فهرست مطالب
فصلنامه پژوهشهای تولیدات دامی
پیاپی 17 (پاییز 1396)
- تاریخ انتشار: 1396/11/01
- تعداد عناوین: 25
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صفحات 1-10این آزمایش به منظور ارزیابی اثر ال-کارنیتین (صفر، 125 و 250 میلی گرم بر کیلوگرم) و اسید بوتیریک (0 و 2 گرم بر کیلوگرم) بر کیفیت گوشت و خصوصیات لاشه جوجه های گوشتی انجام شد. آزمایش با استفاده از 192 قطعه جوجه گوشتی راس 308 در قالب فاکتوریل 2×3 بر پایه طرح بلوک های کامل تصادفی با شش تیمار، چهار بلوک و هشت جوجه در هر بلوک انجام شد. نتایج نشان داد که جوجه های تغذیه شده با جیره حاوی 125 میلی گرم بر کیلوگرم ال-کارنیتین و جیره حاوی 125 میلی گرم بر کیلوگرم ال-کارنیتین و دو گرم بر کیلوگرم اسید بوتیریک نسبت به گروه شاهد خوراک مصرفی کمتر و ضریب تبدیل خوراک بهتری داشتند (05/0
P). به استثنای روشنی، رنگ گوشت ران و سینه و غلظت لاکتات گوشت سینه تحت تاثیر تیمارهای آزمایشی قرار نگرفت (05/0P>). تغذیه جیره دارای اسید بوتیریک باعث کاهش pH گوشت ران و جیره دارای 125 میلی گرم ال-کارنیتین بدون اسید بوتیریک به جوجه های گوشتی باعث افزایش pH گوشت ران در 45 دقیقه بعد از کشتار نسبت به جوجه های گروه شاهد شد (05/0>P). تغذیه جیره دارای اسید بوتیریک باعث کاهش درصد چربی گوشت سینه جوجه های گوشتی شد در حالیکه تغذیه همزمان جیره حاوی 250 میلی گرم ال-کارنیتین و جیره دارای 2 گرم بر کیلوگرم اسید بوتیریک سبب افزایش درصد چربی گوشت سینه نسبت به جوجه های گروه شاهد شد (05/0>P) اما درصد چربی ران تحت تاثیر جیره ها قرار نگرفت (05/0P>). به طور کلی جیره حاوی 125 میلی گرم ال-کارنیتین و سپس جیره حاوی 125 میلی گرم ال-کارنیتین و 2 گرم اسید بوتیریک اثر مثبتی بر عملکرد تولیدی جوجه های گوشتی داشتند و استفاده از 250 میلی گرم ال-کارنیتین در جیره سبب بهبود درصد سینه جوجه های گوشتی درحالیکه 2 گرم بر کیلوگرم اسید بوتیریک سبب کاهش درصد چربی گوشت سینه شد.
کلیدواژگان: اسید بوتیریک، ال، کارنیتین، جوجه های گوشتی، خصوصیات لاشه، کیفیت گوشت -
صفحات 11-17این پژوهش به منظور بررسی اثرات ال-آرژنین بر عملکرد تولیدی، خصوصیات کیفی تخم مرغ، فراسنجه های خونی و هورمونی مرغان تخم گذار در اواخر دوره تولید به مدت هشت هفته انجام شد. از تعداد 48 مرغ تخم گذار سویه های-لاین (w36) در سن 98-92 هفتگی در قالب طرح کاملا تصادفی با چهار سطح تیمار (کنترل: 20/1، 32/1، 44/1 و 56/1 درصد) با چهار تکرار و سه پرنده در هر تکرار استفاده شد. در سن 90 هفتگی مرغان وزن شدند و به صورت تصادفی در 16 قفس به نحوی پخش شدند که حداقل اختلاف وزنی در بین قفس ها وجود داشت. صفات عملکردی به صورت روزانه و خصوصیات کیفی تخم مرغ هر دو هفته ثبت شد. در پایان آزمایش دو تخم مرغ از هر قفس به منظور اندازه گیری کلسترول زرده تخم مرغ جمع آوری شد. افزایش سطح ال آرژنین در جیره اثر معنی داری بر عملکرد تولیدی مرغان و خصوصیات کیفی پوسته تخم مرغ نداشت (05/0P>). به طور کلی نتایج حاصل از این پژوهش نشان داد که افزایش سطح ال-آرژنین بدون اینکه اثرات منفی روی صفات عملکرد تولیدی بگذارد باعث بهبود واحد هاو، غلظت کلسترول زرده و کاهش پروژسترون خون شد.کلیدواژگان: ضخامت پوسته تخم مرغ، فراسنجه هورمونی، کلسترول زرده، مرغ تخم گذار، واحد هاو، وزن مخصوص
