| The purpose of this experiment is to investigate the effects of dietary supplementation of compound plant(containing wolfberry slags and glycyrrhiza)extract(CPE)instead of in-feed antibiotic(IFA)on the production performance,immune performance and meat quality of yellow feather broilers.A total of 240 healthy one-day-old(half male and half female)Liangfenghua yellow-feather broilers were randomly divided into 4 groups according to the principle of similar bodyweight,and with 6 replicates per group(10 broilers per replicate).The standard control group(CS)was fed with a basal diet supplemented with 45 mg /kg chlortetracycline,while the group Ⅰ,Ⅱ,Ⅲ were fed with basal diet supplemented with 1%,2%,4% CPE(wolfberry slags and glycyrrhiza),respectively.The study was lasted for 56 days,which was divided into two stages: the pre-test period(1-28 days)and the post-test period(29-56 days).At the end of each phases of the experiment,four samples of near-average weight were selected from each repeat for slaughter,Two of them(one male and one female)were used to measure the growth performance,slaughter performance,serum indicators,and the other two(one male and one female)were used to measure the immune organ index,liver antioxidant index,meat quality and muscle histology index.The test results are as follows:Part 1: The effect of dietary supplementation of CPE on growth performance,slaughter performance and serum biochemical indicators of yellow feather broilers:(1)In terms of growth performance,the average daily intake(ADFI)of experimental group Ⅲ was significantly improved compared with the control group(P<0.05),there was a significant linear effect between ADFI and CPE dosage(P<0.05);the feed-weight ratio and CPE content showed a linear trend of significant effects(0.05 <P <0.1);the average daily increase of each test group There was no significant difference in weight(P> 0.05).(2)In terms of slaughter performance,compared with the control group,the chest muscle rate of the test group Ⅲ was significantly improved(P<0.05),and there was a significant linear effect of the chest muscle rate and the CPE content(P<0.05);the slaughter rate and semi-cleaning of the test group There was no significant difference in rate,total net rate,leg muscle rate and abdominal fat rate(P>0.05).(3)In terms of serum biochemistry,compared with the control group,the high-density lipoprotein of the test group Ⅱ was significantly reduced(P <0.05),and there was a significant linear effect of the high-density lipoprotein and CPE content(P <0.05);the test groups Ⅰ,Ⅱ,Ⅲ,triglyceride content and glucose content have a significant decrease trend(0.05 <P <0.1),triglyceride and glucose with a CPE content increased and showed a significant trend of linear effect(0.05 <P <0.1);The total cholesterol,low density lipoprotein,total protein content,albumin content and globulin content of the group had no significant effect(P> 0.05).Part 2: The effect of dietary supplementation of CPE on antioxidant performance and immune performance of yellow-feather broilers:(1)In terms of serum antioxidant indexes,the catalase activity of experimental group Ⅱ was significantly reduced compared with the control group(P<0.05),Catalase activity showed a significant linear effect on the CPE content(P<0.05);glutathione peroxidase activity had a trend of linear effect on the CPE content(0.05<P < 0.1);there were no significant difference in superoxide dismutase activity,total antioxidant capacity and malondialdehyde content in each groups(P>0.05).(2)In terms of liver antioxidant indicators,catalase activity had a significant linear effect on CPE content(P<0.05);there were no significant difference in the glutathione peroxidase activity,superoxide dismutase activity and total antioxidant capacity of the liver in each groups(P>0.05);the content of malondialdehyde in the experimental group Ⅲ was significantly higher than that in the control group(P<0.05),and the content of malondialdehyde had a significant linear relationship with the CPE content(P<0.05).(3)In terms of immune organ index,compared with the control group,the spleen index of the experimental groupsⅠand Ⅲ was significantly reduced(P<0.05),and the spleen index had a significant linear effect on the CPE content(P<0.05);the thymus index of the experimental group Ⅲ was extremely Significantly decreased(P<0.01),the thymus index had a extremely significant linear effect on the CPE content(P<0.01);the bursa index of the experimental group III was significantly reduced(P<0.05),and the bursa index was showed extremely significant Linear effect on the CPE content(P<0.01).(4)In terms of immunoglobulin indicators,compared with the control group,the immunoglobulin-M of the experimental group Ⅲ was significantly increased(P<0.05),and the immunoglobulin-M content showed a extremely significant linear effect on the CPE content(P<0.01);The content of immunoglobulin-G in test group Ⅱand Ⅲ had a significant increasing trend(0.05<P<0.1),and the content of immunoglobulin-G has a significant linear effect on the content of CPE(P<0.05);the immunoglobulin-A in experimental groupⅢwas significantly increased(P < 0.05),the content of immunoglobulin-A had a extremely significant linear effect on the content of CPE(P<0.01);the content of interleukin-2 had a trend of linear effect on the content of CPE(0.05<P<0.1).Part 3: The effect of dietary supplementation of CPE on the meat quality of yellow-feather broilers:(1)In terms of conventional meat quality,compared with the control group,the yellowness(b *)value of the breast and thigh muscles of the experimental group Ⅲ increased significantly(P<0.01),the yellowness(b*)value had a extremely significant linear effect on the CPE content(P<0.01);the redness(a*)value of the breast muscle and the water holding capacity had a significant linear effect on the CPE addition(P<0.05);the thigh muscle shearing force of the experimental group Ⅲ was significantly reduced(P<0.01),and the thigh muscle shear force had a extremely significant linear effect on the CPE content(P<0.01).(2)In terms of muscle histology,the average cross-sectional area and average fiber density of the thigh muscle showed a significant linear effect with the amount of CPE added(P<0.05).(3)In terms of conventional muscle nutrients: the crude ash content of the breast muscles of the experimental group Ⅱ and Ⅲ was significantly lower than that of the control group(P<0.05),and there was a significant linear effect of the crude ash content of the breast muscle on the amount of CPE added(P<00.05);there was no significant difference in the content of dry matter,crude protein and ether extract in breast muscle(P>0.05).Compared with the control group,the crude protein content of the thigh muscle of the experimental groupⅠandⅡ was significantly reduced(P<0.05),and the crude protein content showed a significant linear effect on the amount of CPE added(P<00.05);there was no significant difference on the content of dry matter,ether extract and crude ash(P>0.05).(4)In terms of anti-oxidation performance of the breast muscle,the malondialdehyde content(MDA)of the experimental group Ⅲ increased significantly(P<0.01),and the MDA content showed a extremely significant linear effect on the amount of CPE added(P<0.01);peroxidation;there was no significant difference in catalase activity,glutathione peroxidase activity,superoxide dismutase activity and total antioxidant capacity in each groups(P>0.05).It can be concluded that adding 4% of CPE containing wolfberry slags and glycyrrhiza to the yellow-feather broiler diet instead of the IFA,not only make Satisfactory results in terms of production performance and muscle antioxidant performance,but also improve the meat quality of the yellow-feather broiler.It shows that CPE can be used as an effective feed additive in broiler production. |
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