فهرست مطالب

فصلنامه پژوهشهای علوم دامی ایران
سال سیزدهم شماره 2 (تابستان 1400)

  • تاریخ انتشار: 1400/06/31
  • تعداد عناوین: 12
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  • فرشید صراف، سید علیرضا وکیلی*، محسن دانش مسگران صفحات 161-173

    به منظور بررسی اثرات اسانس‌های نعناع فلفلی، آویشن، دارچین و همچنین پروبیوتیک پروتکسین به شیر بر عملکرد، برخی فراسنجه های خونی، اندازه بدنی و قابلیت هضم مواد مغذی، آزمایشی با استفاده از 25 راس گوساله شیرخوار نژاد هلشتاین (10 راس ماده و 15 راس نر) با میانگین وزن تولد 8 ± 40 کیلوگرم در قالب طرح کامل تصادفی انجام شد. جیره های آزمایشی شامل 1) شیر بدون افزودنی (گروه شاهد)، 2) شیر + 40 میلی لیتر اسانس نعناع فلفلی، 3) شیر + 40 میلی لیتر اسانس آویشن، 4) شیر + 40 میلی لیتر اسانس دارچین و 5) شیر + 5/0 گرم پروبیوتیک پروتکسین بود. گوساله ها در جایگاه انفرادی نگهداری شده و به آب و خوراک دسترسی آزاد داشتند. گوساله ها به مدت 3 روز آغوز و پس از آن با مقدار 10 درصد وزن تولد تا زمان 80 روزگی شیر دریافت کردند. استارتر از روز سوم آزمایش در اختیار گوساله ها قرار گرفت. داده‌های بدست آماده با استفاده از مدل عمومی خطی (GLM) رویه تکرار در زمان آنالیز شدند. نتایج بدست آمده نشان داد مصرف استارتر تحت تاثیر تیمارهای آزمایشی قرار نگرفت، با این وجود گوساله های مصرف کننده اسانس دارچین و پروتکسین دارای افزایش وزن روزانه بالاتری نسبت به دیگر اسانس ها و گروه شاهد بودند. حداقل بازده خوراک مربوط به گوساله های تیمار شاهد و حداکثر آن مربوط به گوساله های مصرف کننده اسانس دارچین و پروتکسین بود. فراسنجه های خونی و نیتروژن آمونیاکی شکمبه تحت تاثیر نوع اسانس و پروبیوتیک مصرفی قرار نگرفت. میزان pH شکمبه ای در گوساله های تغذیه شده با اسانس های مختلف و همچنین پروتکسین نسبت به گروه شاهد پایین تر بود. عرض هیپ، دور سینه، عمق شکم و ارتفاع جدوگاه تحت تاثیر تیمارها قرار نگرفت. با این وجود طول بدن و ارتفاع هیپ در گوساله های دریافت کننده اسانس دارچین نسبت به گروه شاهد بالاتر بود. قابلیت هضم ماده خشک و ماده آلی در گوساله های مصرف کننده اسانس دارچین تمایل به معنی داری بیشتری نسبت به گروه شاهد داشت. بطورکلی مصرف اسانس دارچین و پروتکسین با بهبود بازده خوراک و تخمیر شکمبه ممکن است منجر به بهبود عملکرد گوساله های شیرخوار گردد.

    کلیدواژگان: آویشن، پروتکسین، دارچین، عملکرد، گوساله، نعناع
  • جواد نصیری، حسن علی عربی*، پویا زمانی صفحات 175-192

    این مطالعه به‌منظور بررسی اثر انواع نمک های کلسیمی اسیدهای چرب بر عملکرد و الگوی اسید های چرب شیر انجام شد. در این مطالعه از 21 راس گاو هلشتاین با روزهای شیردهی 5/8 ± 30 استفاده شد. گاوها به سه گروه مساوی تقسیم و جیره های زیر را دریافت کردند: 1. جیره شاهد 2. جیره حاوی منبع چربی A (ساخته شده در آزمایشگاه)3. جیره حاوی منبع چربی B (مرسوم در بازار). گاوها در سه نوبت دوشیده شدند. رکورد و مصرف خوراک به‌صورت روزانه ثبت شدند و نمونه گیری از شیر، خوراک و مدفوع جهت تعیین ترکیب به‌صورت هفتگی انجام گرفت. خون‌گیری از دام ها به عمل آمد. در پایان دوره آزمایش نمونه شیر جهت تعیین الگوی اسید چرب جمع آوری شد. مصرف ماده خشک در جیره شاهد 5 درصد بیشتر از دو جیره دیگر بود در حالیکه میزان تولید شیر در جیره حاوی مکمل چربی A افزایش معنی داری نسبت به جیره شاهد داشت و با جیره حاوی مکمل چربی B تفاوتی نداشت. BCS و تغییرات وزن بدن تحت تاثیر جیره ها قرار نگرفت. مکمل چربی A بر قابلیت هضم فیبر جیره تاثیر منفی نداشت و مشابه جیره شاهد و مکمل چربی B بود. میزان C18:2 شیر گاوهای دریافت کننده جیره حاوی مکمل A نسبت به مکمل B و جیره شاهد به ترتیب 21 و 47 درصد افزایش داشت. درصد چربی و C14:0 شیر در جیره شاهد نسبت به دو جیره دیگر افزایش معنی دار پیدا کرد. مکمل چربی A می تواند به عنوان منبع چربی در اوایل دوره شیردهی استفاده شود و نتایج مشابهی با نمونه تجاری مرسوم داشت.

    کلیدواژگان: ترکیب شیر، تولید شیر، گاو شیری، نمک کلسیمی اسید چرب
  • پروین نصر چالشتری، امیر فدائی فر*، ایوب عزیزی، آرش آذرفر صفحات 193-205

    به‌منظور مطالعه عملکرد و تعیین تغییرات برخی از فراسنجه های خونی بره‌های متولد شده از میش‌های آبستن دریافت کننده قرص آهسته‌رهش مس، 80 راس میش لری-بختیاری (شکم زایش چهارم و نمره وضعیت بدنی 3 الی 5/3) همزمان شده برای زایش به دو گروه 40 راسی تقسیم‌بندی شدند. تیمارها شامل: 1) گروه شاهد و 2) گروه دریافت کننده قرص آهسته رهش مس بود. میش ها 60 روز قبل از تاریخ پیش بینی زایمان، قرص آهسته رهش مس را دریافت کردند. در روز اول آزمایش، 10 و 60 روز پس از زایمان، خون‌گیری از میش ها انجام شد. پس از شروع زایمان، وزن تولد، جنسیت، تک قلو یا چندقلو بودن بره ها ثبت و خون‌گیری از آن‌ها در سن 10 و 60 روزگی انجام شد. غلظت مس و سرولوپلاسمین سرم به‌طور معنی‌داری در میش‌های دریافت کننده قرص مس نسبت به میش های گروه شاهد بالاتر بود (05/0>P). در روز اول آزمایش (60 روز قبل از زایمان) غلظت مس و سرولوپلاسمین سرم خون میش‌ها نسبت به روز 10 و 60 پس از زایش پایین‌تر بود، اما بین روزهای 60 و 10 پس از زایش تفاوت معنی‌داری مشاهده نشد. بره‌های متولد ‌شده از مادران دریافت کننده قرص آهسته رهش مس در مقایسه با بره های متولد شده از میش های گروه شاهد، وزن از شیرگیری، افزایش وزن روزانه، غلظت مس سرم، غلظت سرولوپلاسمین سرم، درصد هماتوکریت، تعداد گلبول قرمز و غلظت هموگلوبین بالاتری داشتند (05/0>P). به طور کلی نتایج نشان داد که خوراندن قرص آهسته رهش مس به میش ها در اواخر دوره آبستنی، باعث بهبود افزایش وزن روزانه و وزن ازشیرگیری بره های آن‌ها شد.

    کلیدواژگان: بره، سرولوپلاسمین، گوسفند، گوگرد، مس
  • ایوب عزیزی*، جهانشیر شاکرمی، فهیمه دهقانی خواه، افروز شریفی صفحات 207-220

    هدف از انجام مطالعه حاضر بررسی ارزش تغذیه‌ای کاه گندم و سرشاخه نیشکر عمل‌آوری شده توسط باکتری‌های تجزیه کننده لیگنین و لیگنوسلولز جدا شده از دستگاه گوارش لارو کرم خراط (Zeuzera pyrina L.) بود. بدین منظور، ابتدا بر اساس آنالیز توالی 16S rDNA، سه ایزوله باکتریایی با قابلیت تجزیه‌کنندگی لیگنین و لیگنوسلولز شامل انتروباکتر کلواسه (Enterobacter cloacae)، استافیلوکوکوس اسکویری (Staphylococcus sciuri) و گونه بروی‌باکتریوم (Brevibacterium sp.) از دستگاه گوارش این کرم جداسازی شد. سپس هر کدام از دو سوبسترای کاه گندم و سرشاخه نیشکر به‌طور مجزا توسط هر کدام از ایزوله‌های مذکور یا مخلوط هر سه آن‌ها (4 تیمار آزمایشی برای هر سوبسترا) فرآوری شدند. در هر دو سوبسترا، بیشترین میزان ناپدید شدن ماده خشک، پروتئین خام، گوارش‌پذیری ماده خشک و انرژی قابل متابولیسم در تیمار حاوی مخلوط باکتریایی روده‌ی کرم خراط و کمترین در تیمار شاهد به دست آمد. بیشترین حجم و پتانسیل تولید گاز (b) پس از عمل‎‌آوری سوبستراها توسط مخلوط باکتریایی روده‌ی کرم خراط در مقایسه با تیمار شاهد به دست آمد. در هر دو سوبسترا، بیشترین غلظت کل اسیدهای چرب فرار شکمبه، استات، نسبت استات به پروپیونات و غلظت آمونیاک توسط انکوباسیون تیمار تلقیح شده با مخلوط باکتریایی در مقایسه با تیمار شاهد به دست آمد. در کل، نتایج این پژوهش نشان داد که عمل‌آوری کاه گندم و سرشاخه نیشکر توسط باکتری‌های مجزای روده‌ی کرم خراط، به خصوص مخلوط آنها سبب بهبود ارزش غذایی پسماندهای مذکور از طریق افزایش قابلیت هضم ماده خشک و غلظت اسیدهای چرب فرار شکمبه جهت استفاده به‌عنوان خوراک دام شد.