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صفحات 18-25آزمایشی برای بررسی تاثیر سطوح مختلف پودردارچین بر عملکرد، وضعیت آنتی اکسیدانی، پایداری اکسیداتیو گوشت، فعالیت آنزیمی و برخی فراسنجه های خونی درجوجه های گوشتی انجام شد. دراین آزمایش تعداد 450 جوجه گوشتی یک روزه (راس 308) در قالب یک طرح کاملا تصادفی بین 3 گروه تیماری تقسیم شدند. هر تیمار دارای 5 تکرار و هر تکرار شامل 30 جوجه بود. تیمارهای آزمایشی عبارت بودند از پودر دارچین (دارای سه سطح صفر، 1/0 و 2/0 درصد). فراسنجه های عملکرد رشد به صورت هفتگی اندازه گیری شد. فراسنجه های خونی شامل گلوکز، پروتئین، گلبول قرمز، هموگلوبین، هماتوکریت، اسیداوریک، کلسترول، تری گلیسیرید، لیپوپروتیئن با دانسیته بالا، فعالیت آنزیم های آلانین آمینوترانسفراز، آسپارتات آمینوترانسفراز، آلکالین فسفاتاز، لاکتات دهیدروژناز و فراسنجه های آنتی اکسیدانی MDA کبد و پلاسما و هم چنین TAS پلاسما، در روزهای 21 و 42 اندازه گیری شدند. اندازه گیری فراسنجه پایداری اکسیداتیو گوشت از طریق اختلاف میزان MDA گوشت روز کشتار و 15 روز بعد از کشتار ثبت شد. نتایج نشان داد هر دو سطح دارچین (1/0 و 2/0 درصد) سبب افزایش خوراک مصرفی و افزایش وزن شد. همچنین سطوح دارچین موجب کاهش فعالیت پلاسمایی آنزیم AST، کاهش سطح MDA کبد، پلاسما و گوشت و هم چنین سبب کاهش تری گلیسیرید و کلسترول پلاسما شد (05/0P≤). هیچ تلفاتی در تیمارهای حاوی دارچین مشاهده نشد. سایر فراسنجه های خونی به طور معنی داری تحت تاثیر سطوح مختلف دارچین، قرار نگرفتند (05/0P≥). می توان نتیجه گیری نمود که از مکمل 2/0 درصد پودر دارچین در جیره می توان افزایش وزن، کاهش تلفات و افزایش ماندگاری گوشت در جوجه های گوشتی را بهبود دهد.کلیدواژگان: پارامترهای خونی، پایداری اکسیداتیو گوشت، دارچین، جوجه های گوشتی، وضعیت آنتی اکسیدانی
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صفحات 26-33این آزمایش به منظور بررسی تاثیر سطوح مختلف پودر صمغ آنغوزه بر عملکرد، مورفولوژی و جمعیت میکروبی روده در جوجه های گوشتی انجام شد. آزمایش با 240 جوجه در قالب طرح کاملا تصادفی با 5 تیمار، 4 تکرار و 12 جوجه در هر تکرار اجرا شد. تیمارهای آزمایشی شامل : 1) جیره پایه 2) جیره پایه حاوی 100 میلی گرم در کیلوگرم آنتی بیوتیک آویلامایسین، 4 ،3 و 5) به ترتیب جیره پایه حاوی 1/0، 2/0 و 3/0 درصد پودر صمغ آنغوزه بودند. نتایج نشان داد در کل دوره تیمار آنتی بیوتیک بیشترین وزن بدن را داشت (05/0P<). مصرف خوراک نیز تحت تاثیر تیمارهای آزمایشی قرار نگرفت (05/0P>). بهترین ضریب تبدیل در کل دوره مربوط به گروه آنتی بیوتیک بود (05/0P<). کمترین تعداد باکتری کلی فرم مربوط به تیمارهای تغذیه شده با آنغوزه بود (05/0P<). بیشترین تعداد لاکتوباسیل به ترتیب در تیمارهای آنغوزه 2/0 و 1/0 درصد مشاهده شد (01/0>P). بیشترین مقدار نسبت طول پرز به عمق کریپت به ترتیب در تیمار آنغوزه 2/0 درصد و شاهد مشاهده شد
