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پژوهشهای علوم دامی ایران - سال دهم شماره 4 (زمستان 1397)
  • سال دهم شماره 4 (زمستان 1397)
  • تاریخ انتشار: 1397/12/26
  • تعداد عناوین: 10
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  • علمی پژوهشی - تغذیه نشخوارکنندگان
  • مجید جعفری، رضا ولی زاده *، عباسعلی ناصریان صفحات 435-447
    این آزمایش به منظور تعیین بهترین سن از شیرگیری بره برای افزایش بازده تولیدی و اقتصادی می شها و بره های بلوچی انجام شد. تعداد 30 راس 47 کیلوگرم و 30 راس بره آنها ( 15 راس نر و 15 راس ماده ) با میانگین وزن ± 0/ میش بلوچی تک قلوزا و شکم دوم زایش با میانگین وزن 5 8 و 12 هفتگی بعد ، 4/5 کیلوگرم به طور تصادفی به 3 گروه 10 راسی شامل 5 راس بره نر و 5 راس بره ماده تقسیم شدند. بره ها در سه سن 4 ± 0/05 از زایش به روش ناگهانی از شیر گرفته و می شها نیز خشک شدند. میزان افزایش وزن روزانه، وزن، ماده خشک مصرفی روزانه، فراسنجه های خونی بره ها در هفته دوازدهم بعد زایش، وزن و ماده خشک مصرفی روزانه میش ها در زمان از شیرگیری و نسبت اقتصادی سود به هزینه در هر تیمار با در قالب طرح کاملا تصادفی بررسی شد. بر اساس نتایج به دست آمده، زود از شیرگیری بره ها در سن 4 هفتگی SAS نرم افزار GLM استفاده از رویه موجب بهبود معن یدار در افزایش وزن روزانه، وزن، مقدار ماده خشک مصرفی روزانه در می شها و بره ها و کاهش مصرف شیر توسط بر ه ها شد . سطح سرم خون بره های از شیرگرفته شده در 4 هفتگی در مقایسه با دو گروه دیگر بالاتر بود. نسبت اقتصادی سود به هزینه IGF- و هورمون 1 ALP آنزیم نیز نشان داد از شیرگیری در 4 هفتگی می تواند موجب افزایش معنی دار سود دامدار در مقایسه با دو روش دیگر شود.
    کلیدواژگان: افزایش وزن روزانه، سن از شیرگیری، فراسنجه های خونی، نسبت سود به هزینه
  • زینب غلامی، فرشید فتاح نیا، حسین جهانی عزیزآبادی*، گلناز تاسلی صفحات 449-462
    هدف از انجام این پژوهش بررسی اثر روش های مختلف خشک کردن برگ بلوط گونه Q. persica و افزودن پلی اتیلن گلایکول بر غلظت ترکیبات فنولی و اثر آن برجمعیت پروتوزوا، کل گاز تولیدی و تولید گاز متان در شرایط آزمایشگاه بود. این آزمایش در قالب طرح کاملا تصادفی و به صورت فاکتوریل دو× چهار با دوازده تکرار برای هر تیمار در دو دوره انجام شد. تیمارهای آزمایشی شامل روش‏های مختلف خشک کردن برگ بلوط (خشک کردن در آفتاب، در سایه، در آون و به روش انجماد) با و بدون پلی‎اتیلن‎گلایکول بودند. روش های مختلف خشک کردن بر غلظت کل ترکیبات فنولی، تانن متراکم و تانن قابل هیدرولیز اثر معنی‎داری داشت. اما روش خشک کردن بر محتوای کل تانن تاثیر معنی‎داری نداشت. در همه تیمارهای آزمایشی جمعیت پروتوزوآ تحت تاثیر پلی‎اتیلن‎گلیکول افزایش معنی‎داری را نشان دادند. بیشترین و کمترین جمعیت پروتوزوآ به ترتیب در تیمار خشک کردن با انجماد و آون مشاهده شد. با افزودن پلی‎اتیلن‎گلیکول تولید گاز افزایش غیر معنی داری نشان داد. در همه تیمارها (به جز برگ خشک شده در آفتاب و آون) با افزودن پلی‎اتیلن‎گلیکول تولید گاز متان به طور معنی داری افزایش یافت (6/53 درصد). بیشترین و کمترین درصد متان به ترتیب در تیمار خشک کردن با انجماد و آون (به ترتیب 14 و 7/8 درصد کل گاز تولیدی) مشاهده شد. نتایج پژوهش حاضر نشان داد که خشک کردن با استفاده از آون غلظت کل ترکیبات فنولی و تانن قابل هیدرولیز برگ بلوط و تولید گاز متان ناشی از تخمیر میکروبی برگ را نسبت به سایر روش های خشک کردن به میزان بیشتری کاهش داد. بنابراین با توجه به یافته های این مطالعه به نظر می رسد خشک کردن برگ بلوط با آون روش مناسب تری می‎باشد.
    کلیدواژگان: برگ بلوط، پروتوزوآ، ترکیبات فنولی، روش‎های خشک کردن، گاز متان
  • شهرام نجفی، محمد مهدی طباطبایی، خلیل زابلی*، علی اصغر ساکی، احمد احمدی صفحات 463-476
    این آزمایش به منظور بررسی تاثیر موننسین و شکل فیزیکی دانه جو (پرک کردن) بر قابلیت هضم اجزای جیره و متابولیسم پروتئین در گوسفند مهربان انجام شد. بدین منظور از تعداد 24 راس گوسفند نر مهربان با میانگین وزن 15/6 ± 98/52 کیلوگرم به صورت آزمایش فاکتوریل 2×2 در قالب طرح کاملا تصادفی استفاده شد. تیمارهای آزمایشی شامل جیره های حاوی 1) دانه جو کامل، 2) دانه جو کامل به همراه موننسین، 3) دانه جو پرک شده و 4) دانه جو پرک شده به همراه موننسین بودند. مقدار موننسین در تیمارهای مربوطه 30 میلی گرم به ازای هر کیلوگرم خوراک مصرفی بود. آزمایش تعیین قابلیت هضم به صورت جمع آوری مستقیم مدفوع (روش درون تنی) انجام شد. خون گیری در روز آخر آزمایش (در ساعات 1 و 5 بعد از خوراک دهی صبح) و جمع آوری ادرار در طول کل دوره آزمایش انجام گرفت. نتایج نشان داد اثر اصلی شکل فیزیکی دانه جو (پرک کردن) باعث کاهش قابلیت هضم ماده خشک و ماده آلی شد. اما مصرف موننسین و اثر متقابل بین موننسین و شکل فیزیکی دانه اثری بر آنها نداشت. قابلیت هضم سایر مواد مغذی جیره تحت تاثیر شکل فیزیکی دانه جو و مصرف موننسین قرار نگرفتند. ابقاء نیتروژن، نیتروژن میکروبی سنتز شده و آلانتوئین دفعی تحت تاثیر شکل فیزیکی دانه جو قرار نگرفت. اما مصرف موننسین سبب افزایش ابقاء نیتروژن و کاهش آلانتوئین دفعی شد. غلظت گلوکز و اوره پلاسما نیز تحت تاثیر تیمارهای آزمایشی قرار نگرفتند. به طور کلی، شکل فیزیکی دانه جو سبب افزایش قابلیت هضم و بهبود متابولیسم نیتروژن نشد. اما مصرف موننسین ابقاء نیتروژن در گوسفندان را افزایش داد.
    کلیدواژگان: ابقاء نیتروژن، پرک کردن، دانه جو، قابلیت هضم و موننسین
  • فاطمه گنجی، مسلم باشتنی *، همایون فرهنگ فر، سید احسان غیاثی صفحات 477-488
    این مطالعه به منظور بررسی ارزش غذایی، خصوصیات آنتی اکسیدانی، ترکیبات فنولی برگ بنه در مراحل مختلف رشد و همچنین قابلیت هضم شکمبه ای - رو ده ای برگ بنه به روش کیسه های نایلونی انجام شد. برگ بنه طی سه مرحله از کوهپایه های اطراف شهرستان بیرجند جمع آوری و خشک گردید. ترکیب شیمایی، فراسنجه های تجزیه پذیری، مقدار کل ترکیبات فنولی، تانن و فعالیت آنتی اکسیدانی به وسیله 2،2- دی فنیل-1- پیکریل هیدرازیل (DPPH) اندازه گیری شد. با پیشرفت مرحله رشد درصد ماده خشک، چربی خام، NDF و ADF افزایش یافت. در مراحل اولیه رشد بیشترین میزان ترکیبات فنولی و آنتی اکسیدانی مشاهده شد. مقدار کل ترکیبات فنولی و آنتی اکسیدان کل برگ بنه در پایان مرحله رشد به ترتیب 36/5 و 27/83 درصد گزارش شد. بیشترین اسید چرب غیراشباع برگ بنه اسید لینولنیک به میزان 54/26 درصد گزارش شد. بخش سریع تجزیه ماده خشک برگ بنه 03/28 درصد و تجزیه پذیری موثر آن در نرخ عبور 04/0، 06/0 و 08/0 به ترتیب 29/48، 39/43 و 40/40 درصد بود. کمترین نرخ تجزیه پذیری (c) در مورد پروتئین خام دیده شد (0137/0). قابلیت هضم ماده خشک در کل دستگاه گوارش بیشتر از قابلیت هضم پروتئین خام بود. برگ بنه به دلیل دارا بودن اسید لینولنیک به عنوان یک منبع امگا-3 و نیز ترکیبات فنولی و آنتی اکسیدانی بالا دارای ارزش غذایی بالایی است و می توان در جیره نویسی دام ها به منظور غنی سازی و افزایش پایداری اکسیداتیو محصولات دامی نظیر شیر و گوشت، از این اطلاعات بهره برد.
    کلیدواژگان: آنتی اکسیدان، برگ بنه، تجزیه پذیری، کیسه های نایلونی، مرحله رشد
  • علمی پژوهشی- تغذیه طیور
  • حسن کیهانی یزدی، سیدجواد حسینی واشان *، نظر افضلی، محسن مجتهدی، علی الله رسانی صفحات 489-500

