فهرست مطالب

  • سال نهم شماره 1 (بهار 1396)
  • تاریخ انتشار: 1396/06/05
  • تعداد عناوین: 12
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  • علمی پژوهشی - تغذیه نشخوارکنندگان
  • سعید کامل ارومیه، عباسعلی ناصریان، رضا ولی زاده، فاطمه هلن قانع، محمد بنایان اول صفحات 1-12
    جهت تعیین سطح مناسب کربوهیدرات های غیر الیافی و اثر آن بر ماده خشک مصرفی، تولید و ترکیبات شیر، قابلیت هضم ظاهری ترکیبات خوراک، فراسنجه های شکمبه ای و وزن بدن تعداد 8 راس گاو شیری هلشتاین با چند شکم زایش و میانگین روزهای شیردهی 28±107 و میانگین وزن 68±644 کیلوگرم در قالب طرح مربع لاتین 4×4 تکرار شده با دوره های آزمایش 21 روزه مورد استفاده قرار گرفت. تیمارهای آزمایش به ترتیب شامل 33، 36، 39 و 42 درصد NFC در ماده خشک جیره بود. از جایگزینی ذرت و کنجاله سویا با سبوس گندم جهت دستیابی به سطح مورد نیاز کربوهیدرات غیر الیافی استفاده شد. افزایش NFC جیره منجر به افزایش معنی دار در میزان مصرف ماده خشک، تولید شیر روزانه، FCM 5/3 درصد و پروتئین، لاکتوز و مواد جامد فاقد چربی شیر شد. این در صورتی بود که درصد چربی شیر به طور معنی داری کاهش یافت. با افزایش NFC وزن بدن افزایش یافت با این حال تیمارها تاثیر معنی داری بر آن نداشتند. درصد ماده خشک مصرفی به ازای وزن بدن تحت تاثیر تیمارها قرار نگرفت. میزان کل پروتئین شیر با افزایش NFC، افزایش یافت.
    همچنین با افزایش NFC میزان کل چربی شیر افزایش یافت، اما تاثیر معنی داری مشاهده نشد. افزایش NFC منجر به افزایش معنی دار قابلیت هضم پروتئین خام، کربوهیدرات غیر الیافی، ماده خشک و ماده آلی خوراک شد. pH و نیتروژن آمونیاکی شکمبه با افزایش NFC کاهش پیدا کردند به طوری که این کاهش برای نیتروژن آمونیاکی معنی دار بود. نتایج این آزمایش نشان می دهد که افزایش کربوهیدرات های غیر الیافی به طور معنی داری موجب افزایش تولید و اغلب ترکیبات شیر می شود. به نظر می رسد جیره های گاوهای شیری در ابتدای دوره شیردهی می بایست حاوی بیش از 36 درصد NFC در ماده خشک جیره باشد.
    کلیدواژگان: عملکرد، کربوهیدرات های غیر الیافی، گاو شیری، مصرف خوراک
  • لیلا بابادی، مرتضی چاجی، طاهره محمدآبادی صفحات 12-23
    هدف از آزمایش حاضر، مقایسه ارزش تغذی های سرشاخه کامل درخت برهان و علوفه یونجه خالص در بزهای نجدی بود. مصرف خوراک، قابلیت هضم مواد مغذی، جمعیت پروتوزوآ و فراسنجه های تخمیری شکمبه ای و خونی مورد ارزیابی قرار گرفت. در این آزمایش شش راس بز نجدی با میانگین وزن 2/2±31 کیلوگرم در قالب طرح کاملا تصادفی مورد استفاده قرار گرفت. تیمارهای آزمایشی شامل دو جیره خالص شامل شاخه کامل درخت برهان یا علوفه یونجه بودند. تجزیه شیمیایی گیاه برهان نشان داد که پروتئین و چربی خام آن بالاتر از علوفه یونجه اما الیاف نامحلول در شوینده اسیدی (ADF) آن کمتر بود. اثر جیره های آزمایشی بر مصرف ماده خشک بزها معنی دار بود و برای جیره های خالص حاوی علوفه یونجه و برهان، به ترتیب 1326 و 1682 گرم در روز بود. استفاده از برهان در جیره بزها موجب افزایش معنی دار مصرف ماده خشک شد، اما بر قابلیت هضم ظاهری مواد مغذی تاثیری نداشت. غلظت نیتروژن آمونیاکی و pH مایع شکمبه در جیره حاوی برهان نسبت به علوفه یونجه به طور معنی داری کمتر بود. غلظت گلوکز و کلسترول خون تحت تاثیر جیره های آزمایش قرار نگرفت، اما تغذیه برهان باعث کاهش غلظت نیتروژن اوره ای خون شد. تغذیه برهان باعث کاهش معنی دار جمعیت پروتوزوآی شکمبه بزها شد. بنابراین، نتایج پژوهش حاضر نشان داد که مصرف و قابلیت هضم مواد مغذی در بزها تغذیه شده با گیاه کامل برهان تفاوتی با علوفه یونجه نداشت و اثر منفی بر فراسنجه های شکمبه ای و خونی مشاهده نشد، لذا شاید بتوان از آن در جیره بزهایی که در طبیعت به آن دسترسی دارند استفاده نمود.
    کلیدواژگان: پروتئین خام، تانن، ساپونین، غلاف و برگ، فراسنجه های خونی، کلسترول، مصرف ماده خشک
  • حمیدرضا میرزایی الموتی، زهرا شاهلیزاده، حمید امانلو، مصطفی حاجی لو، کامران اکبری پابندی صفحات 24-40
    این پژوهش جهت بررسی اثر افزودن موننسین و عصاره گیاهی در جیره های با کنسانتره بالا بر رفتار و عملکرد بره های افشاری انجام گرفت. برای انجام این آزمایش از 32 راس بره نر افشاری با میانگین وزن اولیه 6/5 ± 41 کیلوگرم و سن شش ماه در قالب طرح کاملا تصادفی با چهار تیمار و هشت تکرار به مدت 56 روز دوره آزمایشی و 21 روز سازگاری به جیره آزمایشی استفاده شد. جیره های آزمایشی شامل؛ 1) جیره شاهد بدون افزودن موننسین یا عصاره گیاهی، 2) جیره حاوی 30 میلی گرم موننسین، 3) جیره حاوی دو گرم عصاره گیاهی، 4) جیره حاوی 30 میلی گرم موننسین به صورت دو هفته در میان برای هر راس بره بود. وزن کشی به صورت هفتگی و خوراک مصرفی به طور روزانه اندازه گیری شد. بررسی رفتارهای خوردن و نشخوار کردن و تعیین pH شکمبه هر دو هفته یکبار انجام شد. در پایان دوره بره ها کشتار شدند و تفکیک و تجزیه لاشه صورت گرفت. نتایج حاصل از این آزمایش نشان داد که افزودن مکمل موننسین می تواند اثرات مثبتی بر افزایش وزن، خصوصیات لاشه و رفتارهای تغذیه ای بره های پرواری داشته باشد، ولی اثرات افزودن مکمل موننسین در طول پروار ثابت نبود و در اغلب پاسخ ها اثر جیره در دوره معنی دار بود به علاوه مشاهد شد که افزودن مکمل موننسین بصورت یک دوره در میان می تواند پاسخ های متفاوتی از افزودن آن به طور مستمر داشته باشد همچنین افزودن مکمل عصاره گیاهی به میزان دو گرم در روز تاثیر اندکی بر پاسخ های بره های پرواری داشت.
    کلیدواژگان: بره های پرواری، جیره های با کنسانتره بالا، عصاره گیاهی، موننسین
  • علمی پژوهشی- تغذیه طیور
  • محمد طاهر میرکزهی، حسن کرمانشاهی، ابوالقاسم گلیان، حسن صالح، محمد جواد آگاه صفحات 41-56
    این آزمایش به منظور بررسی اثرات 1-25 دی هیدروکسی کوله کلسیفرول [1، 25 (OH)2 D3] (کلسیتریول) و عصاره هیدرو الکلی ریشه گیاه دارویی بوزیدان (Withania somnifera) بر پاسخ ایمنی و ریخت شناسی روده کوچک جوجه های گوشتی انجام شد. تیمارها در قالب فاکتوریل (2×3×2) شامل جیره کنترل مثبت با سطح کافی کلسیم و کنترل منفی (کاهش 30 درصدی سطح کلسیم)، 3 سطح عصاره بوزیدان (صفر، 75 و150 میلی گرم در کیلوگرم جیره) و 2 سطح 1-25 دی هیدروکسی کوله کلسیفرول (صفر و 5/0 میکروگرم در کیلوگرم جیره) بود. تعداد600 قطعه جوجه گوشتی یک روزه راس 308 به صورت تصادفی در 60 عدد پن و 10 پرنده در هر کدام توزیع گردید. هر تیمار دارای 5 تکرار (50 پرنده در هر تیمار) بود. جیره های آزمایشی به طور نا محدود در اختیار جوجه ها از 1 تا 42 روزگی قرار گرفت. برای بررسی ایمنی هومورال از تست SRBC استفاده گردید. لذا دو تزریق در روزهای 25 و 32 دوره آزمایش برای تعیین پاسخ آنتی بادی اولیه و ثانویه انجام شد. در 21 و 42 روزگی یک پرنده از هر تکرار کشتار و وزن اندام های لنفاوی اندازه گیری و 5/1 سانتی متر از بافت ژژونوم به منظور تعیین خصوصیات ریخت شناسی جدا گردید. آزمایشات پاسخ ایمنی هومورال نشان داد که کاهش 30 درصدی سطح کلسیم جیره باعث کاهش تیتر آنتی بادی کل می گردد. عصاره هیدروالکلی ریشه بوزیدان در سطح 150 میلیگرم فقط باعث افزایش تیتر ایمونوگلوبولین G در تست اولیه گردید. هیچ گونه اثرات اصلی از تیمارهای آزمایشی بر وزن اندام های لنفاوی مشاهده نگردید. اطلاعات ریخت شناسی روده نشان داد که مکمل سازی کلسیتریول در جیره باعث کاهش طول پرز در 21 روزگی و کاهش عرض آن در 42 روزگی می گردد. کاهش 30 درصدی سطح کلسیم جیره منجر به کاهش عمق کریپت در مقایسه با گروه کنترل مثبت گردید. این آزمایشات نشان داد که کاهش سطح کلسیم جیره باعث کاهش پاسخ ایمنی هومورال می گردد. مکمل سازی عصاره بوزیدان در جیره های آزمایشی تاثیری بر خصوصیات پرز نداشت.