(05/0P<). به طور کلی نتایج نشان داد که آنغوزه 2/0 درصد با تاثیر مثبت بر عملکرد، ریخت شناسی پرزهای روده و جمعیت میکروبی می تواند به عنوان جایگزین آنتی بیوتیک مطرح باشد.کلیدواژگان: آویلامایسین، آنغوزه، جمعیت میکروبی، مورفولوژی -
صفحات 34-42در این پژوهش تاثیر اسانس آویشن و دارچین ریزپوشانی شده بر عملکرد، برخی فراسنجه های خونی و خصوصیات لاشه در جوجه های گوشتی، مورد بررسی قرار گرفت. به این منظور، تعداد 320 قطعه جوجه خروس گوشتی سویه راس 308 به صورت هشت تیمار و چهار تکرار در قالب یک طرح کاملآ تصادفی به مدت 42 روز مورد آزمایش قرار گرفتند. تیمارها شامل جیره پایه + آنتی بیوتیک، جیره پایه، جیره پایه + اسانس آزاد آویشن، جیره پایه + اسانس ریزپوشانی شده آویشن، جیره پایه + اسانس آزاد دارچین، جیره پایه + اسانس ریزپوشانی شده دارچین، جیره پایه + اسانس آزاد آویشن و دارچین، جیره پایه + اسانس ریزپوشانی شده آویشن و دارچین بودند. نتایج تحقیق نشان داد که تیمارهای آزمایشی تاثیر معنی داری برصفات عملکردی شامل مقدار مصرف خوراک، افزایش وزن و ضریب تبدیل غذایی در کل دوره نداشت (05/0
P). در بررسی صفات لاشه نیز مشاهده شد که تیمارهای فاقد افزودنی دارای وزن کبد و چربی بطنی بالاتری نسبت به سایر تیمارها بودند (05/0>P ). در کل نتایج این تحقیق حاکی از تاثیر مثبت اسانسهای ریز پوشانی شده در جوجه های گوشتی بر کاهش غلظت کلسترول خون، افزایش فعالیت آنزیم گلوتاتیون پراکسیداز و کاهش وزن کبد و چربی بطنی بود.
کلیدواژگان: آویشن، اسانس، جوجه های گوشتی، ریز پوشانی، دارچین -
صفحات 43-53این آزمایش به منظور مطالعه استفاده از لوامیزول در سنین مختلف پرورش بر عملکرد، وزن برخی اندام های داخلی، گلبول های سفید و فعالیت فاگوسیتوزی جوجه های گوشتی نر سویه کاب 500 انجام شد. آزمایش به صورت طرح کاملا تصادفی، با 300 قطعه جوجه گوشتی نر در چهار تیمار، پنج تکرار و در هر تکرار تعداد 15 قطعه جوجه انجام شد. گروه های آزمایشی شامل: 1) جیره ی پایه (بدون لوامیزول)، 2) جیره ی پایه حاوی سه میلی گرم لوامیزول به ازای هر کیلوگرم وزن زنده بدن در هفته ی اول، 3) جیره ی پایه حاوی سه میلی گرم لوامیزول در هفته ی دوم و 4) جیره ی پایه حاوی سه میلی گرم لوامیزول در هفته سوم بودند. صفات مورد آزمایش شامل عملکرد و فراسنجه های مرتبط با سیستم ایمنی شامل تعداد مونوسیت، لنفوسیت و هتروفیل و پروتئین کل، آلبومین، فعالیت فاگوسیتوزی، تیتر آنتی بادی علیه بیماری های نیوکاسل، آنفلوانزا و گامبورو و وزن