Study On The Oxidative Stability Of Rice Bran Oil And On Performance,intestinal Health And Meat Quality Of Meat Duck

Rice bran oil has a wide range of domestic sources and large output.At present,the utilization ratio of rice bran oil is still low,and the intensive production is not high,which greatly restricts the further utilization of rice bran.Therefore,the reasonable use of rice bran oil can increase the consumption of rice bran oil.On this basis,in this paper,it was studied through two experiments,the first experiment studied oxidative stability of rice bran oil.And then,the effects of rice bran oil and heated rice bran oil on performance,intestinal health and meat quality of meat ducks were studied,providing basic data and theoretical basis for the application and rational use in meat duck breeding of rice bran oil.Exp 1:Study on the oxidative rancidity of rice bran oil at different temperaturesThe purpose of this experiment was to study the oxidative rancidity of rice bran oil at different temperatures.The experiment selected five kinds of rice bran oil from the same source,which were first-grade rice bran oil（rice bran oil 1）,second-grade rice bran oil（rice bran oil 2）,third-grade rice bran oil（rice bran oil 3）,and fourth-grade rice bran oil（rice bran oil 4）)and crude rice bran oil（rice bran oil 5）,stored at high temperature（63℃）,room temperature（average temperature 25℃）and low temperature（4℃）respectively,and storage time 54 d and evaluation of color,acid value,peroxide value,malondialdehyde and fatty acid content.The results showed that:1)Rice bran oil was mainly composed of palmitic acid（C16:0）,oleic acid（C18:1）,linoleic acid（C18:2）and a small amount（1～3%）of stearic acid（C18:0）and linolenic acid（C18:3）.Fatty acid composition between different rice bran oils was significantly different（P<0.05）.The content of polyunsaturated fatty acids in rice bran oil decreased significantly and monounsaturated fatty acids increased significantly at room and high temperature（P<0.01）.The content of polyunsaturated fatty acids in other four kinds of rice bran oil decreased significantly and the monounsaturated fatty acids increased markedly excepted rice bran oil4 at low temperature（P<0.01）.At room temperature and low temperature,the content of saturated fatty acids increased and then decreased（P<0.01）;At high temperature,the saturated fatty acids increased markedly（P<0.01）.2)At low temperature,the acid value of rice bran oil is significantly unchanged,the peroxide value increased,and the content of malondialdehyde decreased;At room temperature,the acid value,peroxide value,and malondialdehyde of rice bran oil increased.At room and low temperature,the acid value,peroxide value and malondialdehyde of rice bran oil are the lowest in rice bran oil 4,and rice bran oil 5 is the highest;At high temperature,the acid value and malondialdehyde of rice bran oil increased,and the peroxide value increased rapidly（linear change）,in which rice bran oil 4 had the lowest acid value,but had the highest peroxide value and malondialdehyde increased the fastest,and rice bran oil 5 had the largest acid value.3)Use linear regression and curves to fit the peroxide value and storage time of five rice bran oils at different temperatures.The results showed that the increase in peroxide value with storage time was close to the linear change law,namely zero-order oxidation kinetics,The fitting correlation coefficient R²was less than 0.8 at low temperature,and greater than0.8 at room and high temperature.The above results suggested that saturated and monounsaturated fatty acids increased only,and polyunsaturated fatty acids decreased at high temperature.Under different temperature conditions,the peroxide value of rice bran oil increased linearly with time.Exp 2:Study of rice bran oil on performance,meat quality and intestinal health of meat ducksThe purpose of this experiment was to study the effect of using rice bran oil in the diet on performance,intestinal health and meat quality of meat ducks.Single factor test design,using rice bran oil from the same source as experiment 1,720 1-day-old meat ducks were selected and randomly divided into 8 treatments:T1:soybean oil group,T2:rice bran oil 4group,T3:15 d at room temperature rice bran oil 4 group,T4:heated rice bran oil 4 group,T5:rice bran oil 5 group,T6:In the late used 