تاثير سطوح مختلف ويتامين A و روي- متيونين بر عملكرد، پاسخ هاي ايمني و مورفولوژي سلول هاي روده در جوجه هاي گوشتي تحت تنش كوكسيديوز

چكيده انگليسي :

75 Effect of Supplemental Vitamin A and Zinc Methionine on Performance Immunity and Gut Health in Broilers Subjected to Coccidia Infection Roya Shiasi R shiasi3897@gmail com September 22 2013 Department of Animal Science Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisor H Rahmani Prof h rahmani@cc iut ac irAbstractThe current study was conducted to evaluate the effect of dietary supplementation of vit A and Zn Met onperformance immunological responses and intestinal morphology of broiler chicks challenged withcoccidiosis So a total of one day old Ross 308 384 broilers were randomly assigned to the 8 experimentaltreatments with 4 replicates of 12 birds each Dietary treatments included four vitamin A levels 0 10000 15000 and 2000 IU kg more than basal lavel and two levels of ZnMet 0 and 40 mg kg as a 4 2 factorialarrangement that fed during a 42 d feeding trial At 26 d of age birds were orally infected by a mixed ofEimeria family with a 3 cc oocysts per chick The mean of weight gain and feed intake as well as feedconversion ratio were measured as periodically for starter 1 10 d grower 11 24 d and final 25 42 d Antibody titer against Newcastle virus disease bronchitis and sheep red blood cell were evaluated at certaintime after vaccination In addition blood samples were collected to enumerate of differential of leukocytes at42 d of age At 33 and 42 d of age two birds of each replicate were randomly weighed and sacrificed anddeudonal and jejunal samples were taken to evaluate the intestinal histology Results showed that inclusion ofvit A and Zn Met level led to an improvement in daily weight gain during grower phase P 0 01 daily feedintake were not affected by dietary addition of vit A and Zn Met Moreover an increase in vit A and Zn Metlevel had no significant effect on feed conversion ratio during total period of experiment Dietarysupplementation of vit A and Zn Met caused a significant increase P 0 05 in breast weight in final phase but they had no effect on other organ weight Dietary addition of vit A and Zn Met had significant impact onthe relative weight of lymphoid organs and titer antibody against Newcastle virus disease bronchitis andSRBC So an increase in Zn Met and vit A level significantly P 0 05 increased the relative weight of bursaof Fabricius and spleen in final period Additionally inclusion of Zn Met markedly P 0 01 increased theantibody titer against bronchitis virus Also the interaction of Zn Met and vit A had significant p 0 05 influence on antibody titer against SRBC Inclusion of vit A and Zn Met could increase heterophil Lymphocyte number and Hetrophil to lymphocyte ratio so an increase vit A and Zn Met level led to anoticeable P 0 01 heterphil to lymphocyte ratio but their combination had no effect on heterohpil tolymphocyte ratio Furthermore villus height villus width and villus height to crypt depth were no affected bydietary inclusion of vit A and Zn Met An increase in Zn Met level remarkably P 0 001 decreased thevillus apical cell ruin and markedly P 0 0001 increased absorptive area of villus of Jejunum In addition inclusion of vit A could significantly P 0 01 increase absorptive area of villus In general the resultsindicated that although inclusion of the high level of vit A and Zn Met could not improve the performanceresponses of broilers they could affect and improve health condition of villus Moreover inclusion of highlevel of vit A and Zn Met could stimulate immunity against coccidiosis parasite and led to improveimmunological responses in birds challenged with coccidiosisKeywords broiler chicks vitamin A Zn Met coccidiosis performance responses immunological response gut health

شياسي، رويا

تاثير سطوح مختلف ويتامين A و روي- متيونين بر عملكرد، پاسخ هاي ايمني و مورفولوژي سلول هاي روده در جوجه هاي گوشتي تحت تنش كوكسيديوز

پاسخ هاي عملكردي , سلامت روده