فهرست مطالب

پژوهش های علوم دامی - سال سی و یکم شماره 3 (پاییز 1400)

نشریه پژوهش های علوم دامی
سال سی و یکم شماره 3 (پاییز 1400)

  • تاریخ انتشار: 1400/10/15
  • تعداد عناوین: 10
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  • فاطمه برومند، سید مهدی قریشی*، سعید حسین زاده، شهریار کارگر صفحات 1-9
    زمینه مطالعاتی

    انار به‏دلیل ترکیبات فنولی (فلاونوییدها و تانن‏ها) که بیش‏تر در پوست و آب انار گردآمده‏اند دارای ویژگی‏های ضدباکتریایی و ضدقارچی است که این ویژگی‏ها در گونه‎ های مختلف انار از لحاظ قدرت و طیف یکسان نیستند.

    هدف

    هدف از این آزمایش بررسی اثرات سیلاژ تفاله (مخلوط دانه و پوسته) و تفاله خشک دانه انار بر دو باکتری مفید (لاکتوباسیلوس) و مضر (اشریشیا کلی) دستگاه گوارش بره‏های پرواری بود.

    روش کار

    شمار 9 راس بره‏ی نر نژاد مهربان (با میانگین وزنی 5/3 ± 03/27 کیلوگرم، و میانگین سنی 4/1 ± 8/ 187 روز)، با سه جیره آزمایشی هم‏ انرژی و هم‏پروتئین (جیره شاهد، جیره دارای 20/27 درصد سیلاژ تفاله انار و جیره دارای 40/31 درصد تفاله خشک دانه ‏انار) به‏ مدت 60 روز در جایگاه انفرادی خوراک‏دهی شدند. برای شمارش فلورمیکروبی روده، پس از کشتار، یک گرم نمونه تازه گوارشی از ایلیوم و سکوم جمع‏ آوری شد. نمونه‏ ها روی سطح محیط کشت آگار گسترش یافت. کلنی‏ها به روش چشمی شمارش و تعداد باکتری‏ها به‏ صورت واحدCFU (تعداد کلنی در هر گرم) محاسبه شد. برای کشت میکروب‏های لاکتوباسیلوس، محیط کشت MRS آگار و برای باکتری اشریشیاکلای (Escherichia. coli) محیط کشت MC (مکانکی) آگار استفاده شد. برای تایید نهایی باکتری‏های جدا شده روی آگار مکانکی از آزمونPCR استفاده شد.

    نتایج

    یافته‏های این پژوهش نشان داد که شمار باکتری‏های لاکتوباسیلوس در ایلیوم و سکوم تحت تاثیر خوراک‏دهی پسماند انار قرار نگرفت (‍P>0.05). میانگین شمار اشریشیاکلای در بره‏ه ایی که پسماند انار دریافت کرده بودند در ایلیوم و سکوم از گروه شاهد کم‏تر بود (‍P<0.05) ولی اختلاف معنی‏داری میان دو گروه تغذیه شده با پسماند انار دیده نشد.

    نتیجه ‏گیری نهایی

    به نظر می‏رسد به‏ کارگیری تفاله انار می‏تواند موجب کاهش جمعیت باکتری‏های اشریشیا کلی در ایلیوم و سکوم بره‏ه ای نژاد مهربان شود.

    کلیدواژگان: اشریشیاکلای، ایلیوم، بره نژاد ‏مهربان، تفاله انار، سکوم، لاکتوباسیلوس
  • موسی زرین*، میثم سنگین آبادی، ماهرخ نوری، امیر احمدپور صفحات 11-26
    زمینه مطالعاتی

    وجود دنبه در گوسفندان این امکان را به آن ها می دهد که در زمان فراوانی علوفه، انرژی مازاد را به صورت چربی در دنبه ذخیره نمایند و هنگام کاهش دسترسی به خوراک با فراخوانی آن، نیازهای متابولیکی را تامین نمایند.

    هدف

    این مطالعه به‎منظور تعیین نقش فیزیولوژیک ذخایر چربی در مواجهه با محدودیت خوراکی از طریق بررسی تغییرات فراسنجه های خونی در میش های غیرآبستن دنبه دار انجام شد.

    روش کار

    تعداد 10 راس میش غیرآبستن با میانگین سن سه تا چهار سال و وزن 60/3±2/49 کیلوگرم انتخاب و به دو گروه شاهد و محدودیت خوراکی اختصاص یافتند. میش ها در جایگاه های انفرادی نگهداری و با جیره های ترازیده تغذیه شدند. میش های گروه محدودیت در هفته اول آزمایش دسترسی آزاد به خوراک داشتند، سپس سه هفته محدودیت 50، 65 و 80 درصد جیره گروه شاهد را تجربه نمودند و هفته آخر دسترسی آزاد به خوراک داشتند. خون گیری و وزن کشی در انتهای هر هفته انجام گرفت. مقادیر فراسنجه‎های خونی، با استفاده از کیت‎های تجاری سنجیده شد. ارزیابی آماری با استفاده از رویه Mixed نرم افزار SAS انجام شد.

    نتایج

    نتایج نشان دادند که هفته های محدودیت خوراکی بر میانگین وزن زنده دام ها تاثیر معنی دار داشتند (01/0P<). گلوکز، NEFAو BHBA در گروه محدودیت نسبت به گروه شاهد تمایل به افزایش نشان دادند (07/0=P و05/0=P). مقدار کراتینین تحت تاثیر محدودیت قرار نگرفت ولی در هفته دوم آزمایش در گروه محدودیت تغییراتی داشت (01/0<P). تاثیر محدودیت خوراکی بر محتوای پلاسمایی اوره، تری گلیسرید، کلسترول HDL، VLDL و آنزیم های LDH، GOT و GPT معنی دار نبود. اعمال محدودیت 80 درصدی سبب کاهش معنی دار LDL در گروه محدودیت شد (05/0<P).

    نتیجه گیری نهایی

    با توجه به عدم تاثیرپذیری بسیاری از فراسنجه‎های خونی چنین استنباط می‎شود که وجود دنبه در نژادهای بومی، خصوصا در شرایط عشایری که دام‎ها معمولا با محدودیت دسترسی به خوراک مواجه هستند، می تواند منبعی جهت تامین نیازهای متابولیکی و تولید شیر باشد.

    کلیدواژگان: انرژی، گلوکز، محدودیت خوراکی، فراسنجه های خونی، گوسفند
  • رضا سیدشریفی*، سونا امیری، نعمت هدایت ایوریق، جمال سیف دواتی، طاهر یلچی صفحات 27-39
    زمینه مطالعاتی

    هدف اصلی یک مزرعه شیری حداکثر سازی سود کل گله است، یکی از مهم ترین مسایلی که روی این سود تاثیر دارد معیارها و میزان حذف است. گاوها به دلایل مختلف حذف می شوند که شایع ترین آنها تولیدمثل ، سلامت وتولید پایین است.

    هدف

    این تحقیق در راستای حداکثرسازی سود سالیانه گله در راستای بهینه سازی و تصمیم گیری در جهت حذف یا نگهداری گاوهای شیری در گله می باشد.

    روش کار

    بدین منظور از داده های خام جمع آوری شده از گاوداری های صنعتی اردبیل بین سال های 1394 تا 1397 استفاده گردید. سپس با استفاده از یک مدل زیست اقتصادی توسعه یافته در نرم افزار Dairy vip، وضعیت گله در شرایط مختلف برای اجرای سیاست های بهینه شبیه سازی شد. همچنین تصمیمات بهینه با استفاده از جعبه ابزار Compecon در نرم افزار MATLAB اتخاذ گردید.

    نتایج

    با اجرای سیاست های بهینه، نرخ حذف سالیانه از11/30 به 8/43 درصد افزایش یافت. با این حال نرخ حذف اجباری به میزان ناچیزی (3/2 درصد)کمتر شد. نرخ آبستنی با اجرای سیاست ها و تصمیمات بهینه از 31/15 به 2/18 درصد رسید و با افزایش 89/2 درصدی مواجه گردید. لذا می توان استنباط کرد که اهمیت اقتصادی افزایش نرخ آبستنی در گله هایی که عملکرد تولیدمثلی ضعیف تری دارند، ضروری تر است. کاهش میانگین روزهای شیردهی گله سبب افزایش تولید روزانه و سالیانه گاوهای مولد به ترتیب به میزان 3 و 935 کیلوگرم شد. برای مقایسه مقدار کارایی اجرای سیاست های حذف بهینه، نرخ سود هر سناریو بر هزینه های اجرایی آن تقسیم شد. عدد حاصل برابر با نرخ بازگشت سرمایه بود که از 7/18به 1/20 درصد بهبود یافت. همچنین براساس نتایج مدل مورد بررسی با افزایش فاصله زایش ارزش حال کاهش یافت ولی تصمیم بهینه در هر سطح تولیدی برای فاصله های مختلف زایش یکسان بود. متوسط عمر بهینه گله(فاصله زمانی بین اولین زایش تا حذف) برای هزینه های تشریح شده در سناریوی پایه 83/4 سال حاصل شد.

    کلیدواژگان: برنامه ریزی پویا، گاو شیری، سود سالیانه، مدل زیست اقتصادی
  • محمد درعلی بنی، فریبا رضایی سرتشنیزی*، سعید کریمی دهکردی، علی محرری، حسین مهربان، مهیار آذری صفحات 41-54
    زمینه مطالعاتی

    این مطالعه به منظور بررسی تاثیر استفاده از پروبیوتیک پروتکسین بر وزن، فراسنجه های هماتولوژی و خونی بره های شیرخوار نژاد لری بختیاری انجام شد.

    هدف

    بررسی وزن، فراسنجه های هماتولوژی و خونی بره های شیرخوار نژاد لری بختیاری بود.

    روش کار

    از 28 میش چند شکم زایش که در ماه آخر آبستی بودند به مدت یک ماه استفاده شد. تیمارهای آزمایشی شامل 1- تیمار شاهد (عدم دریافت پروبیوتیک توسط بره و میش) 2- دریافت یک گرم پروبیوتیک توسط میش 3- دریافت 20/0 گرم پروبیوتیک توسط بره و 4- دریافت 20/0 گرم پروبیوتیک توسط بره و یک گرم پروبیوتیک توسط میش. پروبیوتیک استفاده شده در این تحقیق پروبیوتیک پروتکسین بود. بره ها پس از تعیین وزن اولیه به مدت یک ماه از این پروبیوتیک استفاده کردند. هر هفته تا پنج هفته وزن کشی شدند. برای تعیین فراسنجه های هماتولوژی و خونی در روزهای 3، 14 و21 آزمایش قبل از نوبت غذایی صبح نمونه گیری انجام شد.

