فهرست مطالب

پژوهشهای علوم دامی ایران - سال دهم شماره 3 (پاییز 1397)

فصلنامه پژوهشهای علوم دامی ایران
سال دهم شماره 3 (پاییز 1397)

  • تاریخ انتشار: 1397/10/24
  • تعداد عناوین: 10
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  • جواد بیات کوهسار، عبدالمنصور طهماسبی*، عباسعلی ناصریان، رضا ولی زاده، رشید صفری صفحات 311-324

    به منظور بررسی اثر کشت های زنده باکتریایی بر قابلیت هضم ماده خشک و ماده آلی، pH، غلظت نیتروژن آمونیاکی شکمبه ای و غلظت اسیدهای چرب فرار سه سری آزمایش در شرایط آزمایشگاهی طراحی شد. سویه های خالص باکتریایی شامل پروپیونی باکتریوم فریدرینریچی و انتروکوکوس فیسیوم از مرکز پژوهش های علمی صنعتی ایران خریداری شد. تیمارهای آزمایشی شامل: 1) تیمار شاهد، 2) تیمار مکمل شده با پروپیونی باکتریوم فریدرینریچی، 3) تیمار مکمل شده با انتروکوکوس فیسیوم و 4) تیمار مکمل شده با مخلوط پروپیونی باکتریوم فریدرینریچی و انتروکوکوس فیسیوم بودند. مایع شکمبه از سه گوسفند دارای فیستوله شکمبه ای به دست آمد. در همه آزمایش ها از یک جیره پایه با نسبت کنسانتره به علوفه 90:10 استفاده شد. در آزمایش دوم مقدار یک میلی لیتر ساکارز 10 درصد به محیط کشت تزریق و در آزمایش سوم pH محیط کشت در نقطه 5/5 تعدیل شد. نتایج نشان داد که تیمار شاهد در پایان مدت انکوباسیون پایین ترین قابلیت هضم ماده خشک و ماده آلی را داشت (05/0>P). غلظت نیتروژن آمونیاکی شکمبه در تمامی تیمارها در ساعت 2 انکوباسیون پایین ترین مقدار بود و با پیشرفت زمان انکوباسیون افزایش یافت. بین تیمارها از نظر نسبت استات به پروپیونات اختلاف معنی داری وجود داشت و تیمارهای مکمل شده با پروپیونی باکتریوم و مخلوط پروپیونی باکتریوم و انتروکوکوس پایین ترین نسبت را داشتند (05/0>P). به طور کلی، افزودن کشت های زنده باکتریایی در جیره های غذایی می تواند تاثیر مثبت و معنی داری بر قابلیت هضم ماده خشک، ماده آلی و غلظت اسیدهای چرب فرار داشته باشد که این تغییرات با تثبیت pH شکمبه ای همراه بود که شرایط را برای فعالیت میکروارگانیسم های شکمبه مساعدتر می کند.

    کلیدواژگان: اسیدهای چرب فرار، شرایط آزمایشگاهی، قابلیت هضم، کشت های زنده باکتریایی، نیتروژن آمونیاکی، Digestibility، In Vitro Condition، Live Bacterial Cultures، Ruminal N-NH3، Volatile Fatty Acids
  • ندا نقدی، رضا ولی زاده، عباسعلی ناصریان، احمد آسوده صفحات 325-338
    هدف از انجام این فراتحلیل بررسی و مقایسه اثر مکمل های آلی و غیرآلی روی بر عملکرد بره های پرواری بود. بر اساس جستجوی انجام شده از هفت مطالعه وارد شده در این فراتحلیل، 14 مقایسه برای میانگین افزایش وزن روزانه، 12 مقایسه برای میانگین مصرف خوراک روزانه، 11 مقایسه برای غلظت میزان روی در سرم/پلاسما و فعالیت آنزیم سوپراکسید دسموتاز و در نهایت 13 مقایسه برای فعالیت آنزیم آلکالین فسفاتاز مورد استفاده قرار گرفت. از هر دو مدل اثرات ثابت و تصادفی برای ترکیب اندازه اثر استفاده شد. برای بررسی میزان سوگیری انتشار از نمودار قیفی و آزمون های آماری استفاده شد. نتایج این فراتحلیل نشان داد افزودن مکمل روی در جیره غذایی، تاثیر مثبتی بر افزایش وزن روزانه (17/0±5/0+) ، افزایش روی سرم/پلاسما (225/0±13/1+) ، افزایش فعالیت آنزیم آلکالین فسفاتاز (205/0±4/1+) و سوپراکسید دسموتاز (226/0±8/0) داشت. این درحالی است که مصرف مکمل روی تاثیر معنی داری بر میانگین مصرف خوراک (161/0±05/0-) و ضریب تبدیل غذایی (241/0±06/0) نشان نداد. مقایسه فرم آلی و غیرآلی مکمل روی نیز نشان داد فرم آلی، به ویژه پروتئینات–روی در مقایسه با فرم غیرآلی تاثیر بیش تری بر بهبود عملکرد دام دارد.
    کلیدواژگان: بره پرواری، عملکرد، فراتحلیل، مکمل آلی روی، مکمل غیرآلی روی
  • اکبر ابرغانی، مرتضی چاجی، هرمز منصوری، مرتضی ممویی، خلیل میرزاده، هدایت الله روشنفکر صفحات 339-352
    در این مطالعه ارزش تغذیه ای (ترکیب شیمیایی و تجزیه پذیری) سه گونه گیاهی شورزی تحت چرای شترهای یک کوهانه به نام های سلمکی ساقه سفید، سیاه شور و اشنان به صورت انفرادی یا با جایگزینی صفر، 5/33، 5/66 و 100 درصد به جای همدیگر در قالب 9 تیمار آزمایشی با طرح آزمایشی کاملا تصادفی به روش کیسه های نایلونی مورد بررسی قرار گرفت. از دو نفر شتر ماده چهار ساله تک کوهانه دارای فیستولای شکمبه ای تغذیه شده با کاه گندم، سلمکی ساقه سفید و علوفه یونجه استفاده شد. سلمکی بالاترین همی سلولز، NDF و ماده آلی را بین سه گیاه شورزی داشت. بالاترین غلظت تانن و اگزالات و اسیدهای آلی مربوط به اشنان بود. گیاهان سلمکی ساقه سفید پایین ترین و اشنان بالاترین درصد تجزیه پذیری و تجزیه پذیری موثر ماده خشک را داشتند (05/0>P). تجزیه پذیری ماده آلی تیمار حاوی اشنان و سیاه شور به طور معنی داری بالاتر از تیمار‏های حاوی سلمکی ساقه سفید بودند (05/0>P). تیمارحاوی 5/66 درصد اشنان+ 5/33 درصد سیاه شور (تیمار 7) بالاترین و سلمکی ساقه سفید (تیمار 2) پایین ترین درصد تجزیه پذیری NDF را در بین تیمار‏های آزمایشی داشتند (05/0>P). تیمار حاوی 5/66 درصد اشنان+5/33 درصد سلمکی ساقه سفید (تیمار 1) ، بالاترین تجزیه پذیری پروتئین خام و سلمکی ساقه سفید پایین ترین درصد را داشت. نتایج نشان داد که در ساعات اولیه انکوباسیون، سرعت تجزیه پروتئین بیشتر از سرعت تجزیه ماده خشک، ماده آلی و NDF تیمار‏های آزمایشی بود. لذا، طبق نتایج مربوط به تجزیه ماده خشک، ماده آلی و پروتئین خام، بهترین مخلوط گیاهی برای تغذیه بهتر شترهای چراگر تیمار های فاقد سلمکی (تیمار های 5، 7 و 8) می باشد؛ اما طبق داده های ترکیب شیمیایی و تجزیه پروتئین تیمار های حاوی سلمکی بهترین مخلوط هستند (تیمار های 1، 3، 4 و 6 به جز 2). بنابراین، به نظر می رسد یکی از راه کارها برای بهبود هضم پذیری گیاهان شورزی در شترها مخلوط کردن این گیاهان با یکدیگر است که طبق نتایج آزمایش حاضر به نظر می رسد بهترین تیمار برای تغذیه شترها شامل مخلوطی از سلمکی ساقه سفید با سیاه شور یا اشنان باشد.
    کلیدواژگان: اگزالات، اسیدهای آلی، تانن، ترکیبات فنولی، کیسه های نایلونی
  • کلثوم صالح پور‍‍‍، طاهره محمد آبادی، محمدرضا قربانی صفحات 353-366
    هدف از این آزمایش، بررسی تاثیر برگ مورد بر قابلیت هضم، فراسنجه های خونی و شکمبه ای و جمعیت پروتوزوای شکمبه در گوسفند عربی بود. در مرحله اول سطح مناسب برگ مورد از بین سطوح 2/0، 4/0 و 6/0 درصد همراه با جیره 70:30 کنسانتره به علوفه با روش های آزمایشگاهی تعیین شد. نتایج نشان داد بهترین تخمیر، تولید گاز و قابلیت هضم مربوط به سطح 4/0 درصد برگ مورد بود. در مرحله دوم آزمایش، این سطح در تغذیه 8 راس گوسفند عربی (5/1 ± 23 کیلوگرم) ، به مدت یک ماه استفاده شد. در پایان آزمایش مصرف خوراک، قابلیت هضم مواد مغذی، جمعیت پروتوزوآ و متابولیت های خونی اندازه گیری و داده های به دست آمده در قالب طرح کاملا تصادفی مورد تجزیه و تحلیل قرار گرفت. نتایج نشان داد استفاده از گیاه مورد تاثیری بر میزان مصرف ماده خشک و ماده آلی نداشت، اما مقدار پروتئین مصرفی را کاهش داد. قابلیت هضم پروتئین خام و NDF در تیمار حاوی مورد نسبت به تیمار شاهد افزایش داشت، اما قابلیت هضم ماده خشک، ماده آلی و ADF جیره های آزمایشی تفاوت نداشت. جمعیت پروتوزوآ تحت تاثیر استفاده از برگ مورد در جیره قرار نگرفت، اما میزان نیتروژن آمونیاکی شکمبه، تری گلیسرید و گلوکز خون در تیمار حاوی برگ مورد (29/8) در مقایسه با تیمار شاهد (05/16) کاهش داشت. بنابراین، سطح 4/0 درصد برگ گیاه مورد دارای اثرات بهبود بر تخمیر شکمبه ای و اثرات مفید بر فراسنجه های خونی در گوسفند عربی بود، بنابراین می توان از آن به عنوان افزودنی گیاهی در جیره گوسفند استفاده کرد.
    کلیدواژگان: روتوزوآ، قابلیت هضم، گوسفند عربی، گیاه مورد، متابولیت های خونی
  • صادق کرد زنگنه، محمدرضا قربانی *، احمد طاطار، حسن برزگر صفحات 367-380