15 d at room temperature rice bran oil 4 group,T7:In the late used heated rice bran 4 group,T8:In the late used rice bran oil 5 group.Six replicates per treatment and 15 meat ducks per replicate.The test is divided into two stages,1-14 days and 15-35 days.The amount of oil in each group was 6%.The results showed that:1)Compared with soybean oil group,heated rice bran oil 4 during the whole period had a tendency to reduce the meat duck’s 14 days BW and 1-14-day BWG（P=0.090）,and significantly increased 1-14-day F/G（P<0.05）.Rice bran oil significantly increased the activity of GSH-Px and SOD in the breast muscle of meat ducks on 14 days,and decreased the activity of GSH-Px on muscles of 35 days（P<0.01）.Rice bran oil significantly reduced the p H_45minof duck breast muscles（P<0.01）.In addition,Rice bran oil throughout the period significantly reduced the 35 d muscle SOD activity（P<0.01）.The late addition 15 d rice bran oil 4 and heated rice bran oil 4 significantly decreased the 35 d activity of GSH-Px in the breast muscle,and increased MDA content（P<0.01）.Heated rice bran oil 4 significantly increased 35 d muscle UFA content and UFA/SFA ratio.2)Compared with soybean oil group,the whole period rice bran oil 4 significantly increased the serum corticosterone concentration at 14 days（P<0.01）,and the whole period heated rice bran oil 4 significantly decreased the serum corticosterone concentration at 14 d（P<0.01）.Rice bran oil significantly increased the serum IL-6 and TNF-αconcentration of meat ducks on 14 d,and decreased the concentration of IL-10（P<0.01）.Rice bran oil 4 and heated rice bran oil 4 during the whole period,later 15 d rice bran oil 4 and heated rice bran oil 4 significantly increased the serum corticosterone concentration of meat ducks at 35 days,decreased the IL-6 and TNF-αcontent at 35 d,and increased IL-10 concentration（P<0.01）.15 days rice bran oil 4 significantly reduced the serum ALP activity of meat ducks 14 days（P<0.01）.15 d rice bran oil 4 and late rice bran oil 5 significantly reduced the serum GSH-Px activity of meat ducks on 35 days（P<0.01）.3)Compared with soybean oil group,The whole period rice bran oil 4,heated rice bran oil 4 and rice bran oil 5 significantly reduced the concentration of SIg A in the duck jejunum and increased the concentration of SIg A in the ileum after 35 days（P<0.01）.Rice bran oil significantly reduced the SIg A concentration in the ileum of meat ducks at 14 d（P<0.01）.The whole period 15 d rice bran oil 4 and rice bran oil 5 significantly reduced the activity of GSH-Px and MDA content of jejunum in meat ducks for 14 days（P<0.01）.Rice bran oil significantly increased the activity of GSH-Px in jejunum of meat ducks at 35 d（P<0.01）.The whole period rice bran oil 4 and rice bran oil 5 can significantly increase the ileal GSH-Px activity of meat ducks at 14 d（P<0.05）,and use of rice bran oil in the later stage significantly reduced the ileum 35 d GSH-Px and SOD activities（P<0.01）.The above results suggested that heated rice bran oil 4 only increased the F/G of meat ducks for 1-14 days.The use of rice bran oil throughout the period reduced the blood and intestinal immunity in meat ducks for 1-14 days,and increased the antioxidant capacity of the ileum and muscle for 1-14 days.The use of rice bran oil throughout the period increased the blood and ileal immunity of meat ducks for 15-35 days,and decreased the muscle p H and antioxidant capacity for 15-35 d days.In addition,using rice bran oil in late stage（15-35 d）reduced the antioxidant capacity of the ileum,and reduced the muscle p H and antioxidant capacity.In summary,at different temperatures,the peroxide value of rice bran oil changed linearly with increasing storage time,and rice bran oil 4 peroxide value and malondialdehyde wrer the largest,and rice bran oil 5 had the largest acid value.The whole period heated Rice bran oil 4 increased in the early stage（1-14 d）F/G of meat ducks.The use of rice bran oil throughout the period reduced the early stage blood and intestinal immunity,increased the antioxidant capacity of the ileum and muscles in early stage,reduced the late period（15-35d）muscle antioxidant capacity and increased the antioxidant capacity of the ileum and blood in the later period（15-35 d）.Using rice bran oil in the later stage reduced the antioxidant capacity of the ileum and muscle.