    نتایج

    اثر تیمار بر وزن بدن، فراسنجه های هماتولوژی و خونی در بره ها معنی دار نبود. اثر زمان (سن) بر وزن بره ها، غلظت های هماتوکریت، آلبومین، آلکالین فسفاتاز، گلوبولین، گاما گلوتامین ترانسفراز، گلوکز، نسبت آلبومین به گلوبولین دارای اختلاف آماری معنی دار بود (0001/0=P). اثر زمان (سن) روی تعداد گلبول های سفید (0074/0=P)، پروتئین های فاز حاد (0003/0=P) و غلظت فسفر (01/0=P) معنی دار بود. در مورد اثر متقابل تیمار و زمان (سن) بر وزن بره ها، فراسنجه های هماتولوژی و خونی اختلاف آماری معنی دار مشاهده نشد.

    نتیجه گیری نهایی

    با توجه به نتایج حاصل از این مطالعه پروبیوتیک پروتکسین بر وزن بدن، فراسنجه های هماتولوژی و خونی اثر معنی داری نداشت. نیاز به تحقیقات بیشتر و سطوح بیشتری از این پروبیوتیک در بره های نژاد لری بختیاری است.

    کلیدواژگان: پروتئین های فاز حاد، عناصر معدنی خون، گلبول های سفید، نسبت آلبومین به گلوبولین، وزن بدن، هماتوکریت
  • الیاس ابراهیمی*، محسن کاظمی صفحات 55-71
    زمینه مطالعاتی

    رابطه مستقیمی بین افزایش بیان ژن ناقل اوره نوع ب و جریان سروزی، مخاطی اوره در شکمبه وجود دارد. با این حال، هنوز نمی توان با اطمینان گفت بیان ژن ناقل اوره نوع ب تحت چه شرایطی افزایش می یابد.

    هدف

    پژوهش حاضر با هدف بررسی تاثیر سطوح مختلف پروتئین خام و کربوهیدرات غیر الیافی خوراک بر بیان ژن ناقل اوره نوع ب به صورت فراتحلیل انجام شد.

    روش کار

    پس از جستجو، 11 مقاله انتخاب شد و داده های مربوط به غلظت اسیدهای چرب فرار استیک، پروپیونیک و بوتیریک، نیتروژن آمونیاکی، pH و بیان ژن ناقل اوره نوع ب استخراج گردید. جهت انجام فراتحلیل از نرم افزار Comprehensive Meta-Analysis (CMA) نسخه 3 استفاده شد. با توجه به ماهیت پیوسته داده ها از تفاوت میانگین استاندارد شده و شاخص Hedges’s g برای محاسبه اندازه اثر استفاده شد. از هر دو مدل اثرات ثابت و تصادفی برای ترکیب اندازه اثر استفاده شد. برای بررسی میزان سوگیری انتشار از نمودار قیفی و آزمون های آماری استفاده شد.

    نتایج

    تاثیر پروتئین خام بر غلظت نیتروژن آمونیاکی (0001/0˂P) و بیان ژن ناقل اوره نوع ب (003/0=P) مثبت بود. استفاده از سطوح مختلف پروتئین خام تاثیر معنی داری بر pH و غلظت اسیدهای استیک، پروپونیک و بوتیریک نداشت. مقادیرI2 و Q به ترتیب برای اندازه اثر غلظت نیتروژن آمونیاکی و بیان ژن ناقل اوره نوع ب نشان دهنده وجود ناهمگنی بالا متوسط بود. استفاده از کربوهیدرات غیر الیافی بر pH (001/0˂P) تاثیر منفی داشت. سطوح مختلف کربوهیدرات غیر الیافی تاثیر معنی دار مثبت بر غلظت اسید پروپیونیک (001/0˂P) و بیان ژن ناقل اوره نوع ب (001/0˂P) داشت. مقادیرI2 و Q برای اندازه اثر pH و بیان ژن ناقل اوره نوع ب حاکی از وجود ناهمگنی بالا بود.

    نتیجه گیری نهایی

    استفاده از سطوح مختلف پروتئین خام و کربوهیدرات غیر الیافی در خوراک، افزایش بیان ژن ناقل اوره نوع ب را به دنبال دارد. با این حال به نظر می رسد، استفاده از مکمل های کربوهیدرات غیر الیافی در خوراک تاثیر بیشتری بر افزایش بیان ژن ناقل اوره نوع ب داشته باشد.

    کلیدواژگان: پروتئین، خوراک، کربوهیدرات، فرا تحلیل، ناقل اوره
  • امید خراسانی، مرتضی چاجی*، فرشاد باغبان صفحات 73-87
    زمینه مطالعاتی

    در روده ‏ی کوچک ارتفاع پرز‏ها، عمق کریپت، اندازه ضخامت بافت پوششی و نسبت ارتفاع پرز به عمق کریپت، نقش قابل توجهی در مراحل نهایی هضم و جذب مواد مغذی از دستگاه گوارش دارند.

    هدف

    پژوهش حاضر با هدف بررسی اثر استفاده بافر بی‏کربنات یا باکتری مگاسفرا السدنی به عنوان تنظیم کننده ها‏ی pH بر هیستومورفومتری و هیستوپاتولوژی روده ‏ی کوچک و بزرگ بره های پرواری در حین تغذیه مقدار زیاد کنسانتره انجام شد.

    روش کار

    در آزمایش حاضر از 24 راس بره نر عربی 1 ± 4 ماهه با وزن 15/3 ± 9/23 کیلوگرم در قالب طرح کاملا تصادفی با 3 تیمار و 8 تکرار استفاده شد. تیمارهای آزمایشی شامل 1- جیره ‏ی شاهد 2- جیره ‏ی شاهد + بافر بی‏کربنات سدیم 3- جیره ‏ی شاهد + باکتری مگاسفرا السدنی و مخمر ساکرومایسیس سرویسیه (باکتری-مخمر) بودند. جهت بررسی های بافت شناسی روده ‏ها، از بخش میانی سه ناحیه ‏ی دیودنوم، ژژنوم و ایلیوم و بخش میانی روده ‏ی بزرگ (کولون)، قطعاتی جدا شدند.

    نتایج

    ارتفاع پرز، عمق کریپت و مساحت پرز دیودنوم در تیمار باکتری-مخمر از سایر تیمارها بیشتر بود (05/0<P). ضخامت لایه عضلانی در تیمار بافر نسبت به سایر تیمارها بیشتر بود (05/0<P). عرض پرزهای دیودنومی در تیمارهای بافر و باکتری-مخمر از تیمار شاهد بیشتر بود و در تیمار باکتری-مخمر نسبت به تیمار شاهد معنی ‏داری بود (05/0<P). اختلاف معنی ‏داری بین شاخص‏ های بافتی ژژنوم در تیمارها مشاهده نشد. ارتفاع پرزهای ایلیومی درتیمارهای بافر و باکتری- مخمر از تیمار شاهد بیشتر بود و در تیمار باکتری-مخمر نسبت به تیمار شاهد معنی ‏داری بود (05/0<P). عمق کریپت و مساحت پرز ایلیوم در تیمار باکتری-مخمر نسبت به سایر تیمارها بیشتر بود (05/0P<).

    نتیجه گیری نهایی

    در مقایسه با شاهد، مصرف عوامل تنظیم کننده‏ ی pH از نظر هیستوپاتولوژی باعث کاهش آسیب‏ های بافتی نظیر نفوذ سلول های التهابی تک هسته ای، نکروز پرزها و هایپرپلازی پلاک ‏های پی‏یر در روده ‏ی کوچک و روده ‏ی بزرگ و در نتیجه ی آن بهبود ساختار بافتی و کاهش آسیب‏ های بافتی در روده ‏های کوچک و بزرگ شد.

    کلیدواژگان: بافر، ساکرومایسیس سرویسیه، هیستوپاتولوژی، هیستومورفومتری، مگاسفراالسدنی
  • علی هاشمی*، نوشین قهرمانی، مختار غفاری، قربان الیاسی صفحات 89-98
    مقدمه

    بلدرچین به دلیل خصوصیاتی از قبیل کوچک بودن اندازه بدن، فاصله نسلی کوتاه، میزان رشد بالا و تولید تخم و گوشت بیشتر به طور گسترده در مطالعات آزمایشگاهی استفاده می شود. IGF-I به عنوان یک ژن کاندید مرتبط با صفات وزن بدن و رشد در گونه های مختلف حایز اهمیت است. این آزمایش به منظور بررسی چندشکلی ژن IGF-I و ارتباط آن با صفت وزن بدن در بلدرچین ژاپنی انجام گرفت.

    مواد و روش

    در مطالعه حاضر رکوردهای مربوط به وزن بدن 110 قطعه بلدرچین ژاپنی در دوره های پرورشی مختلف ثبت و DNA ژنومی با کیفیت مطلوب از نمونه های خون با استفاده از پروتکل پروناز استخراج شد. واکنش زنجیره ای پلی مراز (PCR) جهت تکثیر قطعه 465 جفت بازی از ژن IGF-I استفاده شد. روش تفاوت فرم فضایی رشته های منفرد (SSCP) جهت تعیین الگوهای ژنوتیپی نمونه ها بکار گرفته شد. تجزیه و تحلیل آماری ارتباط بین صفت وزن بدن و الگوهای ژنوتیپی با استفاده از رویه GLM نرم افزار SAS انجام گرفت.

    نتایج و بحث

    نتایج SSCP نشان داد جایگاه ژنی اگزون 4 چندشکل بوده و سه الگوی ژنوتیپی با فراوانی های 7/27 ، 91/50 و 82/41 درصد بدست آمد. نتایج ارایه شده در این تحقیق نشان داد که بین الگوهای ژنوتیپی و وزن بدن در سن 30 روزگی از لحاظ آماری تفاوت معنی داری وجود داشت. در ارتباط با تاثیر جنس با وزن بدن نیز در سن 60 روزگی اختلاف معنی داری برقرار بود.

    نتیجه نهایی

    با توجه به این پژوهش جایگاه منتخب برای بررسی ژن IGF-I در بلدرچین می تواند به عنوان یک جایگاه پیشنهادی موثر بر صفت وزن بدن به شمار آید. همچنین می تواند به عنوان یکی از عواملی باشد که باعث تفاوت وزن بدن در دوره های مختلف می شود.

    کلیدواژگان: وزن بدن، ژن IGF-I، بلدرچین ژاپنی، چندشکلی
  • حسین محمدی*، امیرحسین خلت آبادی فراهانی، محمدحسین مرادی، ایمان حاج خدادادی صفحات 99-111
    زمینه مطالعاتی

    درک کنترل ژنتیکی صفات رشد یکی از مهم ترین اهداف اصلاح نژادی در صنعت طیور است.