    کلیدواژگان: بوزیدان، پاسخ ایمنی، جوجه گوشتی، ریخت شناسی روده، کلسیتریول
  • علی نوبخت، ولی قربانعلی نژاد صفحات 57-72
    این آزمایش جهت ارزیابی اثرات استفاده از سطوح مختلف پوست هندوانه با و بدون استفاده از آنزیم بر عملکرد، خصوصیات لاشه، صفات ایمنی و فراسنجه های بیوشیمیایی خون جوجه های گوشتی انجام گرفت. تعداد 384 قطعه جوجه گوشتی سویه راس- 308 در 8 تیمار، 4 تکرار و 12 قطعه جوجه در هر تکرار با آرایش فاکتوریل (4× 2) شامل 4 سطح پوست هندوانه (صفر، 2، 4 و 6 درصد) و دو سطح آنزیم روابیو (صفر و 025/0 درصد) در قالب طرح کاملا تصادفی در دو دوره آزمایشی رشد (11 تا 24 روزگی) و پایانی (25 تا 42 روزگی) مورد آزمایش قرار گرفتند. استفاده از سطوح مختلف پوست هندوانه و آنزیم اثرات معنی داری بر عملکرد جوجه های گوشتی داشت (P<0/05). دو درصد پوست هندوانه افزایش وزن، وزن نهایی و ضریب تبدیل خوراک را بهبود داد (P<0/05).. استفاده از آنزیم در جیره وزن نهایی جوجه ها را افزایش داد (P<0/05). استفاده از آنزیم به همراه پوست هندوانه نیز، وزن نهایی جوجه ها را افزایش داد (P<0/05). سطوح مختلف پوشت هندوانه و آنزیم اثرات معنی داری بر صفات لاشه و سطح ایمنی جوجه ها نداشت (P>0/05). پوست هندوانه نتوانست اثرات معنی داری در رابطه با سطح فراسنجه های خونی داشته باشد، ولی استفاده از آنزیم موجب کاهش معنی دار سطح ldl خون جوجه هآ شد (P<0/05). به طور کلی استفاده از پوست هندوانه تا 6 درصد جیره اثرات سویی بر عملکرد جوجه ها نداشت. لیکن بهترین نتیجه با سطح 2 درصدی آن به دست آمد. در استفاده از آنزیم به همراه پوست هندوانه، وزن نهایی جوجه ها بهبود یافت.
    کلیدواژگان: آنزیم، پوست هندوانه، جوجه گوشتی، عملکرد، متابولیت های خون
  • صفورا صلاحی، جواد نصر، کیومرث امینی، سعید شالباف صفحات 73-83
    این تحقیق با هدف بررسی اثر گیرنده های محیطی هیستامین در حالات سیری و گرسنگی بر مصرف خوراک و آب، در جوجه های گوشتی انجام شد. 32 قطعه جوجه گوشتی یک روزه، تا 4 هفتگی به صورت گروهی پرورش یافتند، اما در هفته چهارم به صورت انفرادی نگهداری شدند. داده ها در قالب طرح اندازه گیری های تکرار شده در زمان تجزیه واریانس شدند و مقایسه میانگین ها با استفاده از آزمون LSMEANS صورت گرفت. تیمارها شامل کلرفنیرامین با مقادیر تزریقی40 میلی گرم بر کیلوگرم، فاموتیدین با مقادیر 5/2 میلی گرم بر کیلوگرم، هیستامین با مقادیر یک میلی گرم بر کیلوگرم و سرم فیزیولوژی بودند که در سن 4 هفتگی جوجه ها با حجم تزریقی 5/0 میلی لیتر و بصورت داخل صفاقی تزریق شدند. نتایج نشان دادند که بین میزان دریافت خوراک در جوجه های گرسنه با جوجه هایی که دسترسی آزاد به خوراک داشتند، اختلاف معنی داری وجود دارد، به طوریکه، هیستامین در حالت گرسنگی و سیری موجب کاهش در مصرف خوراک شد، ولی تاثیر هیستامین در حالت سیری قابل ملاحظه تر بود. تزریق کلرفنیرامین در هر دو حالت گرسنگی و سیری، موجب کاهش مصرف خوراک شد. فاموتیدین در در حالت گرسنگی اثری بر میزان مصرف خوراک نداشت ولی حالت سیری موجب کاهش مصرف خوراک گردید. در رابطه با مصرف آب می توان گفت که کلرفنیرامین موجب کاهش مصرف آب پرندگان گردید در حالی که مهار گیرنده های H2 هیستامین توسط فاموتیدین، سبب افزایش مصرف آب در حالت گرسنگی و سیری شد. به طور کلی دو گیرنده H1 و H2 در میزان اشتها و دریافت خوراک و آب دخالت دارند.
    کلیدواژگان: جوجه های گوشتی، فاموتیدین، کلرفنیرامین، هیستامین
  • علمی پژوهشی- ژنتیک و اصلاح دام و طیور
  • فرشته قدمگاهی، سعید زره داران، مجتبی آهنی آذری، مونا صالحی نسب صفحات 84-92
    هدف از تحقیق حاضر، بررسی خصوصیات ژنتیکی صفات رشد و تولید تخم مرغ شامل وراثت پذیری و همبستگی های ژنتیکی و فنوتیپی مرغان بومی استان خراسان رضوی بود. برای این منظور از اطلاعات جمع آوری شده مربوط به حدود 18000 مرغ طی سالهای 1389 تا 1391 استفاده شد. پارامترهای ژنتیکی صفات مورد بررسی با استفاده از روش آماری بیزی مبتنی بر نمونه گیری گیبس با نرم افزار GIBBS3F90 تخمین زده شد. وراثت پذیری و همبستگی های ژنتیکی و فنوتیپی بین صفات با استفاده از مدل حیوانی تک و دو صفتی برآورد گردید. وراثت پذیری صفات وزن بدن در سنین 8 و 12 هفتگی، سن و وزن بلوغ جنسی، تعداد و وزن تخم مرغ به ترتیب 37/0، 40/0، 30/0، 31/0، 46/0 و 11/0 برآورد شد. متوسط به بالا بودن توارث پذیری های تخمین زده شده برای صفات مورد مطالعه بیانگر سهم قابل توجه ژن ها در واریانس فنوتیپی و موثر بودن انتخاب در بهبود ژنتیکی این صفات است. همبستگی ژنتیکی وزن بدن در سنین 8 و 12 هفتگی و وزن بلوغ جنسی با سن بلوغ جنسی مثبت بود. بنابراین انتخاب برای افزایش رشد در سنین مختلف، به شکل نامطلوبی باعث افزایش سن بلوغ جنسی نیز می شود. با توجه به دو منظوره بودن مرغان بومی، توجه به عملکرد رشد در کنار تخم گذاری حائز اهمیت است. بنابراین، با توجه به همبستگی ژنتیکی نامطلوب صفات رشد با سن بلوغ جنسی، انتخاب هم زمان مرغان بومی برای افزایش وزن بدن و کاهش سن بلوغ جنسی با قرار دادن این صفات در شاخص انتخاب، برای بهبود صفات اقتصادی مرغ های بومی خراسان رضوی ضروری به نظر می رسد.