    کلیدواژگان: ارزش تغذیه ای، تولید گاز، کرم خراط، لیگنوسلولز، نشخوارکنندگان
  • سعید فیروزه*، امیرهوشنگ فلاح راد، پژمان میرشکرایی، عباس پرهام، محسن دانش مسگران صفحات 221-233

    دانه کتان منبع غنی از اسید آلفا لینولنیک (امگا3) با خاصیت آنتی اکسیدانی بالا ‌می‌باشد، که ‌می‌تواند در سنتز هورمون‌های جنسی و بهبود کیفیت اسپرم در گونه‌های مختلف نقش داشته باشد. مطالعه حاضر اثرات دانه کتان بر خصوصیات کمی و کیفی اسپرم و برخی پارامترهای خونی را بررسی ‌می‌کند. در این تحقیق که در مدت 12 هفته اجرا گردید 15 راس قوچ نژاد کردی انتخاب و به صورت تصادفی به سه گروه تقسیم شدند. گروه شاهد دریافت کننده جیره پایه و گروه دوم که شامل جیره پایه و 5 درصد دانه کتان و گروه سوم محتوی جیره پایه و 10 درصد دانه بود. نتایج نشان داد که غلظت اسپرم، نسبت اسپرم زنده، تحرک کل و عملکرد غشای پلاسما در تیمار 10 درصد دانه کتان در مقایسه با سایر گروه‌ها بیشتر بود (P<0.05). دانه کتان باعث افزایش درصد اسپرم با آکروزوم نرمال شد (P<0.01). با این حال، درصد اسپرم‌های غیر طبیعی پس از دریافت 10 درصد دانه کتان و در پایان هفته 12 در مقایسه با سایر گروه‌های مربوطه کاهش یافت (P<0.05). نتایج نشان داد که مکمل دانه کتان بر قطر بیضه اثری نداشت اما غلظت تستوسترون پلاسما را در گروه 10 درصد نسبت به گروه شاهد افزایش داد (P <0.05). اثر افزودن مکمل دانه کتان، اثر زمان و اثر متقابل آنها بر فعالیت آنزیم گلوتاتیون پراکسیداز معنی دارنبود. جیره 10 درصد کتان موجب افزایش معنی داری اسید چرب DHA (دوکوزاهگزاانوییک DHA=Docosahexaenoic acid) در چربی اسپرم شد (P<0.05). نسبت اسیدهای چرب امگا سه به شش افزایش یافته و نیز نسبت اسیدهای چرب اشباع به اسیدهای چرب با چند باند مضاعف در گروه 10 درصد در مقایسه با سایر گروه‌ها کاهش یافت (P<0.05). نتایج نشان داد که افزودن 10 درصد دانه کتان به جیره پایه قوچ‌های کردی در خارج از فصل تولید مثل ‌می‌تواند سبب بهبود کمی و کیفی شاخص‌های ازریابی اسپرم و در نهایت بهبود باروری آنها گردد.

    کلیدواژگان: اسپرم، اسید چرب، امگا 3، دانه کتان، قوچ کردی
  • حشمت سپهری*، زینب نوری، امیر آذرلی، علیرضا حسابی نامقی صفحات 235-248

    به منظور بررسی اثر تغذیه سطوح مختلف ضایعات تقطیری گندم بر عملکرد و ریخت شناسی روده جوجه های گوشتی، دو آزمایش مجزا انجام شد. در هر آزمایش تعداد 450 قطعه جوجه گوشتی مخلوط یک روزه سویه راس- 308 در قالب طرح کاملا تصادفی با 5 گروه و 6 تکرار در هر گروه (هر تکرار دارای 15 قطعه جوجه) درطی دوره های آغازین و رشد مورد آزمایش قرار گرفتند. جوجه های انتخابی برای سن 22 تا 42 روزگی از ابتدای دوره تا 21 روزگی با جیره فاقد ضایعات تقطیری گندم تغذیه شدند. در آزمایش اول که جوجه ها از سن 1 تا 21 روزگی مورد آزمایش قرار گرفتند، سطوح صفر،3، 6، 9 و 12 درصدی و در آزمایش دوم که از 22 تا 42 روزگی ادامه یافت، سطوح صفر، 5، 10، 15 و 20 درصدی از ضایعات تقطیری گندم استفاده شد. مطابق نتایج حاصل از تجزیه شیمیایی ضایعات تقطیری گندم، مقادیر پروتئین خام، چربی خام، فیبر خام، لیزین، متیونین، کلسیم و فسفر‌کل به ترتیب 5/30، 5/8، 4، 57/0، 53/0، 26/0 و 93/0 درصد بود. میانگین افزایش وزن روزانه در کل دوره پرورش (1 تا 21 روزگی) بین گروه های مختلف آزمایشی دارای تفاوت معنی دار بود (05/). به طوری که بیشترین میانگین افزایش وزن کل به ترتیب مربوط به گروه های حاوی 3 درصد و شاهد (74/846 و 31/847 گرم) بود. همچنین جوجه‌های تغذیه شده با سطح 12 درصد ضایعات تقطیری گندم مصرف خوراک کمتری (59/1136گرم) نسبت به سایر گروه‌ها و گروه شاهد داشتند (05/0(P<. در سنین 30 تا 37 روزگی و 38 تا 45 روزگی، با توجه به طی شدن دوره عادت‌پذیری (پرنده 7 روز ضایعات تقطیری گندم مصرف کرده است)، مصرف سطوح بالاتر ضایعات تقطیری گندم (15 و 20 درصد) باعث وزن بیشتری در جوجه‌های تغذیه شده با این سطوح نمود‌ (05/0(P<. مصرف خوراک و ضریب تبدیل غذایی در جوجه‌های تغذیه شده با سطوح مختلف ضایعات تقطیری گندم در بازه های زمانی‌ مختلف تفاوت معنی‌داری ایجاد نکرد. افزایش سطح ضایعات تقطیری گندم در هر دو آزمایش، نتایج معنی‌داری بر صفات ریخت‌شناسی ژژنوم نداشت و با افزایش سطح ضایعات تقطیری گندم، ارتفاع پرز ها کاهش و طول کریپت ها در ژژنوم افزایش یافت. مطابق نتایج حاصل از این آزمایش‌ها، بهترین سطح جایگزینی ضایعات تقطیری گندم بر پایه ذرت-کنجاله سویای جوجه های گوشتی در بازه زمانی 1 تا 21 روزگی، 3 درصد و در بازه زمانی 22 تا 45 روزگی 20 درصد بود.

    کلیدواژگان: جوجه، ریخت شناسی ژژنوم، عملکرد، ضایعات تقطیری گندم
  • نظر اکبری زاده، علی خطیب جو*، صیفعلی ورمقانی، هوشنگ جعفری، علی نقی شکری صفحات 249-262

    در این آزمایش، تاثیر پودر گیاه دارویی زوفا، آنتی‌بیوتیک ویرجینیامایسین و آسپرین بر عملکرد رشد، متابولیت‌های خونی، خصوصیات لاشه و جمعیت میکروبی ایلیوم جوجه‌های گوشتی تحت تنش سرمایی بررسی شد. تعداد 500 قطعه جوجه گوشتی نر سویه راس308، در قالب طرح کاملا تصادفی به پنج تیمار، پنج تکرار و 20 جوجه در هر تکرار اختصاص داده شدند. تیمارهای آزمایشی شامل 1) جیره پایه، 2 و 3) به‌ترتیب جیره پایه + 300 گرم در تن ویرجینیامایسین یا آسپیرین و 4 و 5) به ترتیب جیره پایه دارای 5/0 و یک درصد زوفا بودند. نتایج نشان داد که مصرف خوراک با افزودن یک درصد پودر گیاه زوفا به طور معنی داری افزایش یافت. آنتی بیوتیک و هر دو سطح زوفا در مقایسه با شاهد و آسپرین منجر به افزایش وزن، افزایش شاخص کارایی اروپایی و کاهش ضریب تبدیل خوراک شدند. آسپرین و یک درصد زوفا تلفات آسیتی را در مقایسه با سایر تیمارها کاهش دادند. افزودن یک درصد پودر زوفا نسبت به جیره شاهد منجر به کاهش تعداد کل گلبول قرمز، شاخص شکنندگی اسمزی گلبول قرمز و درصد هتروفیل نسبت به گروه شاهد در 21 و 42 روزگی شد. در مقایسه با تیمار شاهد، تیمارهای افزودنی بر تعداد کل گلبول‌های سفید، درصد لنفوسیت و نسبت هتروفیل به لنفوسیت، غلظت کلسترول کل، HDL- و LDL-کلسترول و اوره سرم خون در 21 و 42 روزگی، درصد لاشه، ران و چربی محوطه شکمی تاثیر معنی‌داری نداشتند؛ اما پودر زوفا منجر به افزایش وزن نسبی سینه گردید. افزودن یک درصد پودر زوفا و آنتی‌بیوتیک ویرجینیامایسین منجر به کاهش جمعیت اشریشیاکلی ایلیومی جوجه‌های گوشتی شد.به طور کلی، افزودن یک درصد گیاه زوفا موجب بهبود عملکرد و کاهش تلفات جوجه‌های گوشتی در شرایط تنش سرمایی شد. افزودن آسپرین موجب کاهش درصد تلفات آسیتی شد. به نظر می‌رسد که افزودن آسپرین و یک درصد پودر زوفا به جیره می‌تواند تا حدی اثرات منفی استرس سرمایی در جوجه‌های گوشتی را کاهش دهد.