    هدف

    پژوهش حاضر به منظور مطالعه پویش کل ژنوم بر مبنای تجزیه و تحلیل غنی سازی مجموعه ژنی جهت شناسایی جایگاه های ژنی موثر بر برخی صفات مرتبط با وزن بدن و طول و قطر شانک در یک لاین اینترکراس پیشرفته (AIL) با استفاده از تکنیک توالی یابی GBS بوده است.

    روش کار

    به منظور مطالعه پویش کل ژنومی از 599 قطعه مرغ و رکورد فنوتیپی مرتبط با صفات رشد شامل وزن بدن از هچ تا 14 هفتگی و طول و قطر شانگ از 4 تا 12 هفتگی استفاده گردید. آنالیز پویش کل ژنومی در برنامه GCTA نسخه 92/1 انجام شد. در مرحله بعد آنالیز غنی سازی ژنی با استفاده از بسته نرم افزاری goseq برنامه R و هدف شناسایی عملکرد بیولوژیکی ژن های نزدیک در مناطق انتخابی کاندیدا از طریق پایگاه های برخط GO، Metacyc، KEGG، Reactome و Panther انجام گردید.

    نتایج

    تجزیه و تحلیل بیوانفورماتیکی نشان داد که مناطق ژنومی شناسایی شده به طور مستقیم و غیر مستقیم با ژن های موثر بر رشد عضلات اسکلتی، وزن بدن، متابولیسم انرژی و رشد و توسعه استخوان همپوشانی دارند. در این پژوهش نشانگر تک نوکلیوتیدی معنی داری واقع روی کروموزوم های 1، 2، 4، 5، 7، 8، 10، 11 و 27 شناسایی شدند که با ژن های MSTN، CAPN3، PNPLA3، ANXA2، IGF1، LDB2، LEPR، FN1، TMEM135 ،MC4R ، EDN1 و ADAMTS18 مرتبط بودند. در آنالیز غنی سازی مجموعه ژنی تعداد 19 مسیر هستی شناسی ژنی و مسیر KEGG با صفات وزن بدن و طول و قطر شانک مرتبط بودند (P˂0.05). از این بین، مسیرهای Regulation of muscle organ development، Regulation of cell growth و Anatomical structure homeostasis نقش مهمی در رشد و توسعه عضلات اسکلتی داشتند. همچنین در ارتباط با طول و قطر شانک مسیرهای Positive regulation of ossification، Positive regulation of cytosolic calcium ion وCalcium signaling pathway ارتباط معنی داری داشتند.

    نتیجه گیری نهایی

    با توجه به تایید مناطق قبلی پویش ژنومی صفات وزن بدن و طول و قطر شانک، همچنین شناسایی مناطق ژنومی جدید، آنالیز غنی سازی مجموعه ژنی درک بهتری از کنترل ژنتیکی صفات رشد را نشان می دهد. استفاده از نتایج این تحقیق می تواند باعث تسریع در پیشرفت ژنتیکی برنامه های اصلاح نژادی مرغ شود.

    کلیدواژگان: آنالیز غنی سازی، پویش ژنوم، ژن کاندیدا، مرغ، وزن بدن
  • حسین دقیق کیا*، مهدی نظری، جمیله امامی صفحات 113-124

    آسیب غشایی بعنوان یکی از دلایل کاهش تحرک و باروری اسپرم خروس مطرح است. تاکنون آنتی اکسیدان های مختلفی جهت کاهش یا جلوگیری از آسیب های غشایی در حین انجماد و ذوب مورداستفاده قرارگرفته است.

    هدف

    در این تحقیق از اسیدآمینه سیستیامین بمنظور کاهش استرس اکسیداتیو، پراکسیداسیون لیپیدی و بهبود عملکرد اسپرم طیور استفاده شد.

    روش کار

    بدین منظور نمونه های منی از 15 خروس نژاد راس با سن 28 هفته به روش مالش پشتی-شکمی جمع آوری شدند. نمونه های منی پس از ارزیابی اولیه باهم مخلوط شده پس از رقیق سازی نمونه ها و افزودن سطوح مختلفی از اسیدآمینه سیستیامین، نمونه ها سردسازی شده و سپس فریز شدند. بعد از ذوب نمونه ها فراسنجه های حرکتی اسپرم با استفاده از سیستم آنالیز کامپیوتری اسپرمCASA، زنده مانی با استفاده از روش رنگ آمیزی ایوزین-نیگروزین، یکپارچگی غشاء با استفاده از آزمون هاست، میزان اسپرم های ناهنجار با استفاده از محیط هانکوک و میزان لیپید پراکسیداسیون اندازه گیری شدند. نتایج بر اساس نتایج بدست آمده افزودن سطوح 30 و 45 میکرومول باعث افزایش تحرک کل نسبت به گروه کنترل گردید. افزودن سطح 45 میکرومول باعث افزایش تحرک پیش رونده و پارامترهای حرکتی و همچنین افزودن 30 میکرومول باعث افزایش معنی دار میزان زنده مانی، سلامت غشاء و کاهش معنی دار میزان مالون دی آلدهید نسبت به گروه کنترل شد. افزودن اسیدآمینه سیستیامین باعث کاهش معنی دار اسپرم های با مورفولوژی ناسالم طی انجماد-یخ گشایی نشد.افزایش تحرک پیش رونده و پارامترهای حرکتی و همچنین افزودن 30 میکرومول باعث افزایش معنی دار میزان زنده مانی، سلامت غشاء و کاهش معنی دار میزان مالون دی آلدهید نسبت به گروه کنترل شد. افزودن اسیدآمینه سیستیامین باعث کاهش معنی دار اسپرم های با مورفولوژی ناسالم طی انجماد-یخ گشایی نشده است.

    کلیدواژگان: آنتی اکسیدان، اسپرم، سیستئامین، تنش اکسیداتیو، مالون دی آلدهید
  • بهروز یاراحمدی، محسن محمدی ساعی، کریم قربانی، نادر پاپی صفحات 125-142
    زمینه مطالعاتی

    رشد جبرانی در واقع یک فرایند فیزیولوژیک است که در آن از پتانسیل حیوان، پس از یک دوره اعمال محدودیت غذایی، برای افزایش رشد و بازده رشد در طی دوره تغذیه آزاد می‌توان بهره گرفت.

    هدف

    این تحقیق به‌منظور بررسی اثر وزن متفاوت شروع محدودیت فیزیکی خوراک و دوره تغذیه مجدد بر عملکرد رشد بره‌های لری انجام شد.

    روش کار

    برای انجام آزمایش، تعداد 54 راس بره‌ی نر 26 کیلوگرمی انتخاب و بر اساس روش اندازه‌های تکرار شده در قالب طرح کاملا تصادفی توسط رویه مختلط انجام شد. تیمارها شامل 6 تیمار، گروه شاهد بره 30 کیلوگرمی (جیره پروار بدون محدودیت؛ 2) گروه 80 درصد محدودیت خوراک بره 30 کیلوگرمی ؛ 3) گروه 60 درصد محدودیت خوراک بره 30 کیلوگرمی ؛ 4) گروه شاهد بره 35 کیلوگرمی (جیره پروار بدون محدودیت)؛ 5) گروه 80 درصد محدودیت خوراک بره 35 کیلوگرمی ؛6) گروه 60 درصد محدودیت خوراک بره 35 کیلوگرمی بود ند. پس از 14 روز دوره پیش از محدودیت خوراک یک گروه شامل 27 راس که به میانگین وزن 30 کیلوگرمی رسیده بودند از بقیه جداشده و تحت تیمارهای محدودیت خوراک قرار گرفتند. گروه 27 راسی باقیمانده تحت جیره قبلی به مدت 35 روز تا رسیدن به وزن 35 کیلوگرمی قرار داشتند. پس از رسیدن این گروه به میانگین 35 کیلوگرمی جیره‌های محدودیت خوراک اعمال شد. دوره محدودیت خوراک برای هر دو گروه 30 و 35 کیلوگرمی 35 روز بود. سپس گروه 30 کیلوگرمی به مدت 49 روز و گروه 35 کیلوگرمی به مدت 28 روز تا پایان دوره پروار تغذیه مجدد با جیره شاهد (جیره پروار بدون محدودیت و به صورت دسترسی آزاد) شدند.

    نتایج

    نتایج نشان داد بین وزن نهایی بره‌ها در پایان دوره محدودیت خوراک اختلاف معنی‌دار وجود داشت (05/0>P). در پایان تغذیه مجدد بین گروه‌های شاهد (30 و 35 کیلوگرم) و گروه‌های محدودیتی 80 و 60 درصد محدودیت خوراک اختلاف معنی‌دار مشاهده نشد. بین ماده خشک مصرفی روزانه بره‌ها در پایان دوره محدودیت خوراک اختلاف معنی‌دار وجود داشت (05/0>P). در پایان رشد جبرانی بین گروه‌های شاهد و گروه‌های محدودیتی اختلاف معنی‌دار مشاهده نشد. در دوره تغذیه مجدد ضریب تبدیل خوراک در تیمارهای محدودیت خوراک نسبت به تیمارهای شاهد (30 و 35 کیلوگرم) کاهش داشت. نتایج ترکیب لاشه در دوره تغذیه مجدد نشان داد میانگین اکثر صفات لاشه در تیمارهای شاهد (30 و 35 کیلوگرم) و 80 درصد خوراک برای بره‌های 30 کیلوگرمی با یکدیگر تفاوت معنی‌دار نداشته و بالاتر از سایر گروه‌ها بودند. در این بین وزن دنبه، درصد دنبه و چربی کل لاشه در تیمارهای شاهد (30 و 35 کیلوگرم) بالاتر از کلیه گروه‌های محدودیت بود. نتایج نشان داد درصد گوشت لخم لاشه در گروه‌های جبرانی بالاتر از تیمارهای شاهد بود.

    نتیجه‌ گیری نهایی

    این مطالعه مشخص نمود بره‌های تحت محدودیت 80 درصد خوراک برای بره‌های 30 کیلوگرمی به دلیل افزایش وزن بالاتر، ضریب تبدیل خوراک مناسب‌تر نسبت به بره‌های شاهد که در کل دوره در حد اشتها خوراک مصرف نمودند، ارجحیت داشتند. همچنین تیمار فوق درصد چربی لاشه کمتر ، گوشت لخم بیشتر و درنهایت هزینه‌ تولید هر کیلوگرم لاشه و گوشت لخم پایین تری نسبت به سایر تیمارها داشت.