اندام های دخیل در سیستم ایمنی بودند. نتایج نشان داد، عملکرد جوجه های تیمار شده با لوامیزول در زمان های مختلف نسبت به گروه شاهد معنی دار نبود. افزودن لوامیزول به جیره ی جوجه های گوشتی در زمان های مختلف بر تعداد لنفوسیت ها و هتروفیل ها معنی دار بود (05/0>P). افزودن لوامیزول در هفته سوم دوره پرورش، سبب افزایش غلظت پروتئین کل، آلبومین و فعالیت فاگوسیتوزی در جوجه های گوشتی شد (05/0>P). استفاده از لوامیزول در هفته های دوم و سوم دوره ی پرورش جوجه های گوشتی، باعث افزایش تیتر آنتی بادی علیه بیماری گامبورو در 28 روزگی نسبت به گروه شاهد شد (05/0
کلیدواژگان: تیتر آنتی بادی، سویه کاب، سیستم ایمنی، فعالیت فاگوسیتوزی، لوامیزول
تخم گذار و مرغ های مولد از ایستگاه اصلاح نژاد مرغ بومی مازندران با استفاده از تکنیک PCR-RFLP انجام شد. نمونه های خون به طور تصادفی از 150 قطعه مرغ (هر جمعیت 50 قطعه) جمع آوری و استخراج DNA با روش نمکی بهینه یافته انجام گرفت. با استفاده از PCR و آغازگرهای اختصاصی در مجموع قطعه ای با طول 3792 جفت باز از ناحیه 1723- تا اگزون 4 ژن PEPCK-C تکثیر شد. فراوانی آللی در جایگاه RsaI، در جمعیت مرغان بومی مازندران A (33%) و B (67%) و ژنوتیپ AB و BB به ترتیب با فروانی 66 و 34 درصد، در جمعیت مرغ های گوشتی A (34%) و B (66%) و ژنوتیپ های AB و BB به ترتیب با فروانی 68 و 32 درصد و در جمعیت مرغ های تخم گذار A (24%) و B (76%) و ژنوتیپ های AB و BB به ترتیب با فراوانی 48 و 52 درصد مشاهده شد. برای جایگاه BstEII در جمعیت مرغ های بومی فراوانی آللی A (28%) و B (72%) و سه ژنوتیپ AA، AB و BBبه ترتیب با فراوانی هر یک 2، 52 و 46 درصد، در جمعیت مرغ های گوشتی A (19%) و B (81%) ، سه ژنوتیپ AA، AB وBB به ترتیب با فراوانی هر یک 2، 34 و 64 درصد و در جمعیت مرغ های تخم گذار A (59%) و B (41%) ، ژنوتیپ های AA، AB و BB به ترتیب با فراوانی هر یک 42، 34 و 24 درصد محاسبه شد. فراوانی آللی در جایگاه PstI، در جمعیت مرغ های بومی مازندران A (43%) و B (57%) و سه ژنوتیپ AA، AB و BB به ترتیب با فراوانی هر یک 16، 54 و 30 درصد، در جمعیت مرغ های گوشتی A (52%) و B (48%) و سه ژنوتیپ AA، AB و BB به ترتیب با فراوانی هر یک 18، 68 و 14 درصد و در جمعیت مرغ های تخم گذار A و B (50%) و سه ژنوتیپ AA، AB و BBبه ترتیب با فراوانی هر یک 6، 88 و 6 درصد برآورد شد. نتایج برای جایگاه BstEII (موقعیت 26+ تا 1035+) نشان داد که همه نمونه ها در سویه های مختلف الگوی باندی یکسان (ژنوتیپ وحشی BB) دارند. از میان سه SNP شناسایی شده دو SNP در ناحیه پروموتور و یک SNP در ناحیه اینترون 2 واقع شده بود. با توجه به چند شکل بودن و همچنین بزرگ اثر بودن آن بر صفات تولیدی مختلف، مانند تولید تخم مرغ، ضریب تبدیل غذایی و رشد، این جایگاه ژنی می تواند به عنوان ژن کاندید در مطالعات شناساییQTL مرتبط به این صفات در صنعت طیور مورد توجه قرار گیرد.
