اثر سطوح مختلف اسيدهاي آمينه جيره در سنين ابتدايي و نوع تلاقي بر صفات عملكردي، وزن اندام‌هاي ايمني و نسبت هتروفيل به لنفوسيت در جوجه‌هاي گوشتي سويه آرين

The Effect of different dietary amino acid levels in early ages and strain on performance, immune organ weight and heterophile-to-lymphocyte ratio in Arian broiler chickens

اين آزمايش با هدف بررسي اثر كاهش ميزان اسيدهاي آمينه جيره (پيشنهاد آرين و 6 درصدكمتر از آن تا 25 روزگي) و نوع تلاقي (كلاسيك و جديد) روي صفات عملكردي و برخي خصوصيات سيستم ايمني جوجه‌هاي گوشتي آرين انجام شد. تعداد 500 قطعه جوجه يك روزه مخلوط از دو جنس در قالب يك طرح آماري فاكتوريل با 4 گروه آزمايشي و 5 تكرار براي هر گروه طي مدت 44 روز مورد آزمايش قرار گرفتند. ميزان اسيدهاي آمينه جيره با توجه به ميزان ليزين قابل هضم محاسبه شد. در روزهاي 21 و 42 از وريد بال 2 جوجه (نر و ماده) از هر پن خونگيري و سلول هاي هتروسيت و لنفوسيت شمارش شد. صفات عملكردي در سنين مختلف و وزن اندام هاي ايمني در 44 روزگي اندازه گيري شد. در اين آزمايش مصرف خوراك در 18 روزگي و ضريب تبديل خوراك در 18 و 25 روزگي تحت تاثير كاهش ميزان اسيدهاي آمينه جيره، افزايش يافت (0/05

This study was carried out to examine the effect of reducing dietary amino acid (DAA) levels (recommended dose by Arian and 6% less than recommended dose up to 25 d of age) and strain cross (classic and new) on performance and some of immune system characteristics (ISC) of Arian broilers. Five hundred 1-d-old male and female chicks were allocated in four experimental groups with 5 replicates in each group for 44 days and data were analyzed in a factorial experiment with a completely randomized design. The amounts of DAA were calculated according to the amount of digestible lysine. On 21 and 42 d of age, blood sample were taken from 2 birds (male and female) of each pen via the wing vein and heterophile and lymphocyte were counted. The data on performance were recorded in different ages and weights of immune organs were measured in 44 d of age. Feed intake in 18 d of age and feed conversion ratio in 18 and 25 d of age increased significantly by decreasing the DAA (P<0.05). DAA levels and Arian strain caused no significant difference on the body and immune organs weight, heterophile and lymphocyte cells counts and heterophile-to- lymphocyte ratio (H/L). No interactions were found between DAA and strain on performance and ISC. The results at condition of this experiment showed that growth performance of new strain of Arian broiler was the same with classic strain, and 6 % reduction of DAA levels in early age couldn ’t affect performance and H/L ratio.