    کلیدواژگان: آنالیز بیزی، پارامترهای ژنتیکی، صفات اقتصادی، مرغان بومی
  • علیرضا شهدادی، مجتبی طهمورث پور صفحات 93-103
    در مطالعه حاضر از رکوردهای 191910 راس گاو شیری نژاد هلشتاین در دوره اول شیرواری به منظور بررسی عملکرد صفات تولید شیر و درصد چربی شیر 305 روز گاوهای شیری هلشتاین در اقلیم های مختلف ایران استفاده گردید. داده های مذکور مربوط به 1368 گله بوده که طی سال های 1379 تا1390 توسط مرکز اصلاح نژاد و بهبود تولیدات دامی کشور جمع آوری شده بود. محل جغرافیایی گله ها با توجه به شرایط آب و هوایی و با استفاده از روش طبقه بندی اقلیمی دومارتن پیشرفته به 5 گروه اقلیمی (خشک بیابانی، نیمه خشک، مدیترانه ای، نیمه مرطوب و مرطوب) دسته بندی شد. مولفه های واریانس-کوواریانس ژنتیکی صفات مورد بررسی با مدل حیوانی و روش حداکثر درست نمایی محدود شده بدون مشتق گیری برآورد شدند. وراثت پذیری تولید شیر 305 روز در محدوده 11/0 (اقلیم مدیترانه ای) تا 29/0 (اقلیم خشک بیابانی) و درصد چربی شیر 305 روز در دامنه 10/0 (اقلیم مدیترانه ای) تا 28/0 (اقلیم خشک بیابانی) برآورد شدند. در اقلیم های خشک بیابانی، نیمه خشک، مدیترانه ای، نیمه مرطوب و مرطوب روند ژنتیکی تولید شیر 305 روز به ترتیب 20/22، 37/17، 074/0-، 92/0 و 71/0- و روند ژنتیکی درصد چربی شیر 305 روز به ترتیب 0012/0-، 5-10 ×23/1، 5-10×5، 0002/0 و 0004/0- برآورد شدند. با توجه به اختلافات موجود در پارامترهای ژنتیکی صفات مورد بررسی در اقلیم های مختلف، به نظر می رسد که عملکرد گاوها در مناطق مختلف متفاوت بوده که می تواند ناشی از اثر متقابل ژنوتیپ و محیط باشد.
    کلیدواژگان: اقلیم های ایران، پارامترهای ژنتیکی، عملکرد، گاو شیری هلشتاین
  • حامد امیرپورنجف آبادی، سعید انصاری مهیاری، محمدعلی ادریس صفحات 104-112
    از جمله اهداف اصلاح نژاد در گاوهای شیری افزایش طول عمر تولیدی است. افزایش این صفت از طریق کاهش هزینه های جایگزینی تلیسه ها و ازدیاد فراوانی حیوانات پرتولید نقش بسزایی در افزایش سودآوری دارد. این مطالعه به منظور بررسی تنوع ژنتیکی طول عمر تولیدی گاوهای شیری هلشتاین با استفاده از مدل های تجزیه بقا انجام گرفت. داده ها شامل 35137 رکورد طول عمر تولیدی از زایش اول در گله های استان اصفهان طی سال های 1370 تا 1391 بود. حیوانات حذف شده و حذف نشده به ترتیب به صورت سانسور نشده و سانسور شده درنظر گرفته شد. همچنین هر گله دارای حداقل 20 رکورد بود و اطلاعات حداقل 10 دختر برای هر پدر در دسترس قرار داشت. برآورد فراسنجه های ژنتیکی با استفاده مدل پدری و کاربرد مدل ویبول در نرم افزار Survival Kit انجام شد. وراثت پذیری صفت طول عمر تولیدی براساس مقیاس لگاریتمی 074/0 و بر اساس مقیاس اولیه 18/0 برآورد شد. تغییرات فنوتیپی این صفت با ضریب رگرسیون 01/0 ± 03/0 - نشان داد کاهش خطر نسبی حذف در هر سال در گله های مورد مطالعه روی داده است. با توجه به تغییرات ارزش اصلاحی برآوردشده طول عمر تولیدی امکان افزایش این صفت از طریق انتخاب گاوهای برتر وجود دارد. بنابراین لازم است توجه بیشتری به صفت طول عمر تولیدی در برنامه های اصلاح نژاد گاو شیری انجام گیرد. روند منفی فنوتیپ احتمال خطر حذف نسبی نشان از بهبود فنوتیپی طول عمر تولیدی است اما روند ژنتیکی افزایش احتمال خطر حذف موید کاهش ژنتیکی طول عمر تولیدی در گله های مورد مطالعه است.
    کلیدواژگان: طول عمر تولیدی، گاو شیری هلشتاین، وراثت پذیری
  • رویا یاوری فرد، نوید قوی حسین زاده، عبدالاحد شادپرور صفحات 113-124
    هدف از این پژوهش ارزیابی اثر همخونی بر افزایش وزن روزانه و نسبت کلیبر در گوسفند مهربان بود. اطلاعات داده ای (مشتمل بر 6550 رکورد) و شجره حیوانات مورد استفاده طی سال های 1374 تا 1390 به وسیله سازمان جهاد کشاورزی استان همدان جمع آوری شده بود. صفات مورد مطالعه شامل میانگین افزایش وزن روزانه از تولد تا شیرگیری (ADGa)، از شیرگیری تا شش ماهگی (ADGb)، از شیر گیری تا نه ماهگی (ADGc) و از شیر گیری تا یک سالگی (ADGd) و به طور متناظر نسبت های کلیبر مربوطه (KRa، KRb، KRcو KRd) بود. حیوانات با توجه به ضرایب همخونی به دست آمده از شجره به سه گروه دسته بندی شدند: گروه اول شامل حیوانات غیر همخون و گروه دوم و سوم شامل حیوانات همخون بودند. برای ویرایش داده ها از نرم افزار Foxpro، برای برآورد اثر همخونی بر صفات از نرم افزار SAS استفاده شد و افت همخونی به صورت رگرسیون خطی با استفاده از رویه Reg نرم افزارSAS محاسبه شد. روند معنی دار ضرایب رگرسیون ADGa، KRa، ADGb، KRb، ADGd و KRd از همخونی همه بره ها به ازای افزایش 1% همخونی مشاهده شد. ضریب رگرسیون تمام صفات بجز KRc بر همخونی بره های تک قلو و صفات ADGa و KRa بر همخونی بره های دو قلو معنی دار بود. با توجه به جنس بره، ضریب رگرسیون تمام صفات بجز ADGc و ADGd بر همخونی بره های نر و ADGc و KRd بر همخونی بره های ماده معنی دار بود. نتایج این پژوهش نشان می دهد که همخونی بر میانگین افزایش وزن روزانه و نسبت کلیبر در گوسفند نژاد مهربان موثر بوده است و معنی دار و مثبت برآورد شد.
    کلیدواژگان: گوسفند دنبه دار مهربان، میانگین افزایش وزن روزانه، نسبت کلیبر، همخونی
  • مرجان احمدی، علی اسمعیلی زاده کشکوییه، احسان نصیری فر صفحات 125-134
    یک جمعیت نسل دوم از بلدرچین ژاپنی برای یافتن جایگاه های ژنی مربوط به صفات لاشه روی کروموزوم 5 با استفاده از نشانگرهای ریزماهواره بررسی شد. جمعیت مورد مطالعه حاصل از تلاقی دو سویه سفید و وحشی بلدرچین ژاپنی و صفات مورد بررسی شامل وزن لاشه گرم و سرد، وزن اندام های داخلی و قطعات لاشه پرندگان بودند. بعد از انجام واکنش زنجیره ای پلیمراز، افراد برای نشانگرهای به کاربرده شده با استفاده از نرم افزار AlphaEaseFC 4.0 تعیین ژنوتیپ شدند. والدین (P0)، پرندگان نسل F1 و F2 با استفاده از 3 مارکر میکروساتلایت ژنوتیپ یابی شدند. آنالیز داده ها با استفاده از نقشه یابی مبتنی بر رگرسیون صورت گرفت. QTLهای معنی دار برای صفات بازدهی لاشه، وزن مطلق و نسبی سینه، وزن نسبی و مطلق کبد، وزن مطلق و نسبی پشت، وزن مطلق و نسبی طحال، وزن سنگدان و وزن سر شناسایی شد. نسبت واریانس فنوتیپی نشان داده شده به وسیله آثار معنی دار افزایشی، غلبه و ایمپرینتینگ QTL از 22/2 تا 11/11 درصد بود. نتایج نشان دادند که جایگاه شناسایی شده برای بعضی از صفات لاشه در کروموزوم 5 یکسان بود که با توجه به ویژگی های صفات کمی (شامل اثرات پلیوتروپی و اپیستازی) می تواند در تفاوت فنوتیپی صفت تاثیرگذار باشد. چنین نتایجی نشان دهنده همبستگی ژنتیکی در میان صفات و پاسخ همبسته به انتخاب است.
    کلیدواژگان: بلدرچین ژاپنی، جمعیت F2، صفات لاشه، کروموزوم 5، QTL
  • محبوبه میرزایی ایلالی، سعید حسنی، مجتبی آهنی آذری، روح الله عبدالله پور، سکینه نقویان صفحات 135-145
    در گله های هسته اصلاح نژادی که عمدتا به صورت بسته نگهداری می شوند، بررسی همخونی و اثرات آن بر صفات اقتصادی امری ضروری است. هدف از انجام این مطالعه برآورد مقدار همخونی و اثر آن بر عملکرد صفات رشد، در گوسفندان سنگسری بود. در این تحقیق از اطلاعات مربوط به 7028 راس گوسفند سنگسری که طی 28 سال (1392-1365) در ایستگاه پرورش و اصلاح نژاد گوسفند سنگسری شهرستان دامغان، نگهداری و ثبت شجره شده بودند، استفاده گردید. جهت برآورد ضریب همخونی حیوانات موجود در شجره از برنامه CFC والگوریتم میوسین و لو، جهت تعیین ساختار جامعه از نرم افزار Endog v4.8 و برای برازش مدل های مختلف و محاسبه میزان تابعیت صفات از همخونی بر اساس بهترین مدل ازنرم افزار WOMBAT استفاده شد. میانگین نسل معادل کامل به عنوان معیاری از سطح تکامل شجره برای این جمعیت 59/1 برآورد شد و حدود 21/7 درصد از کل بره های ثبت شده همخون بودند. میانگین ضرایب همخونی کل جمعیت 28/0 درصد و نرخ افزایش سالیانه همخونی 028/0 درصد برآورد شد که از لحاظ آماری معنی دار بود. ضریب تابعیت اوزان تولد، 3، 6، 9 و 12 ماهگی از همخونی به ترتیب 46/1-، 72/7-، 87/14، 92/20 و 46/29- گرم برآورد شد ولی از نظر آماری معنی دار نبود. پایین بودن میزان همخونی در این تحقیق نشان داد که شدت آمیزش های خویشاوندی در این گله نسبتا پایین بوده و با توجه به عدم معنی داری تاثیر همخونی بر صفات مرتبط با رشد، اثرات سوء همخونی در گله قابل توجه نیست، ولی با کنترل شجره ای لازم در زمان جفت گیری، می توان از همخونی بالا در برخی از افراد گله جلوگیری کرد.