    هدف از این آزمایش، ارزیابی اثرات جاذب آلومینوسیلیکاته نانو ساختار فرآوری شده فیزیکی (BF) بر عملکرد، وزن نسبی اجزای لاشه، فراسنجه های بیوشیمیایی خون جوجه های گوشتی تحت چالش با آفلاتوکسین B1 بود. برای این منظور از 160 قطعه جوجه خروس یک روزه راس 308 در یک طرح کاملا تصادفی با 5 تیمار و 4 تکرار و 8 پرنده در هر تکرار به مدت 35 روز استفاده شد. تیمارهای آزمایشی شامل: شاهد منفی (C)، شاهد مثبت (جیره پایه + آفلاتوکسینAFB1) و سه سطح: 0/25، 5/0 و 75/0 درصد جاذب آلومینوسیلیکاته نانو ساختار فرآوری شده فیزیکی (BF) که به جیره پایه آلوده به آفلاتوکسین AFB اضافه گردید بود. مقدار آفلاتوکسین افزوده شده به جیره های آلوده در دوره آغازین و رشد برابر ppb500 و در دوره پایانی ppb1000 آفلاتوکسین بود. در 35 روزگی، خون گیری از یک پرنده از هر تکرار به عمل آمد و یک قطعه پرنده کشتار و اجزای لاشه آن توزین و وزن نسبی آن ها تعیین گردید. نتایج نشان داد که افزودن 0/25BF به جیره آلوده باعث افزایش مصرف خوراک، کاهش درصد چربی بطنی و LDL سرم خون در دوره پرورش گردید (0/05 < P). بالاترین وزن بدن در تیمار 5/0 درصد BF نسبت به شاهد مشاهده شد (0/05 < P). ضریب تبدیل خوراک در جوجه های تغذیه شده با AFB در مقایسه با تیمار شاهد به طور معنی داری افزایش یافت (0/05 < P). کمترین غلظت تری گلیسرید در شاهد مثبت در مقایسه با گروه دریافت کننده همزمان آفلاتوکسین و 0/75 درصد BF مشاهده شد. میزان فعالیت آنزیم آلانین آمینوترانسفراز (ALT) در تیمار AF نسبت به شاهد منفی و 5/0 درصد BF افزایش معنی داری داشت. بنابراین یافته های این آزمایش آفلاتوکسین باعث کاهش شاخص های عملکردی می شود و افزودن جاذب آلومینوسیلیکاته نانو ساختار فرآوری شده فیزیکی در سطح 5/0 درصد به جیره های آلوده به آفلاتوکسین، اثرات منفی آفلاتوکسین را بر عملکرد بهبود بخشیده و درصد چربی بطنی را کاهش می دهد.

    کلیدواژگان: آفلاتوکسین B1، اجزای لاشه، بنتونیت فرآوری فیزیکی، جوجه گوشتی، عملکرد
  • بهنام احمدی پور *، فریبرز خواجعلی صفحات 501-512

    این تحقیق جهت بررسی تاثیر استفاده از پودر برگ گیاه گزنه بر وزن نسبی برخی اندام ها، فراسنجه های سرمی و خونی و بیان ژن های نیتریک اکسید سنتتاز (NOS) و اندوتلین1 (ET1) در قلب و ریه جوجه های گوشتی پرورش یافته در ارتفاع بالا (2100 متر از سطح دریا) در قالب طرح کاملا تصادفی با چهار تیمار اجرا شد. تیمارهای آزمایشی سطوح مختلف پودر برگ گیاه گزنه (صفر، 5/0، 1 و 5/1 درصد) در جیره جوجه های گوشتی بود. نتایج آزمایش نشان داد که افزودن پودر برگ گیاه گزنه به خوراک، موجب کاهش معنی دار وزن نسبی قلب و کبد و همچنین کاهش فعالیت آنزیم های آلکالین فسفاتاز، آلانین آمینو ترانسفراز و آسپارتات آمینو ترانسفراز در سرم جوجه های گوشتی شد (05/0P<). در مقابل، میزان پروتئین تام سرم، آلبومین و نیتریک اکسید سرم در تیمارهای حاوی گزنه افزایش معنی داری نسبت به گروه شاهد نشان داد (05/0P<). سطوح 1 و 5/1 درصد گیاه گزنه موجب افزایش معنی دار بیان ژن نیتریک اکسید سنتتاز (NOS) در قلب و ریه و کاهش معنی دار بیان ژن اندوتلین1 (ET1) در این دو اندام گردید (05/0P<). به طور کلی نتایج این مطالعه نشان داد که افزودن سطوح 1 و 5/1 درصد پودر برگ گیاه گزنه به خوراک جوجه های گوشتی پرورش یافته در ارتفاع بالا دارای اثرات مثبتی بر شاخص های فشار خون ریوی می باشد.