    به منظور بررسی تاثیر سطوح مختلف عصاره برگ پسته وحشی بر عملکرد، جمعیت میکروبی سکوم ها و پاسخ ایمنی جوجه های گوشتی آزمایشی با استفاده از 240 قطعه جوجه گوشتی یک روزه (سویه راس-308) به مدت 42 روز در قالب طرح کاملا تصادفی با 5 تیمار و 4 تکرار به انجام رسید. تیمارهای آزمایشی شامل جیره پایه (شاهد مثبت) ، جیره پایه به همراه 1/0 درصد آنتی بیوتیک فلاوومایسین (شاهد منفی) و جیره پایه به همراه سطوح 1/0، 2/0 و 3/0 درصد عصاره برگ پسته وحشی بودند. نتایج آزمایش نشان داد که ضریب تبدیل خوراک در دوره آغازین تحت تاثیر گروه های مختلف آزمایشی قرار گرفت و گروه شاهد مثبت کمترین و 3/0 درصد عصاره بیشترین ضریب تبدیل خوراکی را داشتند (05/0>P). میزان مصرف خوراک، افزایش وزن بدن و ضریب تبدیل خوراک در دوره رشد و کل دوره تحت تاثیر گروه های مختلف آزمایشی قرار نگرفتند (05/0<P). غلظت تری گلیسرید و لیپوپروتئین های با چگالی بسیار پایین سرم جوجه های گوشتی به هنگام استفاده از 2/0 و 3/0 درصد عصاره نسبت به گروه شاهد مثبت پایین تر بودند (05/0>P). تیمارهای آزمایشی تاثیر قابل ملاحظه ای بر جمعیت باکتری های کلی فرم نداشتند ولی باعث افزایش معنی دار جمعیت میکروبی لاکتوباسیل ها و کاهش معنی دار اشریشیاکولای در محتویات سکوم شدند (05/0>P). به هنگام استفاده از سطوح 2/0 و 3/0 درصد عصاره برگ پسته وحشی، pH ایلئوم به طور معنی داری کاهش یافت (05/0>P). نتایج این آزمایش نشان داد که عصاره برگ پسته وحشی تاثیر قابل ملاحظه ای بر عملکرد جوجه های گوشتی ندارد ولی، باعث کاهش جمعیت باکتری های مضر و افزایش جمعیت باکتری های مفید محتوای سکوم و هم چنین باعث کاهش pH محتویات ایلئومی شد.

    کلیدواژگان: پسته وحشی، جوجه های گوشتی، عملکرد
  • رقیه جباری، حسین جانمحمدی*، سیدعلی میرقلنج، روح الله کیانفر صفحات 381-392

    در پژوهش حاضر نمونه کنجاله های سویای برزیلی، آرژانتینی و ایرانی و یک نمونه کنجاله گلوتن ذرت ایرانی از کارخانجات خوراک طیور استان آذربایجان شرقی جهت تعیین ترکیبات شیمیایی و کیفیت پروتئین تهیه شد. میانگین پروتئین خام کنجاله سویای برزیلی، آرژانتینی، ایرانی و کنجاله گلوتن ذرت به ترتیب 3/47، 2/46، 4/46 و 5/65 درصد و مقادیر عصاره اتری به ترتیب 1/9، 6/8، 4/12و 6/7 درصد بود. برای ارزیابی بیولوژیکی کیفیت پروتئین نمونه های کنجاله سویا و یک نمونه کنجاله گلوتن ذرت از 100 قطعه جوجه خروس سویه راس 308 در قالب طرح کاملا تصادفی با 5 تیمار و 4 تکرار و 5 قطعه جوجه در هر تکرار استفاده شد. جیره های آزمایشی از سن 8 تا 17 روزگی به جوجه ها تغذیه شدند. جیره های آزمایشی شامل یک جیره خالص فاقد نیتروژن و چهار جیره غذایی نیمه خالص آزمایشی حاوی کنجاله های سویا و کنجاله گلوتن ذرت بود. برای ارزیابی شیمیایی کیفیت پروتئین نمونه های کنجاله سویا نیز از شاخص فعالیت آنزیم اوره آز و حلالیت پروتئین در محلول هیدروکسید پتاسیم 2/0 درصد استفاده شد. شاخص اوره آز برای کنجاله سویای برزیلی، آرژانتینی، ایرانی به ترتیب 05/0، 05/0 و 07/0 و حلالیت پروتئین در محلول هیدروکسید پتاسیم 2/0 درصد به ترتیب 39/88، 51/85 و 82/86 درصد تعیین گردید. کمترین مقادیر NPRو PER در کنجاله گلوتن (ذرت 37/1 و 36/0) و بیشترین مقادیر در کنجاله سویای آرژانتینی (74/3 و13/3) یافت شد. نتیجه گیری گردید که کمیت و کیفیت پروتئین نمونه داخلی کنجاله سویا مورد مطالعه قابل مقایسه با نمونه های آرژانتینی و برزیلی می باشد.

