Research On Oxidation Stability And Nutritional Value Evaluation Of Crude Rice Bran Oil

This study was conducted to investigate the Substitution Method for determining metabolizable energy of crude rice bran oil in Xueshan chicken, and the Effects of several antioxidants on the antioxidation of crude rice bran oil. It also was aimed to study the effect of different oils on growth performance, meat quality, digestive enzyme activity, and antioxidant capacity in Zhongbai chicken. The study was divided into four parts:In trial1, the trial was conducted to study the effects of several antioxidants on the antioxidation of crude rice bran oil. Using acid value(AV)、 peroxide value(POV) and malondialdehyde(MDA) as evaluation parameter, the effects of ethoxyquinoline, BHT, BHA and complex antioxidants on the antioxidation of crude rice bran oil were studied under(37±1)℃accelerated oxidation conditions. The results showed that there were no significant differences of the AV between all the groups, and the AV didn’t change significantly with time. The POV increased slowly in19days, but after that the addition of complex antioxidant could improve the antioxidative activity of RBO, which was significantly higher than that of RBO with antioxidant. The content of MDA in the groups with complex antioxidant were lower than that with single antioxidant. Compared to all the data, we could know that the effect of complex antioxidants were better than single antioxidant in improving the antioxidative activity of RBO.In trial2, an experiment was designed to determine the metabolizable energy of crude rice bran oil(RBO). Thirty six90to100-day-old Xueshan chicken were randomly allocated to6groups with6replicates(1broiler per cages), and were fed with the basal diet substituted by different ratios (0%、5%、7.5%、10%、2.5%、15%,respectively)of RBO. All of the excreta of birds used to determine metabolizable energy were collected, and the metabolizable energy of RBO was calculated by using a substitution method. The results showed:The apparent metabolizable energy(AME) values of RBO determined in five groups(5%、7.5%、10%、12.5%、15%)were43.47MJ/Kg,37.19MJ/Kg,35.24MJ/Kg,34.69MJ/Kg and34.79MJ/Kg, respectively, and the utilization ratio of AME were72.62%、73.53%、73.94%、74.45%、74.91%. Furthermore, the true metabolizable energy(TME) of RBO were42.42MJ/Kg,38.98MJ/Kg,38.27MJ/Kg,36.80MJ/Kg and38.97MJ/Kg, the utilization ratio of TME were75.44%,74.82%,75.01%,74.28%,75.15%, respectively. Compared the values of each groups, the average AME of RBO was35.48MJ/Kg, and the average TME was38.23MJ/Kg.In trial3, this study was conducted to investigate the effects of dietary supplementation with different oil on the growth performance, development of digestive organs and digestive enzyme activities in broilers. Two thousand and four hundred1-day-old broiler were randomly assigned into4treatments with6replicates(100birds per replicate). Each treatment fed a diet supplemented with crude rice bran oil(RBO), crude soybean oil(SO), lard(LO) and palm oil(PO). The results showed that:In the starter period, the ADFI of RBO was lower than SO and PO(P<0.05), and the activities of amylase and lipase of pancreas in SO group were significantly higher than LO, PO(P<0.05). Comparing with PO group, the SO group decreased the activities of amylase of intestinal contents on day21. In the grower period, the ADFI of RBO was lower than PO groups(P<0.05), and the organ indexes of heart and pancreas of RBO were higher than other groups(P<0.05). In addition, the activities of lipase of pancreas in SO group were significantly higher than PO(P<0.01) in the day of42, but a significant depression of intestinal lipase in RBO group was observed after comparing with PO group(P<0.05). The results indicate that different oil didn’t affected the growth performance in the whole period. The crude rice bran oil and crude soybean oil could increase the digestive enzyme of pancreas and decrease the digestive enzyme of intestinal contents after comparing lard and palm oil.In trial4, the aim of this experiment was to study the effects of dietary supplementation with different oil on meat quality, fatty acid composition and antioxidant ability of broilers. Two thousand and four hundred1-day-old broiler were randomly assigned into4treatments with6replicates(100birds per replicate). Each treatment fed a diet supplemented with crude rice bran oil(RBO), crude soybean oil(SO), lard(LO) and palm oil(PO). The result indicated that:the cooking loss of RBO group was lower than LO group(P<0.05), and the CP of breast muscles was lower than SO, LO group, as well as the EE of breast muscles lower than LO group(P<0.05). About the fatty acid composition of breast muscles, the content of SPA in PO, LO groups were higher than RBO, SO groups(P<0.05), while the content of UFA in PO, LO groups were lower than RBO, SO groups contrary(P<0.05). In the day of21of the trail, the T-AOC of liver in SO, PO group was higher than LO group(P<0.05), and the T-AOC of liver in SO group was lower than PO group(P<0.05) in day42. Additionally, the T-AOC of serum in RBO, SO group were lower than PO, LO group. Overall, comparing to the other oil, crude rice bran oil could decreased the content of CP of muscles and increased the content of PUFA of breast muscles(P<0.05), but could not make a significant different on meat quality and antioxidant ability of muscles, liver and serum(P>0.05).