    کلیدواژگان: بیان ژن، جوجه گوشتی، فراسنجه های سرم، فشار خون ریوی، گیاه گزنه
  • حمید طیموری، حیدر زرقی *، ابوالقاسم گلیان صفحات 513-523
    این مطالعه به منظور بررسی اثر مکمل آنزیمی "سلولاز-بتاگلوکاناز-زایلاناز" بر میزان انرژی قابل سوخت وساز ظاهری تصحیح شده برای ازت (AMEn)، قابلیت هضم ظاهری پروتئین خام (CPD) و قابلیت هضم ماده خشک (DMD) دو واریته جو بدون پوشینه در جوجه های گوشتی به روش جمع آوری کل مدفوع با استفاده از تعداد 64 قطعه جوجه خروس گوشتی"سویه راس308" در سن 23-16 روزگی انجام شد. آزمایش در قالب یک طرح کاملا تصادفی به روش فاکتوریل 2×2 شامل دو واریته جو بدون پوشینه (بومی طبس و HMB-83-7) با و بدون افزودن مکمل آنزیمی، با 4 تیمار، 4 تکرار و 4 قطعه پرنده در هر تکرار انجام شد. جیره های آزمایشی به نحوی تنظیم شدند که غلات مورد آزمایش تنها منابع تامین کننده انرژی و پروتئین خام جیره ها باشند. میزان DMD، CPD و AMEn جو بدون پوشینه به ترتیب 80/2±39/64 درصد، 66/7±50/59 درصد و 212±3034 کیلوکالری در کیلوگرم ماده هوا خشک به دست آمد. میزان AMEn، DMD و CPD در جو بدون پوشینه واریته بومی طبس به طور معنی داری از واریته HMB-83-7 بیشتر بود. افزودن مکمل آنزیمی باعث افزایش AMEn، DMD و CPD جو بدون پوشینه به میزان 41/2، 18/5 و 93/5 درصد نسبت به مقدار برآورد شده برای جیره های بدون آنزیم شد. بر اساس نتایج این آزمایش میزان AMEn، قابلیت هضم ماده خشک و پروتئین خام جو بدون پوشینه تحت تاثیر واریته واقع است. افزودن آنزیم های برون زادی به جیره باعث بهبود انرژی قابل سوخت وساز ظاهری تصحیح شده برای ازت، قابلیت هضم ماده خشک و پروتئین خام جو بدون پوشینه می شود.
    کلیدواژگان: آنزیم، انرژی قابل سوخت وساز، جو بدون پوشینه، جوجه های گوشتی، پروتئین خام
  • فاطمه صاحبی اعلا، احمد حسن آبادی *، ابوالقاسم گلیان صفحات 525-540
    هدف از این آزمایش بررسی تاثیر سطوح و منابع متیونین و جایگزینی آن با بتائین بر عملکرد و صفات لاشه جوجه های گوشتی در دو شرایط دمایی متداول و تنش گرمایی از سن 1 تا 42 روزگی بود. 1200 قطعه جوجه گوشتی راس 308 در قالب طرح کاملا تصادفی با آرایش اسپلیت فاکتوریل با سه سطح متیونین (30 درصد کمتر از احتیاجات، احتیاجات، 30 درصد بیشتر از احتیاجات)×دو منبع متیونین (دی ال و یا ال-متیونین)× دو حالت جایگزینی و یا عدم جایگزینی بتائین مصنوعی با 30 درصد متیونین مصنوعی) × دو شرایط دمایی با 5 تکرار و 10 پرنده در هر تکرار استفاده شد. دمای یکی از سالن ها متداول و دیگری از 24-10روزگی روزانه به مدت شش ساعت در °C32 حفظ شد. مصرف خوراک پرندگان تغذیه شده با جیره دارای متیونین بالاتر از احتیاجات به طور معنی داری کمتر از دو سطح دیگر بود. افزایش وزن در جیره های برابر با احتیاجات و بیشتر از احتیاجات متیونین به طور معنی داری بالاتر بود. ضریب تبدیل در جیره دارای ال-متیونین کمتر از احتیاجات، نسبت به دی ال-متیونین در همان سطح بهبود معنی داری داشت. شاخص کارایی تولید با افزایش سطح دی ال-متیونین جیره بهبود یافت. کمترین سطح متیونین کاهش معنی داری در وزن لاشه و ران نسبت به بالاترین سطح متیونین داشت. بالاترین سطح متیونین در دمای متداول، وزن سینه بالاتری نسبت به همان سطح در تنش گرمایی داشت. تنش گرمایی عملکرد و تولید لاشه را کاهش و چربی شکمی و تلفات را افزایش داد. به طورکلی، بتائین با 30درصد از متیونین مصنوعی جیره قابل جایگزین است و همچنین، ال-متیونین ضریب تبدیل خوراک را نسبت به دی ال-متیونین بهبود بخشید.
    کلیدواژگان: بتائین، تنش گرمایی، جوجه گوشتی، عملکرد، متیونین
  • علمی پژوهشی- ژنتیک و اصلاح دام و طیور
  • حمیدرضا ایزدنیا، مجتبی طهمورث پور*، محمدرضا بختیاری زاده، محمدرضا نصیری، سعید اسماعیل خانیان صفحات 541-552
    باقیمانده خوراک مصرف شده (RFI) تفاوت بین مقدار واقعی خوراک مصرف شده با مقدار مورد انتظار آن در هر دام می باشد. انتخاب برای بهبود بازده خوراک دام از طریق RFI به دلیل استقلال فنوتیپی آن از وزن متابولیکی بدن و افزایش وزن بدن پیشنهاد شده است. جهت کشف ارتباط بین ساختار بیان ژن ها و ایزو فرم های مرتبط با آن ها و همچنین نقش تنظیمی آن ها در باقیمانده خوراک مصرف شده در مرغ، پروفایل ترانسکریپت های کبد در سن 42 روزگی در دو گروه مرغان بومی اصفهان و مرغان سویه راس مورد بررسی قرار گرفت. باقیمانده خوراک مصرف شده جوجه های بومی اصفهان و سویه راس به ترتیب(+13.430±5.393 g/day) و(-11.212±4.435g/day) بود. آنالیز تفرقی بیان با استفاده از بسته نرم افزاری Cuffdiff (v2.2.1) برای بیش از 45070 ایزو فرم مربوط به 19003 ژن انجام شد. طبقه بندی ایزو فرم های بر اساس نتایج Cuffcompare تعداد 16121 ایزو فرم در مرغ بومی اصفهان کاهش بیان نشان دادند و 28949 ایزو فرم افزایش بیان نشان دادند. از کل ایزو فرم های شناسایی شده 21081 ایزو فرم جدید بودند. 206 ایزو فرم تغییر بیان یافته بین مرغ سویه راس و مرغ بومی اصفهان شناسایی شد. از بین این ایزو فرم ها، در مرغ بومی اصفهان نسبت به مرغ سویه راس، تعداد 126 ایزو فرم مربوط به 99 ژن کاهش و 80 ایزو فرم مربوط به 55 ژن، افزایش بیان نشان دادند. نتایج تجزیه و تحلیل عملکردی ژن ها نشان داد ایزو فرم های کاهش بیان یافته ی گونه بومی عمدتا در فرآیندهای زیستی مختلف ازجمله واکنش دهی به استرس، پاسخ به ترکیب حاوی اکسیژن، واکنش دهی به چربی، توسعه ارگان های حیوان، واکنش دهی به مواد مغذی، واکنش دهی به سیتوکین ها، پاسخ به سطوح تغذیه، فرآیند بیوسنتز مولکول های تکی، فرآیندهای بیوسنتز چربی ها و فرآیندهای تنظیم ارگانیزم های چندگانه نقش داشتند. شناسایی ژن های اختلاف بیان یافته و ایزو فرم های آن ها بین جوجه های دو نژاد منجر به شناسایی ژن های کاندید مهم برای برنامه های به نژادی، ازجمله RSAD2، IL15، EGR1 و DUSP16 شد. این ژن ها می توانند با باقیمانده بالاتر نژاد بومی مرتبط باشند.
    کلیدواژگان: ایزو فرم، باقیمانده خوراک مصرف شده، مرغ، RNA seq
  • فرهاد غفوری کسبی، علی گودر تله جردی * صفحات 553-560
    هدف از این تحقیق بررسی عملکرد الگوریتم هوشمند تجزیه مقدار تکین31(SVD) در بازیابی ژنوتیپ های از دست رفته بود. به این منظور، ژنومی متشکل از 1 کروموزوم به طول یک مورگان که بر روی آن در سناریوهای مختلف به ترتیب 500، 1000، 1500، 2000، 2500 و 3000 نشانگر تک نوکلئوتیدی دو آللی (SNP) با فراوانی اولیه یکسان 5/0 توزیع شده بود برای 1000 فرد شبیه سازی شد. در ادامه جهت ایجاد فایل اطلاعات در چهارچوب اطلاعات”تعیین ژنوتیپ با توالی یابی“42(GBS) اطلاعات ژنوتیپی به ترتیب 5%، 10%، 25%، 50%، 75% و 90% از SNPهای افراد از ماتریس ژنوتیپی حذف شده و مجددا توسط روش SVD بازیابی شدند. درصد ژنوتیپ های به درستی بازیابی شده (نسبت تعداد ژنوتیپ های به درستی بازیابی شده به کل ژنوتیپ های از دست رفته) به عنوان شاخصی از صحت بازیابی ژنوتیپ (r) در سناریوهای مختلف مورد استفاده قرار گرفت. صحت بازیابی ژنوتیپ های از دست رفته با استفاده از روش SVD قابل توجه بود به طوری که با افزایش درصد ژنوتیپ های از دست رفته تا 50%، SVD با صحتی در حدود 80% ژنوتیپ های از دست رفته را بازیابی نمود. در سناریوهای 75% و 90% ژنوتیپ از دست رفته صحت بازیابی ژنوتیپ کاهش یافته و به ترتیب 70% و 48% بود. در شرایط برابر از تعداد نشانگر و درصد ژنوتیپ از دست رفته، با افزایش تعداد افراد حاضر در جمعیت از 1000 به 2000 فرد، توانایی بازیابی ژنوتیپ توسط روش SVD افزایش یافت. در یک درصد ثابت از ژنوتیپ های از دست رفته، با افزایش تعداد نشانگر صحت بازیابی ژنوتیپ افزایش یافت به نحوی که با افزایش تعداد نشانگر از 500 به 3000 نشانگر، حدودا 10% به صحت بازیابی ژنوتیپ افزوده شد. یک رابطه معکوس بین میزان فراوانی آلل نادر (MAF) و r مشاهده شد به گونه ای که با افزایش MAF از 01/0 به 40/0 صحت بازیابی ژنوتیپ به میزان 8 درصد کاهش یافت. به طور کلی نتایج این تحقیق نشان داد که الگوریتم SVD با صحت بالایی می تواند ژنوتیپ های از دست رفته را بازیابی کند به ویژه زمانی که درصد ژنوتیپ های از دست رفته کم باشد، اندازه جمعیت بزرگ باشد و فراوانی آلل نادر نیز پایین باشد.
    کلیدواژگان: الگوریتم SVDI، بازیابی ژنوتیپ، SNP
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  • Majid Jafari, Reza Valizadeh *, Abbas Ali Naserian Pages 435-447
    Introduction
    Early-weaning of lambs could led to improve the efficiency and profitability of Baluchi ewes and lambs in Iranian sheep husbandry. Early weaning of lambs can stimulate growth of gastrointestinal tract, minimize weaning stress and guarantee post-weaning health. However, results on weaning age of lambs vary widely because of the effects of available feeds, feeding management and genotype. Iranian rural and nomadic herders are usually weaning their lambs when the pastures are in good condition. Reducing the duration of suckling lamb can be associated with optimal results, including sales of surplus milk of ewes and helping the herder household’s economy and entering the early weaned lambs into the feedlot systems and breed the ewes in a well-controlled condition. The aim of this study was to determine the appropriate weaning age of Baluchi lambs to achieve the better production and economic performances as well as the higher ewe's reproductive efficiency.
    Materials and Methods
