فهرست مطالب

  • سال یازدهم شماره 3 (پاییز 1398)
  • تاریخ انتشار: 1398/09/25
  • تعداد عناوین: 10
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  • محمدرضا مشایخی، محسن ساری*، نعیم عرفانی مجد، مرتضی رضایی صفحات 273-291

    هدف از انجام این آزمایش بررسی اثرات اوره آهسته رهش (با نام تجاری نیتروزا) در مقایسه با اوره معمولی، با یا بدون افزودن ملاس، بر عملکرد، خصوصیات لاشه، تخمیر شکمبه ای و فراسنجه های خونی بره های پرواری بود. آزمایش در قالب طرح کاملا تصادفی با 5 تیمار شامل کنترل، دو منبع نیتروژن غیر پروتیینی اوره معمولی (6/1 درصد) و اوره آهسته رهش (8/1 درصد) با یا بدون ملاس (صفر و 20 درصد) و 7 تکرار با استفاده از 35 راس بره نر عربی، به مدت 105 روز انجام شد. جایگزینی اوره معمولی با اوره آهسته رهش و نیز افزودن ملاس به جیر ه، در مقایسه با گروه کنترل، موجب ایجاد تغییر در افزایش وزن روزانه، ضریب تبدیل خوراک، وزن نهایی پروار، صفات و وزن قطعات لاشه، فراسنجه های رنگ سنجی گوشت و قابلیت هضم مواد مغذی نشد. در جیره های حاوی اوره غلظت پروپیونات و نیتروژن آمونیاکی شکمبه، نسبت به جیره کنترل، بالاتر بود. افزودن ملاس به جیره موجب افزایش غلظت بوتیرات و کل اسیدهای چرب فرار شکمبه نسبت به جیره کنترل شد. در تیمار کنترل، pH شکمبه نسبت به تیمار های حاوی منابع نیتروژن غیر پروتیینی پایین تر بود. همراه شدن ملاس با اوره، باعث کاهش نیتروژن اوره ای خون شد. در کل نتایج آزمایش نشان داد که اگرچه جایگزینی اوره معمولی با اوره آهسته رهش و نیز همراه شدن ملاس با آن، در جیره های پرکنسانتره برخی فراسنجه های تخمیری شکمبه و متابولیت های خونی را تحت تاثیر قرار داد ولی این تغییرات به اندازه ای نبود که بتواند بهبودی در عملکرد پروار و قابلیت هضم مواد مغذی ایجاد نماید.

    کلیدواژگان: اوره آهسته رهش، تخمیر شکمبه، عملکرد پروار، قابلیت هضم، ملاس
  • یدالله چاشنی دل*، سیروس شکرالهی، مصطفی یوسف الهی، اکبر سلیمانی، مهدی بهاری صفحات 293-306

    به منظور تعیین اثرات جایگزینی سطوح مختلف سبوس برنج روغن کشی شده با کنجاله سویا، بر تولید و ترکیبات شیر، الگوی اسیدهای چرب شیر، نمره وضعیت بدنی و برخی فراسنجه های خونی گاوهای شیری، آزمایشی با استفاده از تعداد 12 راس گاو شیرده نژاد سیمنتال دو شکم زایش، با میانگین وزن ابتدای دوره27±630 کیلوگرم، میانگین تولید شیر 7/1 ±35  لیتر در روز و میانگین روزهای شیردهی17± 109روز در قالب طرح کاملا تصادفی با چهار تیمار و سه تکرار انجام شد. تیمارهای آزمایشی شامل جیره شاهد فاقد سبوس برنج روغن کشی شده و جیره های حاوی سبوس روغن کشی شده جایگزین 50، 75 و 95 درصد از کنجاله سویا بود. نتایج آزمایش نشان داد که جیره های آزمایشی در مجموع اثر معنی داری بر ترکیب و تولید شیر داشتند، طوری که تولید شیر در تیمار حاوی سبوس برنج روغن کشی شده جایگزین شده با 75 درصد از کنجاله سویا، بیش از سایر تیمارهای آزمایشی بود. نمره وضعیت بدنی به طور معنی داری تحت تاثیر جیره های آزمایشی قرار نگرفت. اثر تیمارها روی الگوی اسیدهای چرب شیر معنی دار نبود. همچنین افزودن سبوس روغن کشی شده برنج، تاثیر معنی داری روی فراسنجه های خون داشت، طوری که با افزایش سطح سبوس برنج در جیره تا 75 درصد جایگزین کنجاله سویا، سبب کاهش معنی داری مقادیر فراسنجه های خونی به جز گلوکز شد. با توجه به نتایج حاصل از این آزمایش، سبوس برنج روغن کشی شده جایگزین 75 درصد از کنجاله سویا در جیره نسبت به  تیمار شاهد باعث افزایش تولید شیر و کاهش درصد چربی در گاوهای شیری شد.

    کلیدواژگان: اسیدهای چرب شیر، سبوس برنج، فراسنجه های خونی، گاو شیری، محصولات فرعی غلات
  • سمیرا دهقانی، اکبر تقی زاده*، حمید محمدزاده صفحات 307-317

    تحقیق حاضر به منظور ارزیابی اثر اشکال مختلف سلنیوم بر تولید گاز، تخمیر شکمبه و جمعیت پروتوزوآی شکمبه گوسفندان قزل گرفت. تیمارهای آزمایشی شامل 1. کنسانتره بدون مکمل سلنیوم 2. کنسانتره +ppm 3/0 نانوسلنیوم 3. کنسانتره + ppm 3/0 سلنیوم آلی و 4. کنسانتره + ppm 3/0 سلنیوم معدنی بودند. در روش تولید گاز 300 میلی گرم از هر نمونه در ساعات 2، 4، 6، 8، 12، 16، 24، 36، 48، 72 و 96 انکوباسیون گردید. به منظور بررسی تاثیر اشکال مختلف سلنیوم بر اکوسیستم شکمبه، فاکتورهای pH، اسیدهای چرب فرار، نیتروژن آمونیاکی و جمعیت پروتوزوآیی مورد بررسی قرار گرفت. از ساعت 36 انکوباسیون به بعد میزان تولید گاز تیمارهای حاوی سلنیوم به طور معنی داری بیشتر از تیمار کنترل بود، اما تفاوت معنی داری از نظر تولید گاز بین این 3 تیمار وجود نداشت. پتانسیل تولید گاز در تیمارهای حاوی سلنیوم از تیمار کنترل بیشتر بوده (به ترتیب 9/201، 0/344، 7/321 و 8/319 میلی لیتر در تیمارهای شاهد، سلنیوم نانو، آلی و معدنی) ولی تفاوت معنی داری بین تیمارهای حاوی انواع مختلف سلنیوم وجود نداشت. تفاوت معنی داری بین تیمارها از نظر pH شکمبه وجود نداشت. تیمار نانو به طور معنی داری موجب افزایش غلظت اسیدهای چرب فرار نسبت به تیمارهای آلی و معدنی شد (به ترتیب 83/109، 00/98 و 83/89 میلی مول بر لیتر در تیمارهای سلنیوم نانو، آلی و معدنی). تفاوت معنی داری بین تیمارها از نظر میزان نیتروژن آمونیاکی شکمبه وجود نداشت. تیمار سلنیوم آلی موجب افزایش معنی دار تعداد کل پروتووزآ نسبت به تیمار سلنیوم معدنی و نانو سلنیوم شد. نتایج تحقیق نشان داد که افزودن مکمل سلنیوم خصوصا به شکل نانو نسبت به فرم رایج معدنی آن، احتمالا از طریق بهبود فرآیند تخمیر در محیط شکمبه، موجب افزایش پتانسیل تولید گاز شد.