دوره های شیردهی اول، دوم و سوم به ترتیب 141670، 115395 و 82529 رکورد وجود داشت. داده ها بر اساس سطوح مختلف تولید گله-سال به سه دسته بالا، متوسط و پایین گروه بندی شدند. ناهمگنی واریانس ها با آزمون بارتلت بررسی شد و نتایج آن در هر سه دوره شیردهی معنی دار (01/0P<) بود که نشان دهنده ناهمگن بودن واریانس ها بین سطوح تولیدی است. به منظور برطرف نمودن احتمالی و یا کاهش ناهمگنی واریانس ها از روش های تبدیل جذری و باکس کاکس و همچنین روش پیش تصحیح ویشر استفاده شد. پارامترهای ژنتیکی، وراثت پذیری ها و اجزای واریانس با استفاده از مدل حیوانی و نرم افزار VCE برآورد شدند. برآوردهای وراثت پذیری در روش پیش تصحیحی ویشر نسبت به سایر روش ها بالاتر بود که ممکن است به دلیل تخمین صحیح تر اثرات ژنتیکی افزایشی در نتیجه در نظر گرفتن ناهمگنی واریانس ها باشد. همبستگی های اسپیرمن و همچنین نسبت حیوانات انتخاب شده قبل و بعد از تبدیل داده ها بر اساس ارزش های اصلاحی برآورد شدند. برآوردهای همبستگی وقتی که تمامی حیوانات نر و ماده ممتاز در نظر گرفته شدند بالا بودند. ناهمگنی واریانس تاثیر قابل ملاحظه ای بر تغییر رتبه و انتخاب 5%گاوهای نر و 1% ماده های ممتاز داشت. روش های تبدیل باکس-کاکس، جذری و پیش تصحیح ویشر باعث شدند به ترتیب 4%، 19% و 10% گاوهای نر و 10، 21 و 7% ماده های برتر در مقایسه با سناریوی واریانس همگن از لیست انتخاب خارج شوند. نتایج مطالعه حاضر نشان داد که واریانس ها بین سطوح مختلف تولید گله-سال همگن نبوده و ممکن است روی رتبه بندی و انتخاب گاوهای ممتاز تاثیر گذارد.
جمع آوری شده بود. برای بررسی معنی داری عوامل ثابت موثر بر این صفات از نرم افزارSAS نسخه 2/9 استفاده گردید. همچنین با استفاده از روش حداکثر درستنمایی محدود شده نرم افزار WOMBAT، پارامترهای ژنتیکی برآورد شدند. وراثت پذیری مستقیم وزن بدن در سنین مختلف بر اساس مناسب ترین مدل به ترتیب 02/0±13/0، 05/0±57/0، 05/0±52/0، 04/0±79/0 و 05/0±73/0 برآورد گردید. بیشترین ضریب وراثت پذیری مادری برای وزن نه ماهگی (02/0±32/0) محاسبه شد. نسبت واریانس محیطی دائمی مادری به واریانس فنوتیپی برای صفات وزن تولد 04/0 برآورد شد. همچنین همبستگی بین ژنتیک افزایشی مستقیم و مادری در تمامی صفات مورد بررسی منفی بدست آمد. اگرچه مقادیر وراثت پذیری مادری وزن بدن در تمام سنین پایین بدست آمد، اما احتمالا منظور نمودن اثرات مادری در مدل آماری باعث برآورد دقیق تری از پارامترهای ژنتیکی صفات رشد بدن در تمام سنین خواهد شد.هدف از انجام این پژوهش، بررسی پارامترهای ژنتیکی و فنوتیپی وزن بدن بره های نژاد شال در سنین مختلف بود. به این منظور رکوردهای مربوط به صفات رشد 6692 راس بره حاصل از 195راس قوچ و 1288 راس میش استفاده گردید. صفات مورد مطالعه شامل وزن های تولد (6690 رکورد)، سه (6654 رکورد)، شش (6662 رکورد)، نه ( 6599 رکورد) و دوازده (6528 رکورد) ماهگی بودند که طی سال های 1376 تا 1392 در ایستگاه پرورش و اصلاح نژاد گوسفند شال واقع در استان قزوین
جمع آوری شده بود. برای بررسی معنی داری عوامل ثابت موثر بر این صفات از نرم افزارSAS نسخه 2/9 استفاده گردید. همچنین با استفاده از روش حداکثر درستنمایی محدود شده نرم افزار WOMBAT، پارامترهای ژنتیکی برآورد شدند. وراثت پذیری مستقیم وزن بدن در سنین مختلف بر اساس مناسب ترین مدل به ترتیب 02/0±13/0، 05/0±57/0، 05/0±52/0، 04/0±79/0 و 05/0±73/0 برآورد گردید. بیشترین ضریب وراثت پذیری مادری برای وزن نه ماهگی (02/0±32/0) محاسبه شد. نسبت واریانس محیطی دائمی مادری به واریانس فنوتیپی برای صفات وزن تولد 04/0 برآورد شد. همچنین همبستگی بین ژنتیک افزایشی مستقیم و مادری در تمامی صفات مورد بررسی منفی بدست آمد. اگرچه مقادیر وراثت پذیری مادری وزن بدن در تمام سنین پایین بدست آمد، اما احتمالا منظور نمودن اثرات مادری در مدل آماری باعث برآورد دقیق تری از پارامترهای ژنتیکی صفات رشد بدن در تمام سنین خواهد شد.