    کلیدواژگان: جوجه خروس گوشتی، حلالیت پروتئین در هیدروکسید پتاسیم، شاخص اوره آز، نسبت بازده پروتئین
  • مهرنوش فروتن، سعید انصاری مهیاری، فلاویو شنکل، مهدی سرگلزایی صفحات 393-402
    امروزه استفاده از اطلاعات هاپلوتایپ به منظور تخمین ارزش اصلاحی ژنومی (GEBV) با صحت و دقت بالاتر مورد توجه قرار گرفته است. استفاده از شباهت بین هاپلوتایپ ها نسبت به مستقل در نظر گرفتن اثرات هاپلوتایپ ها می تواند منجر به قابلیت پیش گویی بالاتر برآوردهای ژنومی گردد. هدف از این مطالعه بررسی صحت و اریبی GEBV به روش بهترین برآورد نااریب خطی ژنومی (GBLUP) با استفاده از ماتریس روابط خویشاوندی ژنومی بر پایه اطلاعات نشانگرهای چندشکلی تک نوکلئوتیدی (GSNP) و هاپلوتایپ (GHAP) و ماتریس هیبرید شامل اطلاعات هاپلوتایپ ها وSNPها (GSNP, HAP) بود. ماتریس های روابط خویشاوندی ژنومی با استفاده از تراشه k50 برای جمعیت گاو شیری هلشتاین آمریکای شمالی برای صفات تولید چربی شیر، تولید شیر، نمره سلول بدنی، تیپ و روزهای باز تشکیل گردید. مقادیر صحت GEBV با استفاده از ماتریس GSNP و GHAP به ترتیب از 49/0 (روزهای باز) تا 72/0 (تولید چربی شیر) و 50/0 (روزهای باز) تا 73/0 (تولید چربی شیر) متغیر بود. استفاده از ماتریس GHAP در مقایسه با دیگر ماتریس های مورد بررسی در این مطالعه منجر به برآوردهای نااریب تری در تمام صفات شد. استفاده از ماتریس GHAP نسبت به GSNP موجب 6 تا 15 درصد کاهش اریبی برآوردها در صفات مختلف گردید. یکی از دلایل بهبود اریبی برآوردها می تواند برآورد بهتر واریانس ژنتیکی در سطح جمعیت توسط هاپلوتایپ نشانگرها نسبت به نشانگر انفرادی باشد. بر اساس نتایج حاضر ماتریس GHAP می تواند جایگزین مناسبی برای GSNP در ارزیابی های ژنومی به منظور دستیابی به برآوردهای ارزش اصلاحی نااریب تر و دقیق تر باشد.
    کلیدواژگان: اریبی برآوردها، صحت، گاو هلشتاین، ماتریس روابط خویشاوندی ژنومی، هاپلوتایپ
  • سید نادر آلبوشوکه، مجتبی طهمورث پور *، محمدرضا بختیاری زاده، محمدرضا نصیری، سعید اسماعیل خانیان صفحات 403-416

    این آزمایش به منظور بررسی و شناسایی تفاوت های ژنتیکی و مسیرهای متابولیکی مرتبط با میتوکندری بین توده مرغ بومی اصفهان و یک سویه جوجه تجاری راس 708 با سرعت رشدهای متفاوت، انجام شد. بدین منظور از روش توالی یابی RNA-seq با استفاده از چهار نمونه ماهیچه سینه 28 روزگی استفاده شد. مقایسه آماری بیان ژن های توالی یابی شده در مرغ بومی و جوجه تجاری، 606 ژن با تفاوت معنی دار را مشخص نمود و از این تعداد 249 ژن در مرغ بومی و 357 ژن در جوجه تجاری افزایش بیان داشتند. بر اساس نتایج بیان ژن ها در مرغ بومی، فاکتور رونویسی FoxO3 موجب فعال شدن مسیر آتروفی لیگازهای یوبیکویتینی E3 و افزایش شکست پروتئین و در نتیجه کاهش حجم ماهیچه اسکلتی در مقایسه با جوجه تجاری شده است. هیپوکسی و تنظیم فرآیند متابولیکی گونه های اکسیژن فعال (ROS) از مهم ترین فرآیندهای بیولوژیکی فعال در مرغ بومی بودند. بررسی و مقایسه ژن های مرتبط با پروتئوم میتوکندریایی نشان داد در این مرغ تغییرات معنی داری در بیان بسیاری از پروتئین های وابسته به رشد و تنظیم کننده رونویسی وجود دارد. این تغییرات نشان دهنده برنامه سازگاری پیچیده ای است که شکست پروتئین را تسهیل نموده و سوخت گلوکز در ماهیچه را کاهش می دهد. این مسیرهای متابولیسمی در جهت کاستن سطح نیازمندی های مرغ بومی به گونه ای تکامل یافته اند تا توان این مرغ را در غلبه بر شرایط و تنش های محیطی و تحمل کمبودهای غذایی تقویت نمایند.

    کلیدواژگان: ماهیچه سینه، مرغ بومی، میتوپروتئوم، RNA-Seq
  • میثم لطیفی صفحات 417-424
    هدف از این تحقیق برآورد وراثت پذیری کروموزم های اتوزمی و وابسته به جنس در صفات قبل از شیرگیری گوسفند مهربان بود. داده ها و اطلاعات شجره در طی سال های 1373 الی 1389 توسط جهاد کشاورزی استان همدان جمع آوری شده بود. به منظور تعیین اثرات ثابت از رویه GLM نرم افزار SAS استفاده شد. اثرات ثابت مدل شامل گله-سال، فصل زایش، جنسیت، تیپ تولد و سن مادر بود. سن بره در زمان از شیرگیری به عنوان متغیر کمکی برای وزن شیرگیری در نظر گرفته شد. به منظور برآورد پارامترهای ژنتیکی و همبستگی ژنتیکی صفات مورد بررسی از روش حداکثر درستنمایی محدود شده و نرم افزار Wombat استفاده شد. وراثت پذیری های مستقیم اتوزومی و وراثت پذیری های مستقیم وابسته به کروموزوم جنسی برای صفات قبل از شیرگیری، به ترتیب در دامنه ی 18/0 تا 55/0 و 03/0 تا 11/0 برآورد گردید. همبستگی های ژنتیکی اتوزومی، کروموزم های وابسته به جنس، ژنتیکی مادری و محیط دائم مادری، به ترتیب در دامنه ی 31/0- تا 91/0، 33/0 تا 98/0، 33/0 تا 99/0 و 26/0- تا 99/0 متغیر بود. نتایج نشان داد، واریانس مستقیم کروموزم وابسته به جنس، همانند واریانس ژنتیکی مادری دارای اثر می باشد و وارد کردن این اثر به مدل، می تواند برآورد دقیق تری از وراثت پذیری مستقیم کروموزم اتوزومی را حاصل نماید.
    کلیدواژگان: صفات قبل از شیرگیری، گوسفند مهربان، وراثت پذیری کروموزم وابسته به جنس، وراثت پذیری مستقیم کروموزم اتوزمی
  • محمود احمدی همدانی صفحات 425-434
    یجاد محدوده مرجع اختصاصی نژاد، ابزار مهمی جهت پایش سلامتی در نژادهای مختلف گوسفند محسوب می شود. هدف از مطالعه حاضر ایجاد محدوده مرجع فراسنجه های بیوشیمیایی منتخب سرم برای گوسفندان بالغ به ظاهر سالم نژاد سنگسری با روشReference Value Advisor (RVA) و مقایسه فراسنجه های تحت مطالعه در بین دو جنس نر و ماده این نژاد بود. نمونه خون 60 راس گوسفند سالم و بالغ (رنج سنی 2 تا 4 سال) سنگسری از هر دو جنس (26 میش و 34 قوچ) از مرکز اصلاح نژاد گوسفند سنگسری در دامغان برای تعیین محدوده مرجع مورد استفاده قرار گرفتند. مهمترین فراسنجه های بیوشیمیایی سرم توسط دستگاه اتوآنالایزر (Mindray, BS-120) اندازه گیری شدند. محدوده مرجع فراسنجه های اندازه گیری شده با روش RVA مطابق با دستورالعمل انجمن کلینیکال پاتولوزی دامپزشکی آمریکا، تعیین شد. محدوده مرجع داده ها باتوجه به حجم نمونه با روش Robust Box-cox transformation، گزارش شدند و سطح اطمینان 90% به وسیله روش بوت استرپینگ غیرپارامتری تعیین گردید. محدوده مرجع تعیین شده برای فراسنجه های بیوشیمیایی سرم بدین شرح بودند: آسپاراتات آمینو ترانسفراز 40/338-86/10 واحد/ لیتر، آلکالین فسفاتاز 84/564-24/49 واحد/ لیتر، گاما گلوتامیل ترانسفراز 23/62-14/24 واحد/ لیتر، ازت اوره خون 43/26-91/6 میلی گرم/ دسی لیتر، آلبومین 63/3-92/0 گرم/ دسی لیتر و پروتئین تام 95/13-19/5 گرم/ دسی لیتر. از میان فراسنجه های مذکور تنها میزان پروتئین تام در نرها به صورت معنی داری بیشتر از ماده ها بود. با مشخص نمودن محدوده مرجع می توانیم اطلاعات پایه ای را جهت تفسیر نتایج بیوشیمایی در گوسفند سنگسری ایجاد و به بهینه سازی مدیریت این گونه نیز کمک نماییم.
    کلیدواژگان: بیوشیمی بالینی، جنس، گوسفند سنگسری، محدوده مرجع
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  • Javad Bayatkouhsar, Abdolmansoor Tahmasbi, Abas Ali Naserian, Reza Valizadeh, Rashid Safari Pages 311-324
    Introduction

    Rumen microbial manipulation has been of interest to ruminant nutritionists in order to achieve improvement in the profitability and health of lactating cows. Concerns regarding the use of antibiotics and other growth stimulants in animal feed industry have caused attention to find other alternative agents to replace antibiotics. For these reasons, in ruminant, microbial cultures have been used to replace antibiotics to enhance milk production in dairy cattle and improve feed efficiency and daily gain in beef cattle. Rumen bacteria, that have ability to ferment carbohydrate, are primarily responsible for causing lactic acidosis in ruminant. Propionibacteria are natural inhabitants of the rumen that comprise 1.4 % of the ruminal microflora and produce propionic and acetic acid in the rumen. Therefore, propionibacteria have been used as a direct-fed microbial to prevent the risk of acidosis in feedlot cattle. Last studies have reported that combinations of propionic bacteria and lactobacilli resulted in increased average daily gain and improved feed efficiency in feedlot cattle. The purpose of this study were preparation of live bacterial culture in laboratory and investigate the effect of adding live bacterial culture on digestibility and ruminal fermentation parameters on in vitro condition.  