    کلیدواژگان: آسیت، تنش سرمایی، جوجه گوشتی، متابولیت خونی، صفات لاشه
  • محمدرضا قربانی*، احمد طاطار، سمیه سالاری، محمدهادی سلیمانی، سلماز خلیلی سامانی صفحات 263-273

    به منظور بررسی تاثیر سطوح مختلف کنجاله سیاه‌دانه در جیره بر عملکرد مرغان تخم‌گذار در سیکل دوم تولید، آزمایشی با استفاده از 120 قطعه مرغ تخم‌گذار لگهورن، در قالب طرح کاملا تصادفی با 5 تیمار، 4 تکرار و 6 قطعه مرغ در هر تکرار به انجام رسید. تیمارهای آزمایشی عبارت بودند از سطوح صفر (شاهد)، پنج، ده، پانزده و بیست درصد کنجاله سیاه دانه که جایگزین کنجاله سویا در جیره پایه شدند. طول دوره آزمایش هشت هفته بود و نتایج صفات عملکردی و کیفیت تخم‌مرغ بصورت چهار هفته اول، چهار هفته دوم و کل دوره گزارش شدند. نتایج آزمایش نشان داد که در چهار هفته اول، دوم و کل دوره آزمایش مصرف خوراک به هنگام استفاده از کنجاله سیاه‌دانه بصورت معنی‌داری کاهش یافت و کمترین مصرف خوراک در گروه 20 درصد کنجاله سیاه‌دانه مشاهده گردید. در کل دوره آزمایش، توده تخم‌مرغ به هنگام استفاده از سطوح 10، 15 و 20 درصد کنجاله سیاه‌دانه کاهش یافت. غلظت کلسترول و تری گلیسرید سرم خون مرغان تخم‌گذار در سطح 5 درصد استفاده از کنجاله سیاه‌دانه بصورت قابل‌ملاحظه‌ای پایین‌تر از گروه شاهد و سایر گروه‌های استفاده کننده از کنجاله سیاه‌دانه بود. نتایج آزمایش نشان داد که استفاده از کنجاله سیاه‌دانه تا سطح 5 درصد بدون تغییر در صفات عملکردی باعث کاهش کلسترول و تری‌گلیسرید خون مرغان تخم‌گذار شد.

    کلیدواژگان: عملکرد، کنجاله سیاه دانه، کیفیت تخم مرغ، مرغان تخم گذار
  • سید محمدرضا صلواتی، ابوالقاسم گلیان*، احمد حسن آبادی صفحات 275-290

    این پژوهش به منظور بررسی اثر فرآوری حرارتی بر انرژی قابل متابولیسم، قابلیت هضم ظاهری پروتئین و ماده خشک گندم به روش جمع‌آوری کل فضولات با استفاده از 96 قطعه جوجه گوشتی مخلوط دو جنس سویه راس-308 در سن21- 18 روزگی با جیره حاوی 11/70 درصد گندم‌ به نحوی که تنها منبع انرژی و پروتئین جیره‌ها یکی از چهار گندم فرآوری شده و یا نشده بود، انجام شد؛ همچنین آزمایشی به منظور بررسی عملکرد 576 قطعه جوجه گوشتی سویه راس-308 از سن 24-11روزگی در قالب طرح کاملا تصادفی به روش فاکتوریل 2 × 4 شامل 8 تیمار با 6 تکرار و 12 قطعه پرنده در هر تکرار طراحی شد. گندم‌های مورد استفاده فرآوری نشده و یا فرآوری شده در کاندیشنر با دماهای C° (55، 70 و 85) به مدت 5/2 دقیقه با و بدون مکمل آنزیمی بودند. فرآوری حرارتی در دمای C° 85 منجر به افزایش انرژی قابل متابولیسم ظاهری و قابلیت هضم ماده خشک بترتیب به میزان 32/5 و 61/5 درصد و افزایش وزن بدن، وزن روزانه و مصرف خوراک نسبت به تیمار شاهد شد. همچنین منجر به افزایش ارتفاع ویلی‌های ناحیه ژژنوم نسبت به تیمار شاهد شد. مکمل آنزیمی باعث افزایش وزن بدن، وزن روزانه، ضریب تبدیل غذایی، کاهش وزن ایلیوم و پهنای ویلی شد. با توجه به نتایج حاصل، فرآوری حرارتی گندم باعث بهبود انرژی قابل متابولیسم ظاهری، قابلیت هضم ماده خشک، مورفولوژی روده کوچک و فعالیت میکروبی ناحیه ایلیوم جوجه‌های گوشتی سن 24- 11 روزگی شد.

    کلیدواژگان: آنزیم، جوجه گوشتی، عملکرد، فرآوری حرارتی
  • رضا وکیلی*، قاسم رمضانی صفحات 291-302

    هدف از انجام این آزمایش بررسی اثر سطوح مختلف نانو ذرات نقره و پری‌بیوتیک بر عملکرد رشد، شاخص‌های بیوشیمیایی خون، جمعیت میکروبی روده کور و پاسخ ایمنی جوجه‌های گوشتی سویه راس 308 بود. آزمایش در قالب طرح کاملا تصادفی به روش فاکتوریل 3×3 با 9 تیمار و 4 تکرار و 12 مشاهده در هر تکرار و در مجموع با 432 قطعه جوجه گوشتی انجام شد. عوامل مورد بررسی شامل سه سطح نانوذرات نقره (400،800 و0 میلی لیتر در مترمکعب آب آشامیدنی) و سه سطح پری‌بیوتیک (5/0 و 25/0 ،0درصد در جیره غذایی) از 1 تا 42 روزگی بود. جیره‌های آزمایشی براساس احتیاجات غذایی سویه راس 308 تنظیم گردید. بیشترین افزایش وزن و کمترین ضریب تبدیل در تیمارهای حاوی نانوذرات نقره (400 و 800 میلی‌لیتر) بدون و با 5/0درصد پری‌بیوتیک مشاهده شد. 5/0 درصد پری بیوتیک در جیره غذایی جوجه‌های گوشتی و 800 میلی لیتر سبب کاهش تعداد باکتری‌های کلی باسیل، سالمونلا و افزایش باکتری‌های لاکتوباسیل در روده کور جوجه‌های گوشتی شد. پری‌بیوتیک سبب افزایش HDL و کاهش معنی‌دار پروتئین تام سرم خون بین سطح صفر و 5/0 درصد شد. نتایج حاصل از این تحقیق نشان داد که استفاده از سطح 5/0 درصد پری بیوتیک در جیره غذایی سبب افزایش وزن و بهبود ضریب تبدیل جوجه‌های گوشتی شد. همچنین استفاده از 800 میلی لیتر نانوذرات نقره درآب آشامیدنی سبب کاهش تعداد باکتری‌های کلی باسیل و سالمونلا در روده کور جوجه‌های گوشتی شد.

    کلیدواژگان: باکتری های روده کور، پری بیوتیک، جوجه گوشتی، شاخص های بیوشیمیایی خون، نانو نقره
  • نصیر کریمی، محمدتقی بیگی نصیری*، ارسلان برازنده صفحات 303-312

    بهره وری اقتصادی پرورش گوسفند تا حد زیادی تحت تاثیر میزان زنده مانی آن است. هدف این مطالعه بررسی پارامترهای ژنتیکی صفات زنده مانی گوسفند عربی از تولد تا یک‌سالگی بود. بدین منظور از تعداد 5452 رکورد زنده مانی بره های نژاد عربی که طی سال های1371 تا 1383 توسط سازمان جهاد کشاورزی شهرستان اهواز جمع آوری شده بود استفاده گردید. داده ها با مدل های خطی و نسبت خطر با تابع ویبال تجزیه شدند. این مدل ها شامل اثر عوامل ثابت سال و ماه تولد بره، نوع تولد، سن مادر و متغیر کمکی وزن تولد بره ها به صورت درجه دوم و اثرات تصادفی ژنتیکی افزایشی مستقیم، ژنتیکی افزایشی مادری، محیط دایمی مادری و باقی مانده بودند. وراثت پذیری مستقیم میزان زنده مانی بره ها با مدل های مختلف خطی، در بازه 025/0 تا 061/0 برآورد گردید. وراثت پذیری های مستقیم در مقیاس لگاریتمی، مقیاس اولیه و وراثت پذیری موثر نسبت خطر به دست آمده از مدل پدری دارای تابع ویبال دامنه 13/0 تا 75/0 را نشان داد. نتایج بیانگر وراثت پذیری کم برای مدل های خطی و متوسط تا بالا برای تابع ویبال بود. تخمین های متوسط تا بالای وراثت پذیری صفات بقا، با استفاده از مدل های نسبت خطر با تابع ویبال، می تواند ایده بهبود بقای بره از طریق انتخاب درون نژادی و گنجاندن آن در شاخص انتخاب نژاد گوسفند عربی را مورد توجه قرار دهد.

    کلیدواژگان: زنده مانی، گوسفند عربی، وراثت پذیری
  • مژگان قاسمی ساب، شیدا ورکوهی*، محمدحسین بناءبازی صفحات 313-319

    مطالعه در سطح ترانسکریپتوم می تواند فاصله بین ژنوتیپ و فنوتیپ را پر نموده و به درک ساز وکارهای تبدیل توالی به عملکرد کمک نمایند. در این مطالعه به منظور کشف چند شکلی های تک نوکلیوتیدی (SNP) از داده های RNA-Seq دو جمعیت گاوهای هلشتاین آمریکا (Bos taurus) و کلیستانی پاکستان (Bos indicus) استفاده شد. کنترل کیفیت و ویرایش داده ها توسط نرم افزار های FASTQC و Trimmomatic انجام شد. با همردیفی و مکان یابی خوانش های RNA-Seq بر روی ژنوم مرجع گاو با استفاده از نرم افزار TopHat2، ترانسکریپتوم تشکیل شد، سپس با استفاده از بسته نرم افزاری Samtools ، آنالیز کشف SNP بر روی ترانسکریپتوم صورت گرفت که منجر به شناسایی 50183 و 137954 جایگاه SNP به ترتیب در گاوهای هلشتاین و کلیستانی شد، که 15308 جایگاه مشترک بود. ارتباط مستقیمی بین تعداد SNP های یافت شده و طول کروموزوم ها مشاهده نشد. همچنین 12 نوع SNP شناسایی شد که چهار نوع جایگزینی نوکلیوتیدی عامل و هشت نوع جایگزینی نوکلیوتیدی غیر عامل بودند. شایعترین SNP های شناخته شده، از نوع جایگزینی نوکلیوتیدی عامل بودند، که 6/70 % در نژاد کلیستانی و 6/69 % در نژاد هلشتاین وجود داشت. درمطالعه حاضر 12 نوع SNP شناسایی شد. چهار نوع از SNP ها، از نوع جایگزینی نوکلیوتیدی عامل وهشت نوع جایگزینی نوکلیوتیدی غیر عامل بودند. شایعترین SNP های شناخته شده، SNP های از نوع جایگزینی نوکلیوتیدی عامل بودند، که به ترتیب 6/70 % SNP ها در نژاد کلیستانی و 6/69 % SNP ها در نژاد هلشتاین را شامل شد. نسبت جایگزینی نوکلیوتیدی عامل به غیر عامل (Ts/Tv) SNP ها در نژاد کلیستانی برابر با 4/2 و در نژاد هلشتاین برابر با 3/ 2 بود.

