Effects Of Cumin Essential Oil On Growth Performance、Serum Biochemical Indices And Nutrient Metabolic Rate Of Broilers

Objective:In this thesis,yellow feather broiler chickens were used as experimental animals to study the effects of cumin essential oil on growth performance,serum biochemical indexes,nutrient metabolic rate and the number of intestinal flora.Methods:A total of 192 one-day commercial yellow feather broilers were randomly divided into 4groups,each group with 4 repetitions and 12 broilers per replicate set.Cumin essential oils of 0 mg/kg(CON),150 mg/kg(CEO1),250 mg/kg(CEO2),350 mg/kg(CEO3)were added to the basal ration when feeding broilers.The trial period was 70 days,which was divided into three stages: 1-21 days,22-56 days,and 57-70 days.Experiment 1: 1)The broilers were weighed on an empty stomach at 1,20,56,and 70 days,and the feed intake at each stage was recorded,and the ADG,ADFI,F/G.2)On the 70 th day,three broilers of similar body weight were randomly selected from each group in each replicate,slaughtered and weighed,and each slaughter performance index was calculated.3)The feces were collected 3 days after each stage,mixed and made into dried samples,and the contents of CP,Ca,P,and EE in the feed and feces were determined,and their nutrient metabolism rates were calculated.Experiment 2: On the 35 th and 70 th days of the trial,Three broilers of similar body weight were randomly selected for each group per replicate,blood was collected from the fin vein,and the serum was separated by centrifugation at 4000 r/min,and stored at-20℃for testing.1)Antioxidant index: T-SOD,GSH-Px,MDA were detected by using kit.;2)Immunoglobulins: IgA,IgG,IgM are detected by ELISA;3)NDV antibody titer:determined by hemagglutination-hemagglutination inhibition(HA-HI)assay;4)Indicators of immune organs: On the 35 th and 70 th days of the experiment,Three broilers of similar body weight were randomly selected for each group per replicate,and the bursa and spleen were dissected after slaughter,weighed and recorded,and their organ indexes were calculated.Experiment 3: On the 35 th and 70 th days of the experiment,Three broilers of similar body weight were randomly selected for each group per replicate.After slaughtering,the contents of the cecum and ileum were taken and placed in sterilized EP tubes,which were refrigerated for testing.After doubling dilution,they were inoculated on a specific medium for constant temperature cultivation,and the number of bacterial colonies was determined and calculated by the method of plate colony counting.1)E.coli was cultured in EMB medium at 37℃for 24h;2)Lactobacillus was cultured in MRS medium at 37℃ for 48h;3)Total aerobic bacteria were cultured in NA medium at 28℃for 24 h.Results: Experiment 1:1)At 1-70 days,the ADG of broiler chickens in the CEO2 and CEO3 groups was significantly higher than that in the CON group(P<0.05),the ADG difference between the CEO1,CEO2,and CEO3 groups was not significant(P>0.05);the ADFI of broiler chickens in the CEO1,CEO2,and CEO3 groups was significantly higher than that in the CON group(P<0.05),and the ADFI difference between the CEO1,CEO2,and CEO3 groups was not significant(P>0.05);the F/G in the CEO2 group was significantly lower than that in the CON group(P<0.05),and the F/G difference between the CEO1,CEO2,and CEO3 groups was not significant(P>0.05).2)The differences in slaughtering rate,semi-net rate,full clearance rate,leg muscle rate and abdominal fat rate of broilers between the experimental groups were not significant(P>0.05),the chest muscle rate of broiler chickens in the CEO2 group was significantly higher than that in the CON group(P<0.05),and the difference between the CEO1,CEO2 and CEO3 groups was not significant(P>0.05).3)Compared with CON group,CEO2 group significantly increased the metabolic rates of CP and P in broilers during the whole experimental period(P<0.05),and significantly increased the metabolic rate of EE at 19-21 days and 54-56 days and the metabolic rate of Ca at 68-70 days(P<0.05).Experiment2:1)Compared with the CON group,the activities of T-SOD and GSH-Px in broiler chickens in the CEO2 group were significantly increased(P<0.05),and the level of MDA was significantly reduced(P<0.05).2)Compared with the CON group,the level of IgG in the CEO2 group was significantly increased(P<0.05),and there was no significant difference in the IgA and IgM levels amongthe groups(P>0.05).3)There were no significant differences in NDV antibody titer,spleen and bursal index between the experimental groups(P>0.05).Experiment 3: Compared with the CON group,the CEO1 and CEO3 groups could significantly reduce the number of E.coli in the 35-day-age ileum and cecum(P<0.05),the total number of aerobic bacteria in the 35-day-age ileum and 70-day-age cecum(P<0.05),and the CEO2 group could significantly reduce the number of E.coli and total aerobic bacteria in the ileum and cecum at the age of 35 and 70 days(P<0.05),and the experimental group had no significant effect on the number of lactic acid bacteria in the ileum and the cecum(P>0.05).Conclusion: The addition of 250 mg/kg of cumin essential oil to broiler diets significantly improved growth performance,increased antioxidant capacity,enhanced immune function,promoted nutrient metabolism in the diet,and effectively suppressed the number of E.coli and total aerobic flora in the intestinal tract.