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Pages 1-10This experiment was conducted in order to conside the effect of L-carnitine (0, 125 and 250 mg/kg) and butyric acid (2 g/kg) on Carcass characteristics and meat quality of broiler chicken. In a 2×3 factorial arrangement in randomized complete block design 192 Ross 308 one-day-old broiler chicks were assigned to 6 dietary treatments with 4 replicates and 8 birds. Results showed that broilers fed basal diet plus 125 mg/kg L-Carnitine and basal diet plus 125 mg/kg L-Carnitine plus 2 gr/kg butyric acid had lower FI and the better FCR as compared to control group (P>0.05). Broilers fed basal diet plus 250 mg/kg L-Carnitine had higher breast percentage as compared to 125 mg/kg L-Carnitine (P0.05). Broilers fed basal diet plus 2 gr/kg butyric acid without L-Carnitine had lower tight percentage compare to control group (P0.05). Broilers fed basal diet plus 2 gr/kg butyric acid without L-Carnitine decreased tight meat 45min postmortem and 125 mg/kg L-Carnitine without butyric acid treatment increased tight meat 45min postmortem pH as compared to control group (P 0.05). In conclusion basal diet plus 125mg/kg L-Carnitine and basal diet with 125mg/kg L-Carnitine plus 2 gr/kg butyric acid had the best effect on broiler chickens performance and using basal diet plus 250 mg/kg L-Carnitine increased broiler breast percentage while 2 gr/kg butyric acid decreased breast meat lipid percentage of broiler chicken.Keywords: Broiler Chicken, Butyric Acid, Carcass characteristics, L-Carnitine, Meat Quality
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Pages 11-17This experiment was conducted to investigate effects of l-arginine on productive performance and egg quality parameters, blood and hormone parameters of laying hens in late phase of production for 8 weeks. Forty eight Hy-Line W-36 were used in a completely randomize design with four level of l-arginine (1/20=control diet, 1/32, 1/44 and 1/56 percent) and four replicate from 92-98 weeks of age. Layers were weighed at 90 week of age and randomly distributed into 16 cages in order to have a similar pen body weight. The performance data were recorded daily, whereas the egg quality traits were determined biweekly. At the end of experiment 2 eggs from each cage were collected for egg yolk cholesterol analysis. Supplementation of l-arginine in diet did not have significant effect on productive performance and egg shell quality in layers. Furthermore, the addition of l-arginine to diet did not have significant effect on the egg yolk cholesterol (P> 0.05). The results of this study showed that supplementation of l-arginine improved Hough unit and yolk cholesterol and blood progesterone with no adverse effect on productive performance.Keywords: Egg Shell Thickness, Hormone Parameters, Hough Unit, Layer Hen, Specific gravity, Yolk Cholesterol
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Pages 18-25An experiment was carried out to evaluate the effects of different levels of cinnamon powder on performance, antioxidant status and meat oxidative stability in broiler chickens. Four hundred fifty day-old broilers (Ross 308) were divided into three experimental treatments (with three levels of 0, 0.1 and 0.2% of Cinnamon powder in diets) in a completely randomized design. Each treatment had five replications including 30 chicks. The growth performance parameters were determined weekly. Blood parameters including; plasma glucose, protein, red blood cell, hemoglobin, hematocrit, uric acid, cholesterol, triglyceride, HDL, enzymes activity including; ALT, AST, LDH and ALP and antioxidant parameters including; MDA in liver, plasma and TAS were determined at day 21 and 42. It is also, the meat oxidative stability was determined as deference MDA in meat at slaughter days and 15 after slaughter. The results showed that, both levels of cinnamon (0.1% and 0.2%) increased feed intake and body weight. It is also, Cinnamon levels reduced plasma AST enzyme activity, MDA in liver, plasma and meat(P≤0.05).Moreover, Cinnamon levels, significantly, reduced cholesterol and triglyceride in plasma at day 42. No mortality was observed with cinnamon. The other blood parameters were not affected significantly by treatments (P≥0.05). It can be, supplementation 0.2% cinnamon powder in diets could improve body weight gain, reduced mortality and increased meat oxidative stability in broilers.Keywords: Antioxidant Status, Blood Parameters, Broiler Chickens Cinnamon, Enzymes Activity, Meat Oxidative Stability