    کلیدواژگان: تولید گاز، سلنیوم، فراسنجه های تخمیر شکمبه، گوسفند، نانو
  • امیر موسایی* صفحات 319-329

    به منظور بررسی اثر تغذیه مکمل های روی-متیونین و سولفات روی بر غلظت مواد معدنی و برخی فراسنجه های خون بره های نر کرمانی، 21 راس بره 7 ماهه با متوسط وزنی 90/0± 28 کیلوگرم انتخاب و جیره های شاهد (فاقد مکمل روی)، روی متیونین (40 میلی گرم در کیلوگرم ماده خشک) و سولفات روی (40 میلی گرم در کیلوگرم ماده خشک) در قالب یک طرح کاملا تصادفی با 3 تیمار و 7 تکرار به مدت 9 هفته بر روی بره ها اعمال شد. خون گیری در شروع (زمان صفر) و هفته های 3، 6 و 9 آزمایش انجام شد. غلظت کلسیم و فسفر سرم در طی زمان افزایش یافت (05/0>P) اما بین گروه های آزمایشی تفاوتی وجود نداشت. یافته های این آزمایش نشان داد که غلظت روی سرم بره ها قبل از شروع آزمایش کمتر از حد نرمال (90-150 میکروگرم در دسی لیتر) بود، اما در طی آزمایش افزایش یافت. میانگین غلظت روی سرم خون در گروه های تغذیه شده با مکمل های آلی و معدنی روی به طور معنی داری بالاتر از گروه شاهد بود (05/0>P) و این تفاوت بیشتر در هفته سوم آزمایش مشهود بود. غلظت مس، گلوکز و پروتئین تام سرم تحت تاثیر تیمارهای آزمایشی قرار نگرفت. اما در طی زمان، غلظت گلوکز و پروتئین تام افزایش یافت (01/0>P). میانگین فعالیت آنزیم سوپراکسید دیسموتاز در گروه روی-متیونین بیشتر از شاهد بود (05/0>P). فعالیت آنزیم آلکالین فسفاتاز، مشابه با تغییرات روی، در بره های تغذیه شده با مکمل های روی در هفته 3 آزمایش بالاتر بود (05/0>P). نتایج این آزمایش نشان داد که استفاده از مکمل های روی-متیونین و سولفات روی به میزان 40 میلی گرم در کیلوگرم خوراک بره های نر تغذیه شده با جیره پایه حاوی 48 میلی گرم روی و 7/11 میلی گرم مس در هر کیلوگرم ماده خشک، سبب افزایش غلظت روی سرم خون و فعالیت آنزیم های سوپراکسید دیسموتاز و آلکالین فسفاتاز شد و بر غلظت سرمی کلسیم، فسفر، مس، گلوکز و پروتئین تام اثر منفی نداشت. همچنین تفاوتی بین اثرات دو مکمل آلی و معدنی روی بر فراسنجه های یاد شده مشاهده نشد.

    کلیدواژگان: بره کرمانی، روی-متیونین، سولفات روی، سیستم آنتی اکسیدانی، متابولیت های خون
  • عباس علیپناه، محسن دانشیار*، پرویز فرهومند، غلامرضا نجفی صفحات 331-340

    اثرات لیزین و بتائین بر کیفیت و کمیت گوشت و استخوان جوجه های گوشتی تحت آسیت، با استفاده از 300 قطعه جوجه گوشتی یکروزه ماده سویه راس 308 در قالب طرح کاملا تصادفی با چهار تیمار و پنج تکرار بررسی شد. تیمارهای آزمایشی شامل جیره شاهد (جیره بر پایه ذرت- سویا بدون افزودنی)، لیزین به مقدار30 درصد بالاتر از توصیه راهنمای پرورش راس 308، بتائین در سطح 15/0 درصد جیره و لیزین 30 درصد بالاتر از مقدار سطوح توصیه شده و بتائین 15/0 درصد بودند. برای القای آسیت در پرندگان، دما در سنین 7، 14 و 21 روزگی به ترتیب به Cο 26،C ο20 و Cο 15  کاهش داده شد و بعد از 21 روزگی در محدوده Cο 15 تا آخر دوره حفظ شد. نتایج نشان داد که مصرف لیزین و بتائین به تنهایی یا توام باعث افزایش وزن بدن، وزن نسبی لاشه، سینه و ران شد (05/0P<). چربی حفره بطنی با مصرف بتائین به تنهایی یا همراه با لیزین کاهش پیدا کرد (05/0P<). جیره های حاوی لیزین و بتائین به تنهایی یا توام باعث کاهش تلفات آسیت و نسبت وزن بطن راست به کل بطن گردید (05/0P<). رطوبت، پروتئین، چربی، خاکستر، pH و رنگ گوشت سینه و گوشت ران تحت تاثیر تیمارهای آزمایشی قرار نگرفت (05/0P>). تیمارهای آزمایشی تاثیری بر خاکستر، کلسیم و فسفر یا ابعاد استخوان به‌جز قطر استخوان درشت‌نی نداشتند (05/0P<). به طور کلی، مصرف بتائین و لیزین موجب بهبود عملکرد، کمیت (وزن لاشه، ران و سینه) و کیفیت لاشه (کاهش چربی حفره بطنی) وتلفات ناشی از آسیت در جوجه های گوشتی شد.

    کلیدواژگان: آسیت، استخوان، بتائین، رنگ گوشت، لیزین
  • سلیمان محمدی، حسن درمانی کوهی*، نوید قوی حسین زاده صفحات 341-352

    این آزمایش در یک دوره 42 روزه با استفاده از 200 قطعه جوجه گوشتی سویه راس 308 در قالب طرح کاملا تصادفی با 5 تیمار و 4 تکرار و هر تکرار با 10 قطعه جوجه به منظور ارزیابی اثرات سطوح مختلف مواد معدنی بر عملکرد، خصوصیات استخوان درشت‌نی، پر درآوری و میزان تجمیع عناصر معدنی در سرم و پر جوجه‌های گوشتی انجام شد. جیره‌های آزمایشی شامل: 1- جیره شاهد (بدون پیش مخلوط مواد معدنی) و 2، 3، 4 و 5 جیره های حاوی پیش مخلوط مواد معدنی ‌در سطوح 25، 50، 75 و 100 درصد سطح پیشنهادی بودند. افزایش وزن و خوراک مصرفی روزانه در گروه های مکمل شده در مقایسه با تیمار شاهد بیشتر و ضریب تبدیل خوراک کمتر بود، ولی بین تیمارهای دریافت‌کننده پیش مخلوط این تفاوت ها معنی‌دار نشد. در خصوص استخوان درشت نی فراسنجه‌هایی از قبیل قطر، طول و حجم تحت تاثیر پیش مخلوط مواد معدنی قرار گرفت و تیمارهای دریافت‌کننده پیش مخلوط تفاوت معنی‌داری با تیمار شاهد نشان دادند، ولی وزن نسبی، چگالی و درصد خاکستر تفاوت معنی‌داری را نشان نداد. میزان پوشش پر در تیمارهای دریافت‌کننده پیش مخلوط افزایش یافت و به موازی آن میزان پارگی و آسیب‌دیدگی پرهای نواحی دم و بال کاهش یافت. غلظت سرمی کلسیم و غلطت های پتاسیم و روی در پر با استفاده ار پیش مخلوط موادمعدنی افزایش یافت، ولی عناصری از قبیل منگنز، سدیم، فسفر، کروم و نیکل تحت تاثیر قرار نگرفتند. اگرچه تفاوت معنی داری در رابطه با خصوصیات عملکردی و فراسنجه های مرتبط با استخوان درشت نی جوجه های مکمل شده با سطوح متفاوت پیش مخلوط مواد معدنی مشاهده نشد اما با توجه به تاثیر پذیری وضعیت پر درآوری جوجه های گوشتی، استفاده از پیش مخلوط در سطح 100 درصدی به منظور اطمینان از تامین نیازمندی ها پیشنهاد می شود.

    کلیدواژگان: پر درآوری، جوجه گوشتی، عناصر معدنی کم نیاز، وضعیت پر درآوری
  • محمود قزاقی، احمد حسن آبادی*، مهران مهری صفحات 353-364

    این مطالعه به منظور تعیین قابلیت هضم ظاهری و ایلئومی استاندارد شده اسیدهای آمینه ذرت، گندم، کنجاله سویا و کنجاله گلوتن ذرت در بلدرچین ژاپنی در سن 14 تا 21 روزگی انجام شد. در سن 14 روزگی، تعداد 600 قطعه جوجه بلدرچین ژاپنی مخلوط نر و ماده به‌صورت تصادفی در 5 تیمار، 4 تکرار و 30 قطعه پرنده در هر تکرار قرار گرفتند. پنج جیره آزمایشی شامل جیره فاقد نیتروژن، ذرت، گندم، کنجاله سویا و کنجاله گلوتن ذرت به نحوی تهیه شدند که در هر جیره تنها منبع آن پروتئین و اسیدهای آمینه ماده مورد آزمایش بود. میزان دفع درون زادی پایه اسیدهای آمینه متیونین، لیزین، ترئونین، آرژنین، والین، ایزولوسین، لوسین و هیستیدین به‌ترتیب 6/32، 306، 241، 104، 355، 497، 6/49 و 1/80 میلی گرم در کیلوگرم ماده خشک مصرفی به‌دست آمد. مقادیر قابلیت هضم استاندارد شده اسیدهای آمینه متیونین، لیزین، ترئونین، آرژنین، والین، ایزولوسین، لوسین و هیستیدین به عنوان اسیدهای آمینه ضروری در ذرت به ترتیب 48/94، 96/83، 33/88، 80/89، 15/92، 0/94 و 53/97 درصد؛ در گندم به ترتیب 54/92، 48/95، 81/89، 48/88، 11/90، 17/84 و 15/84 درصد؛ در کنجاله سویا به ترتیب 27/95، 08/83، 47/81، 45/91، 82/87، 92/81 و 87/85 درصد و در کنجاله گلوتن ذرت به ترتیب 27/86، 23/71، 03/78، 11/90، 23/93، 21/76 و 38/74 درصد به‌دست آمد. به‌طورکلی بیشترین مقدار ضرایب قابلیت هضم استاندارد شده متیونین، لیزین و آرژنین در کنجاله سویا و ترئونین در دانه ذرت به‌دست آمد. از طرف دیگر، کمترین مقدار ضرایب قابلیت هضم ایلئومی استاندارد شده برای اسیدهای آمینه مذکور به ترتیب در کنجاله گلوتن ذرت، ذرت و گندم به‌دست آمد.

