8161

7559

كارشناسي ارشد

علوم دامي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1392

دوازده،47ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

رحمان جهانيان

مسعود عليخاني

29/8/92

اميرحسين مهدوي، جهانگير خواجه علي

مهندسي كشاورزي

ID7559

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Effect of Dietary Supplementation of 1 25 Dihydroxy Cholecalciferol on Performance Immune Responses Eggshell Quality and Mineral Digestibility in Aged Laying Hens Mehdi Ahmadi Dastgerdi mehdiahmadi1355@gmail com Sep 15 2013 Department of Animal Sciences College of Agriculture Isfahan University of Technology Isfahan 84156 83111 IRAN Degree M Sc Language Farsi Supervisor Dr Rahman Jahanian r jahanian@cc iut ac ir Abstract The present study was conducted to investigate the effect of active metabolite of vitamin D 1 25 dihydroxy cholecalciferol or calcitriol in comparison with vitamin D 3 on performance egg quality and ileal nutrient digestibility of aged laying hens A total of 150 Hy line W 36 laying hens of 92 wk of age were used in a completely randomized design with 5 replicates of 5 birds each Dietary treatments consisted of the 3 levels of vitamin D 3 d for adaptation and 70 d as main recording period Results showed that during the first 35 d period increasing dietary vitamin D3 significant increases P 0 05 in egg production Also these levels tended P 0 0507 to improve egg mass However in the second 35 d period the moderate levels of vitamin D3 and calcitriol improved egg production egg mass P 0 01 and feed conversion efficiency P 0 05 Among egg quality indexes only eggshell thickness P 0 05 and shell breaking strength P 0 01 were improved by vitamin D level in the first trial period The vitamin source and level hadn t significant effect on antibody production titer against Newcastle disease virus during both 6 and 12 days post vaccine inoculation Hens fed on calcitriol diets had greater quantities of ash and Ca in their eggshell compared with vitamin D3 counterparts However eggshell P content wasn t influenced by the level or source of vitamin D Furthermore dietary calcitriol supplementation resulted in significant P 0 05 increase in tibial ash and tended to increase tibial Ca P 0 0789 and P P 0 0863 Serum mineral analysis showed that source of vitamin D had a considerable P 0 01 impact on serum calcium and zinc concentrations so that birds on calcitriol diets had higher levels of theses two elements in their serum Although ileal digestibilities of crude protein and P weren t affected by dietary treatments source and level of vitamin D had significant impact on Ca and total ash digestibilities The highest digestibility coefficients were achieved by using 62 5 and 10 vitamin D3 and calcitriol respectively The present findings indicate that supplementation of 10 into the aged laying hen s diets in addition to maintaining laying performance could improves both eggshell thickness and strength Keywords Laying hen Vitamin D3 Calcitriol Performance Eggshell Quality Ileal Digestibility PDF created with pdfFactory trial version www pdffactory com

رحمان جهانيان

مسعود عليخاني

اميرحسين مهدوي، جهانگير خواجه علي