| This study was aimed to explore the impact of dietary fat of lactating sows on fatty acid composition of colostrum and longissimus dorsi of progeny and adipose tissue lipid metabolism. This experiment investigated the effects of dietary fat of lactating sows on the progeny through measuring blood routine biochemical parameters, enzyme activity, fatty acid composition, hormone content and gene and protein expression related to lipid metabolism.1. Dietary fat of lactating sows affects the longissimus dorsi fatty acid composition on progenyFourteen Large White × Landrace sows (2rd to 3rd parity) were randomly assigned to either a control or a high-fat diet (HF) group. Starting seven days before farrowing and continuing throughout the lactation period, the control sows were fed a control diet, and the sows in the HF group were fed a diet containing 8% corn oil. Both groups after 28 days weaning piglets fed the same standard diet until finishing stage. One male pig with average weight per litter at weaning (28 days) and finishing (6 months old) was selected and slaughtered and collected the colostrum, blood, longissimus dorsi and subcutaneous fat.Dietary fat of lactating sows reduced weaning weight (P< 0.05), psoas muscle weight (P< 0.01), blood tyrosine concentration (P< 0.05), but significantly increased the longissimus dorsi a* (P< 0.05) and b* (P< 0.01) values of progeny. The backfat thickness decreased significantly (P< 0.05), yet serum globulin (P< 0.05), triglycerides (P< 0.05) and longissimus dorsi 24 h pH (P< 0.01) of progeny increased significalty at the finishing stage.Dietary fat of lactating sows increased C18:2n-6 (P< 0.05), ΣPUFA (P< 0.05), n-6 PUFA (P< 0.05) and n-6/n-3 PUFA (P< 0.01) ratio, however the C18:3n-6 (P< 0.01), and C20:5n-3 (P< 0.01) ratio in the colostrums of sows were decreased. The results of the longissimus dorsi fatty acid composition of progeny at weaning stage.showed that, the C18: 2n-6 (P< 0.01), C20:2n-6 (P< 0.01), ΣPUFA (P< 0.05), n-6 PUFA (P< 0.05) and n-6/n-3 PUFA (P< 0.01) were significantly increased, and C20:3n-6 (P< 0.05), C20:4n-6 (P< 0.05), C24:0 (P< 0.05) and n-3 PUFA (P< 0.01) were significantly reduced The longissimus dorsi fatty acid composition of progeny at finishing stage had a higher C18:2 n-6 (P< 0.05) and C20:4n-6 (P< 0.05) proportion; while the content of ΣPUFA (P= 0.06), n-6 PUFA (P= 0.06) and n-6/n-3 PUFA (P-0.09) only had a differences tendency. The real-time quantitative PCR was used to detect the longissimus dorsi genes expression related to fatty acid composition of progeny at weaning and finishing stages. The results showed that dietary fat of lactating sows significantly downregulated FADS2 (P< 0.05) and SREBP1 (P< 0.05) gene expression of progeny at weaning stage, yet no impact on progency at finishing stage. These results indicated that dietary fat of lactating sows changed the fatty acid composition of colostrum, and affected the longissimus dorsi fatty acid composition at weaning stage, meanwhile some changes have persistent effects in later life.2. Dietary fat of lactating sows affects the adipose tissue fatty acid composition and lipid metabolismDietary fat of lactating sows significantly increased the triglyceride content of adipose tissue at weaning stage (P< 0.05), but had no impact at finishing stage. The content of SPUFA (P< 0.01), n-6 PUFA (P< 0.01), n-3 PUFA (P< 0.01), n-6/n-3 PUFA (P< 0.01), and C18:2n-6 (P< 0.05) was elevated and the proportion of ESFA (P< 0.01) and EMUFA (P< 0.01) was decreased in adipose tissue at weaning stage. The content of C20:2n-6 (P< 0.05) and n-3 PUFA (P< 0.05) were significantly increased and the proportion of C18:In-9 (P< 0.05) and ΣMUFA (P< 0.05) was reduced in adipose tissue at finishing stage.The real-time quantitative PCR was used to detect the longissimus dorsi genes expression related to fatty acid composition of progeny at weaning and finishing stages. The results showed that dietary fat of lactating sows upregulated the PPARy (P< 0.05), Leptin (P< 0.05), UCP2 gene expression (P< 0.05) and UCP3 (P< 0.05) genes expression in adipose tissue at weaning stage, however the SCD1 gene expression (P< 0.05) was decreased. Dietary fat of lactating sows downregulated the FAS (P< 0.05) and SCD1 (P< 0.05) gene expression and exist the tendency of C/EBP-β (P= 0.06) gene expression in adipose tissue of progeny at finishing stage. The results of western blot suggested that dietary fat of lactating sows significantly reduced the SCD1 protein expression in adipose tissue of progeny at weaning and finishing stages.These results suggested that dietary fat of lactating sows changed the fatty acid composition in adipose tissue, and SCD1 gene may be involved in the regualtion. |
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