    کلیدواژگان: اسید آمینه، بلدرچین ژاپنی، قابلیت هضم استاندارد شده، قابلیت هضم ظاهری
  • جعفر پیش جنگ آقاجری*، قدرت الله رحیمی میانجی، سید حسن حافظیان، محسن قلی زاده، قربان الیاسی صفحات 365-375

    ناحیه ی MHC مرغ‌ها در پاسخ‌های ایمنی، مقاومت به بیماری‌ها و فرایندهای تکاملی، دارای اهمیت است. در این تحقیق 200 نمونه ی خونی از مرغ های بومی نژاد های عمومی، آذربایجان غربی، مرندی و مازندرانی اخذ شد و DNA ی ژنومی به روش بهینه شده ی نمکی استخراج و چند شکلی های آللی در جایگاه‌های ژنی B-L، B-F و B-G با استفاده از تکنیک PCR-RFLP بررسی شد. برای شناسایی جهش در جایگاه‌های ژنی یاد شده از آنزیم Msp I استفاده شد. در جایگاه ژنی 374 جفت بازی B-L، فقط ژنوتیپBB  اما در جایگاه ژنی 1048 جفت بازی B-F، دو ژنوتیپ CG و GG شناسایی شد. در این جایگاه آلل C شامل باندهای 515، 410، 75 و 47 جفت بازی و آلل G نیز دارای باندهای 410، 302، 213، 75 و 47 جفت بازی بودند. در جایگاه ژنی 401 جفت بازی B-G، سه ژنوتیپ MM، MN و NN و دو آلل M شامل یک باند 401 جفت بازی و آلل N دارای باندهای 350 و 51 جفت بازی مورد شناسایی قرار گرفت. در کل جمعیت ها شاخص اطلاعات شانون در دو جایگاه ژنی B-F و B-G به ترتیب 37/0 و 59/0 و شاخص تثبیت به ترتیب 13/0- و 17/0- محاسبه شدند. بیشترین مقدار شاخص هتروزیگوسیتی مشاهده‌ شده برای جایگاه های ژنی یاد شده به ترتیب 25/0 و 48/0 برآورد شد. با توجه به وجود چندشکلی در دو جایگاه ژنی B-F و B-G، می‌توان با استفاده از پاسخ ایمنی ژنوتیپ‌های مشاهده ‌شده، از این جایگاه‌ها به ‌عنوان نشانگر برای اصلاح نژاد ژنتیکی جهت افزایش مقاومت مرغ‌های بومی به بیماری ها‌ استفاده کرد.

    کلیدواژگان: چندشکلی، کمپلکس اصلی سازگاری بافتی، مرغ بومی، PCR-RFLP
  • سعید شادپور، مجتبی طهمورث پور*، محمد مهدی شریعتی صفحات 377-388

    در پژوهش حاضر توانایی پیش‌بینی ارزش های اصلاحی ژنومی شبکه‌های عصبی بیزی و روش‌های پارامتری در چهار معماری ژنتیکی شبیه سازی شده و چهار صفت واقعی موش با یکدیگر مقایسه شد. تعداد QTLها در معماری‌های ژنتیکی اول و سوم 50 و در معماری‌های ژنتیکی دوم و چهارم 500 در نظر گرفته شد. مقدار وراثت‌پذیری در معماری‌های ژنتیکی اول و دوم 3/0 و در معماری‌های ژنتیکی سوم و چهارم 7/0 بود. بیشترین صحت پیش‌بینی ژنومی حاصل از شبکه‌های عصبی بیزی در چهار معماری ژنتیکی شبیه‌سازی‌شده برابر با 644/0، 654/0، 800/0 و 81/0 بود. این مقادیر در روش‌های پارامتری برابر با 717/0، 685/0، 903/0 و 836/0 بود. حداکثر توانایی پیش‌بینی حاصل از شبکه‌های عصبی بیزی در پیش‌بینی وزن شش هفتگی، شیب رشد، شاخص توده بدنی و طول بدن به ترتیب برابر با 474/0، 359/0، 154/0 و 214/0 بود. توانایی پیش‌بینی روش‌های پارامتری در پیش‌بینی ژنومی این صفات مشابه و به‌طور متوسط برابر با 477/0، 369/0، 170/0 و 221/0 بود. میانگین مربعات خطای پیش‌بینی شبکه‌های عصبی بیزی در معماری‌های ژنتیکی شبیه‌سازی‌شده اندکی کمتر از روش‌های پارامتری و در داده‌های واقعی مشابه روش‌های پارامتری بود. مدت‌زمان اجرای شبکه‌های عصبی بیزی با افزایش تعداد نرون در لایه مخفی به‌صورت صعودی افزایش یافت. نتایج بدست آمده نشان داد با وجود بهتر بودن صحت و توانایی پیش بینی روش های پارامتری، شبکه‌های عصبی بیزی می توانند ارزش‌های اصلاحی ژنومی را با دقت مناسبی پیش‌بینی کنند. همچنین توانایی پیش‌بینی ژنومی شبکه‌های عصبی به صفات هدف، گونه موردنظر و معماری شبکه عصبی بستگی دارد.

    کلیدواژگان: ارزیابی ژنومی، روش های پارامتری، شبکه های عصبی، مقایسه کارایی
  • نعمت هدایت ایوریق*، رضا خلخالی ایوریق، رضا سیدشریفی، مصطفی عمری صفحات 389-398

    علیرغم وجود تنوع بالا در ژنوم میتوکندریایی و خط مادری، تنوع کمی در کروموزوم Y و خط پدری در اغلب پستانداران، از جمله اسب‌ها وجود دارد. تاکنون مطالعات کمی در زمینه شناسایی تنوع ژنتیکی در کروموزوم Y اسب‌ها در جهان صورت گرفته است. در مطالعه کنونی، از تعداد 53 اسب از شش جمعیت نژادی مختلف در ایران شامل شامل اسب‌های موجود در باشگاه های سوار کاری شهرستان اردبیل (24 نمونه)، اسب‌های بومی شمال غرب (باشگاه ها) (17 نمونه)، اسب‌های کردی (15 نمونه)، اسب‌های عرب (10 نمونه)، اسب‌های دره شوری (10 نمونه) و اسب‌های قره‌باغ (5 نمونه) نمونه‌گیری شده و برای شناسایی تنوع در کروموزوم Y قطعه 264 جفت بازی از طریق روش توالی یابی سانگر مورد بررسی قرار گرفتند. نتایج بدست آمده نشان داد که شش جایگاه متغیر در بین توالی‌ها وجود دارد که منجر به ایجاد نه هاپلوتایپ مختلف می‌شوند. از بین هاپلوتایپ‌های شناسایی شده، هاپلوتایپ دو (H-2) با در برگرفتن 15 نمونه، بزرگترین هاپلوتایپ محسوب شد. میانگین تنوع نوکلئوتیدی و تنوع هاپلوتایپی به ترتیب برابر با 0067/0 و 81/0 برآورد شد. هاپلوتایپ‌های یک (H-1) و دو (H-2) با در برگرفتن پنج نژاد از شش نژاد مورد مطالعه، متنوع‌ترین هاپلوتایپ‌ها بودند. اسب‌های عرب و دره‌شوری با فاصله ژنتیکی 00327/0 نزدیکترین نژادها و اسب‌های نمونه‌گیری شده از باشگاه های سوارکاری اردبیل و قره‌باغ با فاصله ژنتیکی 00822/0 دورترین نژادها نسبت به هم هستند. همچنین مشخص شد که برخلاف نژاد عرب، نژاد قره‌باغ دارای کمترین قرابت ژنتیکی پدری با اسب‌های ایرانی می‌باشد.