    Materials and Methods

    Three in vitro experiments designed in order to determine the effects of bacteria strains supplementation on dry matter and organic matter digestibility, pH, VFA and ammonia nitrogen concentration. Bacterial pure strains were Propioni bacterium freudenreichii and Enterococcus faecium. Stock cultures of freeze-dried strains were individually inoculated into 5 mL Brain Heart infusion (BHI) and sodium lactate broth (SLB) respectively and incubated at 37 °C for 24 h under anaerobic conditions. By pour plating serial 10 fold dilutions (in sterile ringer’s solution) on demand, Rogosa, sharp agar and SLB agar plates were incubated anaerobically at 37 °C for 48h. 108cfu /ml of culture were produced after 24 and 36 h of culturing. Rumen fluid was collected 3 h after morning feeding from three ruminally fistulated sheep with mean body weight of 45+2.5 kg. Buffer was prepared as proposed by Goering and Van Soest (1970). In an anaerobic condition, 50 ml of buffered rumen fluid (ratio of buffer to rumen fluid was 1:1), was dispensed into a 100 ml serum bottle containing 0.5 g DM of the experimental diet (four replicate) for each experimental incubation time (2, 4, 6, 12 and 24 h). The experimental treatments were: CON) control (basal diet without any additive), P) basal diet inoculated with 108cfu Propionibacteria feriderinrichii, E) basal diet inoculated with 108cfu Enterococcus faecium and P+E) basal diet inoculated with 108cfu Propionibacteria fredrinrichii + Enterococcus faecium. Rumen fluid was collected before morning feeding from three ruminally fistulated sheep. In all experiments a diet based on concentrate were used with the ratio 90: 10 of concentrate to forage. In the second experiment 1 mL sucrose (10% w/w) injected to the diet and in third experiment pH adjusted to 5.5 at the beginning of experiment. After 2, 4, 6, 12 and 24 h of the incubation, the bottles were respectively transferred to an ice bath to stop fermentation and then opened to measure medium pH using a pH meter (Metrhom pH meter, Model 691). Then, each bottle content was filtered (42 μm pore size) and a 5 ml sample of each filtrate bottle was taken and acidified with 5 ml of 0.2 N HCl and frozen at -20°C. for analyzing VFA by gas chromatography, 4 mL of each filtrate bottle were stabilized with 4 mL meta-phosphoric acid Liquid effluent was collected in flasks containing a solution of H2SO4 to maintain pH values below 2, and samples were taken for volatile fatty acids The filtrated residual was oven dried (60 °C for 48 h) and used to calculate in vitro dry matter and organic matter disappearances.  

    Results and Discussion

    DM and OM digestibility for all treatments increased during incubation. Control treatment had lowest DM digestibility. Changes in OM digestibility was in same manner with DM digestibility in all treatments and control had lowest OM digestibility significantly. In comparison with initial pH, treatments control, Propionibacterium fredrinrichii, enterococcus faecium and mixed of Propionibacterium fredrinrichii + Enterococcus faecium had decreased 0.91, 0.73, 0.76 and 0.58 unit, respectively. NH3-N concentration after 2h after incubation was low in all treatments and increased during incubation, but for control it was low in compare with other treatments during incubation. Adding bacterial culture had significantly effect on VFA concentration. There was significantly difference among treatments on acetate: propionate ratio and treatments 2 and 4 had lowest ratio.  

    Conclusion

    Generally, DM and OM digestibility and VFA concentration can be affected positively and significantly by live bacterial cultures additives. These changes would be associated with the stabilization of rumen pH and provide favorable conditions for microorganisms’activity in the rumen.

