| In order to study the effects of oregano oil on production performance,nutrient utilization,intestinal health and antioxidant of AA broiler.In this test,500 AA broiler chicks of 1 day old were randomly divided into 5 treatments,each treatment was repeated 5 times,and 20 for each repetition.In the experiment,the coops were raised and the powder feed was fed.The control group was fed a basic diet without any plant essential oils and antibiotics.In the experimental group,7.5,10.0 and 15.0 mg/kg oregano oil were added to the diet of the control group,and another treatment was used as an endogenous blank control to determine the true utilization rate of feed nutrients.The trial period was 42 days,there are two stages:chicken(1-21 day)and big chicken(22-42 day),feed intake of experimental AA broiler was recorded on a daily repeat basis.Weight on an empty stomach on days 21and42.Experiment broiler 21 day and 42 day,10 broiler(2 broiler / repeated)were randomly selected for each treatment,and slaughter experiment was conducted to determine slaughter performance,serum and liver antioxidant,serum biochemistry,immune organ index,intestinal score and caecum microbe determination.The results of production and slaughter performance show that:compared with the control group,adding oregano oil powder to the diet could increase the daily gain,feed intake and reduce the feed to weight ratio(P < 0.05).Reduce the feed to weight ratio at the later stage(22-42 day).Compared with the whole feeding period,adding oregano oil powder to the diet increased the weight on the market(P < 0.05),reduced the feed to weight ratio(P < 0.05),there was a trend of increasing daily gain(0.05 < P < 0.1).Comparing the three groups,the addition of 10.0 mg/kg oregano oil meal to the diet was more conducive to reducing the feed to weight ratio.Compared with the control group,the diet supplemented with oregano oil could increase the half net bore rate,the full net bore rate and the chest muscle rate(P <0.05).And increased the leg muscle rate of 42 d broilers(P <0.01).Compared with the three origanum oil powder levels,the addition level of 10.0 mg/kg had a higher 21 day full bore rate(P < 0.05).The results of antioxidation and serum biochemistry showed that:compared with the control group,the T-SOD activity in serum and liver of AA broilers was significantly increased(P < 0.05)and MDA content in serum and liver was significantly decreased(P <0.05).When oregano oil was added to the diet,with a trend of increasing GSH-PX activity in serum for 42 days(0.05 < P < 0.1).The results showed that the addition level of 15.0 mg/kg of origanum oil improved the antioxidant effect of serum and liver of AA broilers better(P <0.05).Compared with the control group,the serum LDH,TG,TCHO,HDL at 21 day and LDH,TG,LDL at 42 day in broilers were significantly reduced by adding oregano oil powder for 21 days(P < 0.05).The contents of LDH,TG and LDL in 42 day old serum were decreased(P < 0.05).The results showed that 10.0 mg/kg of origanum oil had better effect on serum biochemistry(P < 0.05).The results of immune organ index,intestinal score and intestinal microorganism study showed that:compared with the control group,the addition of oregano oil significantly increased the thymus index of 21 d and 42 d in AA broilers(P < 0.05).The thymus index(P >0.05)was the highest at the level of 15.0 mg/kg;Compared with the control group,the small intestine,caecum and yolk trace scores of AA broilers were decreased by adding oregano oil(P < 0.05);Compared with three origanum oil powder levels,the addition levels of 10.0 and15.0 mg/kg of origanum oil obtained lower scores of small intestine,cecum and yolk trace(P< 0.05);Salmonella(< 3.00 lg(CFU)/g)was not detected in all four broilers.Compared with the control group,the total number of aerobic bacteria increased 21 days after adding oregano oil powder(P < 0.05),The number of anaerobic lactobacilli increased(0.05 < P < 0.1)and the total number of Escherichia coli decreased(P < 0.05)in 42 days.There was no difference among the three levels of origanum oil(P > 0.05).The results of nutrient utilization rate study showed that:compared with the control group,the apparent and real utilization of OM,CP,EE and GE were increased by adding oregano oil in AA broiler diet(P < 0.05),There was a trend of increasing the apparent and real utilization of DM(0.05 < P < 0.1).The results showed that 10.0 mg/kg and 15.0 mg/kg of origanum oil had better effects on the improvement of conventional nutrients and energy utilization;compared with the control group,the apparent utilization of Lys,Met,Arg,His,Ile,Phe,Thr,Val,TEAA,Asp,Ser,Pro,Tyr and TNEAA in AA broiler diets increased(P <0.05),and there is a trend to increase the apparent utilization of Trp,Leu,Glu and Cys(0.05 <P < 0.1).In addition to Lys and Trp,the real utilization rate of other essential amino acids(P <0.05)and Ser,Pro,Ala,Tyr(P < 0.05)were increased,and there is a trend to improve the real utilization rate of Asp and TNEAA(0.05 < P < 0.1).Compared with the control group,adding7.5,10.0 and 15.0 mg/kg oregano oil to the diet can increase the benefit of 3.50,36.77 and18.25 yuan/ton respectively after deducting the increased cost of adding oregano oil.In conclusion,oregano oil can improve the anti-oxidation ability of AA broilers,improve the thymus index,regulate the intestinal flora,slow down the intestinal injury,improve the nutrient utilization and production performance of AA broilers,and increase economic benefits.This is of great significance to the application of origanum oil in AA broiler culture. |
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