    کلیدواژگان: اسب های ایرانی، تنوع ژنتیکی، خط پدری، کروموزوم Y، هاپلوتایپ
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  • Mohammadreza Mashayekhi, Mohsen Sari*, Naeim Erfani majd, Morteza Rezaei Pages 273-291
    Introduction

    One of the limitations of conventional urea usage in ruminant diet is rapid hydrolysis and increase in ruminal ammonia concentration and its lack of synchrony with carbohydrate degradation and microbial growth in the rumen. An alternative strategy is continuous supply of nitrogen using slow release urea (SRU) and gradual release of ammonia in the rumen. Sugar-containing liquid feeds can increase the energy density of the diet, stimulate dry matter intake (DMI), and serve as carriers for fat, non-protein nitrogen (NPN), and other ingredients. Sugars can change the ruminal fermentation pattern, typically decreasing ruminal NH3 concentration and increasing ruminal butyrate concentration. The purpose of this study was to investigate the effects of SRU in comparison with conventional urea, with or without the addition of molasses on the growth performance and rumen fermentation of fattening lambs.

    Materials and Methods

    The experiment was conducted in a completely randomized design with 5 treatments including control, two sources of non-protein nitrogen (conventional urea and SRU) with or without molasses (0 and 20 % of ration DM) and 7 replicates using 35 Arabian lambs. Forage to concentrate ratio was 30 to 70. The length of the fattening period was 105 days, including 15 days for adaptation and 90 days of data collection. At the beginning of the main period of fattening and then once a month, weighing the lambs was carried out with 14 to 16 hours of starvation. The lambs had free access to water during the test period. The lambs were fed the total mixed ration ad libitum twice daily at 0800 and 1600 hours. The digestibility coefficients of dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber, (NDF), acid detergent fiber (ADF) and ether extract (EE) were determined by the total fecal collection method. Daily feed intake, daily weight gain, feed conversion ratio, carcass compositions, meat colour, rumen and blood parameters were recorded. Data were analyzed as a completely randomized design using the General Linear Model (GLM) procedure of SAS.

    Results and Discussion

    Replacement of urea with SRU and the addition of molasses did not affect dry matter intake, daily weight gain, feed conversion ratio, final body weight, cold and hot carcass weight, carcass efficiency and components, meat colorimetric parameters and nutrient digestibility. The lack of difference between control and treatment groups in the growth performance could be due to sufficient supply of the microbial protein production in the rumen. Addition of SRU and molasses did not have a significant effect on dry matter intake and digestibility of nutrients. The hydrolysis rate of SRU may not be reduced to the extent that it could improve the efficiency of rumen microorganisms in utilizing the available energy source of molasses. Propionate and NH3-N concentration in the rumen increased in animals provided with NPN in comparison with the control diet. The concentration of acetate in rumen of animals fed diets containing NPN sources was lower than those on the control diet. The concentration of total volatile fatty acids in SRU diets and also diets containing conventional urea was higher than control diet. Molasses addition in diets, increased butyrate and total volatile fatty acids and decreased blood urea nitrogen concentrations, compared to control diet. Animals fed NPN diets showed higher rumen pH than the control diet. The ruminal pH decreased in diets containing molasses. Reducing the saliva secretion, due to the physical and chemical properties of molasses and the high amount of fermentable sugars supplied by molasses in the rumen, may possibly explain the decrease in the rumen pH. Animals that had received urea containing diets showed higher rumen pH presumably due to the buffering capacity of urea. An increase in ruminal ammonia concentration due to urea hydrolysis can increase the pH of the rumen by obtaining H+ by ammonia and turning it into NH4+. However, it is likely that the result reflects the higher grain content of the control diet relative to NPN containing diets.

    Conclusion

     In general, the results of the present study showed that although replacement of soybean meal with conventional urea and/or SRU, with or without molasses, in high concentrate diets, influenced some rumen fermentation and blood metabolites, but these changes were not large enough to improve fattening performance, carcass characteristics and nutrient digestibility.

    Keywords: Digestibility, Fattening Performance, Molasses, Rumen Fermentation, Slow Release Urea
  • yadollah chashnidel*, Sirous Shokrolahi, Mostafa Yousefelahi, Akbar Soleymani, mehdi bahari Pages 293-306
    Introduction

    The use of agricultural products that are often less costly has long been considered by researchers, and due to some problems with the direct use of these products in animal nutrition, their processing seems to be necessary in a variety of ways. In the meantime, by-products derived from cereals, such as wheat bran and rice bran, are especially important due to their high production and low prices. Rice bran can be one of the world's largest cereal processing by-products. Considering the significant amount of rice bran production in the northern provinces of Iran, its low price and the possibility of replacing it as part of the ration and, on the other hand, due to the presence of unsaturated oil, it seems that its lubrication It will probably increase the maintenance time and improve its nutritional value. The main problem is the use of rice bran, phosphate phytate, oil and high silica. Considering the significant amount of rice bran production in the northern provinces of the country, its low price and the possibility of replacing it as part of the ration and, on the other hand, due to the presence of unsaturated oil, it seems that its lubrication It will probably increase the maintenance time and improve its nutritional value. The objective of this study was to evaluate the different levels of de-oiled rice bran replacement to soybean meal on milk production and composition, the profile of fatty acids in milk, body condition score and some blood parameters of dairy cows.

    Material and methods

    An experiment was conducted using 12 of Simmental dairy cows with a mean weight of 630±27 kg, a mean milk yield of 35±1.7 liters per day and an average of 109±17  days of lactation in a completely randomized design with four treatments and three repetitions. The experimental treatments were included control diets without de-oiled rice bran and diets containing de-oiled rice bran replacing 50, 75 and 90% to soybean meal. The diet used was based on the table of nutrient requirements of NRC, (2001) and the diet was prepared by the NRC, (2001) software. The traits studied in this experiment included milk composition and production, body condition score, profile of milk fatty acids and some blood serum parameters of dairy cows. The oil-rice bran used in this experiment was prepared from Mazand factory, located in Mazandaran province, Babolsar city. The data were collected and experimental design was a completely randomized design with four treatments and three replicates using 12 heads of dairy cows with repeat measurement and using the GLM and SAS software (9.1).

    Results and discussion

     The experimental results showed that the experimental diets had a significant effect on the composition and production of milk, so that the production of milk in a treatment containing de-oiled rice bran replaced with 75% soy meal was more than other experimental treatments. The percentage of milk protein in a treatment containing de-oiled rice bran replaced with 50% soy meal was more than other experimental treatments. Also, the results showed that the highest percentage of milk fat in the control treatment and the lowest milk fat in the treatment of de-oiled rice bran was replaced with 75% soybean meal, which had a significant difference with other treatments. There was no significant difference in the number of somatic cells between treatments. Body condition scores were no significantly affected by experimental diets. The effect of treatments on milk fatty acids was not significant. Also, the addition of de-oiled rice bran had a significant effect on blood parameters, so that by increasing the level of rice bran in the diet, up to 75% of the soybean meal replaces a significant decrease in blood levels other than glucose. In addition, the control treatment had the highest levels of triglyceride and cholesterol and the amount of HDL in treatment containing de-oiled rice bran replaced with 75% soy meal was significantly higher than other treatments.

    Conclusion

    According to the results of this experiment, the use of 75% of de-oiled rice bran replacement to soybean meal in the diet, increased milk yield and reduced fat percentage in dairy cow compared to control treatment. Also, the reduction of cholesterol, triglycerides and HDL levels in dairy cows were observed treatment containing de-oiled rice bran replaced with 75% soy meal. It seems that the use of 75% of de-oiled rice bran replacement to soybean meal in the diet, showed better performance than the other levels in the production factors of dairy cows in this study.

    Keywords: Blood parameters, Dairy cow, Milk fatty acids, Performance, Rice bran
  • Smira Dehghani, Akbar Taghizadeh*, Hamid Mohammadzadeh Pages 307-317
    Introduction

    Generally, most feeds used in livestock nutrition are deficient in some nutrients, and require nutritional supplements. Among the supplements, micro and macro minerals are particular importance. Selenium (Se) plays an important role in the reproductive function and immune system and is known as an antioxidant and catalyst for the production of thyroid hormone. It is believed that low selenium absorption in ruminants is due to the deficiency of selenium in ration and its conversion into insoluble form. Nano-particles are smaller and more active than larger particles. The importance of Selenium for rumen microorganisms are not entirely clear. Also, selenium is an essential trace element, and its importance for animal health and productivity has been well confirmed. Selenium has known to be involved in enzyme activity and preventing oxidative damage to body tissue.  Selenium plays important roles in antioxidant systems, prevents cell damage and is necessary for growth, fertility, and immune system in farm animals. Recently, nano -elemental Se has attracted wide spread attention due to its high bioavailability and low toxicity, because nanometer particulates exhibit novel characteristics, such as great specific surface area, high surface activity, a lot of surface active centers, high catalytic efficiency and strong adsorbing ability and over and above the character of low toxicity of Se0. Dietary selenium is an essential trace element for animals and humans with a variety of biological functions. It plays important roles in the regulation of thyroid hormone metabolism, cell growth and antioxidant systems thus, together with alpha-tocopherol prevents cells against oxidative stress damage, also these compounds are necessary for growth, fertility, and immune system health in animals and humans. The objective of this research was to investigation the effects of different sources of selenium on digestion characteristics of concentrate mixture of diets in high producing lactating dairy cows using in vitro gas production technique.