    کلیدواژگان: ترانسکریپتوم، جایگزینی نوکلئوتیدی، چند شکلی تک نوکلئوتیدی، داده های RNA-Seq
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  • Farshid Sarraf, Seyyed Alireza Vakili *, Mohsen Danesh Mesgaran Pages 161-173

    Introduction:

     The present study was conducted to investigate the efficacy of inclusion peppermint, thyme, cinnamon essential oils and also probiotic supplement (Protexin, Probiotics International Ltd., south Petherton, UK) when added to whole milk on performance, some blood parameters, skeletal growth, and nutrient digestibility of Holstein dairy calves.

    Material and Methods :

    A total of 25 Holstein dairy calves (10 females and 15 males; 1–10 days) with 42 ± 8 kg of average birth weight were used in a completely randomized design in which calves were randomly assigned to one of five different dietary treatments including 1) control diet without inclusion of any milk essential oil supplementation, 2, 3 and 4) control diet + 40 ml (20 ml in the morning and 20 ml in evening meals) per day of peppermint, thyme, cinnamon essential oils, respectively and 5) control diet + 0.5 g per day probiotic Protexin. Calves were individually housed and bedded with straw that was replaced every day. Feed and water were available ad libitum throughout the experiment. Calves were fed colostrum for 3 days and then fed with 10% of their birth weight until 80 days of age. The rations were iso-energetic. Ruminal fluid samples were collected by esophagus tube after morning feeding at the end of study. Starter intake was recorded individually and daily. The amount of feed consumed daily was calculated throughout the experiment from the difference between the feed poured and the remaining feed. Edible samples from calves were kept in the freezer (-20 °C) for approximate analysis experiments. Performance was analyzed in repeated measures of the mixed model (PROC MIXED) including initial BW as a covariate (covariate structure: compound symmetry) with treatment, week and their interaction as fixed components and animal as random effect. Structural growth data were evaluated by GLM. Gender was considered a block but was not significant and drop from the model. A mixed-effects regression analysis, which included calf and period as random effects and treatment and time relative to weaning (before or after) as fixed effects, was then performed. Analytical model was Yij = µ + Ti + Aij + β (BWij - x) + eij, where Yij was each observation, μ was the overall mean, Ti was the fixed effect of treatment i, Aij was the random effect of calve j in treatment i, β (BWij - x) was using initial BW as a covariate and eij was residual error. Treatments means were statistically compared by the test of Duncan.

    Results and Discussion:

     The results showed that starter intake was not affected by the experimental treatments (p> 0.05). However, calves consuming cinnamon essential oil and probiotic Protexin had higher daily weight gain than other essential oils and control group (p <0.05). Calves fed milk without any additives had the lowest feed efficiency but it was highest for calves fed whole milk based on cinnamon essential oil or Protexin (p<0.05). Rumen parameters and ammonia nitrogen concentration were not affected by essential oils and probiotic intake (p> 0.05). Ruminal pH value was lower in calves were fed milk supplemented with different essential oils and Protexin than those fed control treatment (p<0.05). This decrease in pH by inclusion of essential oil and Protexin was probably due to increased ruminal propionate to acetate ratio. Addition of peppermint, thyme, cinnamon essential oils and probiotic Protexin to milk of Holstein calves had no detectable effect on the mean concentration of glucose, cholesterol, total protein, albumin, urea, aspartate-aminotransferase and alanine-aminotransferase (p> 0.05). The concentration of triglyceride in calves fed cinnamon essential oil was higher than that of other essential oils as well as probiotic Protexin (p <0.05). Inactivation of blood urea nitrogen concentration by the addition of essential oils was associated with a significant lack of ruminal ammonia nitrogen concentration. Increased ammonia nitrogen levels, more than the microbial requirement, lead to absorption through the rumen wall and hepatic vein, and most of it is converted into urea in the liver and ultimately increases in blood urea concentrations, which in this study did not affect the essential oils. Different effects of Protexin on ruminal ammonia nitrogen concentration resulted in no significant blood urea nitrogen concentration.Hip width, heart girth, body barrel and wither height were not affected by the addition of essential oils, as well as probiotic supplementation (p> 0.05). However, body length and hip heights were higher in the calves fed cinnamon essential oil than the control group. The apparent digestibility of dry matter and organic matter in calves consumed cinnamon essential oil tended to increase than the control group (p=0.06 and p=0.07, respectively). The digestibility of crude protein and neutral detergent fiber was not affected by the type of essential oil and Protexin supplementation in Holstein dairy calves.

    Conclusion :

    Overall, essential oils especially cinnamon and probiotic Protexin may improve growth and performance by increasing daily gain and feed efficiency of Holstein dairy calves.

    Keywords: Blood, ruminal parameters, Calf, Essential oil, Protexin, Performance
  • javad nasiri, hasan aliarabi *, pouya zamani Pages 175-192
    Introduction

     Cows need a lot of energy to produce milk in early lactation. Due to the low dry matter intake in this period, it is necessary to increase diet energy concentration. Therefore, fat supplements are often used to increase the concentration of metabolizable energy for reduce mobilization of adipose tissue in fresh cows. Many studies shown that adding fat to diet of lactating cows, improves milk production and increases lactation persistency. Increasing milk yield by 2 to 10 percent was reported in cows receiving fat supplement compared to control. One of the limitations of using fat supplements for ruminant is its negative effects on digestion of fiber. In some studies, using of unprotected fat sources reduced digestibility of fibers and milk fat percentage in early lactation. In contrast, some researchers have reported that adding protected fats to the diet of lactating cows increased milk production and had not negative effect on milk fat. The reason for this was minimum effect of protected fat on ruminal fermentation. Usual protected fats include crystalline or prilled fatty acids, formaldehyde treated protein encapsulated fatty acids, hydrogenated lipids, fatty acyl amides and calcium salts of fatty acids. Calcium salts of fatty acids are lower degradable than other fat sources in rumen. More studies should be done because of the low production of calcium salts of fatty acids in Iran and as well as the demand for better quality of fat supplements.

    Materials and Methods :

    Twenty one Holstein cows were used under days in milk 30±8.5 with body weight 573 ± 69.4. The cows were divided into three groups (3primiparous and 4 multiparous) and were offered following rations for 100 days period:1- control (without fat supplementation), 2- ration containing fat supplement A (laboratory made for this research in Bu-Ali Sina University), 3- ration containing fat supplement B (Persia fat, Kimia Danesh Alvand Co, Tehran, Iran). Diets were designed to be iso-nitrogenous. After morning milking and before feeding, cows were weighed and body scored in 30, 70 and 100 days in milk. The cows were milked three times daily. The TMR was fed at 0530, 1430 and 2230hours daily. Feed intake and milk yield were recorded daily and weekly sampling was performed to determine milk, feed and feces compositions. Milk samples were analyzed for protein, fat and lactose. Feed and feces samples were analyzed for DM, Ash, CP, ether extract and ADF. Digestibility of ration nutrients was determined using acid insoluble ash as an indigestible marker. Blood samples were withdrawn on 45, 70 and 100 days in milk. Blood samples then were centrifuged at 4 ºC and 3000×g for 15 minutes. Then plasma was analyzed for glucose, cholesterol, triglyceride and non-esterified fatty acids. At the end of the experiment milk samples were collected to determine milk fatty acids profile. The fatty acids were determined using a direct method for fatty acid methyl ester synthesis using a gas chromatograph. Data were analyzed as a completely randomized design using the MIXED procedure of SAS.    

    Results and Discussion

     in this study using fat supplements had not effect on BCS. Dry matter intake was not affected by diets. Milk production were higher in cows receiving fat supplement A than control while was not different compared to fat supplement B. milk production increased significantly after two weeks. During the treatment period, control increased milk fat percentage. Milk fat increasing was started in second week of experiment. The amount of milk lactose increased due to the milk production increasing in cows receiving fat supplement compared to control. FCM was not different between treatments. In this study, fat supplement A and B increased blood cholesterol. Amount of triglyceride increased but was not significant. NEFA and glucose were not affected by diets. C14:0, C14:1 and C18:2 were influenced by rations. Percent of C8:0 was higher in control than other treatments by 16 percent, it was not significant. Percent of C18:1 was higher in cows receiving fat supplement A and B than control, but was not significant. Rations had not affected on nutrients digestibility.

    Conclusion

     according to the results, fat supplement A can be used as fat source in early lactation.

    Keywords: calcium salt of fatty acids, Dairy cows, Milk production, Milk Composition
  • Parvin Nasr Chaleshtori, Amir Fadayifar *, Ayob Azizi, Arash Azarfar Pages 193-205
    Introduction

     The provision of nutrients during the late gestation not only affects maternal status and reproductive performance, but also affects prenatal and postnatal litter growth and offspring’s health. Although trace elements are needed by the body in small amounts, they are essential nutrients for several metabolic functions such as growth, development, reproduction, and immunity. Copper (Cu) is often one of the most limiting trace elements for the fetus and neonate for normal development and copper play a major etiologic role in decrease of fetal growth and development. Deficiency of copper impairs fetal growth and causes serious consequences and can cause death. When intakes of Cu are deficient, maternal transfer of Cu to the fetus is insufficient for normal development, and abnormalities to the central nervous system, skeleton, and metabolism result. In ruminants, newborn animals are dependent on their dams for transferring nutrients via the placenta and mammary glands. To our knowledge, little information is available on the effects of maternal supplementation of copper via intra-ruminal administration of slow-release bolus at the late gestation on the copper status of ewes and their lambs. Because the slow-release ruminal bolus cannot be used in the newborn lambs until weaning, this study aimed to determine the effects of maternal supplementation of copper via intra-ruminal administration of slow-release boluses at the late gestation (8 weeks prepartum) on performance and some blood metabolites of ewes and their lambs until weaning.

    Materials and Methods

    To evaluate the performance and changes in some blood parameters of lambs born from ewes receiving slow-release boluses of copper, 80 Lori-Bakhtiari ewes (The fourth pregnancy with a body condition score 3 to 3.5) were divided into two groups of 40 heads each in a completely randomized design. Treatments were 1) control ewes and 2) ewes received slow-release boluses of copper, 60 days prepartum. After parturition, birth weight, sex, and the birth status of lambs (singlet or twin) were recorded. Lambs were weighed at birth and weaning at age 90 days. On the first day, days 10 and 60 postpartum, blood samples were taken from the ewes, while the blood samples of their lambs were taken at age 10 and 60 days. Serum samples were used to determine copper and ceruloplasmin concentrations in the ewes and their lambs, while iron, zinc, hematocrit, red blood and white cells, and hemoglobin were only determined in the born lambs.

