Effect Of Essential Oil Supplementation On Growth Performance,Meat Quality And Immune Function Of Yellow Feather Broiler

In this experiment,different doses of plant essential oils were added to the diet to study its effects on the growth performance,slaughter performance,meat quality,immune function and antioxidant capacity of fast-large yellow-feather broilers.The experiment selected healthy 1-day-old male yellow-feather broilers with the same body weight and randomly divided them into 4 groups,each with 6 replicates,each with 30 chickens,and a total of 720chickens.The experiment set up a control group（basic diet）,a PE200 group（basic diet+200 mg/kg essential oils）,a PE400 group（basic diet+400 mg/kg essential oils）,and a PE600 group（basic diet+600 mg/kg）.kg plant essential oils).The test period is 48 days,divided into three stages:1-21d in the early stage,22-42d in the middle stage,and 42-48d in the later stage.The test results are as follows:（1）Growth performance:In the early stage of the test（1-21 days old）,compared with the control group,the ADFI and ADG of the test group increased linearly（P<0.05）;there was no significant difference in F/G of each group（P>0.05）.In the later stage of the experiment（22-48 days old）,the ADFI of the PE200 group was significantly lower than that of the control group（P<0.05）;the ADG of the experimental group was not significantly different from the control group（P>0.05）;the F/G of the PE200 group and the PE400 group Significantly lower than the control（P>0.05）;in the whole period（1～48 days old）,compared with the control group,adding different doses of essential oils significantly increased the ADG of broilers and decreased F/G（P<0.05）,but it was not ADFI had no significant effect（P>0.05）.（2）Slaughter performance and meat quality:The abdominal fat rate of the experimental group was linearly significantly reduced（P<0.05）,and the abdominal fat rate of the PE600group was significantly lower than that of the other experimental groups（P<0.05）.The slaughter rate,half evisceration rate,full evisceration rate,pectoral muscle rate and leg muscle rate of each group had no significant difference（P>0.05）.Compared with the control group,the pectoral muscle brightness value L*of the PE400 group and the PE600 group was significantly lower than that of the control group and the PE200 group（P<0.05）.The pectoral muscle redness a*of the PE200 group was significantly higher than that of the other groups（P<0.05）.The pectoral muscle yellowness b*of the PE200 group was significantly higher than the other groups（P<0.05）,the yellowness value b*of the PE400 group and the PE600 group was significantly lower than the control group（P<0.05）,and the yellowness value b of the PE600 group*Significantly lower than the PE400 group（P<0.05）.There was no significant difference in the p H_45min of each group（P>0.05）.The pectoral muscle PH_24h of the PE600 group was significantly higher than that of the control group and PE200（P<0.05）,and the pectoral muscle PH_24h of the PE400 group was significantly lower than that of the other groups（P<0.05）.The pectoral muscle drip loss of PE400 group and PE600 group was significantly lower than that of the control group.The chest muscle compression loss in the PE600 group was significantly higher than that in the other groups（P<0.05）.（3）Immune organ index and plasma immunoglobulin level:At the 21st day of age,the liver index and spleen index of the PE600 group were significantly higher than those of other groups（P<0.05）;the thymus index of the PE600 group was significantly lower than that of the control group and PE200 Group（P<0.05）;The bursal index of PE400 and PE600 groups was significantly lower than that of the control group and PE200 group,and the bursal index of PE600 group was significantly lower than that of PE400 group.At the 48th day of age,the thymus index of the experimental group decreased significantly（P<0.05）;the liver index,spleen index,and bursa index of each group had no significant difference（P>0.05）.Compared with the control group,the 21-day-old serum Ig G,Ig M and Ig A contents of the PE200 group did not change significantly,while the 21-day-old serum Ig G,Ig M and Ig A contents of the PE400 and PE600 groups were significantly higher than those of the PE200group and the control group（P<0.05）.（4）Antioxidant function:at the 21st day of age,compared with the control group,the addition of 400 mg/kg plant essential oil significantly increased serum and liver T-AOC（P<0.05）;the serum SOD activity of the PE600 group was significantly higher than that of the control group,PE200 and PE400 groups（P<0.05）,the liver SOD activity of PE200 and PE600 groups was significantly higher than that of the control group（P<0.05）;the serum MDA levels of PE400 and PE600 groups were significantly higher than those of the control group and PE200 group（P<0.05）.At the 48th day of age,the serum T-AOC of the PE400group was significantly higher than that of the control group,PE200 and PE600 groups（P<0.05）,and the liver T-AOC of the PE400 group and PE600 group was significantly increased（P<0.05）,and the PE400 group and PE600 group The group was significantly higher than the PE200 group（P<0.05）;the serum CAT activity of the PE600 group was significantly lower than that of the control group,PE200 and PE400 groups（P<0.05）,the liver SOD and CAT activities of the PE600 group were significantly higher than that of the PE200 group,while the MDA level was significantly lower In the other groups（P<0.05）.In summary,adding plant essential oil to the diet can effectively improve the early growth performance and feed-to-weight ratio of yellow feather broilers,reduce abdominal fat rate,improve meat quality,improve immune function and increase antioxidant function,and PE600 group has the best effect.