    Materials and Methods

    Four male ruminally fistulated sheep, average 43±4.8 kg of BW, were used in a replicated 4×4 Latin square experiment. Sheep were fed twice daily (08:00 and 18:00 h) at maintenance nutrition requirements with a basal diet consisting of 400 g/kg (dry matter) DM of basal concentrates and 600 g/kg DM of forage. Sheep were placed in metabolic cages individually and fresh water was freely available during the experimental period. This experiment was conducted in four periods of 28 days with 21 d adaptation period and 7 d for data tacking. Treatments were: 1. Basal diet 2. Basal diet + 0.3 ppm nano selenium, 3. Basal diet + 0.3 ppm seleno methionine, 4. Basal diet + 0.3 ppm selenite sodium. The rumen fluid was mixed with artificial saliva (1:2 ratio, respectively) in lab, and then nano-Selevels and seleno methionine added to it. In gas production method, 300 mg of each treatment weighted and incubated for 2, 4, 6, 8, 12, 16, 24, 36, 48, 72, 96 hours.  In order to determine the effects of different forms of selenium on rumen parameters, concentrations of VFA and NH4, value of pH and population of protozoa were examined. Samples of rumen fluid were collected through the cannula at 4 h after feeding on days 19 and 20 of each collection period for pH, NH3-N, and volatile fatty acids (VFAs) determination. Ruminal pH was immediately measured using an electric pH meter. The samples were subsequently stored frozen at −20 ◦C until analyses.

    Results and Discussion

     Potential of gas production (fraction A) of nano, organic and inorganic treatments were higher (201.9, 344.0, 321.7 and 319.8 ml in control, nano, organic and mineral treatments, respectively) compared to control treatment (P<0.05). The nano selenium treatment had higher VFA concentration (109.83, 98.00 and 89.83 mmol/l in nano, organic and mineral treatments, respectively) when compared with organic and inorganic treatments (P<0.05). Rumen NH4 concentration was not effected by treatments. The organic treatment caused a significant increase in total protozoa population when compared with nano and inorganic treatments (P<0.05).

    Conclusion

     The results indicated that selenium supplementation in ruminant diet improves ruminal nutrients degradability's compared to control. Therefore, the use of nano-Se resulted to increase digestibility and fermentation of nutrients resulted improved rumen microorganisms activities. Although nano and organic selenium was better than inorganic treatment in ruminal degradability and rumen parameters, however there was not any significant differences between these two treatments.

    Keywords: Gas production, Nano, Selenium, Sheep, Rumen fermentation parameters
  • Amir Mousaie* Pages 319-329
    Introduction

    Sheep production in arid and semi-arid parts of Iran undergoes feed shortage due to poor natural vegetation. Trace minerals, as metabolic modifiers, are essential in ruminants’ diets because of their contribution in biochemical processes required for normal growth and development. Zinc (Zn) is one of the most deficient minerals in soils of many parts of the world including Iran. Zinc is known to affect growth, reproduction and immune system of the animals. Although administration of Zn supplements in ruminants’ diets has been receiving increased attention in recent years, however, it is not well-established that how much of Zn supplement is more effective for improving fattening lambs’ performance, metabolism and antioxidant status. Furthermore, there are a few information about blood minerals of Kermani sheep. Thus, the aim of this study was to evaluate the likely effects of different Zn sources on some blood parameters related to animal health and production.

    Materials and Methods

    This study was conducted at the Research Station of Department of Animal Sciences, University of Jiroft, Iran. Twenty-one Kermani male lambs (7 months of age, 28 ± 0.9 kg of body weight) were assigned to 1 of 3 following treatments (7 lambs each) for 9 weeks in a completely randomized design: (1) Control diet; (2) Control diet plus supplemental zinc-methionine (Zn-Met, 40 mg/kg dry matter (DM)) and (3) Control diet plus supplemental zinc sulfate (ZnSO4, 40 mg/kg DM). Two weeks adaptation period to basal diet was done before the experimental period. Basal diet contained 48 and 11.7 mg/kg DM of Zn and Cu respectively. Blood samples were collected before commencement (time 0), and at weeks 3, 6 and 9 of the experiment. Serum minerals and metabolites concentrations and whole blood superoxide dismutase activity (SOD) were measured. Maximum air temperature and minimum relative humidity data were used to calculate the temperature-humidity index (THI). Statistical analysis was carried out using SAS software. A mixed model with fixed effects of treatment, week and treatment × week, as well as the random effect of lamb within treatment × week were used. Time of sampling (week) was used as a repeated effect and subject for the repeated statement was lamb within dietary treatment. Where biologically worthwhile and significant, the initial values for blood metabolites (before supplementation (time 0)) and initial body weight were included in model as a covariate to further improve the analysis precision. The significant differences were declared and tendencies .

    Results and Discussion

     Based on the findings, Kermani male lambs of this study had deficient blood Zn contents (under 90 µg dl-1) before the commencement of the experiment. Lambs on Zn-Met- and ZnSO4- supplemented diets had higher serum average Zn concentrations than those on the control diet (P<0.05). Serum Zn content showed a time-dependent trend so that Zn-supplemented groups had higher Zn concentrations at week 3 in spite of weeks 6 and 9 of the experiment (P<0.05). The concentrations of serum calcium, phosphorous and copper were not affected by the treatments. However, calcium and phosphorous increased by time (P=0.02). Dietary Zn supplementation of lambs, irrespective of its source, led to increased average blood alkaline phosphatase activity (ALP) which was more obvious in week 3 of the experiment (P<0.05). This similar trend between Zn and ALP contents through time may imply to the close association between blood Zn concentration with ALP activity. Lambs on Zn-Met-supplemented diet exhibited improved SOD activity comparing those on the control diet (P<0.05). These findings, suggesting that at least the supplemented Zn is being incorporated in the system, resulting in increased SOD activity. Serum glucose and total protein concentrations increased during time (P<0.01) but no differences were observed among experimental groups.

    Conclusion

     These results indicated the beneficial effects of dietary Zn supplementation of 40 mg/kg diet for increasing serum Zn concentration and alkaline phosphatase activity of male lambs. Zn-Met was more effective than ZnSO4 for improving antioxidant status. In addition, no adverse effects of Zn supplementation on serum copper, calcium, phosphorous, glucose and total protein concentrations were observed. Additionally, some blood parameters such as Zn concentration and ALP activity revealed a time-dependent variation in this study which suggests that repeated blood sampling may be more appropriate than endpoint sampling particularly in respect to blood metabolites.

    Keywords: Kermani lamb, Minerals, Superoxide dismutase, Zinc supplement
  • Abbas Alipanah, Mohsen Daneshyar*, Parviz Farhoomand, Gh.R Najafi Pages 331-340
    Introduction

     Nowadays commercial broiler strains need more oxygen for the faster growth and higher meat production and are susceptible to ascites syndrome due to higher growth rate. Ascites is a metabolic disorder that causes the increased free radical production, decreased level of body antioxidant capacity and hence meat muscles destruction, pale color and lower quality. It damages the gut morphology and reduces the absorption of amino acids and minerals and as a result leg problems. Lysine and betaine are nature osmotic nutrients and control the water status in the absorptive cell and so protect the cell during the conditions of ascites. Thus lysine and betaine may help the synthesis of protein, lowering the carcass fat, change the oxygen needs and results in ascites in broiler chickens. Therefore, the purpose of this study was to investigate the effect of lysine and betaine on meat characteristics and bone condition of broiler chicks under cold induced ascites.