    کلیدواژگان: ساختار جمعیت، ضریب همخونی، گوسفند، وزن بدن
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  • Saeid Kamel Orumieh, Abbasali Naserian, Reza Valizadeh, Fatemeh Helen Ghaneh, Mohammad Banayane Aval Pages 1-12
    Introduction
    Carbohydrates (CHO) are the most important source of energy which provides over half of the energy in livestock diets. They are also the major sources of energy for ruminal microorganisms in a dairy cow’s diet. Carbohydrate nutrition influences both the quantity and quality of milk. Carbohydrates are mainly divided to two types of fiber and non-fiber. Determining the quantity of non-fibrous carbohydrates lead in the balance in dairy cows’ diet. The required levels of structural carbohydrates are known and available, but the desired level of non-fibrous carbohydrates is not defined in details. NFC is fermented fast and almost completely in the rumen. They include: starch, sugars, pectins and β-glucans. According to researchers, non-fiber carbohydrates (NFC) can be estimated by subtracting crude protein, NDF, ether extract and Ash from 100 with a correction for crude protein bound to Neutral Detergent Fiber. To reach the highest level of microbial growth, the availability of carbohydrates and protein must be synchronized. It could happen with the best availability level of NFC and rumen degradable protein (RDP).The purpose of this study was to evaluate the levels of non-fibrous carbohydrates in the range of 33 to 42% of the dry matter intake, milk production, milk composition, and body weight in Holstein dairy cow.
    Materials And Methods
    To determine the effect of dietary nonfiber carbohydrate (NFC) level on dry matter intake, milk production and body weight, eight multiparous Holstein cows averaging 107±28 d in milk and 644±68 kg BW in the beginning of trial were used in a replicated 4 × 4 Latin square arrangement (21-d periods). Treatments were 33, 36, 39 and 42% NFC in the DM bases. Experimental diets were formulated to meet the requirements according to National Research Council (2001) for Holstein cows of 620 Kg of BW and production 50 Kg of milk with 3.2% fat per day. Corn and soybean meal were substituted for wheat bran to achieve the requested level of non-fiber carbohydrates. Diets were fed as Mixed Ration (TMR) 37:63 forage to concentrate ratio and were offered three times daily ad libitum (0800, 1600 and 2400 h) for 10% refusals and cows had free access to fresh water. Data were analyzed in a changeover design using the mixed procedure of SAS Institute Inc (2003). The model included fixed effects of treatment and period, random effect of cow and residual error. Least squares means procedure (LSMEANS) was used to detect the difference between dietary treatments.
    Results And Discussion
    The glucose absorption is less when the animal uses the diet with low NFC level and then the glucose intake in hepatic portal vein increase. So, the less portion of glucose is provided to make production (e.g Milk) in animal tissues and as a result, the animal production decreases. With the supply of protein requirements and also the increase of fermentable carbohydrates, due to the synchronizing availability of protein and energy for ruminal microorganisms, their growth will increase which leads the VFA production to increase. The more production of VFA results in more supply of glucose and then energy in ruminants. So it seems that, the growth of NFC will cause to increase the production. Increasing the dietary nonfiber carbohydrate enhanced dry matter intake, body weight, milk production, fat corrected milk production (FCM 3.5%), protein percentage, lactase and solid nonfat (SNF) while, the fat percentage decreased significantly. Although, by increasing NFC the BW increased, the treatments had not any significant effects on that. DMI percentage of body weight was not affected by treatments. The amount of total milk protein was increased by growth in nonfiber carbohydrate. Increasing level of NFC led to significant increase in CP, NFC, DM and OM digestion. The pH of the rumen is the key factor in normal and stable function of it. Because the fermentation and physiologic function of the rumen influences ruminal microbial population. The pH value and the quantity of ammonia N in rumen fluid are substantial parameters to reflect the ruminal fermentation. Ruminal pH and ammonia were decreased by increasing the NFC in which the decrease in treatments for ammonia was significant.
    Conclusion
    Results showed that increasing nonfiber carbohydrate significantly increased milk production and milk protein percentage. It seems that diet of lactating cows in early lactation should contain over 36% NFC on DM bases.
    Keywords: DMI, Lactating dairy cows, NFC, Performance
  • Leila Babadi, Morteza Chaji, Tahereh Mohammadabadi Pages 12-23
    Introduction
    Due to the growing human population, the supply of animal protein for them is considered as an important goal. About 70-60% of the costs of livestock raising is associated with nutrition and one of the most important measures to reduce the cost of feed, is the applying of new materials in the livestock rations. Albizia is a native tree in tropical Africa and Asia, northern Australia and tropical America and also in many tropical and subtropical areas of the world. It could be also used in the diet to reduce the cost of livestock ration, but because of some anti-nutrients substances such as tannins and saponins, may be restricted its use in feed. Many studies have shown that it can be used as a protein and mineral supplement in animal feeds. The aim of the present study was the comparison of the nutritional value of the Albizia with alfalfa hay as sole feed source, in the Najdi goats.
    Materials And Methods
    Whole plant of Albizia containing seeds, pods and leaves were collected from ranges of Mollasani-Khuzestan region, and air-dried under shadow. In this experiment, six Najdi goats with an average weight of 31 ± 2.2 kg and 19±2 months old in a completely randomized design was assigned to two experimental diets. The experimental diets only were whole plant of Albizia or alfalfa. The diets was fed 28 days, include 21 days adaptation and 7 days sampling period, for measuring the nutrients digestibility. Chemical composition of experimental samples including: crude protein, ether extract, neutral detergent fiber, acid detergent fiber, dry matter and Tannin was measured according to standard methods. Feed intake, nutrient digestibility, protozoa population and ruminal fermentation (pH and Ammonia nitrogen) and blood parameters (glucose, blood urea nitrogen and cholesterol) were measured according to standard biochemical kits.
    Results And Discussion
    According to results detecting of the chemical composition, compared with alfalfa, Albizia contained more protein and ether extract and lower ADF than alfalfa forage. The dry matter intake of the goats which were fed by Albizia were significantly higher than they fed alfalfa (respectively, 1682 and 1326 grams per day), but the digestibility of nutrients were not significantly differed among them. The nutrients intake of diet containing Albizia was higher than alfalfa, due to more DM intake and difference in chemical composition of Albizia than alfalfa hay. As the consumption DM of Albizia and percentage of its NDF and crude protein was higher in comparison with alfalfa hay, so the intake of these nutrients was higher. In this experiment, in spite of presence the tannins in the branches of the Albizia, the nutrients digestibility, did not decreased. In the literatures, usually the tannin mentioned as a reduction factor of nutrients digestibility. But if the diet or its ingredients had high percentage of protein, the negative effect of tannins on the digestibility of nutrients due to its binding with proteins reduced, so perhaps due to the high protein of Albizia, its tannin had no negative impact on nutrients digestibility, in present study. The concentration of ammonia nitrogen and pH of the rumen fluid in diets containing Albizia was significantly lower than hay. Perhaps the reason reduction the concentration of ammonia nitrogen in Albizia diet was due to the tannins in that diet. The researchers reported that tannin sources, reduces the protein degradation and concentration of ammonia nitrogen in the rumen. Glucose and cholesterol concentration were not affected by the treatments, but feeding Albizia decreased the concentration of blood urea nitrogen.
    The feeding of Albizia significantly reduced the rumen protozoa population of the goats. Perhaps it was due to the present of tannin and saponin in the Albizia. The negative effect of saponin and tannin on rumen protozoan has been proved.
    Conclusion
    Therefore, the results of this study were shown that in compared to alfalfa hay, the presence of tannin and saponin of Albizia in diet of goats, had no adverse effect on intake and digestion of nutrients, also has beneficial effects on rumen fermentation as decreasing ruminal ammonia-N concentration, So Albizia can be used as part of the diet of goats, even as replacement for alfalfa hay. Although conducting a performance study to ensure is also recommended.
    Keywords: Blood parameters, Crude protein, Pod, leaf, Saponin, Tannin
  • Hamidreza Mirzaei Alamouti, Zahra Shahalizadeh, Hamid Amanlou, Mostafa Hajilou, Kamran Akbari Pabandi Pages 24-40
    Introduction
    The ionophore antibiotics have been added to high-grain diets as feed additives and reduced digestive problems with this compound have been reported in many studies. Monensin is an important ionophore that has been used for approximately four decades based on its potential to control rumen fermentation pattern and to decrease the incidence of acidosis and increase efficiency of nutrient utilization. These ionophores facilitate the release of ions from the lipid membrane of bacteria and protozoa also ionopheres increase propionate and decrease methane production. However, the use of antimicrobial agents as feed additives can contribute to antimicrobial resistance both in animals and humans, posing a serious risk to the public health. More recently, there has been a growing interest in the potential use of plant extracts as alternatives for antimicrobial feed additives in ruminants. The essential oils are second metabolites of plants, which have some effects on ruminal protein degradation and mitigate methane production. We hypothesized that replacing the plant extract for monensin would affect behavior and performance of Afshari lambs fed high concentrate diet.