    Results and Discussion

    The serum concentration of copper in the ewes were within the normal physiological range of 0.55 to 0.95 mg/l. Serum copper and ceruloplasmin concentrations of ewes at the first day of experiment were lower compared to days 10 and 60 postpartum (P<0.05), but similar between days 60 and 10 postpartum (P>0.05). Lambs born from ewes receiving slow-release bolus of copper had higher weaning weight, average daily weight gain, copper and ceruloplasmin concentrations, hematocrit percentage, red and white blood cell counts, and hemoglobin concentration compared to those born from control ewes (P<0.05). The serum concentration of ceruloplasmin was higher in lambs born from ewes receiving two boluses than those born from ewes receiving only one bolus (P<0.05). Ceruloplasmin concentration is also a reliable indicator of copper deficiency as it carries between 60-95 percent of serum copper, and changes in serum copper concentration usually parallel the ceruloplasmin concentration in the blood. Lambs born from ewes in the control group had lower serum copper concentrations, and 3 lambs in this group showed the symptoms of paralysis, especially in their hind legs, imbalances, dog sitting, and lost appetite. Adequate maternal intake of Cu is essential for development of the central nervous system (CNS) of the embryonic lamb. Consequences of Cu deficiency during intrauterine life may include gross brain lesions, with affected lambs born dead or dying shortly after birth. 

    Conclusion

    Overall, serum copper concentrations of ewes were in the normal range, but lambs born from ewes received slow-release copper bolus had greater weaning weight, average daily weight gain, serum copper and ceruloplasmin concentrations, hematocrit percentage, hemoglobin concentration, and red blood cell count compared to those born from control ewes. In conclusion, the results of the present study showed that lambs were benefited from copper supplementation of their dams via intra-ruminal administration of slow-release boluse of copper in the late gestation.

    Keywords: Ceruloplasmin, copper, lamb, Sheep, sulfur
  • Ayoub Azizi *, Jahanshir Shakarami, Fahimeh Dehghanikhah, Afrooz Sharifi Pages 207-220
    Introduction

     There is a shortage of animal feed and water resources in many countries around the world. Numerous agricultural by-products are produced annually in all countries, thus their proper use is often a useful means of overcoming this problem. Large proportions of these materials are important feeds for ruminant animals and can be used as a potentially significant source of energy. However, the use of these materials as ruminant feed is limited because of their complex structure, low protein and high lignin content. Different physical and chemical methods have been used to increase the nutritive value of such by-products. Although these methods have advantages, they are costly, relatively ineffective and environmentally unfriendly and require the application of technology. Recently, biological processing of lignocellulosic biomass has been considered as an alternative approach. Three groups of organisms are able to biodegrade lignin namely, white rot fungi, some soil microbes and termites. In recent years, increased attention has been given to the role of bacteria in lignin degradation in agricultural by-products. Insects that utilize wood as a food source are beetles, cockroaches and termites. Termites are especially well known for their ability to break down the lignin barrier and digest carbohydrate polymers. Researcher has isolated 3 bacterial species from the Anacanthotermes vagans termite gut, including Bacillus sp., Enterobacter sp., and Ochrobacterium sp. These bacteria could grow on different media containing lignin and lignocellulosic materials prepared from water extracted wheat straw and sawdust as a sole source of carbon and energy. In another study three bacteria include Bacillus licheniformis, Ochrobactrum intermedium and Microbacterium paludicola were isolated by culturing the gut contents of the termite Microcerotermes diversus on different media containing lignin and lignocellulose as a sole source of carbon and energy. Isolates could partially change the chemical composition of the wheat straw and date leaves, while nutrient digestibility increased. However, Zeuzera pyrina L. is also another insect which degrade lignocellulose. Larval tunnels in the wood and girdling burrows under the bark are visible at the ends of broken stems. Numerous partly broken branches with dead brown foliage hanging in tree crowns are characteristic of heavy infestations. In our knowledge, little work has been done on the isolation of lignin and lignocellulose-degrading bacteria from gut of Zeuzera pyrina. Therefore, the aim of the present study was to isolate and identify symbiotic lignocellulosic degrading bacteria from the Zeuzera pyrina L. gut, and to investigate their effects on the nutritive value of wheat straw and sugarcane tops as ruminant feed.

    Material and Methods

     This experiment was conducted in animal house and laboratories of Lorestan University. Two Lori cows (about five years old) with permanent rumen fistula were used as rumen liquor donor in present study. A two-week diet adaptation period was followed by collection of the rumen contents from each cow before the morning feeding. The aim of the present study was investigate nutritive value of wheat straw (WS) and sugarcane tops (ST) treated with bacteria isolated from gut of Zeuzera pyrina. For this purpose, first, based on 16S rDNA sequence analysis, 3 bacteria including Enterobacter cloacae, Staphylococcus sciuri and Brevibacterium sp., with lignin and lignocellulose-degrading potential were isolated from gut of this insect. Thereafter, each of WS or ST were processed with these isolated individually or with mix of them (totally 4 treatment group for each substrate) in liquid medium. Chemical composition, in vitro gas production (IVGP) and fermentation parameters of these two processed by-product were determined compared to control treatment.

    Results and Discussion

     Results showed that highest amount of dry matter (DM) loss, crude protein, in vitro DM digestibility and metabolizable energy was observed in both substrates (i.e., WS and ST) treated with bacterial mixture of Zeuzera pyrina compared to control. Highest volume of IVGP and potential of GP (b) were observed after processing by bacterial mixture of Zeuzera pyrina compared to control treatment (P>0.05). Highest volatile fatty acid (VFA) concentration, acetate, acetate to propionate ratio and ammonia-N concentration were observed in substrates inoculated with bacterial mixture in comparison with control treatment (P<0.05).

    Conclusion

     In this experiment, we isolated three bacteria including Enterobacter cloacae, Staphylococcus sciuri and Brevibacterium sp., with lignin and lignocellulose-degrading potential from the gut of Zeuzera pyrina. Processing WS and ST with these individual bacteria, especially media containing their mixture improved their nutritive value as ruminant feed via increasing DM digestibility and VFA production.

    Keywords: Gas production, Lignocellulose, Nutritive value, Ruminants, Zeuzera pyrina
  • saeed firouzeh *, AmirHooshang Falla rad, Pezhman Mirshokraei, Abbas Parham, M. Danesh Pages 221-233
    Introduction 

     Reproductive performance of domestic animals has a great impact on the profitability of the farms. It has been shown that several factors such as breed, age, season and nutritional management affect the quality of the produced semen and consequently fertility of rams. Among various nutritional factors influencing semen quality, fat has a great impact on both quantity and quality of produced spermatozoa so that its value is correlated with cell membrane fluidity, potent intracellular signal transduction molecules, and susceptibility to oxidative damage. It has been postulated that by participating in sperm plasma membrane fatty acids (FA), the ingested fat can change the ratio of polyunsaturated to saturated fatty acids (PUFA: SFA) and thereby improve several aspects of sperm quality. Also, lipids comprise a wide-range class of molecules that not only is served as a source of energy but also play a crucial role in the structure and function of spermatozoa. Dietary n‑3 PUFA supplementation has also shown to improve semen quality parameters in rams. Flaxseed oil contains up to 90% PUFAs, of which about 50% is α-linolenic acid. Several studies conducted during past decades indicate that dietary flaxseed supplementation improves sperm parameters of different species such as bovine, goat and rabbit.

    Materials and Methods :

    Fifteen mature 3-5 years old Kurdish ram weighing 65±2.5 kg (mean ±SE) were randomly allocated into three groups during 12 weeks of the experimental period. Animals were individually fed a standard basal diet supplemented with different levels of flaxseed. Treatment included FLS-0 (basal diet; control), FLS-5 (basal diet containing 5% flaxseed) and FLS-10 (basal diet containing 10% flaxseed. Blood and fresh semen samples were collected at weeks 1 and 12 of the experiment. The collected samples were examined for sperm concentrations, sperm motility, viability, acrosome integrity, host test and fatty acids profiles. The testis circumference was measured with flexible cloth tape. The largest circumference of the testes and both scrotum was measured after pushing the testes firmly into the scrotum. To measure plasma concentrations of glutathione peroxidase and testosterone, blood samples were collected from the jugular vein of all the rams at the beginning and after 1 and 12 weeks of feeding experimental diet.

    Results and Discussion:

     Flaxseed supplementation did not affect testicles circumference, however, supplementation of flaxseed increased plasma concentrations of testosterone in (10% flaxseed) FLS-10 group compared to (5% flaxseed) FLS-0 (P<0.05). Treatment, time and their interaction did not affect glutathione peroxidase (GPX) activity. Semen concentration, proportion of live sperm, total motility and plasma membrane functionality was higher in FLS-10 compared to FLS-5 and FLS-0 groups (P<0.05). Flaxseed supplementation tended to increase percentage of sperm with normal acrosome (P<0. 01); however, percentage of abnormal was decreased in FLS-10 compared to the other corresponding groups (P<0.05). Treatment, time and interaction effect of treatment × time did not affect LIN, STR, ALH and VCL (P>0.05). However, BCF and VSL were improved in FLS-10 group as compared to the FLS-5 and FLS-0 group (P<0.05). A significant interactive effect of treatment × time was noted for VAP, where flaxseed supplementation did not affect VAP at first week of the experiment but higher VAP was recorded in FLS-10 compared to FLS-0 and FLS-0 groups after 12 weeks of flaxseed feeding (P<0.05). Flaxseed supplementation did not affect percentage of myristic, palmitic, stearic, oleic, linoleic, EPA and DPA, but the proportion of DHA, and the ratio of n-3:n-6 PUFA and SFA:PUFA was affected by the treatments (P<0.05). Dietary inclusion of flaxseed increased proportion of DHA and n-3: n-6 PUFA ratio and decreased SFA: PUFA ratio in FLS-10 compared to FLS-5 and FLS-0 (P<0.05). The interactive effect of treatment × time on DHA, n-3: n-6 and SFA: PUFA ratio revealed that there was no significant effect between treatment after first week of the experiment; however, proportion of DHA and n-3: n-6 PUFA ratio was higher and SFA: PUFA ratio was lower in FLS-10 compared to FLS-5 and FLS-0 (P<0.05). the significant correlations between addition of 10% flaxseed and most of the evaluated semen characteristics including live sperm, total motility, plasma membrane functionality, and acrosome status following 12 weeks of treatment feeding was in agreement with previous findings in male goat and rabbit. Other fatty acids concentrations, such as, linoleic acid, and docosahexaenoic acid (DHA) was improved by dietary flaxseed supplementation.

