatty acid composition and relationship between the expression of related genes were studied.Experimental design was a single-factor design which totally randomized block,twenty-four F2 male lambs of heathy Dorper???×Small-Tailed Han sheep with similar body weights was allocated into four groups with six sheep in each group.The control?CON?group was fed with basal diet,the experimental groups were fed with linseed oil?LO?,linseed oil microcapsule?LOM?,linseed?L?and fat with 4%oil as equivalent added in the diet,according to the determination of oil content,the added amount is 4%,8%and 10%of concentrate feed,respectively.Experiment 1:Effects of supplementation of different forms of linseed oil on growth performance,slaughtering performance,meat quality and rumen fermentation indexs in fattening sheep.At the beginning of the experiment,the weight of each group was close to?P>0.05?,at the end of the experiment,the body weight and ADG of each group were significantly higher than those of LO group?P<0.05?;LOM group significantly improved the back fat thickness of sheep?P<0.05?,but there was no effect on slaughtering and meat production?P>0.05?;In addition to the LOM group,the shear force of the dorsal muscle?P<0.05?was significantly reduced,and the tenderness of the mutton was improved,In general,the different forms of linseed oil had no effect on the meat quality?P>0.05?;The dietary fat did not affect the rumen p H?P>0.05?,but there was significant influence on BCP and NH₃-N?P<0.05?,BCP content in LOM group was significantly higher than other groups?P<0.05?,the effect of NH3-N was significantly higher than CON group and LO group?P<0.05?,and there was no significant difference between group L and CON group?P>0.05?.Experiment 2:Effects of supplementation of different forms of linseed oil on serum lipid metabolism related indicators and back muscle fatty acid composition in fattening sheep.The content of GLU,TG and LEP in sheep serum were not significantly affected by the addition of different forms of linseed oil?P>0.05?,but the content of TC,LDL-C and HDL-C in each test groups were significantly higher than CON group?P<0.05?.The INS content of L and LO group was significantly lower than CON group?P<0.05?;Adding different forms of linseed oil had no significant effect on the total FA content?P>0.05?,but the total FA content in the test group was close to that,and higher than CON group was about 20%;The effect of MUFA on the content of C16:1 in the L group was significantly increased?P<0.05?,but there was no significant effect on the content of C17:1,C18:1,TVA and total MUFA?P>0.05?;In terms of PUFA,the test groups significantly increased the content of CLA,ALA and AA in the dorsal muscle of sheep?P<0.05?,but had no significant effect on LA content?P>0.05?,the n-3 PUFA content in LOM and L groups was significantly increased by 178%and 151%compared with CON group,significantly higher than LO group 54%and 39%?P<0.05?,and the effect on n-6PUFA was not significant?P>0.05?,compared with the CON group,the test groups decreased the S/P value?P<0.05?,and the change trend was similar to the effect of the test on n-6 PUFA/n-3 PUFA,In addition,the n-6/n-3 value of mutton is less than 5,which satisfies people's health needs for PUFA in meat,and makes up for the nutritional deficiency with high n-6 PUFA content in housting sheep.Experiment 3:Effects of supplementation of different forms of linseed oil on the mRNA abundance for key regulators and lipid metabolism related enzymes in the muscle of fattening sheep.The addition of different forms of linseed oil to the diet significantly affects the key regulatory factor of muscle lipid metabolism,PPAR-?and SREBP-1mRNA expression compared with group CON,LO,LOM and L groups could increase the expression of PPAR-?m RNA 53%,68%and 36%respectively,and down regulated the expression of SREBP-1 mRNA 47%,49%,53%?P<0.05?;The addition of linseed oil in each group inhibits the expression of FAS and SCD genes in lipid metabolism related enzymes,the expression level of SCD in LOM group was significantly higher than in L group?P<0.05?,and significantly increased the expression of mRNA of LPL gene,which was 2.7 times higher than in CON group?P<0.05?,but had no significant effect on ACC expression?P<0.05?.The results showed that the growth performance,performance,meat quality,rumen fermentation indexs and fatty acid content of the fattening sheep were affected by dietary addition of different forms of linseed oil,It also played a significant role in regulating the expression of PPAR-gamma,SREBP-1 and related enzymes FAS,SCD and LPL genes in lipid metabolism.The direct addition of linseed oil to the diet reduced ADG,influenced the production performance,and had a negative effect on the rumen fermentation function,linseed oil microcapsule increased the back fat thickness and tenderness of the mutton.The diet supplemented with rich in PUFA fat regulated the lipid metabolism of blood,increased the content of TC,LDL and HDL,reduced the concentration of INS,and increased the content of ALA and CLA in meat,the content of n-3 PUFA in mutton with linseed oil microcapsule and linseed was higher than with linseed oil,which reduced n-6/n-3 value and improved fatty acid composition in meat.In addition,different forms of linseed oil raised the expression level of PPAR-gamma,LPL genes and inhibited the m RNA expression of SREBP-1,SCD and FAS genes.