    Materials And Methods
    Thirty two Afshari lambs with an average initial weight of 41 ± 5.6 kg and six months old were used in a completely randomized design with four treatments and eight replications in each treatment for 56 days with 21 days as an adaptation period and 35 days as an experimental period. In these periods, four diets for feedlot lambs were given. The basal diet was contained 20 % alfalfa hay, 65 % ground barley and 11% soybean meal. The basal diet was formulated with Cornell model software. Crude protein and metabolizable energy were 16 % and 2.75 Mcal/kg of dry matter respectively. The experimental diets were; 1) basal diet without additives, monensin or essential oil, 2) basal diet with 30 mg monensin/d for each lamb, 3) basal diet with two grams of a commercial plant extract, and 4) basal diet with periodically inclusion of 30 mg monensin/d for each lamb for two weeks and no for next two weeks. The lambs were weighed weekly and feed intake was measured daily. Feeding behavior and rumination and rumen pH determination was performed every two weeks. At the last day the lambs were slaughtered and the carcasses characteristics were determined.
    Results And Discussion
    Differences in dry matter intake did not differ due to relatively large individual variation in voluntary intake, but it tended to lower (P = 0.06) with monensin fed lambs. Effect of monensin on feed intake varied over time. The increases in feed efficiency and propionate production have hypothesized in many studies for decreasing DMI with monensin supplementation. Monensin can increase propionate production and its supply to liver and it has a hypophagic effect. Monensin inclusion to basal diet result to increase the time spent eating, chewing activity and the mean of eating meals, and also it increased eating and chewing activity for each kg of dry matter intake (P 0.05). The lambs fed monensin periodically had numerically lowest weight gain and monensin fed lambs had greater hot and cold carcass weight. Proposed that increased propionic acid as a result of the effects of monensin may be used in gluconeogenesis, thus it spared the amino acids for glucose and indirectly increase muscle or protein accretion. In addition, monensin stimulates micro-organisms in the digestive tract, so it optimizes nutrient synthesis in rumen and improves nutrient absorption in the digestive system.
    Conclusion
    The results showed that periodically inclusion of monensin to lambs diet may compromise performance compared to daily inclusion of monensin and plant extract. Inclusion of plant extract had a positive effect on daily weight gain and could be replaced for monensin, but further research is need to warrant these effects and ruminal and metabolic aspects of plant extracts and monensin.
    Keywords: Essential oil, Finishing lamb, High grain diet, Monensin
  • Mohammad Taher Mirakzehi, Hassan Kermanshahi, Abolghasem Golian, Hassan Saleh, Mohammad Javad Agah Pages 41-56
    Introduction
    1, 25-dihydroxycholecalciferol [1, 25 (OH)2 D3], the major biologically active metabolite of vitamin D3 is produced by two sequential hydroxylation reactions. The first hydroxylation occurred when vitamin D3 is transported to the liver, forming 25-hydroxycholecalciferol [25-(OH) D3] and the second in the kidney, by the enzyme 1-alpha-hydroxylase (VD3 1 hydroxylase) forming 1, 25 (OH)2 D3. Vitamin D3 may have a role in regulating the morphological and functional development of intestinal villus mucosa. Calcium ions have an essential role function in activation and maturation of lymphocytes. Previous studies have demonstrated that the intracellular concentration of free Ca2 increases in several types of cells during stress. For example, acute restraint stress enhances Ca2 mobilization in lymphocytes from mice. In addition, Ca2 ions are essential for production of interleukin-2 by T cells (22). Withania somnifera (WS) is an annual herb and a rich source of bioactive compounds. Several pharmacological activities of the plant have been attributed to its roots. Oral administration of root extract of WS at 10, 30 and 300 mg/kg body weight for 15 days stimulated B and T cells proliferation, induced type 1 immunity, increased the activity of machrophage and levels of immunoglobulin which indicated the potent role of extract on humoral and cellular immunity. The present study aimed to evaluate the main effects and interaction of calcitriol and WS root extract in either low or adequate Ca diets on immune response and small intestinal morphology of broiler chickens.
    Material and
    Methods
    Six hundred male day old Ross 308 broilers obtained from a commercial hatchery, and reared in 60 floor pens with wood shavings litter at a stocking rate of 10 birds per pen (1×1 m). Feed and water were provided ad libitum throughout the 6–wk experimental period. The experimental design was a 2×3×2 factorial comprising of two dietary concentration of Ca (negative and positive control), three concentrations of WS root extract (0, 75 and 150 mg/kg diet), two concentrations of 1, 25 (OH)2 D3 (0 and 0.5 g/kg diet). SRBC test was used to measure humoral immunity response. So, at 25 and 32 days of age chicks were injected to evaluate the primary and secondary antibody response. On d 21 and 42, one bird per replicate was killed to determine small intestinal morphology and lymphoid organ weights. Sample sections (2.5 cm in length) were taken from the middle region of the jejunum. The tissues were stained for measurement of villus length, villus width, crypth depth and thickness of muscle layer. The General Linear Models of SAS were used to analyse all the data.
    Results And Discussion
    The results of humoral immune response showed that reduction of dietary Ca level by 30% resulted to depression of immunoglobulin M and total antibody levels. Supplementation of WS at 150 mg/kg significantly improved the level of immunoglobulin G only in primary test. Calcium ions have an essential role function in activation and maturation of lymphocytes (10). Previous studies have demonstrated that the intracellular concentration of free Ca2 increases in several types of cells during stress. For example, acute restraint stress enhances Ca2 mobilization in lymphocytes from mice. In addition, Ca2 ions are essential for production of interleukin-2 by T cells. It was found that supplementation of calcitriol resulted in shorter villus length at 21 d and shorter villus width at 42 day of age, respectively. Reduction of dietary Ca level by 30% resulted to shorter crypth depth compared to positive control diet. A researcher reported that supplementation of 25-OH-D3 decreased the length and weight of small intestine. The duodenal putrescine content was enhanced in parallel with the increase in intestinal calcium absorption, suggesting that polyamines, in particular putrescine, may be involved somehow in the intestinal calcium transport mechanism. The aliphatic polyamines, putrescine, spermidine, and spermine, are considered to be essential cell constituents that play an important role in modulating cell proliferation and differentiation.
    Conclusion
    The results of humoral immune response showed that decreasing of dietary Ca level to 30% resulted to reduction of total antibody response. The findings showed that supplementation of calcitriol did not exert beneficial effects on intestine morphology. Supplementation of WS root extract did not affect intestine characteristics.
    Keywords: Broiler chicken, Calcitriol, Immune response, Intestine morphology, Withania somnifera
  • Ali Nobakht, Vali Gorbanalinejad Pages 57-72
    Introduction
    Watermelon is a fruit that is usually produced in large scales in many reigns of Iran. The annual production of watermelon in Iran is more than 3 million tons. Watermelon not only is a rich source of some vitamins and essential minerals, but also it contains considerable levels of secondary materials such as antioxidants. More than 25% of watermelon is skin and most of nutrients and secondary substances that present in whole watermelon, can be find in watermelon skin. In our country we usually do not use in all circumstances and change to garbage and discharge to environment and increase the environmental problems. As, watermelon skin is a valuable source of some essential nutrients and secondary substances and has low price, so it thought that using it in broiler diets not only can improve their performance and body health status, but also can solve some of environmental problems. The present study was conducted to evaluate the effects of different levels of watermelon skin powder with and without using enzyme on performance, carcass traits, blood biochemical parameters and immunity system of broilers.
    Materials And Methods
    This experiment was conducted as a (4*2) factorial arrangement included 4 levels (0, 2, 4 and 6% watermelon skin) and two levels (0 and 0.025% enzyme) with 384 Ross-308 broilers in 8 treatments, 4 replicates and 12 chicks in each replicate in two experiment period (grower from 11 to 24 days and finisher from 25 to 42 days) in a completely randomized design. Chicks were fed from 1 to 10 days with a common starter diet that recommended by Ross company. During experiment birds had free access to water and feed. Measuring of weight gain and feed intake were done at the end of experiment periods and feed conversion ratio was calculating by dividing the amount of feed intake to the amount of weight gain.