    Thirty monoparous Baluchi ewes in their second lambing with an average body weight of 47± 0.5 (Kg) and their lambs (15 males and 15 females with an average birth weight of 4.5 ± 0.05 Kg) were allocated to the experimental groups randomly. The lambs were left with their mothers for 3 days, in order to consume adequate colostrum and then were divided into 3 groups according to their gender (5 males and 5 females in each group) and kept in individual boxes. The experimental ewes were also kept separately in individual boxes. These lambs were allowed to be with their mothers twice a day for 2 hours. Lambs had free access to water and TMR ration including 10% Alfalfa leaves and 90% concentrate. Ewes also had free access to water and a TMR ration containing 65% alfalfa hay and 35% concentrate. The respective lambs were weaned at ages of 4, 8 and 12 weeks, abruptly and fed with the above noted TMR ration. The birth weight of each lamb and the weight of ewes were recorded at birth and until the end of the test weekly, each of the ewes and lambs were weighed individually before morning feeding. During the experiment, every two weeks, samples were taken from forage, consumed concentrate and existing residues, and their dry matter and nutrient content were determined. The average daily weight gain, weight fluctuations, dry matter intake, milk consumption and blood parameters at age of 12 weeks in lambs, weight fluctuations, dry matter intake at weaning time in ewes and benefit to cost ratio were measured. Data were analyzed with Proc GLM of SAS (9.1) software in completely randomized design.
    Results and Discussion
    Based on the results, early weaning of lambs at age of 4 weeks led to a significant (P<0.05) improvement in average daily weight gain, body weight, dry matter intake, reduction in milk consumption at the end of week 12 by lambs, and improvement in body weight and dry matter intake at the weaning time by ewes. Also, the daily milk consumption of lambs showed that the production of milk decreased gradually from the ninth week after lambing. ALP enzyme levels and IGF-1 hormone in serum of lambs weaned at age of 4 weeks were higher in comparison with the other 2 groups. In this experiment, the average cost of feed for lambs weaned at age of 4 weeks was significantly higher than the other two groups, and in the ewes, this ratio was in contrast. On the other hand, the average cost of milk consumed by lambs in the three groups was completely reverse the feeds and the differences between groups were significant. The cost of labor was also significant in the groups due to the variability of the number of days. Average weight loss of ewes from lambing to weaning their lambs at age of 4 weeks was significantly lower than the other two groups. The average benefit from lamb weight gain in the group weaned at age of 4 weeks was significantly higher than the other two groups. Also, the benefit from ewe weight gain from the weaning to mating (2 weeks after weaning) was significantly higher in the ewes weaned their lambs at age of 4 weeks than in the other two groups. The benefit to cost indicator showed weaning of lambs at age of 4 weeks could be a suitable and economical management practice in rural and nomadic situation in sheep industry.
    Conclusion
    The obtained results revealed that early weaning of lambs (at age of 4 weeks) may be regarded as a method of lambs and ewes' management in Iranian sheep husbandry. Preparing ewes for the next pregnancy and reducing the lambing interval are the noticeable results. The offered feeds can be used efficiently, and ewe's readiness for the next pregnancy increased by lowering metabolic stress. Furthermore, according to the benefit to cost ratio indicator, better economical outcome could be resulted.
    Keywords: Age of weaning, Benefit to cost ratio, Blood parameters, Body weight, Early-weaning
  • Zainab Gholami, Farshid Fattahnia, Hossein Jahani, Azizabadi *, Golnaz Taasoli Pages 449-462
    Introduction
    Zagros forests that are classified as semi-arid forests, approximately includes around 40 percent of the Iran forests. Dominant tree species of Zagros forests is Oak trees. Oak leaves are an inexpensive and available feed source for ruminant, in particular in low forage seasons. The main problem for the use of Oak leaves and fruit are their phenolic compounds and its negative effects on animal performance at high concentration. The negative effects of high concentration of tannin and phenolic compounds on ruminant performance dependent on the kind and concentration of phenolic compounds, diet composition, and animal species. There are evidence that supplementation of polyethylene glycol (PEG) at high concentration of phenolic compounds resulted in a decrease of the negative effect of phenolic compounds. In contrast, low concentration of phenolic compounds resulted in an improvement in daily gain, milk production, ovulation rate and a decrease in methane and ammonia production. The objective of this study was to investigate the effect of different drying methods of oak leaves (Q. persica) on the concentration of phenolic components of dried leaves and PEG supplementation on in vitro protozoa population and total gas and methane production.
    Materials and Methods
    This experiment was conducted in a completely randomized design with a 4× 2 factorial arrangement of treatments to investigate the effects of dryings methods (sunshine, shadow, oven and freeze drying ) on the concentration of phenolic compounds of Oak leaves and effects of PEG supplementation on in vitro ruminal microbial fermentation of dried Oak leaves. An in vitro gas production technique was used to measure the effects of drying methods and PEG supplementation on total gas and methane production and protozoa abundance with fermentation of Oak leaves. Rumen content was obtained from two fistulated sheep (39±4.5 kg body weight) before morning feeding. The ruminal content was immediately strained through four layers of cheesecloth. Animals were fed twice daily with a 50:50 alfalfa hay: concentrate diet that formulated for maintenance requirements. In the laboratory, under anaerobic conditions, 37.5 mL of buffered rumen fluid (ratio of rumen fluid to buffer was 1:2) was added into 120 mL bottles containing 0.375 g of ground Oak leaves with (0.75g) or without PEG (12 replicates for each treatment in two runs). The buffer was prepared as proposed by McDougall. Bottles were sealed and placed in shaking water bath for 96 h at 38.6°C. Headspace gas pressure was recorded using a pressure transducer at 2, 4, 6, 9, 12, 24, 48, 72 and 96 h of the incubation. Methane production and protozoa population were determined at 24 h of incubation. The concentration of phenolic compounds, condensed and hydrolysable tannins were determined.
    Results and Discussion
    Results of the present study showed that concentration of phenolic compounds, condensed and hydrolysable tannins affected by drying methods (P<0.01), but total tannins was not affected (P>0.01). In all experimental treatments, the protozoa population was increased by PEG supplementation (P<0.01). The highest and the lowest protozoa population were observed in freeze and oven drying methods, respectively (P<0.05). In all treatment (except for sunshine and oven drying) adding PEG resulted in a significantly increased (P<0.01) in the methane production after 24 h of incubation. It is notable that the highest and the lowest percentage of methane production were observed in freeze and oven dryings methods, respectively (P<0. 01). The effect of drying method on the gas production was not significant (P<0.05) and the addition of PEG resulted to numerically increase in gas (P>0.05). Although, gas production at 24h of incubation not affected by treatments, but results of this experiment demonstrated an increase in 96h gas production with PEG supplementation.
    Conclusion
    The results of the present study demonstrated that the oven drying of oak leaves resulted in a further reduction in total phenolic compounds and hydrolysable tannins concentration and the most decrease in methane production due to microbial fermentation of oak leaves, relative to the control. In addition, it appears that PEG supplementation not recommendable method for decrease negative effects of tannins, because resulted in an increase in the methane production.
    Keywords: Drying methods, Methane production, Oak leaves, Phenolic compound, Protozoa
  • Shahram Najafi, Mohammad Mehdi Tabatabaei, Khalil Zaboli *, Ali Asghar Saki, Ahmad Ahmadi Pages 463-476
    Introduction
    In ruminants, dietary manipulation such as applying feed additive or increasing fermentable carbohydrate in diet, improve rumen fermentation and enhance animal performance. Monensin, as a feed additive, increases propionate production, decreases ammonia production and protein degradation in rumen, this lead to improving energy and protein utilization. In addition, grain processing effects on starch fermentation; this could be increasing availability of energy for ruminal microorganisms. One of these processing methods is cracking barley grain. Since, monensin may be influenced on this processing and starch fermentation pattern, therefore the aim of this study, was evaluated the effects of monensin applied in diet and grain processing (cracked barley grain) on nutrients digestibility and protein metabolism in Mehraban sheep.
    Materials and Methods
