اثر متقابل اسيدهاي آلي سيتريك و بوتيريك با سطح پروتئين جيره بر عملكرد، پاسخ هاي ايمني، مولفه هاي خوني و مورفولوژي روده در جوجه هاي گوشتي

چكيده انگليسي :

AbstractThe present study was designed to investigate the interactive effect of dietary organic acid OA supplementation and crude protein CP level on performance blood parameters immunity and gutmorphology of broiler chickens A total of 540 Ross 308 broiler chicks were randomly distributed into the 4replicate pens of each of 9 dietary treatments according to a 3 3 factorial arrangement of treatments Experimental diets consisted of three dietary CP levels Ross values and 1 and 2 percentage points lowerthan and three situations of dietary organic acid supplementation control group or groups supplementedwith 0 25 of citric or butyric acids Average daily gain ADG feed intake ADFI and feed conversionratio FCR were recorded periodically as 1 14 starter 15 28 grower and 29 42 finisher d of age At d12 of age birds were vaccinated against Newcastle disease virus NDV thereafter the serum samples weretaken to evaluate antibody production titers against NDV at d 6 and 12 after vaccine inoculation Similarly antibody responses against infectious bronchitis virus IBV and infectious bursal disease IBD weremeasured after respective antigen inoculations At the final trial day two randomly selected birds perreplicate were slaughtered to measure carcass characteristics Also sections of jejunal epithelial cells wereembedded in 10 formalin solution to evaluate morphological alterations of absorptive cells in response tomentioned dietary modifications Results showed that dietary supplementation of citric and butyric acidscaused significant P 0 01 increase in body weight gain during finisher period compared with birds oncontrol diet however decrease in dietary CP level had no effect on ADG values In addition CP by OAinteraction was shown to significantly affect ADG during both finisher and overall trial periods so that dietary OA supplementation was more effective in diets contain in two higher CP levels Although ADFIwasn t influenced by experimental variables but interactive effect of dietary CP and OA was significant forfeed consumption during finisher and entire experimental periods Dietary inclusion of organic acidsespecially butyrate caused marked P 0 05 decrease in FCR values Also FCR was affected P 0 05 bydietary CP level with the best values assigned to the birds fed on highest CP diet Decrease in dietary CPcontent was associated with decreases in relative weight of liver P 0 05 and carcass percentage P 0 01 and significant increase in abdominal fat Similarly OA supplementation reduced P 0 01 liver weight andimproved P 0 05 carcass percentage Interestingly the relative weight of gizzard was reduced P 0 01 bydietary OA supplementation Dietary reduction of CP caused considerable P 0 05 decrease in relativeweight of bursa of Fabricius while spleen weight was increased in chicks fed on OA supplemented diets The results demonstrated that serum triglycerides high density lipoproteins and low density lipoproteinsweren t affected by OA supplementation or dietary CP level at d 21 of age On the other hand serum uricacid significantly P 0 01 decreased with lowering dietary CP level at both d 21 and 42 of age Antibodytiters against NDV was significantly P 0 01 affected by butyric acid supplemented diets at d 12 postvaccine inoculation however this parameter wasn t influenced by dietary CP level Similarly IBV and IBDantibody responses were significantly P 0 05 improved by dietary OA supplementation Although cryptdepth wasn t affected by dietary treatments villi height to crypt depth ratio decreased by dietary CPreduction From the present findings it can be concluded that dietary supplementation of 0 25 citric andparticularly butyric acid could improve weight gain and feed efficiency and dietary CP content could bereduced by minimum 1 percentage point via dietary addition of citrate or butyrate Keywords Broiler Chicks Dietary Crude Protein Organic Acid Performance Immune Responses Intestinal Morphology

دهقاني تفتي، نغمه

اثر متقابل اسيدهاي آلي سيتريك و بوتيريك با سطح پروتئين جيره بر عملكرد، پاسخ هاي ايمني، مولفه هاي خوني و مورفولوژي روده در جوجه هاي گوشتي

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