    Results And Discussion
    Different levels of watermelon skin powder and enzyme had significant effects on performance of broilers (P>0.05). Use of watermelon skin in 2% in diet increased the amounts of daily weight gain and final live weight of chicks and improved their feed conversion ratio (P>0.05). Different levels of watermelon skin powder had no effects on the amount of daily feed intake (P>0.05). Feeding enzyme in diet increased the amount of chicks final live weight (P>0.05). Different levels of watermelon skin powder and enzyme had no significant effects on carcass traits and immune condition (P>0.05). Watermelon skin could not significantly change the values of blood biochemical parameters, but using enzyme in diet, significantly reduce the amount of blood low density lipoprotein( LDL) (P>0.05). Without LDL, other blood biochemical parameters did not significantly change by using watermelon powder (P>0.05) Improving of performance by using watermelon skin powder can be having some reasons. As previously mentioned, watermelon skin is a valuable source of essential nutrients such as vitamins and minerals and useful secondary substances such as antioxidants. These matters can supply sufficient amounts of essential nutrients those need for health and growth of broilers and upgrade body health condition. Watermelon skin is a main source of diet potassium. Potassium is an effective nutrient in heat stress. As, the present study was done in summer, so this element may be had good effects on broiler performance. As watermelon skin contain highly amount of crude dietary fiber and birds especially broilers cannot tolerate highly level of crude fiber in their diets, so, using enzyme in broiler diets can degrade the crude fiber physical structure and improve the digestion efficiency of broilers. As seen in the present study, enzyme with watermelon skin in contrast to diets did not contain enzyme, improved the amounts of daily weight gain, final live weight and feed conversion ratio of broilers and reduced the amount of feed price for one kilogram of body weight gain.
    Conclusion
    The overall results showed that in broilers, using 6% of watermelon skin not only do not make any adverse effects on broiler performance, but also in contrast to diet with no watermelon skin, can improve some of them. However in absent of enzyme, the best result was obtained with diet contained 2% watermelon skin powder. More than 2% increased the amount of feed price for one kilogram of weight gain. Using enzyme with watermelon skin not only reduced the feed price, but also improved the final weight of chicks.
    Keywords: Blood metabolites, Broilers, Enzyme, Performance, Watermelon skin
  • Safoura Salahi, Javad Nasr, Keyiomars Amini, Saeed Shalbaf Pages 73-83
    Introduction
    Feed intake includes a set of physiological mechanisms that affects different parts of the central nervous system. Histamine as a central neurotransmitter involved in regulating appetite. This study is conducted to evaluate the effects of determining the importance of nutrition mode, on the effect caused by histamine via intra-peritoneal injection histamine peripheral receptors in satiety and hunger on feed and water of broilers. When the histamine injected central, feed consumption will be through of H1 histamine receptor. It seems peritoneum injection of histamine, prevents the feed consumption in broilers. We also designed some tests to determinate the effects of H1 and H2 receptors on feed consumption in growing broilers. Histamine through its H1 receptors prevents the feed absorption in broilers.
    Materials And Methods
    In this study, environmental impacts of histaminergic system on feed intake male Ross broiler chickens were studied in 2 phases. 32 one-day-old broilers were raised to four-week-old in group and then in the 4th week as single. The temperature in the first week of nourishment was set at 32-31 °C, and the every week the temperature was lowered 3-2 degrees, so that during the tests the temperature was adjusted between 24-21 ° C. Average weight of chickens at the time of the experiment (4 weeks), was 720 gr.
    Data was analyzed in form of repeated measurements and averages were compared using LSMEANS test. Data analysis was performed using SAS software. Treatments included 40 mg/kg inject able chloramphenicol, 5.2 mg/kg famotidine, 1 mg/kg histamine, and saline. The amount of water consumed was measured by drinker scaled with accuracy 1ml. Total volume injected was 5.0 ml intra peritoneal.
    Results And Discussion
    Results showed a significant difference between feed intake of hungry broilers and broilers who had free access to feed. Histamine induced lower feed intake in both satiety and hunger, but its effect was more significant in satiety. The tests showed that water intake in satiety and hunger modes were significantly different. The amount of water usage in hungry chickens was more as feed intake in hungry chickens was also more. We can say that water intake depends on the amount of feed intake and water intake also rises with increased feed intake. Serotonin is effective in reducing the amount of feed intake and reduces the duration and frequency of feed intake, but it is not effective on latency time before eating. Histamine through leptin may decrease feed intake. It also recognized that the saturation of cholecystokinine depends on liberalization of histamine, which is bound on H1 and H2receptor and ultimately reduces feed intake. Chloramphenicol reduced feed intake in both satiety and hunger. Famotidine induced lower feed intake in first minutes, but had no effect in hunger. Water appetite was decreased by chloramphenicol but famotidine increased water appetite by inhibiting H2 receptor, both in satiety and hunger. Seems that histamine and cholinergic systems are linked together and histamine modifies cholinergictrans mission. Theoretically cholinergic system reduces blood pressure, thus it reduces water loss from the kidneys and there by leads to secretion of kidneys and affect brain and causes sense of thirst and result in increasing water intake.
    Conclusion
    Finally, H1 and H2 receptors play role in feed and water intake. These antagonists were involved in controlling feed intake if they cause increased feed intake and may other receptors be involved reduced feed intake result from histamine. Receptor antagonistH1 (chlorpheniramine), in both satiety and hunger modes causes significant decrease in feed intake, also receptor antagonistH2 (famotidine) at limited times significantly decreased feed intake in chickens with no limitation period, that this reduction in feed intake in satiety mode was more and total, chickens in satiety mode consume less feed than hungry chicks. Chlorpheniramine causes significantly decreased water intake in both satiety and hunger. Famotidine significantly increases water intake in hunger mode and in satiety mode it significantly increases water intake in the first hours after injection. Histamine resulted in significant reduction of water intake in satiety and cause to significant increase of water intake in hunger mode. Considering the increased water intake by histamine and reducing water intake by chlorpheniramine at the same time, in hunger mode H1receptor is involved in increased water intake caused by histamine. Peritoneal injection of histamine shows that water consumption increase with feed consumption and it seems this occurrence regulated with some different mechanisms such as release of angiotens in and histamine.
    Keywords: Broiler chickens, Chlorpheniramine, Famotidine, Histamine
  • Fereshte Ghadamgahi, Saeed Zerehdaran, Mojtaba Ahani Azari, Mona Salehi Nasab Pages 84-92
    Introduction
    Iranian native fowl, which are kept in different parts of Iran, are characterized by a long history and vast diversity. Iranian indigenous chickens are meat-cum-egg type. There is evidence of variation in Iranian native fowl for different traits. In many developing countries, the local gene pool still provides the basis for the poultry sector. The genetic resource base of indigenous chickens can form a basis for genetic improvement and diversification to produce a breed adapted to local conditions. However there is little information about existing or potential productivity and production characteristics of indigenous chickens. Breeding of native fowl is important for small farmers to produce more income and also to conserve genetic variation of native breeds. Extensive investigations on the genetic characteristics of economic traits should be conducted before designing a breeding program. The correct method of evaluation of genetic parameters to select the best animals is very critical. Gibbs sampling Bayesian method was used to estimate genetic parameters. This method includes the definition of prior and posterior distribution and then combines to form full conditional posterior distributions for the analysis of complex models with a large number of records. This method is expected to better results achieved. The objective of the present study was to study the genetic characteristics of growth and egg production traits consisting heritability and genetic and phenotypic correlations in native fowl of Khorasan Razavi province.
    Materials And Methods
    The collected information of about 21000 native fowl of Khorasan Razavi Province during 2009 to 2012 were used. Genetic parameters of studied traits were estimated via Bayesian implementation of Gibbs sampling using GIBBS3F90 software. Heritability and genetic and phenotypic correlations between traits were estimated using univariate and bivariate animal models. First, to increase the accuracy of calculations, according to the characteristics of the normal distribution, records with more or less than three standard deviations from the mean of each character were considered as outliers and were omitted from the data. Analysis of variance was performed for each studied trait to find out the significant fixed effects. To obtain the marginal posterior distributions for each parameter, Gibbs sampling technique in a special case of MCMC algorithm was used.
    Results And Discussion
    Average values of body weight at 8 (BW8) and 12 weeks (BW12) of age, weight and age at sexual maturity (WSM, ASM), egg number (EN) and egg weight (EW) were684.16 g, 1243.75 g, 1811.41 g, 164.21 days, 50.36 g, 38.86 number, respectively. Heritability of BW8, BW12, WSM, ASM, EN and EW were 0.37, 0.40, 0.30, 0.31, 0.46 and 0.11, respectively. The highest heritability among performance traits belonged to egg weight between 28 to 32 weeks of production period (0.46) and the lowest heritability was observed for egg number during first 12 weeks of production (0.11). Moderate to high heritability values show the importance of genes effect on the phenotypic variance and the effectiveness of selection for genetic improvement in the studied traits. Genetic correlation between BW8 and BW12 was high (0.86) and they showed high genetic correlations with ASM (0.84 and 0.69, respectively). These results demonstrated the similarity of genetic structure of these traits. Genetic correlations of BW8, BW12 and WSM with ASM were positive. Therefore, selection for increased growth rate at different ages will unfavorably increase ASM. Growth and egg production traits are both important in native fowl because they are dual-purpose breeds.
    Conclusion
    The average body weight at different ages in native fowl of Khorasan Razavi Breeding Center were higher than other native fowl breeding centers which shows their proper capacity for meat production. Native fowl of Khorasan Razavi showed relatively suitable performance in egg weight and the age of sexual maturity but the produced egg number needs more attention and must be improved in this breeding center. Because of unfavorable genetic correlations between growth traits and ASM, selection for increased growth and decreased ASM using a selection index would be necessary to improve the economic performance of native fowlin Khorasan Razavi province.
    Keywords: Bayesian analysis, Economic traits, Genetic parameters, Native fowl
  • Alireza Shahdadi, Mojtaba Tahmoorspur Pages 93-103
    Introduction
    The purpose of dairy cattle breeding is improvement of productive and fertility performance. The breeding of dairy cows was done to increase milk production, longevity, disease resistance and fertility efficiency. In most countries, importation of bulls’ semen with highly breeding values was increased. Global sales of semen expose progeny of sires to climates and production systems vastly different from their original selection environment. This may cause sire re-ranking because the progeny of some sires are not expected to perform to their optimum in every different environment. The objective of this study was to investigate 305 d milk yield and 305 d fat percentage performance of Holstein dairy cows under different climates of Iran.