    Conclusion:

     It can be concluded that adding 10% flaxseed to the Kurdish ram diet out of the breeding season can improve sperm quality. Sperm fatty acid composition can also be affected by dietary fat. But more research is needed to look at the effects of other flaxseed products, such as oil and powder. It is recommended that similar studies be conducted during the breeding season and with other amounts of flaxseed.

    Keywords: Fatty acid, Flaxseed, Omega-3, Kurdish Ram, Sperm
  • heshmat sepehri*, zeynab noori, amir azarli, alireza hesabi nameghi Pages 235-248

    Introduction:

     Emerging low cost animal feed stock, originating from bioprocessing and food production is increasing on a global scale. In particular, dried distillers’ grains soluble (DDGS) is a by-product of the ethanol industry created in the fermentation process of cereal grains starch in dry mill ethanol plants. DDGS is defined as the product obtained after removal of ethyl alcohol by distillation from the yeast fermentation of a grain or a grain mixture by condensing and drying at least 75% of the resultant whole stillage by methods employed in the grain distilling industry. DDGS present a high concentration of energy, protein. Especially with respect to the original grains. DDGS are mainly obtained from corn, wheat, barley, sorghum and rice, as well as from grain blends. DDGS could be considered a poultry feed stuff as an alternative source of protein in poultry ration with other protein source or after dietary supplementation with lysine. The aim of this study is to investigate the effect of different levels of DDDS on performance and histology of jejunum in broiler chicken in starter, grower and finisher and analyzed DDGS.

     Materials and Methods :

    This experiment was done in 2 periods (first experiment was 1-21 days and second was 22-42 days). In first experiment 450 multiple Ross 308 broiler chicks were divided randomly into 5 experimental treatments and 6 replicates and second experiment had 5 treatment and 6 replicates and each replicate was assigned to a pen with 15 birds. Birds had given ad-libitum access to water drinking and diet. The experimental treatments received a basal diet that was supplemented as follows: control (without DDGS), 3%, 6%, 9% and 12% DDGS at first experiment and control (without DDGS), 5%, 10%, 15% and 20% DDGS at the second experiment. Prior to formulating the experimental diets, it was analyzed for dry matter, protein, amino acids, fat, crude fiber, ash. The amount of feed intake and body weight gain were measured weekly. At 21 and 45 days, 2 birds of each replicate were killed and intestinal segments removed. Samples (approximately 4 cm) were taken from the midpoint between the point of entry of the bile duct and Meckel's diverticulum (jejunum) for histology characteristics. Data were analyzed using GLM procedures of SAS software (SAS, 2006) in a completely randomized design. Differences between means were tested using Duncan’s test (1995). Differences were considered significant at P<0.05

    Results and Discussion:

     The chemical composition of the DDGS samples was determined at the beginning period. Crude protein, crude fat crude fiber, lysine and methionine were 30.5, 2.5, 3, 0.31 and 0.15% respectively. The differences between DDGS in this experiment with the others are depended upon plant species, genotype, climate, and stage of growth, the kind of soil and storage conditions. The results of the first experiment have shown that body weight gain increased in broiler fed 3% DDGS and control (847.31, 846.74). Results showed that 3% levels of DDGS fed to broilers increased body weight gain significantly from 11-21 d (P<0.05). The least body weight gain and feed intake was belonged to 12% DDGS vs. broilers fed 0, 3 and 6% DDGS from 1-21d. The feed intake decreased in broilers fed to 12% of DDGS in comparison to control groups and the other treatments. Feed conversion ratio was not significantly affected by treatments from 1-21 d. There was not any significant difference between feed conversion ratios in 1-21 day between treatments. There was significant difference (P<0.05) between body weight gain in 30-37 days old. The lowest and highest body weight gain observed in birds fed 20% and 5% DDGS, respectively. There was not any significant difference between feed intake and feed conversion in 22-45 days. Villus height decreased to 881.01 μm in 12% containing diets in comparison to the other treatments. Crypt depth was lowest in control (156.79 μm). Effect of DDGS on the histology of jejunum broiler chickens in 21 and 42 days was not significant. There was a tendency for an increased in crypt depth and decreased in villi height as dietary DDGS increased from 0 to 20%, however it was not significant.‌

    Conclusion:

     It can be concluded from this study, in first experiment (1-21 d) the dietary treatments containing 3% DDGS shows better performance in comparison to the other treatment. In second experiment (22-45%), 20% of DDGS was the best treatments for performance.

    Keywords: Broiler Chickens, DDGS, histology, Performance
  • Nazar Akbari zadeh, Ali Khatibjoo *, Sefali Varmaghani, Hoshang Jaefari, Alinaghi Shokri Pages 249-262
    Introduction

     During decades, growth rate of broiler chickens was increased more than 4 times whereas growth rate of cardiovascular and respiratory tracts did not increase as muscle growth rate. Imbalance between oxygen consuming orangs and oxygen supplying organs led to increase metabolic disorders like ascites in broiler chickens. Low oxygen supplementation is the important factor in ascites syndrome by reducing arterial oxygen pressure and increasing pulmonary artery pressure. Increased pulmonary artery pressure led to hypertrophy of cardiac right ventricle and finally ascites incidence in broiler chickens during cold environment condition.Antibiotics as growth promoters in poultry feed are posing serious health risks to human health, because of their residual effects in poultry meat and eggs, as well as result pathogens develop resistance to antibiotics. Currently, poultry scientists are challenged to find out alternatives to antibiotic growth promoters with no side effects for poultry that could be more or as effective against harmful microorganisms in the gastrointestinal tract and to stimulate the growth by increasing the efficiency of feed utilization and to enhance the immunity. Regarding to this subject, supplementing the dietary herbs or plant extracts would stimulate the productive performance of poultry. One of the most frequently consumed herbal remedies available today is the hyssop preparations prepared from Hyssopus officinalis (L) which is gaining increased importance as a minty flavor, condiment and spices in food industries as well. The GC and GC-MS analysis of the essential oil led to the identification of 21 compounds representing 95.6% of the oil, comprising seven monoterpene hydrocarbons (32.3%), five oxygenated monoterpenes (60.5%), one phenol (0.2%) and six sesquiterpene hydrocarbons (0.35%). The major constituents of the camphorous predominant monoterpenes of the oil were pinocamphone (49.1%) >β-pinene (18.4%). According to the results of the studies, hyssop extract showed much weaker antioxidant activity as compared to the rosemary, sage, and thyme extracts in different methods of antioxidant evaluations. The aim of this study was comparing the effects of Hyssopus Officinalis powder, Virginiamycin antibiotic and Aspirin on performance, blood metabolites, carcass parameters and ileum microbial population of broiler chickens which subjected to cold stress were studied.

    Materials and Methods :

    In a completely randomized design, a total of 500 male Ross-308 broiler chickens were allocated to 5 treatments with 5 replicates and 20 birds in each. Dietary treatment consisted of: 1) control, 2 and 3) basal diet plus 300 g/ton Virginiamycin or Aspirin respectively and 4 and 5) basal diet containing 0.5 or one percent Hyssopus, respectively. The diets were formulated to meet the requirements of broilers as established by the Ross 308 broilers feeding guide in starter (1-11 d), grower (12-25 d) and finisher (26-42 d). The birds were kept under conventional conditions for vaccination, temperature, ventilation, and lighting based on Ross catalogue recommendations. Standard management practices of commercial broiler production were applied. The broiler diets were formulated based on standardized ileal digestible amino acids and other requirements were obtained from Ross catalogue recommendations. Broiler chicken performance (feed intake, body weight gain, feed conversion efficiency, total and ascytic mortality and European production efficiency factor), erythrocyte osmotic fragility (EOF), blood cell count and blood metabolites including triglyceride, total cholesterol, HDL and LDL Cholesterol were measured at the 21 and 42 d of age. Carcass and abdominal fat percentage were calculated. Finally population of Lactobacillus and Escherichia coli of ileum were detected.

    Results and Discussion :

    As compared to control, inclusion of 1 percent Hyssopus increased feed intake (P < 0.05). Addition of Hyssopus and antibiotic increased weight gain, EPEF and decreased FCR compared to control and aspirin groups. Addition of one percent Hyssopus decreased red blood cell count, erythrocyte osmotic fragility (EOF) and heterophil percentage at 21 and 42 d of age as compared to control (P < 0.05). Escherichia coli population was reduced by antibiotic and one percent Hyssopus inclusion into broiler’ diet. Dietary treatments had no effect on WBC count, lymphocyte percentage, heterophil to lymphocyte ratio, serum total cholesterol, HDL- and LDL-cholesterol and urea concentration of broiler chickens at 21 and 42 d of age, carcass, and thigh meat and abdominal fat percentages at 42 d of age (P > 0.05) whereas broiler chickens fed diet containing 0.5 and 1 % hyssopus powder had higher breast meat percentage.

    Conclusion :

    In conclusion addition of aspirin or Hyssopus powder improved broiler chicken’s performance and decreased mortality due to ascites and heterophile to lymphocyte ratio in cold condition. Virginiamycin improved broiler chickens body weight gain in cold condition but due to probable drug resistance, it may suggest that Hyssopus supplementation in broiler diet as a good replacement for antibiotic in cold stress.

    Keywords: Ascites, Blood metabolites, Broiler chicken, Carcass parameters, Cold stress
  • MohammadReza Ghorbani *, ahmad tatar, somaye salari, M.hadi soleymani, Solmaz Khalili Samani Pages 263-273
    Introduction

     It has been estimated that feed is the major cost associated with commercial poultry production. Conventional plant proteins, such as soybean meal tend to increase the poultry production costs due to limitation in cultivation in some region and therefore, their being transported from other countries. Hence, inclusion of non-conventional feed resource becomes of primary importance in poultry production to maintain the productivity at a lower cost. Black seed (Nigella sativa) referred to an important medical crop in many countries and is primarily consumed as medical oil. Black seed meal (BSM) is by-product after oil removal and can be used as a protein-rich meal (21). Black seed meal contains about 31.75 % crude protein and 19.37 % ether extract and it can be used as good sources of protein and energy (21) and substitution of soybean meal in laying hens practical diets. However, reports on the use of BSM in laying hens diets in second cycle of production are not enough, therefore, in this study, we considered the effect of different levels of black seed meal on laying hens performance in second production cycle.

