饲粮中添加翻白草提取物对肉鸡生长性能、养分表观代谢率和肉品质的影响OA

The experiment was conducted to investigate the effects of dietary supplementation with Poten-tilla discolor Bunge extract on growth performance,apparent metabolic rate,slaughter performance and meat quality of broilers.A total of 200 healthy 1-day-old Arbor Acres(AA)broilers were ran-domly divided into 5 groups:blank control(BL)group,antibiotic control(PC)group and treatment(PT1,PT2 and PT3)groups,with 8 replicates per group and 5 broilers per replicate.Broilers in the BL group were fed a basal diet,those in the PC group were fed the basal diet supplemented with 300 mg/kg chlortetracycline,and those in PT1,PT2 and PT3 groups were fed the basal diet supplemented with 0.9%,1.2%or 1.5%Potentilla discolor Bunge extract,respectively.The feeding trial lasted for 42 days.As a result,compared with the groups BL and PC,the PT1 group gained a significantly higher body weight at 21 and 42 days of age,and a significantly higher average daily gain(ADG)during 1-21 d,22-42 d and 1-42 d(P<0.05).Compared with the BL group,the feed-to-gain ratio(F/G)during 1-42 d significantly decreased in group PT1(P<0.05),average daily feed intake(ADFI)during 1-21 d markedly increased in PC,PT1,PT2 and PT3 groups(P<0.05),but the appar-ent metabolic rates of gross energy(GE),crude protein(CP)and crude ash(Ash)during 1-21 d,as well as the apparent metabolic rates of GE,CP,dry matter(DM)and calcium(Ca)during 21-42 d significantly decreased in PT3 group(P<0.05).Dietary supplementation with Potentilla discolor Bunge extract had no sig-nificant effects on slaughter rate,eviscerated rate,breast muscle rate and thigh muscle rate of broilers in the groups PT1,PT2 and PT3(P>0.05).Compared with the BL group,abdominal fat rate significantly reduced in PT1 and PT2 groups(P<0.05);thymus index and Fabricius bursa index were significantly improved in PT1 group(P<0.05),and the contents of Ca and total phosphorus(TP)in tibia significantly increased in all treatment groups(PT1,PT2 and PT3)(P<0.05);in the PT1 group,breast muscle water-holding capacity and shear force significantly decreased,while the values of pH at 24 h and redness(a*)of breast muscle signifi-cantly increased(P<0.05);CP contents in breast and thigh muscles significantly decreased(P<0.05),whereas intramuscular EE content in breast muscle significantly increased in the PT2 and PT3 groups(P<0.05).In conclusion,dietary supplementation with Potentilla discolor Bunge extract can increase ADG,reduce F/G,enhance immune organ indices and improve meat quality of broilers,and the optimal supple-mental level is 0.9%.