  • Neda Naghdi , Reza Valizadeh , Abbas Ali Naserian , Ahmad Asoodeh Pages 325-338
    Introduction: Zinc (Zn) is well known as an essential trace element in animal nutrition to ensure optimal body functions and animal health. Previous studies have demonstrated that Zn supplementation has improved the rate of animal growth in practical feeding regimes. Traditionally, the farm animal diets have been supplemented with Zn in the inorganic forms as either zinc oxide or zinc sulfate. The use of organic Zn sources in the form of chelates and supplements for ruminant diets has increased in recent years. Many studies have been conducted to interrogate the relative bioavailability of organic Zn sources in comparison to inorganic forms in ruminant nutrition. Meta-analysis is the statistical combination of results from two or more independent studies for the purpose of integrating findings or results for the under study subject. Meta-analysis can be helpful in determining whether multiple tests of an intervention yield effects on an outcome construct of interest that are similar in direction and magnitude. In the current meta-analysis the organic and inorganic zinc supplementation effects on performance of fattening lambs have been compared. Materials and Methods: A literature search was initially conducted using PubMed, Medline, Science Direct, and Google Scholar data bases and investigated references in the papers. It was also based on the following key words: zinc, organic zinc, inorganic zinc, zinc sulfate, zinc oxide, zinc methionine, zinc proteinate (s), zinc polysaccharide, growth performance, and fattening lamb. The resulting 14 articles were examined for inclusion or exclusion in this analysis. Then seven studies were included in this meta-analysis; and prepared 14 comparisons for average daily gain, 12 comparisons for average dry matter intake and feed efficiency, 11 comparisons for serum/plasma zinc concentration and super oxide dismutase activity, and 13 for alkaline phosphatase activity. Meta-analyses were carried out using the Comprehensive Meta-Analysis package, version 2. The size effects of across studies were calculated with fixed and random effect models. The presence of true heterogeneity among studies was identified with Cochran’s Q –tests and quantification of the degree of heterogeneity was done with the I2 index. Possible publication bias was evaluated with funnel plot and statistical tests. Results and Discussion:
    The results of this meta-analysis showed that the addition of Zn in the diet, has a positive effects on average daily body weight gain (+0.5 ± 0.17), increase in serum or plasma zinc content (+1.13 ± 0.225) and alkaline phosphatase enzyme (+1.4 ± 0.205) and superoxide dismutase activity (0.8 ± 0.226). However, Zn supplementation in either form (inorganic or organic) had no significant effects on some variable such as daily feed intake (-0.05 ± 0.161) and feed conversion ratio (0.06 ± 0.241). This quantitative meta-analysis of data from several experiments indicated that dietary Zn supplementation significantly increased average daily body weight gain, serum or plasma Zn concentration, alkaline phosphatase and superoxide dismutase activity in fattening lambs. Superoxide dismutase is a redox metalloenzyme involving in cell defense mechanisms against oxidative stress as well as animal health. This enzyme can reduce oxidative stress therefore improves immune functions.
     Conclusion:
    The results of this meta-analysis confirmed that organic sources of zinc supplements especially the zinc-proteinates are more effective than the inorganic forms for improving lamb growth performances. However, more precise experiments are required for reaching to the practical implementations.
    Keywords: Fattening lamb, Inorganic zinc supplementation, Meta-analysis, Organic zinc supplementation, Performance
  • Akbar Abarghani , Morteza Chaji , Hormoz Mansouri , Morteza Mamouei , Khalil Mirzadeh, Hedayatollah Roshanfekr Pages 339-352
    Introduction
    Halophytic plants constitute a significant part of the local flora in arid and semiarid regions. Native sheep, goats and camels graze these forages. The Suaeda fruticosa, Seidlitzia rosmarinus and Atriplex leucoclada that are belonging to the chenopodiaceae family, have considerable forage potential in the arid and semiarid rangelands. Overall, these plants are tolerant to drought, and used to reclaim degraded rangeland. In addition, they reduce ground water salinity and improve condition and structure of soil. Meanwhile, there are some secondary metabolites in halophytic plants like condense tannin that effect on consume and performance of the animals. Characteristic of a pasture, climatic conditions the pasture, range management, time of grazing in the pasture, animal characteristics and method of study are factors that all or some can influence yield, chemical compositions and rumen degradability of Halophytic plants. There are a few reports about the nutrition value of Atriplex spp., Seidlitzia spp. and suaeda spp. Therefore, the objective of this study was to evaluate of chemical composition and nutrients degradability of these halophyte plants for dromedary camels.
    Material and Methods: This study was conducted in Agricultural Sciences and Natural Resources University of Khuzestan. Two female camels (about four years old) with rumen fistula were used in present experiment. The plants sampling were conducted from three regions of Jofer, Howayzeh and road of Abadan-Khorramshahr on the Khuzestan province in southwest of Iran, an area of approximately 60 Km in diameter. All ranges in term of topography have plain shape, without stone and deep canyons, and with high levels of underground water. The soil of these ranges has salinity characteristic and clay constitution. The study regions climate typified that of south Khuzestan. Annual mean temperature is 24.9°C with average minimum and maximum temperatures ranging from 2.6°C in January to 42°C in August. Precipitation averaged 224 mm per day.  The study area had a fair diversity of vegetation types. Four types of these plants named Atriplex leucoclada (AL), Suaeda fruticosa (SF), Seidlitzia rosmarinus (SR) were evaluated individually or in different mixture in completely randomized design. Treatments were, T1, 33.5% AL + 66.5% SR; T2, 100% AL; T3, 66.5% AL + 33.5% SF; T4, 66.5% AL + 33.5% SR; T5, 100% SR; T6, 33.5% AL + 66.5% SF; T7, 66.5% SR + 33.5% SF; T8, 66.5% SF + 33.5% SR; T9, 100% SF. Dry matter (DM), crude protein CP, ether extract (EE), ash, NDF, ADF, lignin, hemicellulose, cellulose, non-fibrous carbohydrates (NFC), neutral detergent soluble fiber (NDSF), total 80% ethanol-soluble carbohydrate (TESC), organic acids, starch and in situ degradability of DM, OM, NDF, CP of each plants were measured.   
    Results and Discussion
    Atriplex leucoclada had the highest hemicellulose, NDF and organic matter among three halophyte plants. The highest concentrations of tannin and oxalate and organic acids were related to Seidlitzia rosmarinus. The SR and AL had respectively highest and lowest dry matter (DM) degradability and effective degradability (ED) (P<0.05). There was not any difference between Seidlitzia rosmarinus and mixture of Seidlitzia rosmarinus + Suaeda fruticose (Treat 7 and 8). Briefly, according to the results of this section, replacement the high levels of Seidlitzia rosmarinus instead of Suaeda fruticose, increase the dry matter degradability more effectiveness than low levels of that. Organic matter degradability of the SR and SF was significantly higher than the AL (P<0.05). The T7 and T2 treatments had the highest and lowest NDF degradability among others, respectively (P<0.05). Crude protein degradability was highest in the treat containing 66.5% SR+33.5% AL (T1), and AL treat had lowest in situ CP degradability percentage. The results were shown that CP degradation rate was faster than DM, OM and NDF in the initial incubation times.
    Conclusion
    It was concluded that according to DM, OM and NDF degradability, the best plant mix for better feeding of grazing camels are treatments T5, T7 and T8 (without AL); but as protein degradability and chemical composition data, the treatments containing AL (T1, T3, T4 andT6, excepted T2) were the best mix. Therefore, it seems that one of the strategies for improving the digestibility of halophyte plants in camels is mixing these plants with each other, which according to the results of the present experiment, a combination of AL with SR or SF may be caused to more ruminal degradability in feeding of grazing camel and rehabilitation of rangelands.
    Keywords: Nylon bags, Organic acids, Oxalate, Phenolic components, Tannin
  • Kolsom Salehpour , Tahereh Mohammad Abadi , Mohammadreza Ghorbani Pages 353-366
    Introduction
    Myrtle is from Myrtaceae family with scientific name, Myrtus communis. Myrtle leaves mainly containing terpynolen, cineol, linalool, terpineol and acetate lynalyl. Also including the active ingredients as phenolic acids such as galic acid, vanillic acid and ferulic acid, tannins such as galotannin and flavonoids such as, myrcetin, catechin and quercetin. Many plants synthesis secondary metabolites that have antimicrobial activity, regulation of ruminal fermentation and subsequently improve nutrient intake. Information on the use of myrtle leaves in ruminant nutrition is rare, so this experiment was designed to investigate the effect of myrtle leaves on digestion, some blood and rumen parameters and protozoa species in Arabi sheep.  
    Materials and methods
    At first step, the appropriate level of myrtle leaves between the levels 0.2, 0.4 and 0.6 % with diet 70:30 concentrate to forage was determined by in vitro methods (gas test and tilly and terry method). Rumen fluid was collected from sheep before the morning feeding. About 200 mg sample (1.0 mm screen) incubated in 100 ml vials with 35 mL buffered rumen fluid under continuous CO2 reflux for 2, 4, 6, 8, 10, 12, 16, 24, 48, 72 and 96 h, at 39°C. Cumulative gas production data were fitted to the exponential equation Y=B (1−e−ct). Partitioning factor, microbial biomass and truly digested organic matter was calculated. For determination of partitioning factor at the end of each incubation period, the content of vials was transferred into an Erlenmeyer flask, mixed with 20 mL neutral detergent fiber solution, boiled for 1 hour, filtered, dried (in oven at 60 °C for 48 h) and ash. Digestibility of dry matter and NDF of samples were determined using tilly and terry method. Rumen fluid was collected from animals, and were mixed with McDougall buffer in a ratio 1:4. After gasifying with CO2, tubes were incubated at 39 ˚C. After 48 h of fermentation, 6 mL of 20% HCl solution and 5 mL pepsin solution were added and the incubated for 48 h, simulating post-ruminal degradation. After incubation, the residual substrates of each tube were filtered and used to determine digestibility of DM and NDF.
    At the second step of experiment, the appropriate amount of myrtle leaves; 0.4 %; was used in feeding 8 Arabi sheep (23±1.5 kg) for 30 days. In the end of experiment, feed intake, digestibility, protozoa morphology, some blood metabolites and rumen parameters were measured. Data were subjected to analysis as a completely randomized design using the General Linear Model (GLM) procedure of SAS. version 9.1. The Duncan multiple range test was used to compare means at P< 0.05.  
    Results and Discussion
    The results of in vitro step showed that the best fermentation, gas production and digestibility were for 0.4% the myrtle leaves. On the base of the result of in vivo step, using of myrtle leaves had not any effect on dry matter and organic matter intake (P>0.05). Treatment containing myrtle leaves had the highest protein intake in compared with control treatment (P<0.05). Digestibility of crude protein and NDF in diet with myrtle in comparison to control significantly increased (P<0.05). But there was no significant difference between the dry matter, organic matter and ADF digestibility of sheep’s (P>0.05). Protozoa population was significantly not affected by inclusion myrtle leaves in the diet (P>0.05). Ammonia levels in diets treated with myrtle (8.29) significantly reduced in compared with the control (16.5) (p<0.05). The myrtle leaves treatment decreased triglyceride and blood glucose of sheeps (P<0.05). Factors such as period of adaptation to medicinal herbs and interaction with other dietary components and their amounts in the diet, can influence the amount of dry matter intake. Essential oils according to chemical structure, resources and activities have different effects on rumen fermentation and animal performance. The negative effect of active ingredients of medicinal plants on ammonia-producing bacteria caused to decrease of rumen ammonia production, also reducing protozoa and swallowing of bacteria that can be other reason for ammonia decrease. Polysaccharides, flavonoids, glycoproteins, polypeptides, steroids, alkaloids and pectin in plants such as myrtle can justify the hypoglycemic properties of these plants. Medicinal plants and their extracts are effective in reducing blood cholesterol and other lipids. It is reported essential oil reduces pH of intestinal tract through production of degrading enzymes of bile, also inhibit the activity of HMG-COA enzyme.  
    Conclusion
    According to the results, it seems 0.4 % myrtle leaves has beneficial effects on digestibility and can reduce blood glucose and triglyceride; therefore, maybe it can be used as an herbal supplement in Arabi sheep diet.
    Keywords: Arabi sheep, Blood factors, Digestibility, Myrtle leaves, Protozoa
  • Sadegh Kord Zanganeh, Mohammad Reza Ghorbani, Ahmad Tatar, Hassan Barzegar Pages 367-380
    Introduction

    The focus on maximizing productivity, production efficiency, and profitability led to the development of intensive animal husbandry conditions. In this case, many diseases were outbreak, and therefore, for controlling of them and enhance performance of farm animals, using of chemical substances such as antibiotics was inevitable. The use of antibiotics as growth promoters (AGPs) in poultry production began from several years ago. They were added to diets growth stimulation. The usage of AGPs is possibly an important factor that promotes the emergence of antibiotic resistant microorganisms in veterinary and human medicine. The use of AGPs has been banned in some countries. Removal of antibiotics from the diet may negatively affect profitability of the animals. Therefore, the feed industry will have to research alternatives instead of antibiotics (15). Various aromatic plants and spices as well as fruits constitute valuable phytogenic sources. The Pistacia (genus) plant is known for its medicinal property. The plant species Pistacia Atlantica available in western mountains of Iran and in Khuzestan, Ilam, Kermanshah, Lorestan provinces. The antimicrobial and antioxidant properties of the native species are known. Therefore, this study was conducted to evaluate the effect of wild pistachio leaves extract (WPLE) (Ethanolic, EtOH-H2O; 80%) on performance, cecal microbial population and immunity responses of broiler chickens.  