    Materials And Methods
    In this study, the records of 191910 first lactation Iranian Holstein (305 d milk yield and 305 d fat percentage) were used. These records were collected from 1368 herds during 2000 to 2011 by the Animal Breeding Center of Iran. Records from cows without pedigree information were excluded. Age at first calving was required to be between 20 and 40 month and calving interval between 300 and 600 d. According to weather conditions, geographical location of herds was classified to 5 climate groups (arid, semiarid, Mediterranean, semi humid and humid) via De Martonne method.
    In this study, the models were developed based on data availability, literature evidence, genetic evaluation models that are used in other countries, and available computing facilities. Single-trait model for these traits was as follows: where yijk denoted 305 d milk yield and 305 d fat percentage, µ was overall mean, HYSi was a combination of fixed effect of herd by year of calving by season of calving, b1 and b2 were linear regression coefficients of Holstein percentage and age at first calving, respectively, HF was the effect of Holstein percentage, Age was effect of age at first calving, aj was a random animal genetic effect and eijk was a random error term. Variance and covariance components were estimated by restricted maximum likelihood method using DMU program. Genetic and phonotypic trends were computed as a linear regression of yearly means on year of birth using the REG procedure of SAS 9.1.
    Results And Discussion
    The average of 305 d milk yield was the highest in arid climate (7350.34±1558.29 kg) and was the lowest in humid climate (5578.66 ± 1024.2 kg). The higher 305 d milk yield in the arid climate can be due to better management conditions in these regions compared to other climates. It seems that high humidity in Mediterranean, semi humid and humid climates can intensify higher environmental temperature and thus management and control of diseases can be difficult that result in milk production depression in these climates. The estimated heritability ranged from 0.11 (Mediterranean climate) to 0.29 (arid climate) for 305 d milk yield. Logar et. al., (17) reported that additive genetic variance in environments with high milk production was higher than environments with low milk production. Thus, observed differences in additive genetic variance in the climates can be due to several factors including difference in level of herd yield, environmental variation, data size and management strategies in herds. In arid, semiarid, Mediterranean, semi humid and humid climates, genetic trends of 305 d milk yield was 22.20, 17.37, -0.074, 0.92 and -0.71, respectively. According to the results, it seems that genetic gain in herds of Mediterranean, semi humid and humid climates was very low.
    Results showed that average 305 d fat percentage in Mediterranean climate was the highest and in semi humid was the lowest (3.44 ± 0.34% vs. 2.98 ± 0.56%). The estimated heritability for 305 d fat percentage was 0.11 (Mediterranean climate) to 0.29 (arid climate). It is concluded that small size of data in Mediterranean, semi humid and humid climates can lead to lower heritability. Also, differences in the estimated heritabilities in different climates can be due to difference in mean and coefficient of variations of 305 d fat percentage. Genetic trends of 305 d fat percentage was -0.0012, 1.23×10-5, 5×10-5, 0.0002 and -0.0004 for arid, semiarid, Mediterranean, semi humid and humid climates, respectively.
    Conclusion
    According to differences in genetic parameters of traits in different climates, it seems that performance of cows was different, that can be due to genotype by environment interaction.
    Keywords: Climates of Iran, Genetic parameters, Holstein dairy cow, Performance
  • Hamed Amirpour Najafabadi, Saeid Ansari-Mahyari, Mohammad Ali Edriss Pages 104-112
    Introduction
    One of the important breeding goals in dairy cattle is increasing length of productive life (LPL). In the recent decades, genetic evaluations of dairy cattle longevity have been a major concern for breeders. The trait LPL is defined as the number of days from the first calving to culling, death or censoring. Increasing LPL by reducing the costs of replacement of the heifers and increasing the number of high producing cows plays an important role in increasing the herd incomes and profitability.
    Materials And Methods
    This study aimed to evaluate genetic variations for LPL based on the survival analysis models was used to evaluate the impact of environmental and genetic factors on the risk of culling and to estimate the genetic parameters for longevity in Holstein dairy herds. Data included 35,137 records of productive lifetime from the first calving during 1991 and 2012, collected from dairy herds in Isfahan province. Culled and un-culled animals were assigned as uncensored and censored cows, respectively. However, it may be of interest to distinguish between disposal mostly beyond the control of dairy managers such as the sale of profitable but sterile can (involuntary culling) and voluntary disposal of a healthy but not profitable cow. The number of observations was considered with at least 20 records per herd and at least 10 daughters per sire. The last lactation was considered for the animals whose culling date was missed. In this case, cow assigned as culled animal only if the time interval between end of the last lactation and date of recording exceeds 365 days. Three types of cows were excluded in this study: sold, without any records and transferred to other herds. The sires with one daughter in a herd were removed. Genetic parameters were estimated based on a sire model which was implemented in Weibull model in Survival Kit software Survival analysis using proportional hazard model was used to analyze data on LPL. The existence analysis models are the best for the genetic PL evaluation; these models are referred to as the Proportional Risk Models, which are categorized in two semi-parametric Cox and Weibull. Following the designed algorithm in this software, the records with known longevity and low FHL limit were used. Hence, the records were considered uncensored data if the cows were either culled or died for any reason. Therefore, censoring the records represented the cows were sold, exported or leased to other herds. Both Cox and Weibull models were implemented in Survival Kit, and they could be used for continuous and discontinuous (time-dependent) variables.
    Results And Discussion
    The average lifetime in uncensored and censored cows were 937.8 and 1002.8 days, respectively. It is obvious that some cows are culled due to calving difficulties on day one, therefore LPL of One day is considered for them. Heritability could change based on the estimates of ρ and scale (λ). Estimates of heritability of LPL according to logarithmic scale and original scale were 0.074 and 0.18, respectively. In many studies on different populations, the heritability evaluated through survival analysis is higher than what is determined through linear models. Regression of phenotypic changes was -0.03±0.01, which showed that the reduction of relative culling risk has occurred slowly across the studied herds. The genetic trends of culling risk showed that regression coefficient was close to zero and therefore, it can be concluded that according to variance of the estimated breeding values in LPL, it would be possible to increase LPL by selecting the high ranked cows. The range of culling risk were calculated from 0.96 to 0.99. An attempt to estimate the genetic trend for sires was made by grouping sires according to their year of birth. Besides, negative phenotypic trends in this study for the proportional culling risk was achieved which demonstrated that LPL was phenotypically improved but based on the genetic trend, an increase in culling risk was observed that indicated a genetically decreasing in productive lifetime in studied dairy herds. More research is needed to analyze more data in other dairy farms in Iran.
    Conclusion
    Based on the variation of the obtained breeding value, it is possible to increase the lifetime of cows via selecting the higher breeding value cows.
    Keywords: Productive lifetime, Heritability, Holstein dairy cattle
  • Roya Yavarifard, Navid Ghavi Hossein-Zadeh, Abdol Ahad Shadparvar Pages 113-124
    Introduction
    Along with increase in genetic progress, maintaining genetic diversity in any population is very important to adapt with the economic and environmental changes in the future and ensure long-term response to selection for traits that are very important. Intensive use of a few breeding animals, where the selection intensity is high, could result in greater rates of inbreeding in the population. Therefore, a small number of seedstock, with a strong family relationship, is responsible for the maintenance of almost the whole genetic pool in the population. This is an aspect of great influence in the genealogical analysis of a population structure, because of its effect on the probability of genes lost between generations and the consequent reduction in genetic variability. The unavoidable mating of related animals in closed populations leads to accumulation of inbreeding and decreased genetic diversity. Measurement of the effect of inbreeding on these traits is important in order to estimate the magnitude of changes associated with increases in inbreeding although direct selection for lower maintenance requirements is difficult. Some populations may show a very pronounced effect of increased inbreeding for a trait, whereas others may not display much of an effect. The rate of inbreeding needs to be limited to maintain diversity at an acceptable level, so that genetic variation will ensure that future animals can respond to changes in the environment and to selection. Without genetic variation, animals cannot adapt to these changes. Commonly, negative inbreeding effects, or inbreeding depression, are thought to most frequently occur because of an increase in frequencies of recessive alleles that adversely affect the traits of interest. The increased frequency of recessive alleles leads to a larger number of individuals that are homozygous for the recessive alleles, whereas in non-inbred populations, the recessive allele would more frequently be masked by an advantageous dominant allele. Kleiber ratio (KR) allows us to identify efficient animals. This ratio, defined as growth rate/ metabolic weight (body weight0.75), was suggested for measuring growth efficiency. One of the most important breeds of Iranian sheep is Mehraban sheep which is reared in Hamedan province. This breed is adapted to harsh climate and rocky environments in the western regions of Iran. The Mehraban is a fat-tailed carpet wool sheep with light brown, cream or grey color, dark face and neck and primarily used for meat production. The objective of this study was to evaluate the inbreeding effects on daily weight gain and Kleiber ratio in Mehraban sheep.