    Materials and Methods :

    This experiment was conducted to determine the fatty acids composition of black seed meal and its effects on performance and egg qualitative traits of laying hens in second production cycle. In the first step, Gas-chromatography was used for determination the fatty acids composition of BSM. In the second step, a total of One hundred and twenty Hy-Line W-36 leghorn hens were housed in cages and randomly allocated to 5 treatment groups for 8 weeks. Each group was divided in to 4 replicates. Feed and water were provided ad libitum. The hens received basal diet (corn and soybean meal based diet with 14.80 % crude protein and 2813 kcal/ kg metabolizable energy) that was formulated to meet the Hy-line W-36 requirements recommended for nutrients. The diet did not have any antibiotics and coccidiostats. Dietary treatments were included 0, 5, 10, 15, and 20 percentage of BSM by expense of Soybean meal in basal diet and clarified as BSM0 (control), BSM5, BSM10, BSM15 and BSM20 respectively. Experiment was designed in a completely randomized design. Egg weight (gr), egg production (%) and egg mass (gr/hen/day) were recorded daily. Feed consumption was measured weekly and feed conversion ratio (FCR) (grams of feed: grams of egg mass) was calculated weekly too. At the end of 2, 4, 6 and 8 weeks of the experiment, two eggs from each replicate were randomly selected for measurement the egg qualitative traits. In this paper laying hens performance factors and egg quality parameters were calculated in three phase, the first 4 weeks, second 4 weeks and total period. Blood serum characteristics were evaluated in the end of experiment by bleeding from laying hens wings.

    Results and Discussion:

     The results of this experiment showed that linoleic acid (41.51), oleic acid (34.67 %), palmetic acid (16.12 %), stearic acid (5.59), and linolenic acid (1.97) were the major BSM fatty acids. As it clear, the linoleic acid and oleic acid are most abundant fatty acid (unsaturated) in BSM. Feed intake was decreased by inclusion of BSM in laying hens diet and minimum feed intake was observed in BSM20. It seems to be the bitter taste of black seed meal is responsible for the decline of feed intake. It was reported that BSM has anti-nutritional substance and alkaloids (saponins), that these factors can reduce feed intake when used in high amount in poultry diets (21 and El-Dakhakhny, 1996). Laying hens egg mass was decreased in BSM10, BSM15 and BSM20 groups when compared with control group. Egg mass was calculated by multiplying egg weight in egg production. Reduced of feed intake can affect availability of nutrient for egg production and egg weight, and, therefore, egg mass will be decrease. Scientists reported that BSM can increase laying hens’ body weight and increasing body weight can decrease egg production. Laying hens’ serum cholesterol and triglyceride content were decreased significantly in BSM5 when compared with other groups. It was reported that essential oils in BSM can reduce activity of HMG-CoA (3-hydroxy-3-methylglutaryl coenzyme A) reductase that has vital role in cholesterol synthesis (Crowell, 1999).

    Conclusion :

    According to the results of this experiment, using BSM in 5 percent can reduce blood cholesterol and triglyceride without adverse effect on performance parameters.

    Keywords: Black seed meal, Egg quality, Laying hen, Performance
  • Seyyed MohamadReza Salavati, Abolghasem Golian *, Ahmad Hasanabadi Pages 275-290
    Introduction

     Wheat is an important cereal due to high starch, available energy and protein contents and is used in poultry diets. Thermal processing is one of the common ways to increase the digestibility of feed, nutritional value of protein through denaturing the anti-nutritional compounds.

     Materials and Methods:

     This project was conducted in two experiments at the Poultry Research Center of Ferdowsi University of Mashhad.

    First experiment: 

    This trial was designed to determine the apparent metabolizable energy and the digestibility of crude protein and dry matter in four heat treated wheat with and without enzyme supplementation. One hundred twenty mixed sex day-old broiler chicks were fed standard starter (0-10d) and grower (11-15d) diets, 96 of them were divided into 48 groups of two each and randomly assigned to 48 metabolic cages on day 15. Eight diets in which the sole source of energy and protein was wheat, were prepared and each was randomly fed to six replicates of two chicks each from 15-21d. At 18th day of age, 12 hours of starvation were imposed on all chicks; then trays were placed under each cage and feeds were supplied to all cages for 72 hours when the 2nd 12 hours of starvation was imposed and the collection of excreta continued until the end of the second starvation period. The amount of feed consumed by chicks in each cage in three days was determined by the differences of feed supplied and remained. Excreta collected from each cage was placed in a room air flow for 48 hours and then placed in an oven at 60°C for 72 hours to dry completely.Second experiment: in this trial, 576 birds (11d) were divided into two groups, (male and female) from which six males and six females were randomly assigned to one of the 48 pens. To prepare 8 experimental diets, only one grower diet (11-24days) containing 70.11% wheat was formulated based on Ross 308 nutrients recommendation and an untreated and three heat treated wheat with and without enzyme supplementation (Rovabio) were replaced to prepare the 8 diets. The experiment was conducted in a completely randomized design with factorial (2×4) arrangement with 6 replicates of 12 birds each. Diets were randomly assigned to 48 pens in a way that each diet fed 6 replicate birds. On the final day of the trial (24d), one male bird from each replicate group was weighed and slaughtered. The carcass, breast, thighs, back, wings and neck, as well as the weight of internal organs including the heart, spleen, proventriculus, gizzard, liver, pancreas, bursa fabrisius, abdominal fat, duodenum, jejunum and ileum were measured. Duodenum, jejunum and ileum length were also measured. To evaluate the effect of different untreated and heat treated wheat at different temperatures with and without enzyme supplementation on the microbial condition of the digestive contents of the ileum digesta on 24d, about 3 grams of the contents of the ileum region from each slaughtered chicken transferred to the sterile tube containing 9 ml of buffer phosphate and placed in an ice flask and transferred to laboratory.

    Results and Discussion:

     Thermal treatment significantly improved the apparent metabolizable energy, digestibility of crude protein and dry matter of wheat, so that the highest apparent metabolizable energy and dry matter of wheat was obtained when wheat was processed at 85°C. Whereas the highest digestibility of crude protein in wheat was obtained at 70°C thermal processing. The effect of enzyme on apparent metabolizable energy, apparent digestibility of crude protein and dry matter of wheat was not significant. The results of this study showed that thermal processing of wheat has a significant effect on feed consumption, daily gain, body weight gain and feed conversion ratio. Whereas the feed conversion ratio in chicks fed with diet containing wheat processed at 70°C was similar to those fed other diets contained heat treated wheat and was significantly better than those fed control diet. Dietary enzyme supplementation had a significant effect on body weight, daily gain and conversion coefficient, so that the daily gain of chicks fed diet containing enzyme was increased by 4.5% and the conversion factor was improved by 4.2% compared to those fednon-enzyme diet. Thermal treatment of wheat significantly affect relative percentage of thigh weight and relative weight of broiler chickens at 24 day age, so that the highest relative percentage weight of thigh and breast was in chicks fed diet contained wheat processed at a temperature of 70°C. On the other hand, thermal treatment of wheat significantly affect the relative percentage of abdominal fat, which increased compared to untreated wheat. Also, the present study showed that processed wheat did not have a significant effect on the percentage of carcass weight, back, wings and neck, liver, pancreas, heart, spleen and bursa. Also, the interaction effect of thermal processing of wheat and enzyme supplementation on the relative weight of carcass, its parts and internal organs was not significant. The supplementation of enzyme had only a significant effect on ileum weight. Thermal processing of wheat at different temperatures had a significant effect on the height and width of villi in jejunum, but did not have a significant effect on the depth of the crypt and villi height to crypt depth. The lactobacillus population in the ileum region has not been affected by the heat treatment of wheat and a negative response to Salmonella infection was observed in all chickens. On the other hand, the use of enzyme supplementation did not have a significant effect on villi height and depth of crypt and villi height to crypt depth. The interaction effect of heat treated wheat and enzyme supplementation was not significant for neither of the measurements.

    Conclusion:

     The results of this experiment showed that although thermal processing of wheat at 85°C increased the apparent metabolizable energy by 5.32% and dry matter digestibility by 5.61%. In addition, the inclusion of heat treated wheat in diet led to an increase in height and width of jejunal villi and improvement of feed intake weight gain and feed conversation ratio in broiler chickens.

    Keywords: Broiler chicken, Enzyme, heat processin, Performance
  • Reza Vakili *, Qasem Ramezani Pages 291-302
    Introduction

     Prebiotics are non-digestible additives that stimulate the growth or activity of one or more bacteria in the gut, which can have a beneficial effect on the host and thus improve the health of the host animal. Prebiotics increase feed intake, final weight and improve feed conversion when fed to broilers. Prebiotics cause changes in the blood parameters and immune response in broilers. Numerous studies have shown the antibacterial properties of silver nano-particles and their useful applications in the poultry industry. These include increasing feed intake and decreasing the number of pathogen microbes in the gastrointestinal tract that cause bacterial cell death by binding nano-silver to the surface of gram-negative bacterial membranes through sulfur-containing proteins and by altering the membrane permeability and respiratory chain. Inflammation is the result of induction of oxygen-free radicals by silver nanoparticles, which leads to impaired digestion and absorption of nutrients in the bird's gastrointestinal tract. Many studies have shown the importance of natural flora in maintaining bird health and found that the flora in these sites had a profound effect on the process of making prebiotic consumables in poultry. Adding prebiotic compounds, especially fructans to broilers, improves weight gain and feed conversion ratio and carcass weight due to increased length and density villi distribution. The aim of this experiment was to investigate the effect of combined prebiotics and nano-silver on growth performance, blood indices, immune response and microbial population of ceca in broiler.