    Materials and Methods

    241 days old (mixed sex) broiler chicks (Ross308 strain) were used in a completely randomized design in 5 treatments, with 4 replicates and 12 chicks per each replicate. Dietary treatment included: 1)positive control (PC, corn-soybean meal bases diet); 2) negative control (NC, positive control supplemented with 0.1% Flavomicine; 3) WPLE1 (positive control supplemented with 0.1 WPLE); 4) WPLE2 (positive control supplemented with 0.2 WPLE) and 5) WPLE3 (positive control supplemented with 0.3 WPLE).The chicks were fed a corn-soy meal based diet (isocaloric and isonitrogenous (2969.0 kcal/kg metabolizable energy, 21.30% crude protein in starter period (1-21 d) and 3081.0 kcal/kg metabolizable energy, 19.20% crude protein in grower period (22-42 d)) supplemented with different levels of  WPLE and Flavomicine as on top. The diets were in mash form and formulated according to the NRC (1994) recommendations. Feed and water were provided ad libitum during the experiment. Feed intake (FI), body weight gain (BWG) andfeed conversion ratio (FCR) of birds in each pen was recorded weekly and calculated forstarter, grower and total phases for each bird. On day 42, two chicks per replicate were slaughtered and carcass characteristics were determined. Blood samples were collected from two birds per replicate to determine blood characteristics including cholesterol, triglycerides (TG), low density lipoprotein (LDL), high-density lipoprotein (HDL) and very low density lipoprotein (VLDL)at the end of the experiment (42 d of age). On day 42, two chicks per replicate were selected randomly and killed aseptically and cecal content of each bird was pooled for determination of microbial population. The ileum digesta samples collected from two slaughtered birds and mixed with distilled water (1:10) and vortexed vigorously and pH was measured using a standard pH meter. For determination of immune response, at 21 and 35 d of age, 1 mL of 25% sheep red blood cell (SRBC) solution was injected into their breast muscle of 2 chicks per replicate and blood samples were collected from brachial vein of the birds 7 d after each injection.

    Results and Discussion

    The results of this experiment showed that FI and BWG were not affected by antibiotic and WPLE in starter, grower and total phase (P>0.05). FCR was increased significantly in starter by addition of feed additives (WPLE and flavomicine). Means by non-significant differences in this study, maybe due to normal rearing condition. Researcher believed that plant secondary metabolite can exert their positive effects on critical condition. There were no significant differences in immunity and carcass parameters (P>0.05).TG and VLDL content of broiler serum were lower in WPLE2 and WPLE3 groups rather than PC. Dietary treatments did not affected Coliform population but increased Lactobacillus and decreased Escherichia coli population of cecal content significantly (P<0.05). The antibacterial properties of plant extracts could be attributed mainly to their phenolic components and their mechanisms of action on the microbial cell. A possible explanation for the stimulatory effect of polyphenolic compounds on beneficial bacterial growth is that some microorganisms are able touse these compounds as nutritional substrates. In the particular case of lactobacilli, these bacteria possess the ability to metabolize phenolic compounds supplying energy to cells and positively affecting the bacterial metabolism. The pH of ileal digesta was decreased significantly in 0.2 and 0.3% of WPLE (P<0.05). Increasing lactobacilli bacteria population can decrease pH of gut digesta.  

    Conclusion

    The results of this experiment suggest that WPLE can increase population of beneficial bacteria and decrease pathogen bacteria in cecal content and can lowering pH of ileal digesta.

    Keywords: Broiler chickens, Performance, Wild pistachio
  • Rogaye Jabari, Hossein Janmohammadi, Seyed Ali Mirghelenj, Roohollah Kinafar Pages 381-392

    Introduction Plant protein sources have important role in supplying crude protein and amino acids in poultry diets and soybean meal (SBM) and are used widely in the world, including Iran. Domestic production of SBM is relatively low and most of the meal is imported from abroad. Although protein content of SBM is measured at local labs but evaluation of its protein quality is less considered and is necessary to be monitored by chemical and biological assays. Corn gluten meal (CGM) is a co-product of corn and obtained during production of starch and glucose from corn. This meal is frequently contained more than 50 percent crude protein as such is compared with the animal proteins during diet formulation.
    The aim of this study was to determine of chemical composition and protein quality of some commercial samples of soybean and corn gluten meal.
    Material and methods Three commercial samples of soybean meal including Brazilian, Argentinean, Iranian and one sample of corn gluten meal were provided from poultry feed plants in East Azerbaijan province. The samples were subjected to chemical analysis by standard methods and protein quality was evaluated by in vitro and in vivo assays. Urease activity index and protein solubility in KOH was used as in vitro assays. For biological evaluation of protein quality of soybean and corn gluten meal samples, 100 Ross-308 male broiler chicks fed in a completely randomized design with 5 experimented diets each 4 replicates from age 8 to 17 d with nitrogen –free basal diet and 4 semi-purified diets each of test protein samples. Feed intake and weight gain of chick after 6 h fasting was recorded and Protein efficiency ratio (PER) and Net protein ratio (NPR) was calculated according to the corresponding formulas. At end of 17 of age, two chicks in each replication was killed, blood serum collected for uric acid, total protein and glucose assessments. Breast muscles was also separated and weighted. The data was subjected to normality tests and statistically analyzed with GLM procedure of SAS.     
    Results and Discussion The results of chemical analysis showed that average value of moisture, CP,EE and ash were 7.5, 7.4, 7.4, 4.7 and 46.3, 47.4, 46.4 , 65.5 and 8.6, 9.05, 12.4, 7.55 and 6.5, 6.5, 6.5, 2.15 percent in Argentinian, Brazilian, Iranian soybean and corn gluten meals, respectively. Generally, our finding on CP content was in range of CP content of soybean meal from United States, Brazil, Argentina and India (47.3, 46.9, 48.2, and 46.4% (as-fed basis), respectively). Average values of NDF and ADF were 10.93, 12, 10.43, 11.12 and 8.3, 10.9, 9.4, 10.34 percent in Argentinian, Brazilian, Iranian soybean meals and corn gluten meal, respectively.  Our data on NDF values of soy bean meal in samples of Argentina and Brazilian was higher than those values in the corresponding samples. Gross energy value for soybean meals from Brazil, Argentina, Iran and corn gluten meals were found to be 5095, 4677, 4985 and 5924 Kcal/Kg. Urease index and protein solubility in KOH for Brazilian, Argentinian and Iranian soybean meals was 0.05, 0.05, 0.07 and 88.39, 85.51, 86.82 percent, receptivity. The published acceptable data for urease index are inconsistent and generally the recommended value is less than 0.1 pH change. At present study, all value of urease index is lower than 0.1 values. KOH solubility values at this study on soy bean samples are higher than those, however, these values are acceptable from view of Araba et al and non-acceptable. The values of  PER and NPR for soybean meals from Brazil, Argentina, Iran and corn gluten meal in 17 d assay were 2.89, 3.13, 2.57, 0.36 and 3.48, 3.74, 3.14, 1.37, respectively. These biological values were comparable with PER and NPR values of different origin soybean meals. Breast muscle growth and serum blood uric acid level did not show significant difference in the meals.
    Conclusion It was concluded that protein quantity and quality of domestic soybean meal was comparable with two imported samples. NDF value of domestic soybean meal, like foreign ones, is high and this can decrease its available energy and AA. CGM was rich in protein content but poor in view of protein quality.