     In this trial, 24 Mehraban male sheep with an average body weight of 52.98 ± 6.15 kg were used on 2 × 2 factorial experiment in a completely randomized design. Experimental factors were included the effects of monensin (diets containing monensin vs. without monensin) and physical form of barley grain (whole grain vs. cracked grain) as fallowing explanation. Sheep were kept in individual stalls for compatibility to the new environment and experimental conditions for 7 days. Then, were randomly divided into 4 groups (treatments) based on body weight and transferred to metabolic cages to determine the nutrients digestibility and nitrogen retention. The treatments were: Barley grain, Barley grain + monensin, cracked barley grain and cracked barley grains + monensin. Monensin was added to the related treatments in 30 mg per kg of feed intake. Determination of nutrients digestibility was conducted by directly collection of feces (in vivo method) for 14 days (the feces and urine samples were taken at the 7 final days). The experimental diets (40% forage and 60% concentrate) were offered twice in daily at morning (8:00 h) and evening (16:00 h). Urinary nitrogen, allantoin excretion, and chemical composition of feeds and feces (dry matter, organic matter, crude protein, ether extract, crude fiber and nitrogen free extract) were determined. Microbial protein synthesis was estimated by measuring the urinary allantoin excretion. Blood samples were taken on the final day (at 0 and 5 hours after the morning feeding) for determination of plasma glucose and urea concentration.
    Results and Discussion
     The results have shown that the physical form of barley grain significantly decreased dry matter and organic matter digestibility (P<0.05). Dry matter and organic matter digestibility in treatments with whole barley grain were 73.82 and 74.94 and in treatments with cracked barley grain were 71.58 and 72.84 percentage, respectively. Other nutrients digestibility (crude protein, ether extract, crude fiber and nitrogen free extract) were not affected by physical form of barley grain. Also, using of monensin and physical form of barley grain had no effect on dry matter and nutrients digestibility. Nitrogen metabolism parameters (nitrogen intake and % nitrogen in feces, urine and retention) were not affected by physical form of barley grain. Since, crude protein percentage in all treatments was equal, and dry matter intake was adjusted based on animal body weight and was in a similar range, therefore the nitrogen intake was similar in all treatments and there was no differences between them. But, % nitrogen retention significantly was increased by monensin using (P<0.05) and its amount were 21.23 and 26.33 (% of N intake) for treatments with and without monensin, respectively. Monensin prevents the ruminal proteolytic bacteria, and decreases ammonia production and deamination of amino acids in rumen. Thus, it prevents the loss of protein in the rumen, which result is increasing nitrogen retention. Allantoin excretion, microbial nitrogen synthesis, efficiency of microbial nitrogen and urinary urea were similar in the treatments with whole barley grains and cracked barley grains and there were no significant differences between them. Using of monensin significantly decreased allantoin excretion (P<0.05) and its value were 0.32 and 0.23 g/dl in treatments with and without monensin, respectively. Plasma glucose and urea concentrations (at 0 and 5 hours after the morning feeding) were not affected by the physical form of barley grain, monensin and treatments response. Plasma glucose and urea concentrations were 63.52, 67.88, 64.26, 65.48 mg/dl and 17.05, 15.70, 15.74, 14.75 mg/dl for treatments 1, 2, 3 and 4 at 0 hour after morning feeding, respectively. These parameters were 67.50, 66.86, 71.48, 68.06 mg/dl and 17.06, 14.04, 16.94, 14.87 mg/dl at 5 hour after morning feeding, respectively.
    Conclusion
    Generally, nutrients digestibility, nitrogen retention and microbial nitrogen synthesis were not increased by physical form of barley grain. But, increased nitrogen was found by monensin in the sheep.
    Keywords: Barley grain, Cracked barley, Digestibility, Monensin, Nitrogen retention
  • Fatemeh Ganji, Moslem Bashtani *, Homayun Farhangfar, Seyed Ehsan Ghiasi Pages 477-488
    Introduction
    This study was carried out to investigate the chemical composition, antioxidant properties and phenolic compounds of Pistacia atlantica leaf at different stages of growth. Intestinal digestibility of determined by nylon bags method.
    Materials and Methods
     In order to prepare experimental treatments, Pistacia atlantica leaf (PAL) were collected and dried in three stages (early growing season, mid and end of growing season) from foothills of the around the city of Birjand. The treatments were: 1. PAL in early growing season, 2. PAL in middle of growing season, and 3. PAL at the end of growing season. Neutral detergent fiber and acid detergent fiber was determined. The total amount of phenolic compounds was measured. The total amount of tannins was obtained by calculating the difference between before and after the reaction with polyvinyl pyrrolidone (PVP). Condensed tannin was measured. Antioxidant activity was measured by 2, 2 diphenyl-1-picaril hydrazil (DPPH). To investigate nutritional value of Pistacia atlantica leaf (PAL) by nylon bags method, two Holstein cows fitted with a flexible rumen fistula, fed forage and concentrate in total mixed ration (TMR) at maintenance level twice daily. To determine degradability coefficients, 5 g of DM of PAL sample (ground using 2 mm screen mill) were placed in individual polyester bags and feed samples were incubated for 0, 2, 4, 8, 12, 16, 24, 48, 72, 96 and 120 h. Also, ruminal and post ruminal digestibility were determined with the incubation of samples for 16 hours in the rumen by Daisy system.
    Results and Discussion
     The results showed with the advance stage of growth increased, percentage of dry matter, Ash, NDF and ADF. The highest amount of dry matter belonged to the end of the growing season (49.41%) and the lowest was related to the beginning of the growing season (19.51%). The highest amount of crude protein observed at the first stage (early growth) (16.41%) and the lowest at the end of the growing season (P<0.05). With the advancement of the growth stage, the percentage of NDF and ADF was increased (P <0.05). The highest average crude fat was related to the second stage (5.62%) and the lowest average was observed in the first stage (1.82%). The highest average ash was related to the end of growing season (7.27%) and the lowest average was observed in the first stage (5.58%). The highest antioxidant and phenolic compounds was observed in the early stages of growth, this amount decreased in the third stage. The most unsaturated fatty acids of this oil were linolenic acid (26.54%), linoleic acid (10.88%) and oleic acid (12.5%).Also the most saturated fatty acid of this oil was palmitic acid (18.02%). Pistacia leaf oil used in the experiment was contain a 44.85 % saturated fatty acids, 17.83 % unsaturated fatty acid with one double bond, 10.88 % unsaturated fatty acid with two double bonds and 26.54 % unsaturated fatty acids with three double bonds. With increasing incubation time degradability of dry matter and crude protein increased. The rapid part degradation of the dry matter was 28.33% and its effective degradation at the passage rates of 0.04, 0.06 and 0.08 was 48.29, 43.39 and 40.40% respectively. The lowest constant degradation rate (c) was found for crude protein (0.0137). Most effective degradability was observed in 4% pass rate. The effective degradation rate was reduced by increasing the pass rate. Ruminal digestibility of dry matter and crude protein was higher than digestibility of post-ruminal. Overall, the digestibility of dry matter in the total digestive tract was higher than crude protein digestibility. This is due to the high rumen digestibility of dry matter compared with the digestibility of crude protein.
    Conclusions
    Based upon the present research it is concluded that Pistacia atlantica leaf has good degradability. It has high nutritional value and compatible or even is a good alternative to conventional feed ingredients in livestock feed. Also, Pistacia atlantica leaf is rich in phenolic compounds and antioxidant, and it can be used as an alternative to synthetic antioxidants. Due to having about 55.25 percent unsaturated fatty acids, it has a high nutritional value and could be used in livestock diets in order to enrich and enhance oxidative stability of animal products.
    Keywords: Antioxidant, Degradability, Growth Stages, Nylon Bags, Pistacia Atlantica Leaf
  • Hassan Keyhani Yazdi, Seyyed Javad Hosseini vashan *, Nazar Afzali, Mohsen Mojtahedi, Ali Allahresani Pages 489-500
    Introduction