    کلیدواژگان: تغذیه مجدد، خصوصیات لاشه، ضریب تبدیل خوراک، محدودیت خوراک
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  • Fatemeh Broomand, Seyedmehdi Ghoreishi *, Saeid Hosseinzadeh, Shahryar Kargar Pages 1-9
    Introduction

    The antibacterial and antifungal effects of pomegranates peel and seeds are associated with the presence of phenolic compounds (flavonoids and tannin). These compounds accumulate in the skin and pomegranate juice and account for 92% of the antioxidant activity of pomegranates (Abid et al. 2017). Total tannins for pomegranate peel and pulp were reported to be 9.73 and 0.66%, respectively (Delavare et al. 2014). The different species of pomegranate have antibacterial and antifungal properties that can influence on a wide range of microorganisms (Carlton et al. 2000). Phenolic compounds in plants and foods by changing the gut microbial population can increase the amount of useful bacteria and reduce harmful bacteria (Katiyar 2002). It has been found that intestinal microflora plays a critical role in the health of the digestive tract and is dependent on the ration as the final source for metabolism of organic compounds. (Choct et al. 1996). To our knowledge, the effects of pomegranate by-products have been investigated on livestock and rumen function, however their effects on the intestinal microflora in ruminants have not been addressed. Therefore, due to the high concentration of tannins and phenolic compounds in the pomegranate by-products and their effect on intestinal microflora, the aim of this study was to investigate the effects of pomegranate pomace silage and pomegranate air-dried pomace on intestinal microflora in Mehraban fattening lambs.

    Materials and methods

    Nine male lamb of Mehraban breed (mean weight of 27.03±3.5 kg and mean age of 187.8±1.4 d), were fed on three iso-nitrogenous and iso-caloric diets. Diets were balanced according to NRC (2007) recommendation including control diet, diet contain 27% pomegranate pulp silage (mixture of seed and pulp at equal ratio) and diet contain 31% air-dried pomegranate seed pulp. All three diets were fed for 60 d after 3 weeks for adaptation in individual pens with free access to salts lick and water. At the end of experiment all lambs were slaughtered and after than for enumeration of intestinal fluoromicrobes, one gram freshly digested specimens of ileum and cecum were collected. Samples were spread on the surface of agar medium. Colonies were counted by ophthalmic count and bacterial count was calculated as CFU/g (number of colonies per gram). The MRS agar and MacConkey (MC) medium were used for identification and enumeration of Lactobacillus spp and Escherichia coli respectively. All samples were incubated at 37ºC for 24 hours. All colonies were enumerated and recorded as CFU/g of culture suspension. For confirmation of Escherichia coli detection on MacConkey agar medium, polymerase change reaction (PCR) was conducted as DNA extraction using commercial kit (Bioneer, Sout Korea), polymerase change reactions, and electrophoresis of PCR products. Detection of molecular bacteria was done using the primers of 23S rRNA gene PCR. The PCR process was initial denaturation at 94 ºC for 2 minutes and totally 35 cycles, denaturation at 94 ºC for 45 seconds, and extension at 72 ºC for 2 minutes. All data was analyzed as a complete randomized design using SPSS software. Significant difference for means was considered at 0.05 level of differences.

    Results and discussion

    The results of this study showed that in MRS medium either in ilium or cecum, the number of lactobacillus bacteria in all groups were not statistically significant. The mean number of Escherichia coli decreased due to feeding of pomegranate by-products (P<0.05), while the type of pomegranate by-product has not significant effect on number of Escherichia coli. The importance role of gut microflora is well recognized in GIT health, although population of gut microbes has been influenced by diet (Choct et al 1996). In contrast of useful effects of lactobacillus on GIT, Escherichia coli damages the intestine of animals and produces lipopolysaccharide (Munyaka et al. 2012). Tannins are considered as a toxin to microorganisms; these compounds in the soluble environment produce some stable complexes, mainly with protein and to a lesser extent with carbohydrates or some physiological ions elements such as iron and copper (Chung and Chou 1998). The pomegranate peel extract at different levels has antimicrobial effect against microorganisms such as Staphylococcus aureus, Escherichia coli, Candida tropicalis and Candida albicans (Ahmed et al. 2013). The phenolic materials in pomegranate fruit, are responsible for the antimicrobial properties of pomegranates (Seeram et al. 2006). In the present study, reduction of Escherichia coli population in lambs fed pomegranate by-products can be attributed to the adverse effect of phenolic substances in the pomegranate byproducts on Escherichia coli population. Several mechanisms have been introduced for antimicrobial properties of phenolic compounds in the pomegranate. Phenolic substances, with high molecular weight proteins, form complexes and by these complexes can react to the some cytoplasmic and membrane enzymes after absorption (Seeram et al. 2006). These complexes can also prevent cell surface receptors from attachment of harmful microorganisms (Cowan 1999). Phenolic compounds can react with the cellular proteins of microorganisms, alter cell wall structure and function (Hugo and Bloomfield 1971), reducing cell wall permeability and reducing substrate transport to cells (Goel et al. 2005). In addition, phenolic compounds can alter or denature some microbial enzymes, and also form complexes with certain nutrients and remove them from microorganisms (Hugo and Bloomfield 1971). The decline of Escherichia coli can also be attributed to the increase in the number of Lactobacillus; because by increasing the Lactobacillus and consequently increasing the production of lactic acid and creating an acidic environment, the population of Escherichia coli is reduced due to sensitivity of Escherichia coli to acidic environment (Hammer et al. 1999).

    Conclusion

    Feeding of the pomegranate pomace silage and air-dried pomegranate pomace in fattening lambs, decreased the population of Escherichia coli in ileum and cecum, although lactobacillus bacteria was not affected by pomegranate by-products. It seems that the tannins and phenolic compounds present in the pomegranate can effect on Escherichia coli population in ileum and cecum.

    Keywords: Cecum, Escherichia coli, Ilium, Lactobacillus, Mehraban lamp, Pomegranate pulp
  • Mousa Zarrin *, Meysam Sanginabadi, Mahrokh Nouri, Amir Ahmadpour Pages 11-26
    Background

    Livestock systems in developing countries located in tropical and sub-tropical regions are heavily dependent on the natural resources (i.e. pastures). In these countries, decreased pasture availability and quality during the dry season has important consequences on performance and health of dairy ruminants. In these conditions, energy intake does not meet energy requirements for body maintenance, fetal growth and milk production, which results in negative energy balance, and high adipose tissue mobilization. If adaptation to NEB fails, the risk of metabolic disorders increased considerably, affecting not only animal performance, but also animal health and welfare. Fat-tailed sheep, such as the Lori-Bakhtiari and Turkey-Qashqai breeds, are raised in semi-arid regions of Eastern and Southern Africa, Central Asia, as well as numerous countries in the Middle-East. The common characteristic of all fat-tailed sheep is the deposition of a substantial amount of fat in the tail. Fat-tailed sheep are known for being highly resilient to harsh environmental conditions such as those related to the dry season such as water scarcity and low quality pastures and feedstuffs. According to the literature, fat depots are differently regulated in fat-tailed sheep compared to other sheep breeds during periods of feed scarcity. However, most of these studies have been performed in sheep breeds used for meat production.

    Material and Methods

    The present study was carried out in the experimental farm of Yasouj University (Naregah, Yasouj, Iran). All animal procedures followed the ethical law on Animal Protection and were approved by the Committee of Animal Experiments (Yasouj University, Iran). All ewes used in this study were visually healthy and had no signs of diarrhea. The present study was carried out to investigate the consequences of a reduced energy intake on the body weight and blood metabolites of non-pregnant fat-tailed ewes. In this experiment, 10 non-pregnant fat-tailed ewes (Lori-Bakhtiari and Turkey-Qashqai) with average age 3.6 ± 0.3 y and BW 49.2 ±3 3.60 kg were used. During the trial, all animals were kept in individual pens (1.2 × 1.0 m) located in a closed barn. Each pen was equipped with a separate drink and feed container. Two weeks before the start of the experiment all animals were fed with a total mixed ration (TMR) diet formulated to fulfill 100% of the energy requirements recommended by the NRC (2007). Then, animals were randomly allotted into one of the two experimental groups, including the Control (Control; n= 5) and the Feed Restriction (Restriction; n=5) groups. From wk 1 to wk 5 (end of the experiment), ewes of the Control group access to the diet adlibitum. The feed restriction group was feed with a diet equivalent to the 100%, 50%, 65%, 80%, and 100% of the energy content of the dry diet on wk1, wk2, wk3, wk4 and wk5, respectively. During the entire experimental period, total mixed ration (TMR) was provided to the animals twice a day (0800 and 1700). In addition, animals had free access to drinking water and mineral blocks throughout the entire experimental period. The individual feed intake was recorded daily by weighing the offered TMR and the ort in the next morning before feeding. The ewes were weighed weekly on the last day of each experimental week. During the entire experimental period, blood samples were collected weekly from the jugular vein using heparinized vacuum tubes (6 mL) at 0730 (before feeding). All blood samples were kept in wet ice and then centrifuged at 3,500 × g for 15 min. The plasma was then aliquoted (1.5 mL) and stored at -20°C. The plasma concentration of glucose, urea, creatinine, triglyceride, cholesterol, albumin, low density lipoprotein-cholesterol (LDL-C), high density lipoprotein–cholesterol (HDL-C), as well as the plasma activity of lactate dehydrogenase (LDH), glutamate pyruvate transaminase (GPT), and glutamic oxaloacetic transaminase (GOT) were determined using commercial kits (Pars Azmoun, Karaj, Iran), and NEFA and BHBA were measured by a RANDOX (Randox LTD, UK) commercial kit, and an automated analyzer (Mindray, B850, China), following manufacture’s instructions. The concentration of very-low-density lipoprotein (VLDL) was determined using the following equation: VLDL (mg/dl) = TG × 0.20. The data was tested for normal distribution using the UNIVARIATE procedure of SAS (SAS Institute Inc., Cary, NC, USA, 2002-2008, Release 9.2). The data was evaluated using the MIXED procedure of SAS. The model included treatment (Control and feed restriction), time (from wk 1 to wk 5), and the interaction (treatment × time) as fixed effects. The individual ewe was set as a repeated subject. Concentrations of metabolites were considered dependent variables. Significant differences were considered significant if P<0.05, and a tendency if 0.05 

    Results and discussion

    Obtained results showed that feed restriction reduced dry matter intake in the restriction group (P<0.001). different feed restriction percentage affected BW (P<0.01), and the lowest was related to the wk 2 in the restriction group (P<0.05). Among blood metabolites, plasma glucose, NEFA, and BHBA concentration tended to increase in the Restriction group (P= 0.07). Although plasma creatinine concentration was not affected by feed treatment, the sampling times affected of its concentration in the Restriction group (P<0.05). The other plasma metabolites measured were not affected by the feed restriction and sampling times except the LDL concentration at wk 4 in the Restriction group (P<0.05).

