Studies On The Metabolism Of Intramuscular Fat In Quality Chicken And Its Relationships With Meat Quality Traits

Intramuscular fat had the important influence on the meat quality traits. The main aim of this work was to firstly confirm the biological theory of lipid deposit and distribution in the quality chickens, and then conform the key hormone and enzyme related to lipogenesis .This study evaluated the influence of intramuscular fat on the meat quality traits and the nutritional modification for improving IMF.The effect of feed style and breed on the Jipid metabolism and its biochemical elements of quality chickens: The experiment studied the effect of production method and breed on the fat metabolism of quality chickens. The results showed that the mRNA level and activity of hepatic FAS and ME increased with the increasing of age. The hepatic FAS and ME mRNA level and activity in females were higher than that in males. In the three quality chickens, the highest hepatic FAS mRNA level and activity was Beijingyou chickens and the highest hepatic ME mRNA level and activity was Taining Wugu chickens. The correlation analysis showed that there was a significant positive correlation between the hepatic FAS activity and SFP, PAF (p<0.05) , while IMF was not. Oppositely, the hepatic ME mRNA and activity were significantly positive correlated with IMF(p<0.05), but insignificantly correlated with IeMF, SFP and PAF(p>0.05). The hepatic FAS and ME mRNA levels were positively correlated with lipid deposit and distribution. The hepatic FAS and ME mRNA levels were significantly positively correlated with leg IMF and leMF and SFP and PAF. As seen by correlation coefficient, the relationship of hepatic FAS activity association with SFP and PAF was higher than the relationship with IMF. the relationship of hepatic ME activity association with IMF was higher than the relationship with SFP and PAF. The relationship of hepatic FAS mRNA and ME mRNA level association with IMF and IeMF was higher than that with SFP and PAF. Correspondingly, the IMF, IeMF, SFP and PAF levels of free-ranged chickens were lower than that of caged chickens. The highest level of B.IMF, IeMF, SFP and PAF was the Beijigyou-chickens and the highest levels of L.IMF was the Taining Wugu chickens.The correlation between IMF and meat quality traits. The study was conducted to determinate the effect of production method and breed on the lipid deposit and the correlation between IMF and meat quality traits in the quality chickens. The results showed that the levels of quality chickens lipid deposit was significantly decreased in the free-range production method. The effect of free-range on the PAF was higher than on the IMF. The free-ranged chickens had higher slaughter performance, muscle SFV, MFDia and lower muscle pH, dropping loss, cooking loss and muscle fibre density(p<0.05). The results of flavour taste showed that the meat aroma and umami of free-ranged chickens were higher than that of caged chickens and the meat tenderness were lower than that of caged chickens. The total acceptability of room-fed chickens was highest among three production method, but the difference was not significant(p>0.05). The highest levels of B.IMF, leMF, SFP and PAF was the Beijigyou-chickens and the lowest levels of leMF, SFP and PAF was the Taining Wugu chickens. The IMF was positively...