    Material and Methods

    Three hundred one-day-old female chicks (Ross 308) were used by employing a completely randomized design with 4 treatments and 5 replicates (10 birds for each replicate) to investigate the effects of lysine and betaine alone or together on carcass quantity and quality of broiler chickens under ascites. The experimental diets were the control diet (corn-soybean basal diet without the supplement), 30% higher lysine than Ross 308 strain recommendation, 0.15% beatine and 30% higher lysine and 0.15% betaine. The dietary ingredients were analyzed for energy, crude protein and essential amino acids by NIR. All chickens were raised under cold stress from day 7 of age to induce the ascites. To induce cold stress, a temperature of 31 ° C was used in the first week but the temperature on 7, 14, and 21 days was reduced to 26 ° C, 20 ° C and 15 ° C, respectively After 21 days, it lasted from 15 ° C to the end of the period. At 42 days of age, daily intake and feed conversion and ascites mortality rates were calculated. Two bird from each replicate were randomly selected, weighted and slathered. After slaughter, the proportional weights of carcass, breast, thigh and right ventricle were determined with a precision scale of 0.001 gr. Moreover, thigh and breast meat samples were collected from the slaughtered birds and used for laboratory analysis of nutrients, acidity and the color indices. All the data were analyzed using the GLM procedure of SAS (Version 9.1) software. If there was a significant difference between the treatments, then the means were further compared by Tukey-Kramer range test at a 5% level.

    Results and discussion

     The results showed that both the lysine and betaine alone or together caused the higher weight gain and the proportional weights of carcass, breast and thigh (P<0.05). Abdominal fat decreased by consumption of betaine alone or along with lysine (P<0.05). Both the lysine and betaine alone or together caused the decreased feed consumption, feed conversion, ascites mortality and right ventricle to total ventricle ratio (P<0.05). The moisture, crude protein, crude fat, ash of both breast and thigh meat were not affected by the experimental treatments (P>0.05). Moreover, thigh or breast meat pH and color indices (lightness, redness and yellowness) were not changed by dietary lysine or betaine supplementation (P>0.05). None of the experimental treatments affected the bone indices (ash, calcium and phosphorous) but the tibia diameter which was increased by dietary lysine supplementation (P<0.05). It seems that dietary lysine and betaine consumption in broiler chickens adjust the osmotic pressure in gastrointestinal cells and hence protect these cells under stress condition such as the cold situation of current experiment and thus help for the higher L-carnitine synthesis in body. The higher L-carnitine production results in lower carcass fat and greater protein synthesis and improved carcass efficiency (higher breast and thigh meat production). Consequently, body oxygen requirements and right ventricle to total ventricle ratio reduced and this causes the lower ascites mortality.

    Conclusion

    The consumption of betaine and lysine improves the performance, carcass quantity (increased carcass, and thigh and breast weights) and quality (decreased abdominal fat weight), and ascites mortality of broiler chickens. Moreover, no effects of lysine and betaine were detected on meat nutrient contents, pH and color indices and bone parameters.

    Keywords: Ascites, Betaine, Bone, Lysine, Meat color
  • soleyman mohamadi, Hassan Darmani Kuhi*, Navid Ghavi Hossein Zadeh Pages 341-352
    Introduction

     In commercial production, there is often concern about the quantity and/or quality of feathering in both broilers and layers. For broilers, the concern is adequacy of protective feather cover, while in layers usually the necessary degree of feathering needed to optimize feed efficiency. Feather development is under the control of hormones such as thyroxine and estrogen and indirectly by testosterone. Therefore, environmental or nutritional status affecting the hormonal output of the birds will indirectly influence their feathering. Nutrition influences rate of feathering as well as feather structure, color and molting. In spite of the fact that minerals constitute a little proportion of body weight (2 to 5%) in vertebrates, their significance is high for growth, enzyme activation, immune system, regulation of the osmotic pressure, egg production and feathering. Urine and blood serum or plasma are the most commonly used bio fluids for metabolomics-based studies for the simple reasons that they both contain hundreds to thousands of detectable metabolites. In blood, the minerals undergo homeostatic controls, thus the ranges of concentrations are narrow, but the concentration of minerals in hair and feather is broad and can reflect long term metabolic changes. Blood tests can vary significantly depending upon animal’s diet, activity level, the time of day and many other factors. Contrary to the blood, the concentration of minerals in hair and feather is broad and can reflect long term metabolic changes. Hair or feather can be considered as a metabolically inactive tissue, and its composition indicates the levels of trace elements that store in its structure through nutritive blood flow. Feather chemistry has been investigated as a means of identifying the geographic origins of migrating and wintering populations of birds, and as an indicator of environmental pollution. Since the minerals are crucial to the functioning of enzymes, hormones and other biochemical systems, it is possible to read the hair or feather test and see where metabolic patterns are deviating from the norm. The present study was amid to examine the potential applicability of serum or feather samples as a biological indicator to evaluate the broiler responses to (un)sufficient diets with regards to the trace mineral supplementation at 0, 25, 50, 75 and 100% of the recommended requirements.

     Material and Methods

     A total of 200 one-day-old Ross 308 strain of broiler chicks (male and female) were used in a completely randomized design with 4 replicates of 10 chicks each. A large batch of corn and soybean meal basal diet was prepared for each age period (0-14, 14-35 and 35-42 days) and aliquots used for mixing the experimental diets. The experimental diets were prepared by mixing mineral premix at 100, 70, 50, 25, and 0% of normal inclusion rates, resulting in five experimental diets. At the end of the experiment, two male chicks close to average weight of each experimental unit were selected for bone quality assessment and feathering scores for wing and tail using scores of 1 to 5 for feather coverage with 1 representing minimal coverage, i.e. <25% coverage; 2 for 25-50% coverage; 3 for 50-75% coverage; 4 for >75% coverage and 5 for complete coverage. The wing and tail were further evaluated on a scale of 0 to 2 for the occurrence and severity of poor feathering with 0 indicating no defect; 1 for lesion and torn feathers, and 2 indicating blisters had developed on the shaft, near failure of feather to emerge from the follicle, broken feathers and retarded feathering. Tibia bone morphometric parameters, i.e. weight, diameter, length, density, volume and ash, were determined. The serum mineral concentration was measured in the fasting state at the end of the experiment. At this time, a total of 3mL of the blood samples was accumulated in plain vacutainer tubes from the veins under the wing. After collecting, the blood samples were left undisturbed for at least 1 hour to reach the room temperature. The serums were centrifuging at 3,000 rpm for 15 minutes. The obtained sera were kept in 1.5mL micro tubes at -80°C until they were analyzed for mineral concentration. The method of American Society for Testing and Materials, D4638–03 standard, was used for preparing the serum and feather samples.

    Results and Discussion

     The results showed that treatments supplemented with mineral premix caused increase in average daily gain and feed intake compared to the control group (P<0.05), but the difference among mineral premix-supplemented groups was not significant (P>0.05). Feed conversion ratio in the starter period was not affected by the experimental treatments; nevertheless, in the growing and finishing periods a significant difference was indicated compared to the control. Bone parameters including weight, diameter, length and volume showed significant differences to the control group; but the difference for density and ash were not significant. Effects of dietary trace mineral supplementation on the feathering scores of broilers were described.. The results showed that the effect of trace mineral supplementation was significant for feather coverage and defect feather in both wing and tail regions (P<0.05). Feathering score was increased and the amount of damaged feathers was reduced in concordance with the increase in mineral supplementation. Serum concentration of Ca increased in response to trace mineral supplementation. Feather K (p<0.01) and Zn (p<0.05) concentrations were affected by the dietary treatments. Serum concentration of Zn increased linearly in proportion to the dose of Zn supplementation when 10, 25 or 40 mg/kg Zn were added to the basal diet. The diagnostic usefulness of feather analysis is confirmed by authors who have proven the correlation between the concentration of basic elements in feather and their concentrations in the body both in the physiological and pathological states. With regard to the use of feather as a nondestructive monitoring tool, it is noticeable that it presented inter-tissue correlation with the serum in most occasions.

    Conclusion

    Feather could be considered as an appropriate criterion to diagnose the mineral status in the body.

    Keywords: Broiler, Feathering, Feathering Score, Trace minerals
  • M ghazaghi, Ahmad Hasanabadi*, M mehri Pages 353-364
    Introduction

     Excess excretion of nitrogen (N) caused by inaccurate animal feeding might increase the environmental concerns in terms of soil and water pollutions. Nitrogen is one of the most expensive elements in animal nutrition and either under-feeding or over-feeding of this element may be associated with financial losses through the suppressed performance or expensive diets. Determination of nutrient availability could warrant accurate feed formulation to meet animal requirements. Nutrients digestibility determination in poultry is usually carried out by collecting excreta (feces + urine) from the bird or collecting digesta from the ileum. Standardized ileum digestibility is also possible by measuring the endogenous loss of amino acids. endogenous loss of amino acids is affected by the type of protein source, the protein level of the diet, the amount of dietary fiber, the presence of anti-nutritional agents, the method of slaughter, the type of marker used, the age of the bird, the species, diet and body size. Among these factors, the level of amino acids in the diet is a major factor. Therefore, this study was conducted to determine essential amino acids digestibility of corn, wheat, soybean meal and corn gluten meal in Japanese quails during third week of age.