    Conclusion

    In conclusion, feed scarcity in tropical regions could affect on body weight in the non-pregnant ewes. With not changed the most of blood metabolites in the fat-tailed ewes, it could be speculating that, fat-tailed could also be considered as an energy source in these type of breeds, specially during the pregnancy and feed scarcity.

    Keywords: Blood metabolism, Energy, Feed restriction, Glucose, Sheep
  • Reza Seyedsharifi *, Sona Amiri, Nemat Hedayat-Evrigh, Jamal Seifdavati, Taher Yalchi Pages 27-39
    Introduction

    In the livestock industry around the world, most decisions are about increasing profitability per head, which is not an independent process and is affected by the interactions of biological functions such as (production, reproduction and health) and prices that are changed by policy. Replacement and breeding affect profitability (Nasre Esfahani, 2018). Issues such as feed price fluctuations and the lack of coherent policies to support the dairy industry in the country have made the profession one of the most risky jobs in the economy. When a producer wants to make the decision to remove or replace a cow, it is best to compare the future benefits and expected benefits of keeping a cow or replacing an animal with another. The most important objective of a livestock unit is to maximize the profit of the herd, one of the issues affecting this profit is the criteria and rate of elimination (Rogers et al,1988). If culling and replacement are not optimal, the cows are removed sooner or later than the optimal deadline, the profitability of the herd decreases. The need to determine the optimal time to remove cows requires simultaneous consideration of several biological and economic variables (De Vries,2006). The removal decision must be based on the anticipated future earnings of the cow. The longer the livestock has a livelihood in the herd, the more profit the livestock earns. The decision to properly, optimally and reasonably eliminate livestock is made by comparing the present value of the future cash flow of the cow present in the herd to the present value of the future cash flow of its replacement heifers, ultimately occupying the most valuable animal in the present (Groenendall et al,2005). The application of dynamic programming in the animal sciences is more on animal substitution issues. The optimal policy at each stage represents the best decision from that stage to the final stage. This method calculates an expected value for each of the situations that can be faced and the decision maker selects the best decision based on the expected value based on the situations ahead. Several dynamic programming models for optimal replacement decision making in dairy herds have been proposed by (De Vries,2004) and (Van Arendonk,1985). (Cardoso et al,1999) reported optimizing replacement and inoculation policies in dairy cows by calculating monthly income, costs and probability of elimination.

    Material and methods

    In this study, using raw data collected from industrial dairy farms of Ardabil between 2015 and 2018, the biological parameters of the herd, such as the shape of the lactation curve, the risk of forced removal and the possibility of pregnancy in different lactation periods and Different months after calving were estimated. The financial information of the herd was also obtained in the form of an economic questionnaire from the studied units. It was further developed by incorporating biological parameters and financial information into a bio economic model in Dairy Vip software. The feature of this software is that it simulates the livestock over time and also calculates the performance of the herd based on breeding and replacement decisions with the goal of maximizing profitability. Milk production was evaluated using daily milk production records and fitting the incomplete gamma curve (Wood). Dairy Vip software defined average daily milk production levels in the herd by entering lactation data (raw milk quantity, incremental milk slope to peak production and milk slope decrease until peak production). Mean milk yield of 305 days at first to third lactation and peak lactation was reported in Table 1.The mean 21-day inoculation rate and cattle breeding rate were 49.3% and 37%, respectively. By default Dairy Vip software, a maximum livestock can be in the herd 24 months after calving. The risk of fetal loss from the second to the eighth month was 6.24, 4.16, 2.08, 1.11, 0.45, 0.19, and 0.19 percent, respectively. A Dynamic programming model was developed to determine the optimal replacement policy for cows in dairy farms and in economic conditions in Ardabil province. The objective function investigated in this study was to maximize the present value of net income from current cows and alternative heifers. Markov chain simulation was used to estimate the expected statistics under optimal policy.

    Results and discussion

    The implications of the decision policies for optimum and non-optimum removal using Dairy Vip software are presented in Table 3. With the implementation of optimal policies, the overall annual removal rate increased from 30.11% to 43.8%. However, the forced removal rate fell by 2.3%. Pregnancy rate increased from 18/15 to 18.2% and increased by 2.89%. Based on the above results, it can be inferred that the economic importance of increasing the pregnancy rate is more urgent in herds with poorer reproductive performance. Also, the non-optimal catch rate dropped from 33.9% to 37%, indicating an increased likelihood of livestock being pregnant in different months. The 21-day inoculation rate ranged from 47.6 to 49.3%, indicating appropriate cow inoculation. By reducing the days of gestation in dairy cows can increase milk production, which in this study reduced the optimal days of gestation from 139 days to 132 days, which resulted in a significant 7-day decrease in milk production and finally annual. Open days are the interval from birth to the next gestation period, from 167 days to 161 days. With the decline in pregnancy, the rate of pregnancy increased. Calving distance also decreased from 13.6 to 13.3, which was reduced to 0.3 per month, which in turn increased annual milk production. As shown in Table 3, the optimal daily milk yields were increased from 41.4 to 44.2 by the optimal policies, which increased the daily milk yield by 3 kg per cow. And the annual yield of milk increased from 12548 to 13483 kg per cow. Reducing the average days of lactation increased the daily and annual production of productive cows by 3 and 935 kg, respectively.

    Conclusion

    Decisions to optimize voluntary removal and estimation of livestock value by computer simulation in Dairy VIP software enable improved economic returns. This improvement is due to the decrease in average lactation days in the herd resulting in increased milk production, cattle sales and calf production. Although the implementation of optimal policies is associated with increased livestock removal and replacement costs and increased feed costs, however, the increased revenue from implementing these policies could well offset the increased costs. In general, it can be concluded that increasing milk production in medium-sized cows is the most important factor in increasing economic profit. The results of this study showed that low-yielding animals showed their least future benefit in early lactation, indicating that they should be eliminated sooner.

    Keywords: Annual Profit, dairy cow, Dynamic Programming, Bio economic Model
  • Mohammad Doralibeni, Fariba Rezai Sarteshnizi *, Saeid Karimi Dehkordi, Ali Moharrey, Hossein Mehraban, Mahyar Azari Pages 41-54
    Introduction

    Microbial products or probiotics can be added to animal feed and can have a positive effect on improving animal performance and enhancing the growth of young ruminants by maintaining a microbial balance in the intestinal flora and preventing gastrointestinal infections (Noori et al. 2016). The use of bacterial probiotics in replacing milk of suckling animals has improved the feed conversion ratio (Noori et al. 2016) and increased daily weight gain (Kawakami et al. 2010). Improving animal weight gain by feeding probiotic-containing treatments may be due to improvements in microbial ecology (Lascano et al. 2009) and increased nutrient uptake (Khutia and Chayyaderi 2002) and improved feed conversion ratio. The effects of bacterial probiotic use on different performance, health status, and blood counts have been reported, and differences in results may be due to the type of probiotic used, the type of food consumed, the level of management, the method of probiotic use, and environmental conditions (Agarvall 2002). The results of a study showed that the production of growth factors (organic acids, B vitamins and amino acids), creating anaerobic conditions and increasing the growth of cellulosic bacteria and lactate consumption are among the mechanisms of probiotics in increasing the digestibility of food nutrients (Riedel et al. 2010).Considering the benefits of using probiotics in feeding young ruminants and suckling calves to improve growth performance as well as reduce antibiotic use and most importantly healthy growth and breeding of lambs that can in the future replace herds of mature ewes and rams, and ensure the economic future and Herd health of the herd. And also because of the lack of study on the use of these microbial additives orally in lambs and lactating Bakhtiari ewes, so this study investigates the probiotic effects of protexin on blood hematological parameters of lactating Bakhtiari lambs.

    Materials and methods

    In this experiment, 28 ewes with one to multiparous were used. The ewes were divided into two groups. One group (14 head) received no probiotics and the other group (14 head) received 2% (v / w) solution (one gram of probiotic dissolved in five ml of water) per day of probiotics through oral and syringe one month until parturition. Probiotics were discontinued at parturition. The lambs born of these ewes were 28 (male and female). Treatments included 1) Control treatment (non-reception of probiotics by lambs and ewes), 2) Receive 1 g of probiotic by ewes, 3) Receive 0.2 g of probiotic by lambs 4) Receive 0.2 g of probiotics by lambs and 1 g of probiotics by ewes. The lambs were weighed weekly at birth and up to five weeks after birth. In order to measure hematologic and hematological parameters on 3, 14 and 21 days after the morning and by applying food restriction for 2 to 4 hours, blood was taken through the vein from all lambs. Blood samples were taken at 3, 14 and 21 days to measure hematological and blood parameters. Hematological parameters included eosinophils, lymphocytes, monocytes, neutrophils, hematocrits and white blood cells. Blood parameters included glucose, albumin, total protein, globulin, triglycerides, alkaline phosphatase, gamma glutamine transferase, acute phase proteins, oxaloallastic transaminase glutamate, and iron oxalate, including copper and iron, including calcium, iron, phosphorus, zinc. Hematology supplements and blood suppositories were determined using an autoanalyzer (model BT 1500, made in Italy).

    Results and discussion

    The effect of protexin probiotic on body weight in lambs was not significant (p>0.05). Consistent with this result, the use of probiotic supplementation in lamb feeding during the experiment did not have any significant effect on daily weight gain (Baranowski et al. 2007). The effectiveness of compounds such as probiotics, which have different microorganisms, varies and depends on the composition of the animal's diet and nutritional needs, and may be ineffective with the slightest change. Therefore, animal feed management includes feed supply (completely mixed feed, separate forage and concentrate feed), number of feed times and physical shape of feed, chemical composition of feed including forage to concentrate ratio, dietary nutrient percentage, dietary effective fiber percentage and forage type. And the concentrate used in this study can be considered as a possible cause of differences in results. The effect of treatment on hematological data including eosinophil, lymphocyte, monocyte, neutrophil, hematocrit and white blood cell concentration in lambs was not significant (p>0.05). Hematological parameters are important in determining the functional status of animals. Consistent with this, in a report with the addition of biofeedback probiotics in the last month of gestation and by the end of lactation, lambs' red blood cell counts, neutrophils, lymphocytes, basophils, and isosophils percentages were significantly affected at the start and end of the experiment. Regarding the blood parameters, the effect of treatment on the concentration of albumin, alkaline phosphatase, total protein, triglyceride, globulin, gamma glutamine transferase, glutamic oxalacetic transaminase, glucose, albumin to globulin ratio, and Acute phase proteins was not significant lambs (p>0.05). Supplementation of lambs with probiotic had no statistically significant effect on total protein, albumin, globulin, and glucose concentrations in the pre-weaning period (Salim et al. 2017). Also, the addition of probiotics protexin to blood minerals (calcium, zinc, iron, copper) in lambs was not significant (p>0.05). Consistent with our results, no significant effect on blood phosphorus and calcium concentrations was observed with probiotic supplementation of zovitis (Dimova et al. 2013)..