    Materials And Methods
    Data and pedigree information used in this research were collected from 1994 to 2011 in Jihad Agriculture Organization of Hamedan province. Studied traits were average daily gains from birth to weaning (ADGa), average daily gain from weaning to 6 months (ADGb), average daily gain from weaning to 9 months (ADGc), average daily gain from weaning to yearling (ADGd) and corresponding Kleiber ratios (KRa, KRb, KRc and KRd). All animals were grouped into three classes according to their inbreeding coefficients: the first class included non-inbred animals (F=0) and the second and third classes included inbred animals (0
    Results And Discussion
    Significant regression coefficients ADGa, KRa, ADGb, KRb, ADGd and KRd on inbreeding of all lambs were observed for 1% increase of inbreeding. According to the birth type, the regression coefficient of all traits except KRc on inbreeding of single-born lambs and ADGa and KRa on inbreeding of twin-born lambs was significant for a 1%. increase in inbreeding. According to lamb sex, the regression coefficient of all traits except ADGd and ADGc on inbreeding of male lambs and ADGc and KRd on inbreeding inbreeding of female lambs was significant for a 1% increase in inbreeding.
    The results showed both significant and non-significant effects of inbreeding on daily weight gain and kleiber ratio traits. The results of this study showed that inbreeding level of over 90% of animals was between 0 and 50%. These results indicate multiple use of a small number of sires in the herd, also the lack of use of mating programs designed for prevent high levels of inbreeding in Mehraban sheep.
    Conclusion
    The results showed positive and significant effects of inbreeding on average daily gains and Kleiber ratios in Mehraban sheep.
    Keywords: Average daily gain, Inbreeding, Kleiber ratio, Mehraban fat-tailed sheep
  • Marjan Ahmadi, Ali K. Esmailizadeh, Ehsan Nasirifar Pages 125-134
    Introduction
    The purpose of breeding is to rear animals which are biologically and economically important. Among the domestic species, the poultry, due to the large number of offspring per parent and short generation interval, enable researchers to run breeding programs even on small farms. In this regard, quail because of certain characteristics: short generation interval, large numbers of eggs, disease resistance, and low cost farming is of great interest to biologists and commercial growers. Japanese quail (Coturnix coturnix japonica) has been grown for the production of meat and eggs in Asia and for its meat in Europe and America during the recent years. Despite the great diversity of traits in Japanese quail, only a limited number of genes and linkage groups related to the bird have been identified. Japanese quail belongs to the order Galliformes and the Phasianidae family. The considerable phylogenetic similarity between quail and chickens in the number of chromosomes and the genome size makes the quail qualified enough as a model for studies on poultry. Furthermore, the similarities between 9 chromosomes and chromosome Z in quail and chicken have been confirmed and following the divergence, only small numbers of chromosomes of the two species have changed. In recent years, the attempts at mapping of quail genome based on the segregation and identification of microsatellite markers has begun and 50 microsatellite markers were identified in quail. This study examined F2 population of Japanese quail to find the loci for carcass traits on chromosome 5 using microsatellite markers. The population included crosses of two strains of Japanese quail (white and wild strains) and the traits examined included weights of hot and cold carcasses, internal organs and carcass parts.
    Materials And Methods
    Polymerase chain reaction (PCR) amplifications of each marker for 472 birds were carried out on a Thermal Cycler (Eppendorf, UK). Afterward, the population was genotyped using AlphaEaseFC 4.0 software for each marker. Parental (P0), F1 and F2 individuals were genotyped with 3 microsatellite markers. A genetic model, line-cross, was applied for QTL interval mapping analyses using the regression method in the GridQTL software. Data analysis was performed with least squares regression interval mapping method. The line-cross analysis employed the models including joint effects of additive, dominance and imprinting. The QTL by sex interaction was assessed to determine whether the effect did differ between the two sexes. The additive QTL effect by hatch interaction was also analyzed.
    Results And Discussion
    Significant QTLs were identified for carcass efficiency, breast percentage and breast weight, liver percentage and liver weight, back weight and back percentage, spleen weight and spleen percentage, gizzard and head on chromosome 5. The QTL for breast weight and percentage were identified at 19 cM (in position marker GUJ0100) on chromosome 5. The QTL for head weight and percentage and weight of back were identified at 12 cM (in position marker GUJ049) on chromosome 5. Other QTLs were mapped at 10 cM for carcass efficiency and spleen weight, at 0 cM for Gizzard weight, at 17 cM for head weight, at 15 cM for weight of liver, at 16 cM for liver percentage and at 11 cM for spleen percentage. The proportion of the F2 phenotypic variation explained by the significant additive, dominance and imprinting QTL effects ranged from 2.22 to 11.11%. In the current study, QTL affecting different traits were mapped to similar chromosomal regions. These evidence are indicative of genetic correlation among traits and correlated response to selection. If these traits are really controlled by the same pleiotropic QTL or by closely linked QTL, therefore they are in linkage disequilibrium (LD). However, higher resolution analysis is required to distinguish LD from pleiotropic.
    Conclusion
    The present study identified informative QTL regions that may form a useful resource as part of our advance on developing DNA tests for carcass quality and internal organs in Japanese quail. However, it should be noted that to identify candidate genes and informative markers in linkage disequilibrium with QTL affecting carcass and internal organs traits, association studies using SNP markers may be needed for the significant QTL regions detected in this study. The results showed that the identified positions for some carcass and internal organs traits on chromosome 5 were similar to the characteristics of quantitative traits (including pleiotropic and epistasis effects) and can be effective in phenotypic differences of trait. Such results are indicative of genetic correlation among traits and correlated response to selection.
    Keywords: Carcass traits, Chromosome 5, F2 population, Japanese quail, QTL
  • Mahboobeh Mirzaee Ilaly, Saeed Hassani, Mojtaba Ahani Azari, Rohullah Abdullahpour, Sakineh Naghavian Pages 135-145
    Introduction
    The aim of this study was to estimate inbreeding coefficient in Sangsari sheep and its impact on growth traits in order to manage breeding programs and preventing possible negative and harmful effects of excessive increase of inbreeding. Inbreeding is the mating of individuals whose relatedness is greater than the average degree of relationship exists in the population and capable of changing the genotypic frequencies of a population without modifying the gene frequencies. Increase in inbreeding can lead to reduced response to selection of economic traits and the heterozygosity and consequently leads to increase in homozygosity and loss of genetic diversity. Inbreeding also impairs growth, production, health, reproduction and survival of inbred animals. A complete pedigree is also necessary for accurate evaluation of inbreeding and other important population parameters.
    Materials And Methods
    In the present study, data from 7028 Sangsari sheep (3180 males and 3848 females) which were collected during 28years (1987-2014) in the breeding station of Sangsari sheep located near to Damghan city, Semnan province, were used to estimate inbreeding coefficients and its effects on birth weight (BW), weaning weight (WW), 6 month weight (6MW), 9 month weight (9MW) and yearling weight (YW) of animals. Pedigree information for each lamb included animal, sire, and dam and also sex, birth date, type of birth, age of dam and record of studied traits. In order to edit data, FoxPro software (FoxPro 2.6) and to study of fixed effects on growth traits, GLM procedure of SAS 9.1 were used. Before estimation of inbreeding, it is very important to be sure about completeness and depth of the pedigree. In order to estimate inbreeding coefficients of all animals in the pedigree and to determine the population structure, CFC based on Meuwissen and Luo algorithm and Endog v4.8 softwares, were used. The regression of the studied traits on inbreeding coefficient was estimated using WOMBAT software by restricted maximum likelihood method and 12 animal models were used. The most appropriate model for each trait was determined based on Akaike’s information criterion.
    Results And Discussion
    Of all the registered animals, 4772 animals had both parent known. Completeness of the first and second ancestor generations of all animals were 78.52% and 44.33%, respectively, and the completeness decreased progressively for the next generations. The average equivalent complete generation, as a measure of pedigree completeness level, estimated as 1.59. In the studied pedigree, A low proportion of the recorded lambs (7.21percent of the total lambs) were inbred and their average inbreeding coefficients was 3.88 percent. Mean inbreeding of the total population and average relatedness estimated as 0.28% and 0.59%, respectively. In the early years, the number of inbred animals was low, but over time, the average coefficient of inbreeding increased due to the selection of breeding male and female animals within the flock and mating of the related animals and inbreeding coefficient was increased by 0.028 percent per year and was statistically significant. Maximum and minimum inbreeding coefficients were 31.25 percent and 0.024 percent, respectively, in inbred population. Low average coefficient of inbreeding can be mostly due to controlled mating in the flock and also due to having many animals with inbreeding coefficients of zero. Zero inbreeding coefficients were mainly due to lack of pedigree information in the early years. Effects of inbreeding on growth traits were estimated by restricted maximum likelihood method using 12 animal models. The most appropriate model for each trait was determined based on Akaike’s Information Criterion. The regression coefficients of inbreeding on birth weight (model 11), weaning weight (model 8), 6 month weight (model 11), 9 month weight (model 9) and yearling weight (model 3) were -1.46, -7.72, 14.87, 20.92 and -29.46 gram, respectively, which were not statistically significant.
    Conclusion
    Generally, results indicated that the average coefficient of inbreeding in the studied Sangsari sheep population was lower than the values reported in other breeds which could be because of lack of clear information of some parents and common ancestors and also because of the purposive and largely controlled matings therefore there is no serious problem of inbreeding and its effects on body weights in this population, but in order to prohibit the animals with high inbreeding levels, pedigree information has to be considered during mating.
    Keywords: Body weights, Inbreeding coefficient, Sheep, Structure of population