    Fungi can grow in feed that maintained under normal temperature and high moisture condition. At the same condition, the fungi can produce mycotoxins in the feed. In poultry production, mycotoxicosis caused by key mycotoxins such as: Aflatoxin B1, Ochratoxin, T2toxin, Zearalenone and deoxynivalenol (DON, vomitoxin). Mycotoxins especially aflatoxin had undesirable influence on feed intake, body weight, feed conversion ratio and carcass characteristics. The Aflatoxin infected feed cause injuries on poultry's carcass especially liver and heart. Various aspects of the aflatoxicosis in poultry husbandry including effects on bird’s performance, digestion, metabolism, and organ function, metabolism of the toxin, and remnant of toxic residues to poultry products have been the subjects of several comprehensive reviews. The aflatoxin has vast economic losses in poultry industry via increase the mortality and reduces the growth performance. In order to reducing aflatoxin side effects, some ways were proposed such as inactivation of toxin, toxin adsorbent. Bentonite is the main toxin adsorbent. Bentonite can decrease the aflatoxin absorption from gut. Therefore this study was done to evaluate the effects of different levels of physical modified Nanostructure bentonite (PNB) on growth performance, carcass components and blood indices in broilers challenged by aflatoxin B1 (AFB1).

    Material and Methods

    One hundred and sixty day-old Ross 308 broiler chicks were bought from a great hatchery in South Khorasan, Iran. The birds were assigned to 20 experimental units with the same mean group body weight at initial experiment. The birds were reared for 35 days. The experiment was conducted in a completely randomized design with 5 treatments, 4 replicates and 8 birds in each. Experimental groups consisted of: negative control (C), positive control (basal diet with aflatoxin B1) (AF) and three level 0.25, 0.50 and 0.75 % of Physical modified Nanostructure bentonite added to basal diet with aflatoxin B1(positive control). The aflatoxin were added to starter and grower diets at 500 ppm and to finisher diets at 1000 ppm. At 21 and 35 days of age, one bird from each replicate was randomly selected and bled and blood parameters involved the concentration of cholesterol, triglyceride, LDL, HDL, total protein, and enzyme activity of alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase were determined. One bird from each replicate of treatment were slaughtered and carcass components involved breast, thigh, abdominal fat, spleen, bursa of fabricius, and pancreas were weighed and the relative weight of organs were calculated. The data were analyzed by SAS software and general linear model (GLM) was used to analyze the data. The differences among means were determined by Tuckey's multiple range test.

    Results and Discussion

    The results showed that aflatoxin increased feed conversion ratio and reduced triglyceride as compared to control diet. The blood lipid was negatively influenced by infected aflatoxin diets in broilers. Supplementation of 0.25% Physical modified Nanostructure bentonite to the infected diet of broilers was significantly increased the feed intake, decreased the concentration of LDL (P<0.05). The lower relative weight of abdominal fat were observed in broilers fed diets contained aflatoxin and 0.25% Physical modified Nanostructure bentonite (PNB) (P<0.05). Birds fed infected diets and contained 0.75% PNB had higher triglyceride concentration compare to positive control. The ALT enzyme activity significantly increased in negative control treat compare to negative control and 0.50% PNB (P<0.05).In this research, the supplementation of Physical modified Nanostructure bentonite to broilers infected with aflatoxin reduced the undesirable effects of aflatoxin. As with previous research report that aflatoxin increased the feed conversion ratio and decreased the nutrient digestion and absorption. Inclusion of aflatoxin to broiler diets had undesirable effects on liver activity and liver injuries. The liver enzyme activities are indices to evaluate of liver function. The birds had higher liver enzyme activity, which may negatively affected by side effects of aflatoxin. The last literature were reported that the lower nutrient utilization might be a factor of the effects of the toxin on systemic metabolism rather than an effect on digestive functionality. Bentonite can adsorb the aflatoxin and reduce the side effects of them on broiler growth performance, digestive and liver function.

    Conclusion

    The result of this research showed that aflatoxin may decrease the performance parameters and addition of Physical modified Nanostructure bentonite reduced the negative effects of aflatoxin on performance and increased percentage of abdominal fat, therefore, the 0.5% Physical modified Nanostructure bentonite suggested to add in broiler diets contained aflatoxin.

    Keywords: Aflatoxin B1, Physical modified bentonite, Broiler chicken, Growth performance, carcass components
  • Behnam Ahmadipour *, Fariborz Khajali Pages 501-512
    Introduction

    Modern strains of broiler chickens are susceptible to pulmonary hypertension syndrome (PHS) because of the mismatch between oxygen demanding muscles and oxygen-supplying organs (i.e. heart and lungs). Intensive genetic selection for rapid growth over the past several decades has reduced allometric growth of the heart and lungs in modern broiler chickens compared with their chronological counterparts. The susceptibility of broilers to PHS is exacerbated whenever they are raised at high altitudes where the availability of atmospheric oxygen is limited. Pulmonary arterioles in broilers respond to hypoxia by vasoconstriction and if the situation sustains, broiler develop pulmonary hypertension with subsequent right ventricular failure that finally leads to ascites. Research has addressed the impact of nutritional factors including energy, protein, electrolytes and feed restriction on the development of PHS. However, the effects of herbal medicine in the prevention and control of PHS in broiler chickens have not been adequately studied. Urtica dioica is a medicinal herb that belongs to the family of Urticacea and it grows in most parts of the world. Urtica dioica is used because of antioxidant and anti-inflammatory compounds for the treatment of cardiovascular, respiratory, cancerous and allergic diseases. One of the important effects of this plant is the reduction of blood pressure. The purpose of the present study was to examine the effects of different levels of this medicinal plant in preventing pulmonary PHS in broiler chickens.

    Materials and Methods

    The experiment was conducted in the experimental facility of Shahrekord University, Shahrekord, Iran, which had an altitude of 2100 m above sea level. A total of 240 day-old broilers (Ross308) were randomized across16 floor pens (15 birds per pen). A control diet based on corn and soybean meal were formulated for the starting (1–3 weeks of age) and growing (4–6 weeks of age) stages according to NRC (1994) recommendations. Three additional diets were prepared by substituting 0.5%, 1%, and 1.5% Urtica dioica for wheat bran in the control diet. At 42 days of age, 8 birds per treatment were selected for blood collection and then killed by decapitation. Blood samples (3mL) were collected from the brachial vein. Serum samples were used for the determination of nitricoxide (NO), malondialdehyde (MDA), urea, albumin, alkalin phosphatas (ALP), alanine amino transaminase(ALT) and aspartat amino transaminase(AST). To measure the expression of the gene, the heart and lung samples were harvested and the right ventricles dissected and immediately frozen in liquid nitrogen and stored at -70°C for subsequent RNA analysis. The levels of nitric oxide synthase (NOS), Endothelin 1 (ET-1) and β-actin transcripts were determined by real-time reverse transcriptase (RT)-PCR. Results were compared by GLM using SAS (2007) software in a completely randomized design. Means were separated by Duncan's multiple range test.

    Results and Discussion

    The results of the experiment showed that broiler chickens fed a diet containing 0.5 to 1.5% Urtica dioica leaves, the efficiency of heart and liver weight relative to the live weight of the chickens and right ventricular ratio to total ventricles showed a significant decrease compared to control group (P<0.05). Birds received Urtica dioica at 1 and 1.5% had significantly (P<0.05) higher circulatory concentrations of nitric oxide, protein and albumin though significantly (P<0.05) lower serum concentrations of malondialdehyde, alkaline phosphatase, alanine amino transaminase and aspartate amino transaminase when compared to the birds fed the control diet. The expression of endothelin 1 (ET-1) and nitric oxide synthase (NOS) genes in the heart and lung of broiler chickens has been affected by feeding Urtica dioica to broiler chickens. NOS gene has been highly over expressed in the heart and lung of broilers fed Urtica dioica from 1 to 1.5 % increase relative to the control. On the other hand, Urtica dioica significantly suppressed the expression of ET-1 in the heart and lung (P<0.05). The Urtica dioica contains polyphenolic compounds, including phthalides and flavonoids, which have antioxidant properties. This compound can prevent oxidative stress by scavenging of reactive oxygen species (ROS), activation of antioxidant enzymes, metal chelating activity. It also causes more nitric oxide secretion from vascular endothelial cells and opening of potassium channels. The Urtica dioica extract prevents the destruction and necrosis of the liver cells and maintains the consistency of the liver tissue and has a stabilizing effect on hepatocytes.

    Conclusion

    In conclusion, levels of 1 to 1.5% Urtica dioica in the diet can significantly prevent PHS in broiler chickens reared at high altitudes. Beneficial effects of this medicinal plant are attributed to vasorelaxant and antioxidant actions that mediated through polyphenolic compounds Therefore, Urtica dioica is a promising medicinal herb to prevent pulmonary hypertension in broiler chickens reared at high altitude.