    Conclusion

    Probiotic supplementation of protexin had no significant effect on lamb weight, hematological parameters and blood parameters. This indicates that this probiotic had no positive effect on lambs. Amounts and more levels of this probiotic are needed to achieve a rational response in lambs.Keywords: Acute phase proteins, albumin to globulin ratio, blood minerals, body weight, hematocrit, white blood cells

    Keywords: Acute phase proteins, albumin to globulin ratio, blood minerals, body weight, hematocrit, white blood cells
  • Elias Ibrahimi *, Mohsen Kazemi Pages 55-71
    Introduction

    As is already known, urea transport across the ruminant wall is mediated via urea transporters in the epithelium membrane. Facilitative urea transporters are derived from the UT-A and UT-B genes. UT-B mRNA or protein expressions have been characterized in the rumen epithelium (Ludden et al 2009; Marini and Van Amburgh 2003; Marini et al 2004; Stewart et al 2005). Gene transcript abundance for UT-B was observed to be significantly correlated with the ruminal serosal to mucosal urea fluxes. However, the mechanism by which the increased gene expression occurred is unclear (Jin et al 2018). Transcriptome analysis has been used to analyze the rumen epithelium metabolic pathway changes under various conditions (Baldwin et al 2012; Dionissopoulos et al 2014; Naeem et al 2014), and this approach may provide a better means to understand the regulation of these urea transport mechanisms across the rumen wall.

    Materials and methods

    A literature search was initially conducted using various data bases and investigated references in the papers. It was also based on the following key words: carbohydrate, dietary, protein and urea transporter. Then 11 studies were included in current meta-analysis; and prepared comparisons for pH, VFAS, N-NH3 and UT-B expression. Meta-analyses were carried out using the Comprehensive Meta-Analysis package, version 3. The effect sizes of across studies were calculated with fixed and random effect models. The presence of true heterogeneity among studies was identified with Cochran’s Q–tests and quantification of the degree of heterogeneity was done with the I2 index. Possible publication bias was evaluated with funnel plot and statistical tests (Vesterinen et al 2014).

    Results and discussion

    The results of current meta-analysis showed that different levels of CP in diet, has a positive effects on ruminal N-NH3 concentration and UT-B expression (<0.05). However, dietary CP different levels had no significant effects on ruminal pH and VFAS concentration. The values of I2 and Q for ruminal N-NH3 concentration and UT-B expression effect size indicated high and moderate heterogeneity, respectively. Marini and Van Amburgh (2003) noticed expression of ruminal UT-B was changed by nitrogen intake levels. Marini and Van Amburgh (2003) observed greater expression of UT-B (based upon visual evaluation) in ruminal papillae collected from the ventral sac of the rumen in dairy heifers fed high-N diets (2.97 to 3.4% N) compared with low-N diets (1.45 to 1.89% N). Marini and Van Amburgh (2003) suggested that when a high-N diet is fed and ruminal ammonia is high, urea diffuses into the gastrointestinal tract via the paracellular space. Urease activity is known to be reduced by high ammonia concentrations (Bunting et al. 1989), a condition that arises when high-N diets are fed. Therefore, it is possible that the amount of crude protein increase UT-B abundance in the ventral rumen (Ludden et al. 2009). Also, Lu et al (2014) reported that by increasing nitrogen intake levels and increasing the blood urea nitrogen concentration to more than 5 mmol/l, the return of urea to the rumen and stimulate the expression of urea transporter B increase, linearly. Different levels of NFC in diet increase ruminal VFAS concentration and UT-B expression (<0.05). Dietary NFC different levels decrease ruminal pH (<0.05). Ruminal N-NH3 concentration was not influenced by Dietary NFC different levels. The values of I2 and Q for pH and UT-B expression effect size indicated high heterogeneity. Lu et al (2019) reported that the NFC-rich diet caused a reduction of urinal urea-N excretion by about 37%. Ma et al (2015) observed that, in lamb receiving a MNFC diet, the urinary N declined, but that fecal N did not change (Ma et al., 2015). Similarly, in growing steers, dietary carbohydrate facilitated urea being transferred from the blood directly to the rumen (Huntington, 1989; Younes et al., 2001). Lu et al (2019) observed that, in goats consuming an NFC-rich diet, the concentration of ruminal NH3-N was enhanced significantly, together with a significantly reduced urinal urea-N excretion. These data indicate that more urea-N was transferred into the rumen. This findings suggest that adequate dietary NFC feeding can improve nitrogen salvage in ruminant animals (Lu et al., 2019). The effect of dietary NFC on serum urea-N is associated with rumen microbes, which use plant carbohydrate as a fermentation substrate to obtain energy for microbial growth and as an indirect supply to host animals. Among the composition of plant carbohydrate, lignin is known to be non-degradable in anaerobic environments (Triolo et al., 2012). Dietary NFC, namely a fraction of easily-fermentable carbohydrate that includes starches, sugars, pectins, and glucans (Van Soest et al., 1991), leads to the rapid production of microbial metabolites, which are mainly SCFA (Hoover and Stokes, 1991). Previous studies have demonstrated that SCFA regulates blood urea entry into the rumen (Harmeyer and Martens, 1980; Remond et al., 2003). Remond et al. (2003) have reported that the highest rates of urea influx into the rumen and the highest NH3- N concentration in the rumen appears postprandially, when fermentation processes lead to a raise of SCFA in the rumen. Ruminal SCFA rapidly promotes blood urea across the rumen epithelium. A decrease of pH from 7.4 to 6.6 in the mucosal buffer exerted the same effect on flux Jsm urea as SCFA did (Lu et al., 2014). These data are in good agreement with another previous ex vivo study (Abdoun et al., 2010; Lu et al., 2014) providing supporting evidence that SCFA and pH stimulate blood urea entry into the rumen (Lu et al., 2019). According to the results of current meta-analysis, both dietary CP and NFC increase UT-B expression. It seems however that the NFC have a greater effect on increasing UT-B expression than CP.

    Keywords: Carbohydrate, Dietary, Meta-analysis, Protein, Urea Transporter
  • Omid Khorasani, Morteza Chaji *, Farshad Baghban Pages 73-87
    Introduction

    In the small intestine, villi height, crypt depth, epithelial tissue thickness, and the ratio of villi height to crypt depth play a significant role in the final stages of digestion and absorption of nutrients from the gastrointestinal tract (Strusińska et al., 2009, Wang et al 2009). The special shape of the villi and the presence of small intestinal micropores increase the level of intestinal absorption and have a direct effect on their efficiency and function (Kreikemeier et al 1991). The presence and absorption of volatile fatty acids are the keys to developing the tissue structure of the gastrointestinal tract (Attaix and Meslin 1991 and Vi et al 2004). The effect of volatile fatty acids on stimulating cell proliferation and growth of gastrointestinal tissue is not limited to the reticulum and rumen, but also affects the small intestinal villi. (Wang et al 2009). Feeding animals with high concentration diets could cause metabolic problems including acidosis (Aschenbach et al 2002). Its results are included the death of gram-negative bacteria and the release of endotoxins (lipopolysaccharides) into the bloodstream from the damaged rumen wall, activating inflammatory mediators, and affecting the productive function of animals (Garcia Diaz et al 2018). The possible effects of microbial additives on the gastrointestinal tract are through the regulation of ruminal pH and the immune system, which are useful for improving digestion, function, and animal health (Ding et al 2008 and Silberberg et al 2013). The use of yeast and other biologically active compounds such as lactic acid consuming bacteria compared to chemical buffers could be effective in reducing inflammation caused by acidosis. (Aschenbachet al 2019)

    Material and methods

    Twenty-four Arabic male lambs with Four months old and initial body weight of 23.9±3.15 kg were used in a completely randomized design with three treatments and eight replicates. The trial period consisted of 77 days (11 weeks) including 14 days of habituation period and 63 days (9 weeks) of the recording period. The lambs were randomly assigned to one of three treatments: 1-control (no additive) 2-control + Sodium bicarbonate (1% daily diet in two meals) 3-control + Megasphaera elsdenii and Saccharomyces cerevisiae (bacterium - yeast). The amount of Megasphaera elsdenii was 3 ml per animal (4.5 × 108 cfu / ml) plus 2 g of Saccharomyces cerevisiae (DFM) fed to the animals daily in the morning (Sedighi and Alipour 2019). The diets were adjusted using the Small Ruminants Nutrition Requirements (NRC 2007). The lambs were fed a fully mixed (TMR) ratio of 30% forage and 70% concentrate at two meals (8 and 16 hours) with free access to water. For the histological trial of the intestines, fragments were separated from the middle part of the three regions of the duodenum, jejunum, and ileum, and the middle part of the large intestine and each part were emptied with formalin rinsing, Then the two ends of each piece were closed and neutral formalin 10 % was injected into them, and separately in containers with lid containing formalin 10 % were placed. Micrometric studies of different parts of the small intestine: Villus height, crypt depth, villus width, and thickness of tunica muscularis were examined histomorphometrically.

    Results and discussion

    villi height, crypt depth, and villi surface of the duodenum in bacterium - yeast treatment were higher than other treatments (P<0.05). The thickness of tunica muscularis in the buffer treatment was higher than other treatments (P<0.05). The width of duodenum villi in the buffer and bacterium-yeast treatments was higher than the control treatment and was significant in the bacterium - yeast treatment than the control treatment (P<0.05). No significant difference was observed between jejunum tissue indexes in the treatments. The height of ileum villi in buffer and bacterium - yeast treatments was higher than the control treatment and was significant in the bacterium - yeast treatment than the control treatment (P<0.05). Crypt depth and villi surface of ileum in bacterium - yeast treatment was higher than other treatments (P<0.05). In buffer and bacterium - yeast treatment due to pH adjustment and increased activity of fiber degrading bacteria which produce more acetate (Lechartier and Peyraud 2011 and Malekkhahi et al 2016) The dimensions of the villi of the small intestine increased. In Histopathological investigation of the duodenum in all three treatments of control, buffer, and bacterium -yeast, infiltration of mononuclear inflammatory cells in the parenchymal mucosa was observed. In terms of lesion severity, the highest involvement was in the mucosa of the control treatment and then in the sodium bicarbonate buffer treatment and was less in the bacterium-yeast treatment than the other two treatments. In the bacterium-yeast treatment, the penetration of mononuclear inflammatory cells in the parenchyma of jejunal mucosa was much less than control and buffer treatments. In bacterium -yeast treatment, the frequency of Peyer's patches in the ileum is reduced compared to other treatments, which indicates a reduction in tissue inflammation. Histopathological investigation of the large intestine showed the infiltration of mononuclear inflammatory cells in the control treatment. The penetration of mononuclear inflammatory cells in this part was less than that of the small intestine. The severity of tissue lesions in the buffer and bacterium-yeast treatments was lower than the control treatment. In bacterium-yeast treatment, the penetration of mononuclear inflammatory cells was greatly reduced.