    Materials and Methods

     In this experiment, 432 one-day-old male Ross 308 broiler chicks were used in a 3 × 3 factorial arrangement with completely randomized design with 9 treatments, 4 replications and 12 observations per replicate. The composition of the experimental diets was determined using the Ross 308 strain rearing guide. The basal diets were identical in energy and other nutrients. In this experiment silver nanoparticles were added 0, 400, 800 ml in drinking water and prebiotic added 0.025 and 0.5 % to the basal diets. The mean body weight gain, feed intake, feed conversion ratio were determined at the 1 to 42 days. Blood samples were taken from all experimental units for 10, 24 and 42 days to measure the titers of Newcastle, Infectious Bursal, and influenza antibodies. The blood sample was slowly poured into sterile lid tubes and transferred to the laboratory in an ice tank. In the laboratory, blood samples were centrifuged at 10,000 RPM for 10 minutes, followed by Newcastle antibody titers (Hemagglutination inhibition) and Infectious Bursal antibody titers by ELISA (Enzyme-Linked Immunosorbent Assay). The infectious influenza antibody titers were determined by ELISA .At the end of the experiment, after slaughter and carcass analysis, Cecal contents were extracted with a syringe (3 ml). And they were transferred to the lab to count the number of bacteria. Mac County medium was used for counting Coli bacillus, MRS agar for lactobacillus count. Salmonella was cultured on BGA (Brilliant Green Agar) specified media (Merck, Germany) at 37°C for 24 hrs. Data analysis was performed using SAS software and mean comparison with Duncan test at 5% level.

    Results and Discussion 

    There was a statistically significant difference in feed intake, weight gain and feed conversion ratio using silver nano-particles  and prebiotics different levels between in total period of experiment (P<0.05). There was a statistically significant difference in the level of serum HDL, LDL, and TP in different levels of prebiotic (P<0.05). The lowest total number of bacilli and Salmonella was observed in 0.5% prebiotic treatment. The highest number of lactobacilli was observed in the treatments containing 0.25% and 0.5% prebiotics. The highest number of Coli bacilli and Salmonella was observed in the treatment without silver nanoparticles and the lowest in the treatment containing 800 ml. Also, the highest number of lactobacilli in treatment was 800 ml (P<0.05).The results of this study showed that using 0.5% prebiotic level in the diet of broiler chickens improved the growth performance and immune system. Also, the use of 800 ml levels reduced the number of harmful bacteria in the ceca of broiler chickens

    Conclusion

     According to the results of this experiment, the use of prebiotics and silver nano-particles in the diet and water can improve the performance of the chicks during rearing period. 0.5% of prebiotics in broiler diets and 800 ml of silver nanoparticles decreased the number of harmful bacteria and increased the beneficial bacteria in broiler ceca.

    Keywords: Biochemical Parameters of Blood, Broilers, Cecum Bacteria, Prebiotics, Nano-silver
  • Nasir Karimi, MohammadTaghi Beigi Nassiri *, Arsalan Barazande Pages 303-312
    Introduction

     Arabi sheep population includes almost 55% of the local sheep population in Khuzestan province. Lamb mortality is a universal problem in sheep breeding that may be reached to 20-40% of total lambs born and could impact the genetic improvement, animal welfare and economic viability of sheep breeding, adversely. Research on improving survival of lambs is likely to have a higher pay-off than research on improving the number of lambs conceived. Lamb survival is a compound trait affected by many various factors related to climate, management, lamb and ewe behavior and genetic effects. Lamb survivability is controlled by genetics of the animal, contributed by direct genetic and maternal effects and also by environmental effects. There are disagreements among researchers about using a suitable model to analyze the survival traits, and each researcher has suggested the use of specific models. In general, the use of linear and threshold models has been suggested for survival trait analysis. Although survival has great economic importance, in the studies conducted on Iranian livestock, less attention has been paid to it. The aim of this study was to analyze the genetic parameters for the survival of Arabi lambs from birth to one year of age using linear and Weibull models.

    Materials and Methods

     in this study, 5452 lamb survival records collected by the Jahad Agricultural Organization of Ahvaz from 1993 to 2005 were used. Traits included were cumulative survival from birth to the end of one year and on a monthly basis. In order to estimate genetic parameters using linear models, the Restricted Maximum Likelihood (REML) method was used in Wombat software based on a univariate analysis. The Weibull model and Matvec software were also used for estimating variance component and genetic parameters of Survival rate.

    Results and Discussion

     Different models compared using the likelihood ratio test. For survival traits until 1, 4, 5, and 10 months, the model 4 was suitable, which include the direct additive genetic effect, maternal additive genetic effect and their covariance. In the case of until 2 months, the best model was the model 3, which include the direct and maternal additive genetic effects. For until 3, 8, 9, and 12 months, model 1 including direct additive genetic effect was selected. And for other traits Model 5 (direct additive genetic, maternal additive genetic, and maternal permanent environmental effects) was chosen as the best model. The direct heritability of survival rate estimated from different linear models was in the range of 0.025 to 0.061. In general, despite the high economic importance of survival in the breeds until one year of age, due to low estimates of the inheritance of these traits using linear models, it cannot be expected that genetic selection alone can make significant genetic progress. The genetic variance component among sires, heritability on the logarithmic scale, heritability on the original scale, and effective heritability obtained from Weibull sire model were increased to a peak point at 4 months. After that, a decline occurred until 5 months, and then a fluctuation was observed until 9 months. A limited increase was found in the 11 and 12 months. The heritability of sire model, in the logarithmic scale, had a low to medium range (0.13-0.25), and in the original scale had a medium to high range (0.39-0.75). The effective heritability was estimated in the medium range. Estimated values of the survival heritability using the Weibull model was greater than the value obtained from the linear animal model. Although heritability estimations for survival and mortality is low, it is possible that genetic progress may be enhanced by selecting lambs with higher breeding value for survival.

    Conclusion

     Estimation of the genetic parameters for survival lambs from birth to one year of age using linear and Weibull models were low vs medium to high, respectively. Therefore, based on the results of linear models, response to  direct selection to improve the survival of lambs in this breed will be very slow, and more attention should be paid to improving non-genetic factors and indirect selection and outbreeding, but based on The results of Weibull models, it seems that the rate of response to genetic selection to improve survival trait is faster using these models compared to the linear models, suggest that lamb survival could be improved  through direct selection and could be included in the Arabi sheep selection  index.

    Keywords: Arabi sheep, Heritability, Survival
  • Mojgan Ghasmi siab, Sheida Varkoohi*, MohammadHossein Banabazi Pages 313-319
    Introduction

     (SNPs) are single nucleotide base variations, caused by transitions (C/T or G/A) or transversions (C/G, C/A, or T/A, T/G), in the same position between individual genomic DNA sequences. Single nucleotide polymorphisms have been applied as important molecular markers in genetics and breeding studies. About 40% of the Single nucleotide polymorphisms in the genes cause a change in an amino acid. The rapid advance of next generation sequencing provides a high-throughput means of SNP discovery. Transcriptome study can fill the gap between genotype and phenotype and help understanding the mechanisms from sequence to function. RNA sequencing (RNA-Seq) is a next generating sequencing based technology for studying of whole transcriptome and gene expression. It simultaneously enables study of transcriptomics sequences and very accurate quantitative gene expression (digital expression). Hence, these data are very suitable for high-throughput study of expression level of all transcribed genes and their SNPs (Single Nucleotide Polymorphism. Recently, RNA-Seq has also been used as an efficient and cost-effective method to systematically identify SNPs in transcribed regions in different species. A transcriptomics-based sequencing approach offers a cheaper alternative to identify a large number of polymorphisms and possibly to discover causative variants.

    Materials and Methods:

     In this study, RNA-Seq data were used to SNP discovery in American Holstein (Bos taurus) and Pakistanian Cholistani (Bos indicus) cows. RNA-Seq data of 21,078,477 and 20940063 paired end reads with 75 bp length resulted from pooling of whole blood samples of 40 Holstein cows at the University of Wisconsin, Dairy Cattle Center, USA, and 45 Cholistani cows at Gujait Peer Farm, Bahawalpur, Punjab, Pakistan, respectively, obtained from SRA database in NCBI for Holstein cows (http://www.ncbi.nlm.nih.gov/sra/SRX317197) and Cholistani cows http://www.ncbi.nlm.nih.gov/sra/SRS454433). MRNA sequencing was run on Illumina Genome Analyzer IIx (Illumina Inc., San Diego, CA). Data were converted from Sra format to Fastq format by fastq-dump command from Ubuntu linux version of Sratoolkit 2.5.4-1. Data quality control was checked by FastQC (v0.11.3) likewise trimmed for linked adaptors and bad quality reads by Trimmomatic 0.33 Adaptors were considered according to sequencing instrument as default (TruSeq2-PE.fa) and the minimum read length was set at 50 bp. Trimmed reads were aligned on UMD3.1 reference genome (release 81) based on annotation data by Tophat2, which applies Bowtie2 as the aligner. The transcriptome was assembled by TopHat2 software in two cow’s population by aligning and mapping the RNA-Seq reads on bovine reference genome. The SNPs were discovered by Samtools software.

    Results and Discussion

    After data editing, the removed and low quality reads in both breeds were almost equal and relatively low. The length of whole transcriptome assembled, for example 52798651 bases in Holstein, indicates around 2% of the whole genome (around 2.6 Mbp) expressed as mRNA. In Cholistani cows, read mapping rate for forward and reverse reads were 81.3 and 79.9%, respectively, and multiple alignments rate was about 9.4%. Overall read mapping was 80.6% and concordant pair alignment was 70.1%. In Holstein cows, read mapping rate for forward and reverse reads were 66.3 and 55.4%, respectively, and multiple alignments rate was about 7.2%,. Overall read mapping was 60.8% and concordant pair alignment was 51.3%. Results show that 50183 and 137954 SNPs were discovered on the assembled transcriptome of Holstein and Cholistani cow’s samples, respectively, and 15308 SNPs were common in both breeds. No direct relation was found between the number of discovered SNPs and the chromosome length. Also 12 SNP types were identified including 4 transition and 8 transversion. The most commonly discovered SNP were transition, which were 70.6% in Cholistani and 69.6% in Holstein cows. The ratio of transition to transversion SNP (Ts / Tv) was 2.4 and 2.3 in Cholistani and Holstein cows, respectively. The number of discovered SNPs in Cholistani cows were approximately three times higher than Holstein cows. Because, for the alignment of both species used a same reference genome with Herford origin.

      Conclusion:

     the expression difference between two alleles in a single-nucleotide position causes phenotype diversity and probably explains the large part of variances between these two bovine subspecies, especially in diversity, susceptibility to disease and parasites, tolerating environmental stress such as biological and non-biological stresses in different environmental conditions. While, differential gene expression analysis or even allelic specific expression in gene level may not be able to explain phenotype diversity.

    Keywords: Chromosome length, Nucleotide replacement, RNA-Seq data