    Keywords: Chicken, Gene expression, Pulmonary hypertension, Serum biochemical parameters, Urtica dioica
  • Hamid Tiemouri, Heydar Zarghi *, Abolghasem Golian Pages 513-523
    Introduction
    Cereal grains are the major source of energy for commercial poultry nutrition and incorporate about 60-70% of the diet volume. Corn is mainly used in the production of poultry feed mixtures, but the amount of corn production in Iran is not sufficient and more than 50% of corn requirement for poultry production is provided via import, therefore, for economic reasons its content in poultry diets might reduce. Barley can be the preferred grain for cultivation in many areas in Iran due to its resistance to drought region. Hull-less barley (HLB) differs from conventional barley in that the hulls firmly attached to the kernel and consequently is detached after thrashing, leading to a higher level of valuable nutrients and increased nutrient density. Reported that the HLB has a higher AME and protein content than hulled barley because of diluting effect of the fibrous hulls. The high protein content in HLB compared to corn grain and its considerable AMEn make it a potentially good ingredient for poultry diet formulation. However, since the high content of non-starch polysaccharides (NSP) probably decrease nutrient digestibility and performance due to the lack of an appropriate enzyme in the digestive tract of chickens, some concern has been expressed in relation to the inclusion levels of HLB in broiler diets. This experiment was carried out to study the influence of enzyme supplementation on the apparent metabolizable energy corrected for nitrogen (AMEn), apparent digestibility of dry matter (DMD), and crude protein (ACD) of two varieties of HLB by using the total excreta collection method in broiler chickens.
    Materials and Methods
    Sixty-four male broiler chicks "Ross-308", 16d of age, assigned to 16 metabolic cages in a completely randomized design (CRD) experiment with a factorial arrangement (2×2), 4 treatments with 4 replicates/treatment and 4 birds/replicate. The factors included two varieties of HLB (HMB-83-7 and native of Tabas, Iran) and two levels of enzyme cocktail (was a blend of 3500 U/g β-glucanase, 1600 U/g xylanase, 25 U/g cellulase and 1000 U/g phytase activity obtained from Phileo-Lesaffre-Animal-Care, Co. "Marcq-en- Baroeul-France") supplementation (0 and 0.5 g/kg of diet). The experimental diets were made so that the HLB barley was the sole source of energy and nitrogen supply. The digestion trial included a 4-day preliminary period in 16–19d of age, followed by 4 days of total excreta collection. The feed was provided ad libitum during the preliminary and the collection period. During the collection period (20-23d of age) total feed intake was measured, and excreta from each cage were collected twice a day, pooled, and kept frozen at -18oC until subsequent analyses. The excreta samples were freeze-dried to determine DM content. The dried excreta and diet samples were ground through 20 mesh screens, and nutrient content was determined according to AOAC (2000). The gross energy of the dried excreta and diet samples was measured. The apparent digestibility of crude protein (CPD) and dry matter (DMD) of HLB was calculated. The apparent metabolizable energy corrected for nitrogen (AMEn), of HLB was calculated.
    Results and Discussion
    The average DMD, CPD and AMEn of HLB were obtained 64.39±2.80%, 59.50±7.66% and 3034±212 kcal/kg as-fed basis, respectively. The DMD, CPD and AMEn of HLB in Tabas native variety were 67.45, 67.41% and 3189 kcal/kg as-fed basis respectively, which were significantly more than HMB-83-7 variety (Vs 64.67, 55.1% and 2961 kcal/kg for DMD, CPD and AMEn). Dietary enzyme supplementation increased the hull-less barley DMD (64.39% Vs 67.73%, 5.18% improvement compared to basal content), as well as increasing the CPD (50.59% Vs 63.03%, 5.93% improvement compared to base value) and AMEn (3034 Vs 3107 kcal/kg, 2.41% improvement compared to base value), so that the differences were significant (P <0.05). The effectiveness of dietary enzyme supplementation on the improvement of nutritional value of different HLB varieties that used in this experiment was varied. The Tabas native HLB variety was more effected than HMB-83-7 variety by dietary enzyme supplementation. Hull-less barley contains considerably higher levels of anti-nutritional factors consisting mainly of soluble non-starch polysaccharides (NSPs), especially ß-glucans compared to corn and wheat. Water-soluble β-glucan with gel-forming characteristics increases the gastrointestinal (GI) tract contains viscosity, decreases digestive enzymes contact with substrates, increases the thickness of the unstirred water layer in the GI tract mucosa and hence depresses nutrient digestibility. Many researchers have studied the beneficial effects of the addition of exogenous enzymes to the rich non-starch polysaccharide diets. The positive nutritional effects achieved by the dietary supplementation of exogenous enzymes are proposed to be caused by several mechanisms. Mainly, it has been shown that the antinutritive effects of viscous cereals such as barley, wheat, rye, oats, and triticale are associated with raised intestinal viscosity caused by soluble β-glucans and arabinoxylans present in those cereals. These problems are overcome by dietary supplementation of β-glucanases and xylanases. It is assumed that the ability of β- glucanases and xylanases to degrade plant cell walls leads to release of nutrients from grain endosperm.
    Conclusion
    According to the results of this experiment; the hull-less barley AMEn, DMD and CPD value affected by variety. The dietary exogenous enzyme supplementation improved the hull-less barley DMD, CPD and AMEn value.
    Keywords: Apparent metabolizable energy, Broiler chickens, Enzyme, Hull-less barley, Crude protein
  • Fateme Sahebi Ala, Ahmad Hassanabadi *, Abolghasem Golian Pages 525-540
    Introduction
    Heat stress is considered as one of the most important stressors accompanied by economic losses to the poultry industry. It causes reductions in weight gain and a series of metabolic disorders in broiler farms. Methionine is one of the most limiting amino acids, playing a crucial role in body protein synthesis, and therefore it would be beneficial to spare its function as a methyl donor. Broilers can utilize the isomers and analogs of methionine for protein synthesis, because of the unique enzymatic pathways to convert methionine isomers to L-methionine in the liver and kidney. Betaine is a common term for trimethylglycine, a substrate for betaine-homocysteine methyl transferase in the liver and kidney that acts as a methyl donor during methionine synthesis from homocysteine. The present study aimed to evaluate the effects of supplemental methionine sources and betaine replacement on growth performance and carcass characteristics of normal and heat-stressed broiler chickens.
    Materials and Methods
     This experiment was carried out in two adjoining poultry houses (n=1200, Ross 308). The experiment was designed in a 2 (Met sources)×2 (temperature)×3(Met levels)×2 (betaine levels) split-plot form, with two poultry houses (60 pens each) as the main plot and 12 different diets as the subplot, with 5 replicates of 10 birds each. Mash corn-soybean meal basal diets were prepared for starter (1–10 d), grower (11–24 d) and finisher (25–42 d) periods to meet 2014 Ross 308 nutrient recommendations, except for Met. Methionine levels in basal diets were adjusted at 30% lower than recommendation. They were increased to recommendation and/or 30% more than recommendation by supplementing DL-Met and/or L-Met. Betaine was substituted with 30% of supplemental DL-Met and/or L-Met. The betaine levels were calculated according to a molecular weight basis. Betaine contains about 3.75 times the methyl groups compared with Met. The temperature of both houses was set to thermal comfort temperature until 10 d of age. Then, the temperature of one house was gradually decreased by approximately 3°C/week until reached to the basal temperature (23°C) at d 28 and remained constant thereafter. In the other house, the temperature was gradually increased to 32°C between 0800 and 0930 and this high temperature was maintained for 6 h (until 1530). After that, the temperature was gradually decreased to the basal level by 1700. Body weight gain (WG) and feed consumption (FI) were recorded periodically, and feed conversion ratio (FCR) was calculated for each period by dividing feed intake by weight gain taking into account the mortality weights.
    Results and Discussion
    Feed intake in broilers fed diet with 30% higher methionine was significantly lower than the other two groups. Body weight gain was higher in birds fed diets with recommended or 30% higher than recommended methionine compare to those fed diets with 30% less than recommended. It is tendentiously due to the inciting effect of Met on growth by means of growth factors and its influence on protein synthesis and breakdown. FCR in diet of 30% less than recommended methionine and containing L-methionine was significantly improved in comparison to diet containing DL-methionine in the same level. Chicks required 138 or 141 units of DL-methionine to achieve the same daily weight gain and G: F of birds receiving 100 units of L-methionine. Also, a number of studies have shown that the effectiveness of DL-methionine is similar to that of L-methionine in chicks. In this study, replacing of betaine with 30% of supplemental methionine, showed no significant differences on performance parameters, which implies the sparing effect of betaine for methionine. It appears that methionine and betaine supplementation to slightly methionine deficient broiler diets could result in an equivalent growth response and that methionine could be slightly spared by betaine. The production efficiency factor improved by elevated levels of DL-methionine, but no difference was found between highest level of methionine and its standard level. Carcass yield, breast yield and tights yield had significant increase in birds fed diets with recommended or 30% less than recommended methionine. This may be due to increased muscle protein deposition induced by methionine. Birds fed diets with recommended or 30% less than recommended methionine had the lowest and highest percentage of abdominal fat, respectively. The improvement in carcass lean percentage may be attributed to a higher availability of recommended and cystine for protein deposition. This is because an enhanced utilization of dietary amino acids for protein synthesis may result in fewer amino acids available for deamination and eventual synthesis of adipose tissue. In the present study, replacing betaine with 30% methionine showed similar responses to methionine. Changes in hormone levels and growth factors involved in the regulation of fat synthesis and degradation, as well as lower activities of lipogenic enzymes, have been observed following dietary betaine supplementation. Heat stress reduced performance and carcass yield and increased mortality and abdominal fat content. HS disturbs the intestinal flora balance and thereby diminishes nutrient digestibility and absorption.