    Conclusion

    Compared to the control, the use of pH regulators in terms of histopathology reduce tissue damage in the small intestine and large intestine. The use of pH regulators, especially the bacterium-yeast composition, has led to the development of intestinal mucosal indices such as villi height and crypt depth. In addition, the destructive effect of acidosis, such as the penetration of inflammatory cells and necrosis, which was the result of increased consumption of high concentrates on digestive tissues; Has been reduced. Therefore, the use of pH regulators, especially bacterium - yeast, improve the tissue structure of the small intestine and they are reduced tissue damage in the small and large intestines.

    Keywords: Buffer, Histomorphometry, Histopathology, Megasphaera elsdenii, Saccharomyces cerevisiae
  • Nooshin Ghahramani, Mokhtar Ghaffari, Ghorban Elyasi Zarrin Ghobaie Pages 89-98
    Introduction

    In order to take advantage of breeding programs and productivity of poultry and other domesticated animals, it is essential to assess genetic variability and study the strategies to preserve genetic diversity. The Japanese quail is widely used as a model for animal research purposes in laboratory studies because of its small body size, short intergeneration interval, high growth rate, production of more eggs and meat. Although, Japanese quail has various benefits as a laboratory bird, but its genome sequence is not accessible now. The genome sequence of Japanese quail will deliver important genomic resources to accelerate different studies and to authenticate divergent lines of Japanese quail. Growth is a complex physiological pathway that occurs from fertilization until maturity in birds. Insulin-like growth factor I (IGF-I) gene is one of the most important candidate genes in different species which can affect the performance traits because of its function in metabolism and growth. IGF-I is a 70 amino acid polypeptide hormone with endocrine, paracrine, and autocrine effects. It has been reported that there is association of genetic polymorphisms of the IGF-I gene with growth traits in the poultry. There are relatively few reported studies about the relation between genetic markers of the IGF-I gene and body weights in quails. The objective of this study was undertaken to identify polymorphisms of the IGF-I gene using PCR single-strand conformational polymorphism (PCR–SSCP) analysis and to evaluate association of these polymorphisms with body weight in the Japanese quail.

    Materials and methods

    For doing this research, body weight of the 110 quails under study (46 males and 64 females) in different ages were collected. All data were collected from the Natural Resources Research Center of East Azerbaijan. The data included the identification of the animal, year of birth, sex, body weights at 15, 30, 45 and 60 days. Genomic DNA was extracted from 10 μl of blood in presence of Pronase (Bailes et al., 2007) and stored in EDTA-coated tubes and placed immediately inside an ice box and transferred to the laboratory. The samples were stored at -20 until DNA has been extracted. The quality and quantity of extracted DNA were measured by %0/8 agarose gel electrophoresis. PCR was done for amplifying a fragment in size of 465 bp of IGF-I gene. The PCR primers for the IGF1 gene were designed based on GenBank. PCR primers of IGF-I gene was mentioned in Table 1. The PCRs were carried out in 25 μl volumes containing 1 unit Taq DNA Polymerase, reaction buffer 1X (Sina Gene, Tehran, Iran), 1/5 mM MgCl2, 0/2 μM each of dNTPs, 10 μM of each primer (Sina Gene, Tehran, Iran) and 30 ng of genomic extracted DNA as template. PCR was performed using the T-professional thermal cycler. The thermal profile consisted of 3 min at 95°C, followed by 35 cycles of 40 s at 95°C, 30 s at 58°C and 40 s at 72°C, with a final extension of 5 min at 72°C. Amplification was carried out in Mastercycler (Bailes et al.,2007). PCR products were detected by electrophoresis on %1/5 agarose gel containing ethidium bromide and were visualized in a gel documentation system with a UV transilluminator. PCR products were mixed with 20 μl of denaturing loading dye [95% deionized formamide, %0/35 xylene cyanol, %0/25 bromophenol blue and 10 mM EDTA] in a total volume of 10 μl. The mixture was denatured at 95°C for 15 min and was snap chilled on ice. The electrophoresis was performed in 0.5X TBE buffer (Tris 100 mM, boric acid 9 mM, EDTA 1 mM) at room temperature (18°C) and constant 110 V for 16 h. Polyacrylamide gels were stained with silver according to the protocol described (Benbouza et al.,2006). A statistical model included the mean of population, fixed effect of the sex, random effect of the genotype patterns and residual random term was done by using GLM of SAS software to find the association between the SSCP genotype patterns of PCR products with the body weights. Significant differences among means of different genotypes were calculated using Duncan method in the GLM program and P values of 0.05 were considered statistically significant.

    Results and discussion

    The investigation of candidate genes is one of the foremost techniques to reveal whether definite genes are associated with the economic traits in animals. We successfully amplified the exon 4 of the IGF-I gene. All extracted DNAs from quail blood samples yielded a specific single band PCR product without any nonspecific band. Therefore, the PCR products were directly used for SSCP analysis. The results of SSCP showed that this population was polymorphic at the studied loci and three different genotypes with frequencies of 7.27%, 50.91% and 41.82%, respectively were observed in the examined quails (Figure 3). The results indicated that the exon-4 of IGF-1 gene is polymorph and there was a significant difference (P<0.05) between the genotype patterns and body weight on 30 days. However, for association of gender effect on body weight, there was a significant difference (P<0.05) in the age of 60 days. Also the average daily gain in females is more than males in different ages.

    Conclusion

    The goal of this study was to determine genetic polymorphism of IGF-I gene in Japanese quail. According to this research, the selected locus for investigating of IGF-I gene in quail can be considered as a locus that effects on body weight and growth rate of quails. It can be also measured as the factor that cause of difference of body weight in different periods.

    Keywords: body weight, Insulin-Like Growth Factor-I, Japanese quail, Polymorphism
  • Hossein Mohammadi *, Amir Hossein Khaltabadi Farahani, Hossein Moradi, Iman Haj Pages 99-111
    Introduction

    Understanding the genetic control of growth traits is one of the most important breeding goals in poultry industry. Genomic selection has provided the poultry industry with a powerful tool to increase genetic gains on economically important traits such as meat production. One way to identify new loci and confirm existing QTL is through genome-wide association analysis (GWAA). In addition identifying of genes loci with large effects on economically important traits, has been one of the important goal to poultry breeding. QTL assisted selection and genomic regions affecting the production traits have been considered to increase the efficiency of selection and improve production performance. Genome wide association studies typically focus on genetic markers with the strongest evidence of association. However, single markers often explain only a small component of the genetic variance and hence offer a limited understanding of the trait under study. A solution to tackle the aforementioned problems, and deepen the understanding of the genetic background of complex traits, is to move up the analysis from the SNP to the gene and gene-set levels. In a gene-set analysis, a group of related genes that harbor significant SNP previously identified in GWAS, is tested for over-representation in a specific pathway.

    Material and methods

    The aim of the present study genome wide association studies (GWAS) based on Gene set enrichment analysis for identifying the loci associated with related to body weight and shank length and diameter traits in advanced intercross line (AIL) using the high-confidence SNPs that enable us to study 161376 SNP markers simultaneously. For this purpose, the 599 advanced intercross line and 161376 markers were performed with mixed linear model (MLM) approach was used for the GWAS of the F9 generation, as implemented in the GCTA package (v1.92) (Yang et al., 2011) and no any correction to adjust the error rate. The gene set analysis consists basically in three different steps: (1) the assignment of SNPs to genes, (2) the assignment of genes to functional categories, and finally (3) the association analysis between each functional category and the phenotype of interest. In brief, for each trait, nominal P-values < 0.005 from the GWAS analyses were used to identify significant SNP. Using the biomaRt R package the SNP were assigned to genes if they were within the genomic sequence of the gene or within a flanking region of 15 kb up- and downstream of the gene, to include SNP located in regulatory regions. For the assignment of the genes to functional categories, the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway databases were used. The GO database designates biological descriptors to genes based on attributes of their encoded products and it is further partitioned into 3 components: biological process, molecular function, and cellular component. The KEGG pathway database contains metabolic and regulatory pathways, representing the actual knowledge on molecular interactions and reaction networks. Finally, a Fisher’s exact test was performed to test for overrepresentation of the significant genes for each gene-set. The gene enrichment analysis was performed with the goseq R package. In the next step, a bioinformatics analysis was implemented to identify the biological pathways performed in BioMart, Panther, DAVID and GeneCards databases.

    Results and discussion

    Gene set enrichment analysis has proven to be a great complement of genome-wide association analysis (Abdalla et al., 2016). Among available gene set databases, GO is probably the most popular, whereas KEGG is a relatively new tool that is gaining ground in livestock genomics (Morota et al., 2015, 2016). We had hypothesized that the use of gene set information could improve prediction. However, neither of the gene set SNP classes outperformed the standard whole-genome approach. Gene sets have been primarily developed using data from model organisms, such as mice and flies, so it is possible that some of the genes included in these terms are irrelevant for meat production. It is likely that a better understanding of the biology underlying meat production specifically, plus an advance in the annotation of the chicken genome, can provide new opportunities for predicting production using gene set information.11 SNP markers on chromosomes 1, 2, 4, 5, 7, 8, 10, 11, and 27 located in MSTN, CAPN3, PNPLA3, ANXA2, IGF1, LDB2, LEPR, FN1, ‌TMEM135, MC4R, EDN1, and ADAMTS18 genes were identified. Some of the genes were found are consistent with some previous studies and to be involved biological pathways related to muscle skeletal growth, energy metabolism and bone growth and development. According to pathway analysis, 19 pathways from gene ontology and KEGG pathway were associated with the body weight and shank length and diameter trait (P˂0.05). Among those pathways, the regulation of muscle organ development, regulation of cell growth and anatomical structure homeostasis biological pathway has an important role in the growth and skeletal muscle development. Also, the anatomical structure formation involved in morphogenesis, positive regulation of ossification and calcium signaling pathway significant association with body weight and shank length and diameter traits. Some of these regulatory regions, such as enhancers, are located far from the genes. Therefore, although the gene might be part of the analysis, the relevant variant would probably not be included in the gene set SNP class. Finally, linkage disequilibrium interferes with the use of biological information in prediction because irrelevant regions (regions without any biological role) capture part of the information encoded in relevant regions, causing both regions to exhibit similar predictive abilities. The use of very high density SNP data or even whole genome sequence data could alleviate some of these issues. Finally, it is worth noting that our gene-set enrichment analysis was conducted using a panel of SNP obtained from a single marker regression GWAS, which relies on a simplified theory of the genomic background of traits, without considering for instance the joint effect of SNP. Hence, other approaches (e.g., GWAS exploring SNP by SNP interactions) might provide a better basis for biological pathway analysis.