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Pages 26-33This experiment was conducted to investigate the effect of different levels of Ferulaassa-foetida gum powder and antibiotic on performance, intestine morphology and microbial population in broiler chicks. The experiment was carried out in a completely randomized design with 240 chicks in 5 treatments, 4 replicates and 12 chicks per replicate. Treatments included: 1) basal diet without additives, 2) basal diet containing 100 mg per kg of antibiotics Avilamycin.3, 4 and 5) basal diet contain 0.1, 0.2 and 0.3 Ferula assa-foetida gum powder, respectively. The results showed that in whole experiment period, treatment fed antibiotic had the highest body weight (PKeywords: Avilamycin, Ferula assa, foetida, Morphology, Microbial population
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Pages 34-42In this study the effect of microencapsulation of thyme and cinnamon essential oils on performance, some blood parameters and carcass characteristics of broiler chicks were investigated. For this purpose 320 male broiler chicks from 308 strain in four treatments and 4 replications in a completely random design were tested for a period of 42 days. The treatments included basal diet橻扮⨭, basal diet, basal diet纷 thyme essential oil , basal diet 騧⮡檛⺕ꭞ thyme essential oil, , basal diet纷 cinnamon essential oil, basal diet 騧⮡檛⺕ꭞ cinnamon essential oil, basal diet纷 thyme and cinnamon essential oils, basal diet 騧⮡檛⺕ꭞ thyme and cinnamon essential oils. Results the study showed that the treatments had no significant effect on performance traits consist of feed intake, body weight gain and feed coefficient rate (P> 0.05).The result of blood parameters showed that adding essential oil to diet, significantly reduced cholesterol concentration. Adding free cinnamon significantly increased HDL concentration and the treatment include microencapsulated thyme and cinnamon had the most glutathione peroxides enzyme activity (PKeywords: Broiler, Cinnamon Zeylanicum, Encapsulation, Essential oils, Thymus Vulgaris
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Pages 43-53This experiment was conducted to study the effect of levamisole at different rearing ages on performance, some internal organ weights, white blood cells and phagocytic activity in Cobb 500 strain male broilers. The experiment was a completely randomized design, with 300 male broiler chickens in four treatments with five replicates and 15 chicks in each group. The experimental groups consisted of: 1) basal diet (without levamisole), 2) basal diet containing 3 mg levamisole in the first week; 3) basal diet containing 3 mg levamisole in the second week, and 4) basal diet containing 3 mg per kg live body weight of levamisole in the third week. Test duration was 6 weeks. Parameters examined include performance and related parameters with immune system such as number of monocytes, lymphocytes, heterophils, total protein, albumin, phagocytic activity test, antibody titers against Newcastle, influenza and Gambro disease and organs weight involved in immune system. Results showed that performance of chickens treated with levamisole at different rearing ages compared to the control group was not significant. Adding of levamisole in broiler diets increased the number of lymphocytes and heterophils at different ages of rearing (PKeywords: Antibody titers, Cobb strain, Levamisole, Immune system, Phagocytic activity
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Pages 54-60The aim of this study was to consider effect of increasing metabolizable energy and protein during late pregnancy on mammary growth and development in sistani goats. Twenty eight pregnant sistani goats with same average body weight and 2 year old age were selected and randomly assigned to four groups at beginning of late pregnancy period (d 100 of pregnancy): 1- Control group with recommendation level of metabolizable energy and protein according to NRC, 2- group with 10 % greater level of metabolizable energy, 3- group with 10 % greater level of metabolizable protein and 4- group with 10 % greater level of metabolizable energy and protein. After two month feeding, mammary samples were removed by biopsy 24-36 h after parturition to