    Conclusion
    These results indicated that replacing 30% of methionine with betaine resulted same result in broiler performance. The use of methionine below the recommended level, reduces performance in broiler chickens. L-methionine appears to be more effective methionine source in improving the FCR than DL-methionine.
    Keywords: Betaine, Broiler chicken, Heat Stress, Methionine, Performance
  • Hamidrez Izadnia, Mojtaba Tahmoorespur *, Mohammad Reza Bakhtiarizadeh, Mohammad Reza Nassiri, Saeid Esmaeilkhanien Pages 541-552
    Introduction
    In the past decade, many performance traits in chickens have greatly improved to meet the growing demand for chicken meat. On the other hand, due to the 70% share of feed costs in the total cost of livestock production, feed efficiency has become one of the most important genetic traits in livestock and poultry. Residual feed intake (RFI) is the difference between the actual absorption of animal feed and the expected of the animal absorption based on body weight and its level of performance. Selection to improve feed efficiency through RFI is suggested due to its phenotypic independence from body weight and body weight gain. There is evidence for the genetic basis of variation in productivity in all species. Previous studies have shown that some genes may play an important role in controlling RFI through effects on the digestive system and metabolic processes. It seems that changes in the amount of residual feed intake is the result of changes in the expression of the genes associated with it, and the study of transcript changes in chickens with high RFI helps to identify the mechanisms that affect it.
    Materials and Methods
    Experiments were conducted on Commercial breeds (high production efficiency) and Isfahan Native Chickens (low production efficiency). From each breed, 60 chicks were harvested and caged from day 24 to 42 days for 19 days. The chicks of both groups were raised under the same management conditions. In order to measure the residual feed intake of each bird in individual cages and daily intake (FI) of the amount of feed consumed in 19 d (from day 24 to 42) divided by number of days, and daily gain (DG) of the weight difference 24. Using these figures, the amount of residual feed consumed will be calculated. Ten samples of liver tissue were then collected from each breed and immediately transferred to liquid nitrogen and transferred to the laboratory for total RNA extraction. Two pooled samples of every breed (each consisting of three extracted RNA sample) were prepared. Prior to Alignment, the quality of the raw readings sequence was evaluated using the Fastqc software. The reference genome for the chicken (Galgal4) and the annotated file were obtained from the Ensembl database. After controlling the quality and Trimming the reads, the Hisat2 software was used to mapping obtain reads from the genome of the reference. Analysis of differential gene expression was performed using Cufflinks.. To identify different isoform of the gene and to measure the expression of isoform, it is necessary to examine the position of microwave splicing between the exons. Cuff compare compares the transcripts that are assembled with a reference genome and categorizes each transcript into known, new, and potential new isoform.
    Results and Discussion
    The phenotypic results showed that the difference in the mean RFI values between the native (+13.430±5.393 g/day) and commercial (-11.212±4.435g/day) chickens was highly significant (P<0.001). About 83% of the sequenced fragments were matched to the reference genome and Duplex analysis of gene expression was performed..Differential expression analysis for more than 45070 isoform Related to 19003 genes using Cuffdiff showed that 28949 and 16121 isoform were up- and down-regulated (adjusted P≤0.05) in the native breed, respectively. 206 Isoform was identified as a change in expression between the native and commercial chickens. Moreover 21081 novel isoform were identified which have not been included in the gene annotation so far. Moreover, the functional enrichment analysis showed that the down-regulated isoform in the native chickens were mainly involved in the different response to stress،response to oxygen-containing compound،response to cytokine،response to nutrient،response to lipid،animal organ development ،single-organism biosynthetic process،regulation of multi-organism process response to nutrient level and lipid biosynthetic process. The Differentially Expressed Genes and their isoform explored between the chickens of the two breeds led to the identification of some important candidate genes for further breed improvement programs, including RSAD2, IL15, EGR1, and DUSP16. These genes could be related to the higher RFI of the native.
    Conclusion
    Our findings showed that a large number of related genes with metabolism (fat, amino acids, carbohydrates, and vitamins), growth, as well as oxidative stress and immunity, can make a difference in the RFI. Identification of the difference genes and their isoform between two breeds of chickens led to the identification of important candidate genes for breeding programs, including RSAD2, IL15, EGR1 and DUSP16.
    Keywords: Chicken, Isoform, Residual feed intake, RNA, Seq
  • Farhad Ghafouri, kesbi, Ali Goudarz Talleh Jerdi * Pages 553-560
    Introduction
    By implementing genomic selection, high accurate estimates of breeding values in newborn individuals could be obtained in the absence of phenotypic records. In genomic selection, selection decisions are based on genomic breeding values predicted from high-density SNP pannels. Dramatic advances in sequencing technologies are providing highly dimensional molecular marker information at low cost. Next generation sequencing protocols such as genotype by sequencing (GBS) technology have been suggested as an efficient and cost-effective genotyping method for genomic selection in cattle. It capable of providing acceptable marker density for genomic selection or genome-wide association studies at roughly one third of the cost of currently available genotyping technologies. However, polymorphic loci scored by GBS can contain a large proportion of missing data across samples because random fragments of the genome are sequenced at low depth, leading some loci to have zero coverage in some individuals. Most analyses require a complete dataset; therefore, marker imputation is a necessary step before GBS data can be used for most purposes such as genomic selection. Order of markers is unknown in GBS data. Therefore, an imputation method which does not require previous information about the order of the markers is needed for imputing GBS data. Nonparametric models from the machine-learning repository have been proposed as an alternative to deal with such situations. These models do not follow a particular parametric design. Several different machine-learning approaches are currently used for genotype imputation and it is important to assess the performance of diverse methodologies and identify the methods that can provide the greatest predictive accuracy in a given population. Singular value decomposition imputation (SVD is capable to impute missed markers in GBS data. The aim of this study was assessing the performance of intelligent SVD algorithm for imputation of missing genotypes.
    Materials and Methods
     A genome consisted of one Morgan chromosome was simulated using the hypred package on which in different scenarios, respectively, 500, 1000, 1500, 2000, 2500 and 3000 SNPs with equal initial frequency of 0.5 were arrayed for 1000 individuals. Coding for each genotype with A1 and A2 alleles were 2 for A1A1, 0 for A2A2 and 1 for A1A2 or A2A1, respectively. Then, in the framework of genotyping by sequencing data (GBS), genotype information of 5%, 10%, 25%, 50%, %75 and 90% of SNPs were masked and then imputed with SVD algorithm. Imputation accuracy (r) was assessed by the percentage of genotypes imputed correctly (number of genotypes correctly imputed/total number of masked genotypes). The effect of number of genotyped individuals (1000 and 2000 individuals), number of genotyped SNPs (500, 1000, 1500, 2000, 2500 and 3000 SNP) and levels of minor allele frequency (MAF) (0.01, 0.05, 0.1, 0.2, 0.3 and 0.4) on imputation accuracy were also studied.
    Results and discussion
     The SVD imputation accuracy was noticeable. So by increasing the percentage of masked markers up to 50%, SVD was imputed missing genotypes with accuracy equal to 80%. In the scenarios of 70% and 90% of missing genotypes, the accuracy of imputation decreased and was 70% and 48%, respectively. In parallel to increase in the size of the population from 1000 to 2000 individuals, the imputation performance of SVD was increased, especially in the scenarios of 75% and 90% of masked genotypes. In parallel to increase in the number of markers, the imputation accuracy (r) increased in such a way that with increasing the number of markers from 500 to 3000 SNP, the accuracy of imputation increased by almost %10. An inverse relationship was observed between MAF and r in a way that by increasing MAF from 0.01 to 0.40, the accuracy of imputation decreased by 8%. In other words, markers with lower MAF were imputed with higher accuracy.
    Conclusion
    SVD performed well regarding genotype imputation for GBS platforms in a way that missing data can be imputed with reasonable accuracy even if the level of missing data are high; up to 50%and even greater accuracies may result if number of individuals in the population is high and level of MAF of genotyped SNPs is low. Therefore, SVD can be recommended for genotype imputation in genome assisted evaluation.
    Keywords: Genotype imputation, SNP, SVDI algorithm