    Keywords: KOH solubility, Male broiler chicks, Protein efficiency ratio, Urease activity index
  • Mehrnush Forutan , Saied Ansari Mahyari , Flavio Schenkel , Mehdi Sargolzaei Pages 393-402
    Abstract Introduction With the advent of high throughput genotyping technologies, interest has grown in using genomic information to estimate breeding values. Genomic selection, in which genetic markers across the whole genome are used to estimate breeding values of individuals, is routinely applied in dairy cattle breeding programs. In dairy cattle, genomic selection has resulted in a substantial increase in the rate of genetic gain compared to traditional selection. This has been achieved mainly by reducing the generation interval, which became possible because of the higher accuracies of genomic breeding values (GEBV) estimated early in life compared to parent averages. Since single nucleotide polymorphism (SNP) genotypes are bi-allelic and, therefore, their information content is not high, so SNP-based methods may not effectively capture the linkage disequilibrium (LD) between SNPs and multi-allelic quantitative trait loci (QTLs). Haplotypes are in general “multi-allelic” and compared to individual SNPs may better capture LD with multi-allelic QTL. Furthermore, most of the SNPs in the chips are old mutations. This may imply that SNP-based relationship matrix traces very old relationships from distant relatives and, therefore, may not trace changes due to recent selection accurately. It has also been hypothesized that using similarity between haplotypes to model the covariance between genomic effects can result in better predictive ability than modeling covariance based on SNP genotypes. So the objective of this study was to investigate the accuracy and bias of GEBV using genomic best linear unbiased prediction (GBLUP) with alternate genomic relationship matrices (G) based on SNPs and haplotypes information. Materials and Methods The North American Holstein genotype data was provided by the Canadian Dairy Network (CDN). The Holstein bulls with official domestic proofs were genotyped using the Illumina Bovine SNP 50 TM Chip. The genotyped Holstein bulls were classified as estimation group and prediction group. All bulls in prediction group were those bulls who were born from 2007 to 2011 and had official proof in 2015. De-regressed EBV (dEBV) based on the 2015 genetic evaluation (dEBV2015) were used for validation purposes. The estimation group included bulls born mainly between 1960 to 2007. The analyzed traits were fat yield, milk yield, somatic cell score, conformation, and days open. The GEBVs for mentioned traits were estimated based on GBLUP models using SNP1101 software. Three G matrices were built: 1) SNP genotype based relationship matrix (GSNP), 2) haplotype based relationship matrix (GHAP), and 3) hybrid matrix composing of SNP genotype and haplotype based relationship matrices (GSNP, HAP). Accuracy of prediction was calculated as Pearson’s correlation between estimated GEBV and dEBV2015 for prediction group. Bias of prediction was also calculated as regression coefficient of dEBV2015 on GEBV for prediction group. Results and Discussion Observed differences between alternate G matrices were larger in prediction bias than in prediction accuracy. Accuracy of genomic predictions based on GHAP were 0.73, 0.71, 0.62, 0.54, and 0.50 for fat yield, milk yield, somatic cell score, conformation, and days open, respectively. Accuracy of genomic predictions based on GSNP also were 0.72, 0.70, 0.61, 0.56, and 0.49, respectively. Although using GHAP instead of GSNP did not significantly improve the accuracy of prediction, it resulted in estimates with 6 (conformation) to 15% (days open) less bias and closer to one over the different traits. Genomic selection based on GHAP instead of GSNP seems to improve bias of prediction for traits under recent selection, such as days open. This might also be due to the fact that this trait is lowly heritable. Although accuracy of genomic predictions based on GSNP, HAP were similar to GSNP, using GSNP, HAP resulted in higher biases than GHAP or GSNP. Conclusion Based on these findings, GHAP might be an alternative approach to reduce bias of genomic predictions in routine genomic evaluations. Genomic selection based on GHAP instead of GSNP improved bias of prediction especially for low heritable traits under recent selection, such as days open. Small gain achieved with GHAP compared to GSNP may imply that the correlation between IBS and IBD in GHAP is not optimal for maximization of prediction accuracy. Based on current results further research is needed to investigate the use of haplotype length and allele frequency of markers in haplotype segments in the definition of haplotype similarity. In addition, this study suggests further research to assess the effect of recent selection, heritability and genetic architecture of the traits on the performance of haplotype based relationship matrix.
    Keywords: Accuracy, Bias of prediction, Genomic relationship matrix, Haplotype, Holstein cattle
  • Seyed Nader Albooshoke, Mojtaba Tahmoorespur, Mohammad Reza Bakhtiyarizadeh, Mohammad Reza Nassiry, Saied Esmaeilkhanian Pages 403-416

    Introduction Native chicken breeds are important genetic resource and well adapted to the local environmental conditions. However, growth rate and feed efficiency of these breeds are not appropriate. On the other hand modern broilers grow faster and offer a higher nutritional efficiency than the indigenous chicken breeds. This advantage is the result of the severe genetic selection programs, which were designed to increase production. In this study, a systematic identification of mitoProteome genes and new pathways related to growth rate of pectoralis muscle in chicken has been made using gene expression profiles of two distinct breeds: Isfahan native, a slow-growing Iranian breed possessing low growth rate and Ross 708, a commercial fast-growing broiler line.
    Materials and Methods All the birds were reared under the same management, environmental and nutritional conditions. The diet was the same throughout the whole experiment and formulated to contain 20% CP and 3000 kcal ME/kg. The birds received feed and water freely (ad libitum). On day 28 post-hatch, six birds were randomly selected from each breed, weighed and sacrificed. From each bird, 1 to 2 g of tissue was excised from the posterior region of the left pectoralis major muscle. Total RNA was isolated from breast muscle samples. Using Truseq Stranded RNA Prep kit (Illumina), each sample was converted to a uniquely indexed cDNA library, and the resulting cDNA libraries were pooled and sequenced on an Illumina Hiseq 2000 sequencer. An average of 70 million paired end reads (150 bp) were produced from all sample, 70% of which were properly mapped to the reference genome (EnsemblGalgal4). We analyzed the sequence data using bioinformatics tools Hisat2 and Cufflinks. Using Hisat2 aligner, more than 72% of clean reads (in average) were mapped back to the Galgal4 reference genome. In addition, about 90% of reads were aligned concordantly.
    Results and Discussion On the first day after hatching, the weight of commercial chicks were heavier than native. This process continued until the end of the test, 28 days. The commercial chickens have a heavier weight, higher growth rate, and lower feed conversion rates than native chickens. The RNA-Seq of four muscle samples yielded around 131, 590, 636 million of raw 150 bp paired end reads, of which 94, 483, 431 and 37, 107, 205 reads were for native and commercial breeds, respectively. We identified 606 differentially expressed genes (DEGs) between two breeds with at least 2-fold differences (P-adjusted (Benjamini) ≤ 0. 05, log2FC ≥ 2). Of these, 249 and 357 genes were up-regulated in native and commercial broilers, respectively. In the native chickens, FoxO3 transcription factor activated the atrophy pathway related to E3 ubiquitin ligases and led to increased proteolysis and reduced the skeletal muscle size as compared to the commercial broilers. Hypoxia and regulation of the metabolic process of the reactive oxygen species (ROS) were among the most important significant biological processes in native chickens. The analysis of the genes associated with the mitoProteome revealed significant changes in the expression of many genes involved in transcription regulation and growth. Also the increased expression of FoxO3 gene and the releasing of amino acids caused by the degradation of proteins, increased the expression of amino acid catabolism enzyme's (such as MCCC2 and TDH), as well increased expression of pyruvate dehydrogenase kinases (PDK4 and PDK3). This led to reducing of the aerobic oxidation of pyruvate and increasing gluconeogenesis. Increasing the UCP3 gene expression in native chickens can partly reduce mitochondrial efficiency and inappropriate feed conversion ratio compared to commercial chickens. These changes were also reflective of a complicated adaptation program that facilitates proteolysis and reduces oxidative metabolism of glucose and pyruvate in the muscles. These metabolic pathways have evolved to reduce the requirements of indigenous chickens and increase the ability of these strains to overcome the circumstances and environmental stress and resist nutritional deficits.
    Conclusion Our results suggested that different expression patterns of some genes including SGK1, FBXO32, FBX030, IRS2 ، SP3, CUL, PIK3IP1 and FoxO3 in native breed might represent a cause for the poor growth performance for this breed than commercial breed. Hence, evaluation of native chicken based on these candidate genes would accelerate the efficient native chicken breed in near future. These results expand our knowledge of the genes transcribed in the breast muscle of two breeds and provide a basis for future research of the molecular mechanisms underlying the chicken breed differences.