    Conclusion

    Considering, this study supported previous results from GWAS of body weight and shank length and diameter traits, also revealed additional regions in the chicken genome associated with these economically important traits, presented here should be contribute to a better understanding of the genetic control of growth traits in broiler chicken and using these findings can accelerate the genetic progress in poultry breeding programs.

    Keywords: body weight, Candidate gene, Chicken, Genome scan, Gene set enrichment analysis
  • Hossein Daghigh Kia *, Mahdi Nazari, Jamileh Emami Pages 113-124
    Introduction

    Long-term storage of semen is essential for achieving the benefits of artificial insemination (Tuncer et al., 2010). This is carried out by sperm cryopreservation, which stops the sperm metabolic activities, allowing long storage (Bailey et al., 2000). This process affects the sperm quality (Wang et al., 1991) by introducing mechanical and chemical damage, production of reactive oxygen species, oxidative stress, and reducing antioxidant activity (cysteamine is an aminothiol antioxidant as an effective scavenger). Cysteamine is known to have been reported in some studies to improve the freezing of ram sperm (Bucak et al., 2007). The aim of the present study was to determine the antioxidant effects of cysteamine on the functional parameters of cystemine in Lake Extender based on soybean lecithin.

    Method and material 

    This study was carried out in University of Tabriz research station. For this purpose, 15 adult roosters of 25 weeks were used. Sperm collection was done by dorsal-abdominal massage. The roosters were habituation for one month and sperm collection was performed twice a week. First, sperm were examined for volume, concentration and color, and only samples with volume of 0.2 to 0.7 ml and motility greater than 80% were used. To eliminate the individual effects, the confirmed samples were pooled. Four levels containing control, 15, 30, and 45 μM cysteamine were then added to Lake Extender containing 1/4 glycerol and sperm added to the extender containing different levels of antioxidant. The cooling process was carried out in two steps. The samples were adjusted to 4°C and after two hours the samples were cooled to 4°C. Then, samples were transferred to the refrigerator for one hour more, then they were drawn into 0.25 ml straws, placed 4 cm above nitrogen vapor for 7 min, and then immersed in liquid nitrogen. They were stored in liquid nitrogen until carrying out the tests. For thawing, the straw containing the samples was removed from the tank and immersed in water for 30 seconds at 37°C in water bath. The motility parameters were evaluated using CASA, viability by Eosin-Nigrosin staining, membrane integrity by Host tests, sperm abnormality by Hancock test and lipid peroxidation by MDA.

    Results 

    Addition of cysteamine at all levels significantly improved motility parameters. At the 30 and 45 μM levels total motility significantly increased and 30 μM level improved progressive motility, VAP, VSL and VCL parameters (P <0.05). The results show that the addition of cysteamine amino acid improves sperm quality. Addition of 30 μM level significantly increased viability and plasma membrane integrity of rooster sperm (P <0.05); Also significantly decreased malondialdehyde compared to the control group (P <0.05). The addition of cysteamine reduced sperm abnormality which was not significant. Discussion Freezing causes oxidative stress and induces eversible damage such as reduced viability and fertility (Najafi et al., 2014). This study was conducted to evaluate the addition of cysteamine as a supplement to counter oxidative damage during freezing and thawing (Blesbois, 2011). Normally, the antioxidant system in the semen eliminates the free radicals in the semen which are disturbed by cryopreservation process (Safa et al., 2017). Adding antioxidants can control ROS production (Amini et al., 2015). Antioxidants in different species and at different doses have shown different results. Addition of cysteamine to rooster spermatozoa during freezing and thawing significantly increased motility and survival parameters, which was in agreement with the results of Bucak et al., (2007) reported that the addition of cysteamine to ram sperm improved sperm motility parameters (Najafi et al., (2014) also reported an increase in motility and viability of ram sperm with addition of 2, 4 and 6 mM cysteamine levels, but at 8 mM level these parameters were significantly reduced. This was probably due to the high dose of diluent used. But it was in contrast to the study of Thananurak et al., (2019) who reported that adding levels of 0.001, 0.002, 0.004 and 0.01 decreased motility and viability. Low levels of cysteamine induce cysteine to enter the cell, producing glutathione as an intracellular antioxidant. Cysteamine at high doses produces large amounts of hydrogen peroxide, causing oxidative stress and reducing glutathione peroxidase activity (Besouw et al., 2013). According to reports (Partyka et al., 2013) cysteine increases motility and viability of rooster sperm. Glutathione peroxidase is one of the enzymes with peroxidative activity that plays an important role in sweeping high oxidations and protecting the cell from oxidative stress. Glutathione can also restore the oxidized vitamins E and C and restore them to the original antioxidant structure (Almasi et al., 2014). Cysteamine as a glutathione synthase can play a major role in reducing free radicals. In the present study, the amino acid cysteamine decreased malondialdehyde concentration and increased plasma membrane integrity and normal sperm during the freezing-thawing process, which is in agreement with the report of Najafi et al., (2014) which reported that addition of 6 mM reduced the concentration of malondialdehyde in ram semen compared with the control group. Not only does cysteamine improve sperm quality after freeze-thawing, but also it increases sperm resistance during artificial insemination in the reproductive female tract (Najafi et al., 2014). In the present study, cysteamine did not significantly decrease the percentage of abnormal sperm compared to control group.

    Conclusion

    Antioxidants have different results depending on the doses which are used and the treated species, and by understanding the antioxidant mechanism and achieving the optimal dose, the best results can be obtained. In the present study, the use of cysteamine amino acid as an antioxidant supplement improved sperm functional parameters and significantly reduced lipid peroxidation at level 45 μM.

    Keywords: Antioxidant, Cysteamine, Oxidative stress, Malondialdehyde, sperm
  • Behrouz Yarahmadi, Mohsen Mohamadi Saei, Karim Ghorbani, Nader Papi Pages 125-142
    Introduction

    Compensatory growth is actually a physiological process in which the animal's potential, after a period of dietary restriction, can be exploited to increase growth and growth efficiency during the free feeding period (Hornick et al 2000). Compensatory growth is widely used today in various countries. Another specific management approach (short-term strategies) in lamb fattening is appropriate weight at the beginning of fattening (Santos Silva et al 2002). The benefits of applying a compensatory growth mechanism during the breeding period can be improved feed efficiency during the compensatory growth period (Abouhif et al 2013 and Sami et al 2016), reduced feed cost throughout the breeding period, also improved weight gain during the breeding period (Clark et al 2007; Abuhif et a l 2015) and reduced energy maintenance needs (Kamalzadeh et al 2009; Shadnosh et al 2011). Considering the feedlot of 320,000 fattening lambs in Lorestan province per year and the possibility of using feed restriction to promote the use of compensatory growth in lamb fattening, the project was carried out aims to investigate the possibility of process changing the growth rate, fattening and physical and chemical composition of carcass lambs Lori breed by short-term strategies of feed restriction.This study was conducted to investigate the effect of different weight start of feed restriction on growth performance and carcass lambs traits Lori breed lambs.

    Material and methods

    Fifty four male Lori lambs with a mean live weight of 26 kg were selected for the experiment. Treatments were consisted of 6 feed restriction treatments (60,80%) and ad libitum(fattening diet without restriction) for two weights (30 and 35 kg). At the beginning of expriment, 54 experimental lambs were fed the same diet.After a 14 day pre-feed restriction period, a group of 27 individuals that had reached an average weight of 30 kg were separated from the rest and subjected to feed restraint treatments. The remaining 27 lambs were fed the former diet for 35 days until reaching a weight of 35 kg. Upon reaching this group, an average of 35 kg dietary restriction was applied.The feed restriction period for both groups was 30 and 35 kg for 35 days. Then the 30 kg group for 49 days and the 35 kg group for 28 days until the end of the fattening period were re-fed the control diet (fattening ration without restriction and ad libitum). At the end of experiment, daily weight gain, final weight, feed conversion ratio, feed efficiency and feed intake were calculated and then three lambs were slathered from each treatment. Carcass characteristics were calculated with the cost of production per kg of weight gain, carcass and lean meat. Analysis were done by repeated measurements basis on a completely randomized design with a mixed model procedure. Comparison of mean treatments was performed by Tukey test. The statistical model was as follows:Yijk= μ + Ti+ Dk + Aij+ (T*D)ik + εijk.

    Results and discussion

    The results of Table 2 showed that the effect of the experimental diets had no significant effect on all the traits of lambs weighing 30 and 35 kg over the pre-feed restriction period. Results showed that there were significant difference between the final weight of lambs at the end of feed restriction period (P<0.05). At the end of the re-feeding, no significant differences were observed among the control treatment (30 and 35kg) with 60 and 80% feed restriction groups. In the present study, at the beginning of the re-feeding period in the respective treatments, the daily weight gain in the feed restriction treatments was significantly higher than the control groups at 30 and 35 kg. There were significant difference among intake dry matter of lambs at the end of feed restriction period (P<0.05). At the end of compensatory growth, there was observed no significant difference between control and restriction groups. During the re-feeding period, feed conversion ratio was lower in feed restriction treatments compared to control treatment (30 and 35 kg). Compensated feeding reduced FCR in lambs with prior feed restriction compared to control. The results showed that feed efficiency and feed intake needed to maintain live weight are affected by the animal feeding program. Results of physical composition of carcass during re-feeding showed that the average of most carcass traits in the control treatment (30 and 35kg) and 80% of feed restriction treatment for 30kg lambs had no significant difference and were higher than other groups. Also in the compensatory growth experiment, there was no significant difference between the number of empty body weight, hot carcass and cold carcass weight sa well as dressing percentage due to no difference in the final live weight between the 30 and 35 kg control groups with 80% feed intake. Another study in other ruminants was consistent with feed restriction and compensatory growth.Meanwhile, the fat tail weight and percentage and total carcass fat were higher in the control treatment (30 and 35kg) than in all control groups. The results showed that the percentage of carcass lean meat in the compensatory groups was higher than the control treatments. This study showed that lambs with 80% feed restriction for 30kg lambs due to higher weight gain and FCR were more favorable in terms of fattening condition than control lambs who consumed feed during whole period. Also, this treatment was the total carcass fat percentage lower and lean meat higher and ultimately, the production costs per kg carcass and lean meat were lower than other treatments.

    Keywords: Carcass characteristics, Feed conversion ratio, Feed restriction, Re-feeding