    Materials and Methods

     A total of 600 of 14-days-old Japanese quails were assigned in a completely randomized design to five treatments, four replications and 30 birds in each floor pen. The dietary treatments included nitrogen free diet, corn, wheat, soybean meal and corn gluten meal which were prepared in such a way that the test ingredient was the sole source of the protein and amino acids in each diet. The standardized ileal amino acid digestibility (SIAAD) values in aforementioned feeds were determined using direct method, and an N-free diet (NFD) was used to measure the basal endogenous amino acids losses (EAAL) from 14 to 21 d of age. Titanium dioxide was added to all diets as indigestible marker of 5 g / kg. At the end of the experiment, all the birds of each pen were killed by an intracardiac injection of 0.5 mL sodium pentobarbital. Ileal digesta were collected by gentle manipulation and pooled on a replicate basis and were immediately frozen. The ileum was considered as part of the small intestine starting from the Meckel’s diverticulum and up to 15 mm before the ileocaecal junction. Titanium was determined colorimetrically and amino acid profiles were determined for corn, soybean meal, corn gluten meal and wheat using acidic hydrolysis and chromatographically. The house temperature was set at 35, 29 and 26 ° C in the first, second and third weeks of age, respectively and the relative humidity of the house was 55-60%. The birds freely accessed water and experimental diets, and 23 h light and one h darkness was considered throughout the experiment. Data were analyzed by one-way ANOVA in Graphpad software and Tukey’s test was used to compare the means.

    Results and Discussion

     The EAAL values of methionine, lysine, threonine, arginine, valine, isoleucine, leucine, and histidine were determined to be 32.6, 306, 241, 104, 355, 497, 49.6, and 80.1 mg/kg DMI, respectively. The apparent digestibility values of amino acids methionine, lysine, threonine, arginine, valine, isoleucine, leucine, and histidine as a number of essential amino acids in corn were 92.97, 70.38, 79.76, 88.98, 84.75%; in wheat were 90.80, 86.47, 82.63, 86.70, 88.33, 45.79, 96.77, 81.24%; in soybean meal were 94.73, 86.96, 80.09, 14.91, 81.54, 13.85, 80.47, 95.19% and in corn gluten meal were 04.86, 84.67, 82.76, 51.89, 73.83, 18.91, 76.15, 53.67%, respectively. The SIAAD of methionine, lysine, threonine, arginine, valine, isoleucine, leucine, and histidine for corn, wheat, soybean meal, and corn gluten meal were 94.48, 83.96, 88.33, 89.80, 93.85, 92.15, 94.06, 97.53%; 92.54, 95.48, 89.81, 88.48, 94.72, 90.11, 84.17, 84.15%; 95.27, 83.08, 81.48, 91.45, 83.11, 87.82, 81.93, 95.87%; 86.27, 71.23, 87.03, 90.12, 85.11, 93.23, 76.21, and 74.38%, respectively. Research has shown that the type of ingredients and concentration of diet amino acids have a significant effect on the digestibility coefficients. This difference is in fact due to the changes in the endogenous share of amino acids in the total amount of ileal amino acids.

    Conclusion

     Generally, the highest SIAAD coefficients of methionine, lysine, and arginine were obtained in SBM and threonine was obtained in corn. On the other hand, the lowest SIAAD coefficients of these amino acids were observed in corn gluten meal, corn and wheat, respectively. Also, comparing the results of this study with findings from other species showed that the apparent and standardized ileal digestibility of essential amino acids in corn, wheat, soybean meal and corn gluten meal is different in Japanese quail than in broiler chickens.

    Keywords: Amino acid, Apparent digestibility, Japanese quail, Standardized digestibility
  • Jafar Pish Jang Aghajeri*, ghodrat Rahimi mianji, Hasan Hafezian, Mohsen Gholizadeh, ghorban Elyasi Pages 365-375
    Introduction

     Chicken major histocompatibility complex (MHC) region are important in immune responses, resistance to diseases, and relationships with evolution processes. The chicken major histocompatibility complex is composed of two gene regions: the B and Y (Rfp-Y) loci, both located on micro chromosome 16. The B locus includes three gene classes, I (B-F), II (B-L) and IV (B-G). The chicken major histocompatibility complex, consists of several clusters of highly polymorphic genes, some of which are associated with disease resistance. The class I and class II antigens resemble their mammalian counterparts in the encoded protein structure. The class IV region encodes the B blood group antigens, which are readily identified by serological blood-typing. The class III region appears to be divided in chickens, with some elements that are MHC-linked and others that map elsewhere. In addition the Rfp-Y system, which bears a strong similarity to the MHC, maps to the opposite side of the nucleolar organizer region on the same micro chromosome as the MHC. Each class of MHC genes is a potential candidate for a role in disease resistance. The MHC genes show associations with response to diseases as diverse as virally induced neoplasia, bacterial, parasitic and auto-immune diseases.

    Materials and Methods

     In this study, allelic polymorphism in B-L, B-F and B-G loci involved in the immune system in four Iranian indigenous chickens were examined using PCR-RFLP technique. Two hundred birds including common, West Azerbaijan, Marandi, Mazandarani indigenous chicken breeds were selected. As much as 1-2 ml of blood was taken from each of the chicken. Blood samples were transferred to the anticoagulant (Ethylene diamine tetra acetic acid) tubes in the vicinity of the ice to the genetic and biotechnological laboratory of Islamic Azad University, Maragheh branch and until the onset of genomic DNA extraction and subsequent experiments were kept at -20°C. In the extraction of the genomic DNA of blood samples, the salting out method and for amplify of each locus, a pair of specific primers was used. For detection of mutation in the loci the Msp I enzyme was used. For genetic analysis of data derived from digestive enzymes in indigenous chickens, POPGENE software version 1.32 was used. This software is used to estimate the allele and genotypic frequencies, observed and expected heterozygosity, mean heterozygosity, Hardy-Weinberg equilibrium, Fixation index, Shannon information index, and other genetic parameters.

    Results and Discussion

     According to this study results, in the 374-bp locus of B-L, after enzymatic digestion, only BB genotype and monomorphic was detected. In the 1048 bp locus of B-F, two genotypes CG and GG were identified and the C allele included 515, 410, 75 and 47 bp bands, and the G allele also included bands of 410, 302, 213, 75 and 47 bp and the χ2 calculated in this locus was not significant for all populations (P < 0.05), and all populations were in Hardy-Weinberg equilibrium. Three Genotype MM, MN and NN genotypes were identified for the locus of B-G (401 bp), M allele included a 401 bp band and N allele included bands of 350 and 51 bp. The χ2 calculated in this locus was not significant for the indigenous chicken population of Mazandarani (P < 0.05) and this population was in Hardy-Weinberg equilibrium. The Shannon information index was calculated to be 0.37 and 0.59 in markers loci of B-F and B-G, respectively, and the fixation index values were -0.13 and -0.17, respectively. The highest observed heterozygosity index for B-L and B-G loci was 0.24 and 0.57, respectively. Estimation of the negative fixation index values in the studied chickens populations could be due to the high selection rate in the populations. The fixation index values is always variable in range -1 to 1, and its negativity indicates a decrease in heterozygosity and increase in homozygosity or increased inbreeding, as well as a deviation from the Hardy-Weinberg equilibrium in the populations. Shannon's information index is an estimate of genetic diversity in populations. In all of the populations studied, the B-G locus has a relatively high genetic diversity.

    Conclusion

     Regarding the polymorphism in the two gene sites (B-F and B-G) studied and the heterozygosity reduction in the populations studied, can be prevented from occurrence of non-random crosses in populations and prevented the reduction of heterozygosity and thus reduced genetic diversity. Also, by studying the immune responses associated with these two gene sites, from these genes can be used as marker for genetic breeding in indigenous chickens for increase of resistance to diseases.

    Keywords: Indigenous chicken, MHC, PCR-RFLP, Polymorphism
  • Saeed Shadpour, Mojtaba Tahmoorespur*, Mohammad Mahdi Shariati Pages 377-388
    Introduction

     In genomic selection, genetic values of individuals are predicted using genetic markers that are distributed all across the genome and are in linkage disequilibrium with quantitative trait locus. Different methods have been introduced to predict genomic breeding values. These methods take into account different assumptions. Non-parametric methods, including artificial neural networks, have fewer assumptions than parametric methods, and can apply nonlinear relationships in genomic predictions so, in theory these approaches are more robust against genetic architecture changes and are able to provide better predictions.