    Keywords: Breast muscle, Native chicken, Mitoproteome, RNA-seq
  • Meysam Latifi Pages 417-424
    Introduction Mehraban sheep is one of the important Iranian breeds. This breed mainly distributed in the western province of Hamadan, Iran. This breed is fat-tailed and has carpet wool with light brown, cream or grey colour. There are approximately 3 million heads of Mehraban sheep and primarily used for meat production. Accurate estimation of genetic parameters and in particular genetic correlations requires large data sets and effective methods for genetic analyses with considering all potential effects. In livestock, the animal mixed model using REML procedure, which allowed to estimate variance components such as maternal heritability, permanent environmental effects and the correlation between direct and maternal genetic effects for investigated traits, is used extensively for data analysis. Many researchers reported that ignoring maternal effects leads to over-estimation of direct heritability and consequently, reduced accuracy of prediction. Therefore, in order to obtain an optimal genetic gain in a selection scheme, including maternal effects will decrease the bias of predicted responses to selection. In genetic evaluation of animals, it is generally assumed that only autosomal chromosomes are involved and the effect of sex chromosomes ignored.  In Markhoz goat, it has been shown that sex-linked genes may have less effect at the early ages and more noticeable effects were indicated on body weights at older ages. The aim of this study were to estimate the genetic parameters of autosomal and sex-Linked additive genetics effects for pre-weaning traits in Mehraban sheep using multi-trait analyses and to estimate genetic correlations between traits.
    Material and method The data set used in this study was collected between 1994 and 2010 from Mehraban sheep breeding station in Hamadan province, Iran. The analyzed traits were birth weight (BW), weaning weigh (WW), average daily gain (ADG) from birth to weaning and Kleiber Ratio from birth to weaning. The GLM procedure of SAS software was used to identify which the fixed effects that are required to be considered in the animal model. The model accounting for fixed effects included herd-year (combined as herd–year effect), sex (male or female), birth type (single or twin), age of dam (2-6 years old) and the age of weaning (in days) was used as a covariate for WW (P<0.001). Also, random effects included direct additive genetic effects in autosomal chromosomes, direct additive genetic effects in sex-linked, maternal genetic effects, maternal permanent environmental effects and the residual effects. (Co) variance components and genetic parameters were estimated using a multi-trait analysis via the Restricted Maximum Likelihood (REML) method with WOMBAT software. Convergence criterion was assumed 10–8.
    Result and discussion The interaction between herd and year of lambing was significant for all traits. Significant influence of herd and year of lambing could be explained by difference in management, climate conditions and feeding. Also, all traits were significantly affected by sex, birth type and age of dam. The significance of these effects is mainly due to endocrine system between two genders, limited uterine space especially in young ewes, competition for milk between the twins or maternal ability of dam. For birth weight, weaning weight, average daily weight from birth to weaning weight (ADG) and Kleiber Ratio (KR), estimated direct autosomal heritabilities were 0.21, 0.18, 0.34 and 0.55, estimated direct sex-linked heritabilities were 0.03, 0.11, 0.10 and 0.07, estimated maternal heritabilities were 0.01, 0.15, 0.11 and 0.09, and ratio of maternal permanent environmental variance to phenotypic variance were 0.04, 0.0, 0.0 and 0.06, respectively. According to these results, growth rate and Kleiber ratio in Mehraban sheep are categorized as moderate and high heritable traits, therefore a favorable genetic gain would be expected through selection programs. Estimated direct sex-linked heritabilities were close to the estimates of maternal heritabilitiese. This suggests that sex-linked effects need to be considered in selecting for growth traits in Mehraban sheep. The autosomal, sex-chromosome, maternal genetic, maternal environmental effects and phenotypic correlations were ranged from -0.31 to 0.91, 0.33 to 0.99, -0.26 to 0.99 and -0.28 to 0.94, respectively.
    Conclusion The results of this study indicated that the direct variance of sex chromosomes has an affect similar maternal genetic variance, and it could contribute to a more accurate estimation of the direct autosomal heritability. Also, positive genetic correlations between sex chromosomes could increase the response to selection of each sexes.
    Keywords: Autosomal heritability, Mehraban sheep, Pre-weaning weights, Sex-linked heritability
  • Mahmood Ahmadi, hamedani Pages 425-434
    Introduction The expected values of hematologic and serum biochemical parameters in domestic animal species can be affected by breed, age, environment, and nutrition. Established breed-specific reference intervals (RI) are an important tool for monitoring the health of sheep. There is a lack of published data on biochemical RI for Sngsari sheep. Thus, the aims of this study were to establish RI for select of serum biochemical parameters for Sangsari sheep by Reference Value Advisor (RVA) method and provide information on the studied parameters for both sex of this breed in order to form a basis for clinical interpretation. 
    Materials and Methods Sixty healthy Sangsari sheep including 26 ewes and 34 rams (2–4 years old) were chosen from the breeding station of Sangsari sheep among 150 sheep in Damghan, Semnan, Iran. The type of feeding, all the animals had free access to water and to good-quality alfalfa hay (90.0 % DM, 15.8 CP % DM, 50.4NDF%DM, 31.6ADF%DM, 5.8 lignin% DM, and 2.2 EE % DM). Concentrate (23 % oats, 36 % corn, 38 % barley, and 3%mineral and vitamin supplements) was provided once daily (200 g per animal per day). In the sampling day, breeder signed a subscription form and completed a primary questionnaire consisting of specific questions about past and current health status, sexual status, medications used, and familial and reproductive medical history. Complete physical examinations were performed by the same experienced veterinarian on each sheep. In order to reduce stress, blood samples were taken in the station with minimal changes in the usual schedule of the sheep. Blood samples (taken from the jugular vein) were collected in simple tubes in order to separate the serum (centrifuged at 3000 rpm for 10 min) for biochemical analysis. Samples transported at +4 °C to the laboratory department of the Faculty of Veterinary Medicine, Semnan, Iran. Biochemical parameters were measured by a autoanalyzer. These parameters included alkaline phosphatase (ALP), gamma glutamyletransferase (GGT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), total protein (TP) and albumin (Alb). For statistical analysis, data were analyzed by Reference Value Advisor and outliers were deleted if detected according to Tukey or Dixon. RIs, according to sample size, were determined using a robust method and following Box-Cox transformation of data. The data were normally distributed, and differences between sexes in biochemical parameters were analyzed using independent sample T test. A value of P<0.05 was considered as significant.
    Results and Discussion The RI of biochemical parameters obtained from adult healthy Sangsari sheep includes the following: ALP 49.24-564.84 u/l; GGT 24.14-62.23 u/l; AST 10.86-338.40 u/l; BUN 6.91-26.43 mg/dl; TP 5.19-13.95 gr/dl and Alb 0.92-3.63 gr/dl. Established RI of biochemical parameters for ewes and rams, respectively including: ALP 29.98-702.89 u/l; GGT 22.41-54.49 u/l; AST 1.36-279.89 u/l; BUN 5.95-26.86 mg/dl; TP 5.75-12.83 gr/dl; Alb 0.84-2.77 gr/dl and ALP 106.08-568.55 u/l; GGT 20.80-58.30 u/l; AST 360.12 u/l; BUN 8.15-26.04 mg/dl; TP 4.66-15.59 g/dl and Alb 0.74-3.77 g/dl. Interpretation of the biochemical results in different breeds of sheep, with regard to RI for each parameter, in conjunction with history, clinical findings and other paraclinical tests helps the clinician to reach a definitive diagnosis. A unique feature of Sangsari sheep is that they are highly adaptable with desert and mountain ranges with high tolerance of drought conditions. This breed is also relatively small size and light weight, and most studies have focused on genetic characteristics associated with this trait. In view of the characteristics mentioned above and considering the lack of reference range for biochemical parameters, it is necessary to determine reference intervals in Sangsari sheep. In order to establish a comprehensive reference interval in Sangsari sheep, a select biochemical parameters were evaluated in the present study. Almost most of the established RI for biochemical parameters in this study differed from previously published RI, so that the lower and upper limits of RI of theses parameters (with the exception of BUN) were lower and higher than the values previously reported. Differences between obtained RI for the Sangsari sheep and previously reported RI for other breeds may be attributed to variations in hormonal influences, hydration status, dietary differences, or adaptations to a desert environment, age, breed, season of study and analytic method. Conclusion The obtained data provided reference interval for biochemical parameters in Sangsari sheep for the first time. Present study demonstrates significant differences in most of the biochemical parameters. Reference intervals determined in this study provide a baseline for interpreting biochemical results in Sangsari sheep, and contribute to optimization of the management of this species.
    Keywords: Clinical biochemistry, Sangsari sheep, Reference Interval, Sex