| Two experiments were conducted to study the effects of the different supplement level of YC and Flavomycin on performance, intestinal bacteria population, availability of nutrients, immunal function and endocrine secretion in broilers (1-4 week), and the effects of Saccharic-terpenin, YC, probiotics, MOS (Mannan Oligosaccharido), Flavomycin on the control of potential escalation of Escherichia coli during broilers (5-7 week). This study aimed to serve as the base for further research and application on Yeast Culture.In experiment 1: 210 male broilers randomly assigned to seven groups, with three replicates per group. The control group was provided with the basal diet (not including any drug additive), YC was added to the basal diet at the level of 0.1%, 0.3%, 0.5%, 0.7%, 0.9% respectively, and Flavomycin was added to the basal diet at the level of 5mg/kg to seventh experiment diets. The feeding trial started at 1d and ended at 28d. Weight, feed intake and feed efficiency were measured every week. At day 14, 21, 28,three broilers per group were killed by neck's vein and separated serum to test T3, T4, SOD, IgA, IgG IgM, Ca, P, TP, BLB, ALB, Cholesterol; and removed the caecum to test bacteria; and removed the organs (Spleen, Left Thymus, Bursa.F.) to test weights; and gained Icmxlcm small intestine in every broiler to test structure. At 28 day, gained chest to test Cholesterol. Metabolic trial was done at 21 d of age.The results showed that: The dietary 5mg/kg Flavomycin increased significantly (P<0.05) the Daily Weight Gain (DWG)and Feed Conversion Ratio (FCR)of broilers of 1-28 days old by 9.11% and 10.37%. The dietary YC did not significantly improve DWG and FCR of broilers (P>0.05), feed intake was no different among groups (P>0.05). The dietary 0.3%YC improved significantly availability of dietary P by 20.47% and 14.81% respectively, when compared with the control and Flavomycin. The dietary 0.9%YC improved significantly availability of dietary crude fat (P<0.05), in comparison to the control and Flavomycin. YC had no effect on availability of dietary Ca, energy , crude protein (P>0.05). The dietary 0.3%YC improved significantly serum IgG by 12.32% (PO.05), in comparison to the control and Flavomycin, YC had no effect on IgA, IgM, immunal organs (P>0.05). The dietary YC and Flavomycin increased Bifidobacterium concentration and reduces E.coli concentration incaecum (P<0.05); however, the dietary Flavomycin reduced Bifidobacterium and E.coli concentration in caecum (P<.05); the dietary YC reduced NH3 in caecum (P<0.05) and improved structure of intestine, reduces wall depth, increased the villus length. In comparison to the control and Flavomycin, 0.3%YC increased serum T3 by 8.38% and 8.16% (P<0.05), there was on significant difference in serum T4, T3/T4. The dietary YC improved the serum CHOL, SOD and CHOL of chest (P>0.05).In experiment 2: On the base of experiment 1 ,after 0.1%, 0.7%, 0.9%YC were replaced by 750mg/kgSaccharic-terpenin, 0.1%probiotics, 750mg/kgMOS, the experiment was continued, broilers were challenged at day 35 by providing water containing 109 Escherichia coli per milliliter. The situation of disease and death was examined; at day 40, three broilers per group were killed by neck's vein and separated serum to test SOD. Ca, P, TP, BLB, ALB, CHOL; the cecal contents were examined for Escherichia coli.The results showed that : The dietary YC, probiotic, MOS, Flavomycin reduced significantly the disease and death of broilers after challenged by Escherichia coli (P<0.05). In comparison to control, the dietary Flavomycin reduced significantly E.coli concentration in caecum by 75.48% (P<0.05). In comparison to Flavomycin and control, the other supplements had no difference in other hands.The dietary Flavomycin reduced significantly the intestinal wall (P<0.05). There was no difference between groups of 0.5%YC and Flavomycin (P>0.05).Master Candidate: Zhou Shuqin Supervisor: Asso Prof. Sun WenzhiMajor: Animal Nutrition and Feed Science... |
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