    Materials and Methods

     In current study, the prediction ability of Bayesian neural networks with different architectures (1 to 5 neurons in the hidden layer) and parametric methods (GBLUP, Bayes RR, Bayes A, Bayes B, Bayes C Bayes L) in four simulated genetic architectures and four real traits of mouse (six weeks weight, growth slope, body mass index and body length) were compared using the correlation coefficient between predicted and expected values, mean square error of prediction and computation time. All simulated genetic architectures were additive and the gene effects followed a normal distribution. The number of QTLs in the first and third genetic architecture was 50 and it was 500 for second and fourth genetic architecture. The heritability of the first and second genetic architectures was 0.3 and the heritability of the third and the fourth genetic architectures was 0.7. The real data consisted of 1,296 mice which were genotyped with 9,265 SNP markers.

    Results and Discussion

     The highest prediction accuracy of Bayesian neural networks were 0.640 (4 neuron in the hidden layer), 0.664 (4 neuron in the hidden layer), 0.800 (1 neuron in the hidden layer) and 0.810 (1 neuron in the hidden layer), and the highest prediction accuracy of parametric methods were 0.711(Bayes B), 0.685 (Bayes A), 0.903(Bayes B) and 0.836 (Bayes B) respectively for one to four simulated genetic architectures. These results showed the superiority of parametric methods to Bayesian neural networks in terms of prediction accuracy in genetic architectures with additive effects. In additive genetic architectures, the allelic effects of genetic variations are independent. In parametric models, these effects are assumed to be independent, therefore in additive genetic architectures can be expected that parametric methods are able to provide better predictions than nonparametric methods.  The maximum predictive abilities of Bayesian neural networks to predict  six weeks weight, growth slope, body mass index and body length were 0.474 (1 neuron in the hidden layer), 0.349 (4 neuron in the hidden layer), 0.154 (1 neuron in the hidden layer) and 0.214 (4 neuron in the hidden layer). The predictive abilities of parametric methods to predict these traits were similar and equal to 0.477, 0.336, 0.170, and 0.221 in average. The results showed that the predictive abilities of Bayesian neural networks and parametric methods were similar on real data as the difference between the best predictive ability of Bayesian neural networks and parametric methods for Six weeks weight, growth slope and body length were less than 1%. The difference was slightly higher for the body mass index and equal to 1.8%. The mean squared error of prediction of Bayesian Neural Networks was slightly less than parametric methods in the simulated genetic architectures. The results indicate a slight superiority of Bayesian neural networks compared to parametric methods in terms of mean squared error of prediction as an indicator of overall fit. The mean square prediction error is an appropriate criterion for evaluating the prediction performance of different methods because it contains both accuracy and bias. Considering table (3) and table (5), it can be concluded that the prediction of the Bayesian neural network are less accurate but more unbiased than the parametric methods. This could be due to more applied penalty in parametric methods compared to Bayesian neural networks, which can lead to an increase in the average mean squared error of prediction. In real data, the mean squared error of prediction of the Bayesian neural networks and parametric methods were similar. The computation time of Bayesian neural networks was increased with an increase in the number of neurons in the hidden layer. The computation time of the parametric methods was the same with the exception of GBLUP. The GBLUP method took more computation time. The computation time of neural the networks with 1 to 2 neurons in the hidden layer were less than GBLUP. Genomic prediction using Bayesian Neural Networks with a greater number of neurons is really challenging, and improving their performance in terms of computational cost is necessary before applying them in genomic selection.

    Conclusion

     Although parametric methods had better predictive accuracy and predictive ability due to the additive genetic architecture of the studied traits, it can be concluded that Bayesian neural networks are powerful tools in genomic enabled prediction that can predict genomic breeding values with acceptable accuracy. The genomic prediction ability of the neural networks depends on target traits, the animal species, and neural network architecture. Before using Bayesian neural networks in genomic prediction, it is better to compare the results with parametric methods. It is also necessary to improve the computation time of the Bayesian neural networks with a greater number of neurons in hidden layer before applying them in real application of genomic selection.

    Keywords: Efficiency comparison, Genomic evaluation, neural networks, parametric methods
  • Nemat hedayat evrigh*, reza khalkhali evrigh, reza seyed sharifi, Mostaf Omri Pages 389-398
    Introduction

     Among domesticated animals, the horse can be considered as one of the most influential animals in the process of human life modernization. Based on archaeological evidence, the presence of horses in Iran goes back to 3000 BC. Today, over 300 horses are recognized worldwide and a great number that is indigenous to Iran. The statistics provided by FAOSTAT indicate that there are about 140,000 horses. Due to climate diversity in Iran, there are various horse breeds in different parts of the country, such as Turkmen, Kordi, Drehshuri, Arab, Sistani, Northwest native and Caspian horses. Study of variations in Y chromosome and mtDNA make it possible to the characterization of genetic diversity in the maternal and paternal lines, respectively. Despite the high diversity in the genome of mitochondria in horses, but variation in Y chromosome is in low level. Low variation in Y chromosome of horses can be due to small male effective population size and loss of variations due to bottleneck during domestication. Several studies on Chinese indigenous and European modern horses revealed that native horses have more Y chromosomal variation in compared with modern breeds. So, the aim of present study was an assessment of genetic diversity in paternal line of Iranian horses using Y chromosome. Identified the genetic structure is important for appropriate breeding programs.

    Material and Methods

     Blood samples were collected from Jugular vein using 4 ml tubes containing EDTA (1 mg/ml) of 81 horse belonging to six different populations including Ardebil’s stables horses (24 samples), Northwest horses (17 samples), Kordi horses (15 samples), Arab horses (10 samples), Darehshuri horses (10 samples) and Qarebagh horses (5 samples). Total genomic DNA was extracted from whole blood. A total of the 264-bp fragment (locus: Y-50869) of Y chromosome was amplified using a pair of 20-nucleotide primer (Genbank accession number: JX646950). Polymerase Chain Reaction (PCR) was carried out and then, products of PCR sequenced using Sanger sequencing method. Alignment of sequences was performed by MEGA 6.0 software. Also, MEGA 6.0 used for segregating sites identification and also phylogeny tree construction based on identified haplotypes. DnaSP5 was used to the estimation of haplotype diversity (Hd), nucleotide diversity (π), genetic distance (Dxy) and an average number of differences (k). Finally, the median-joining network was generated using the Network 5 program to present the possible relationships among haplotypes.

    Results and Discussion

     Alignment of sequences led to the identification of six segregating sites and consequently nine haplotypes based on Y chromosome sequences. Three haplotypes (H_1, H_2, and H_6) are widely distributed among under study samples, so that, 65 of 81 (more than 80 %) individuals have placed in three haplotypes. Among haplotypes with more than one individual, there is no special haplotype for any of breeds.  Haplotype diversity values ranged from 0.6 for Arab breed to 0.86 for Kordi breed. The nucleotide diversity values ranged from 0.00288 for Arab breed to 0.01442 for the Qarebaghg breed. Average values for nucleotide diversity and haplotype diversity were 0.0067 and 0.81 respectively. Comparison of present results with the previous study on mtDNA diversity of Iranian horses revealed that maternal line of Iranian horses is more divers from paternal line.  Among Iranian breeds, Dareshuri breed has the lowest nucleotide diversity 0.00481 and haplotype diversity 0.00481 and 0.8 respectively. Assessment of genetic distance among breeds revealed that Ardebil and Qarebagh horses have the highest distance (0.00822), while Arab and Dareshuri horses showed the lowest genetic distance (0.00327). Obtained results indicated that, unlike Arab breed, Qarebagh horses had low influence in Iranian horses. Phylogeny tree based on haplotypes of Iranian horses showed that divided into two branches. Generally, 73 individual (90.12% of all horses) and 8 individuals (9.88% of all samples belongs to each of the two branches.

    Conclusion

     The number of haplotypes which was found for Iranian native horses was placed among three haplogroups, which indicate moderate genetic variety and numerous maternal lines in native horses of Iran. It seems that the presence of the accurate pedigree information along genetic studies can help us to better categorize Iranian horses. In fact, to designing effective breeding strategies, we need to identify the precise genetic structure of Iranian horses. What we learned from this study was that Iranian horses in compared with European pure breeds are more diverse. Obtained results from this study showed that Stalions of Arab breed had high impact in Iranian horses.

    Keywords: Genetic diversity, Haplotype, Iranian horses, Paternal line, Y chromosome