consider mammary histological parameters. Results showed number of epithelial cells were greater in goats fed diets with 10 % greater metabolizable energy and protein both compared to control group (35.8±3.70 vs. 26.4±2.64), but there was no difference among control groups and groups with 10 % greater metabolizable energy or 10% greater metabolizable protein alone. Epithelium area (µm) affected by diets and were greater in groups with 10% greater metabolizable energy and protein compared to control groups (P=0.03). Percentage of stroma affected by diets (P=0.001) and were decreased by increasing metabolizable energy, metabolizable protein or both compared to control group. Percentage of epithelium affected by diets (P=0.008) and were greater in groups with greater metabolizable energy and groups with greater metabolizable energy and protein compared to control group. In conclusion increasing 10 % metabolizable energy and protein both during late pregnancy improved mammary growth and development with increasing number and percentage of epithelial cells, increasing alveoli and epithelium area and decreasing percentage of stroma in sistani goats that could have positive effect of cololstrum production and milk yiled in subsequent lactation period.Keywords: Alveoli, Metabolizable energy, Mammary tissue, Epithelial cell, Sistani goat
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Pages 61-65The numerous apparent malformations of eggs from laying breeder flocks are affected by the increased age of the flocks. The bulking and spinning of eggs causes them to be placed in small end up (SEU) condition in the incubation period and eventually inoculation of the virus is done incorrectly. Present study was designed to investigate the effect of egg condition on embryos deaths, amnio-allantoic fluid volume, and the influenza virus replication rate. 1200 one-day-old embryonated chicken eggs from breeder flock at 60-65 weeks of age were divided in three groups. The first group underwent the incubation period before and after inoculation of the virus in large end up (LEU) condition. The second group spent the incubation period pre and post inoculation of the virus in SEU and LEU positions, respectively. The third group passed the incubation period before and after the inoculation in SEU condition. Prior to inoculation of the virus, all groups were incubated for 11 days at 37.6°C and 60% relative humidity (RH), and turned 32 times daily. After inoculation, the eggs were incubated for three days at the same conditions but without turning. Ultimately, in each group, the amnio-allantoic fluid was collected and the percentage of embryos deaths was determined. Titration assays were performed using hem agglutination (HA) and egg infective dose 50 (EID50) tests. All experiments were performed in three replicates. The results showed that the percentage of embryos deaths was 3:1 in the second group in comparison to the first group. In the third group, casualties were 100%. Mean of extracted amnio-allantoic fluid volume from total eggs of first group in comparison to the second group was approximately 8:1. There were significant differences between the groups in all factors (pKeywords: Amnio, allantoic fluid, Egg condition, Embryonated chicken eggs, Incubation
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Pages 66-79In order to evaluate the effects of three organic (Formic, Acetic and Propionic acid) and two inorganic acids (Sulfuric acid and HCL) at different levels (0, 1, 2.5 and 5% (vol/wt)) on dry and organic matter, NDF, CP and ammonia-N content and pH of Iranian clover silage and its ruminal dry matter and nutrients degradability, this experiment carried out using a complete randomized design with 5×3 factorial arrangement of treatments. After harvesting at 15 % of flowering, equivalent of three Kg dry matter of treated and control Iranian clover was ensiled for 35 d. The effects of these treatments on ruminal dry matter and nutrient degradability of Iranian clover silage were determined. Ruminal dry matter and nutrients degradability of Iranian clover silage were measured by nylon bag technique using three fistulated Zel ewes (approximately 2 year old, BW= 30 ± 2 kg). Incubation times consisted of 0, 4, 8, 12, 24, 36, 48, 72 and 96 h. The acid, level of acid and their interactions significantly decreased the NDF, ammonia-N content and pH, whereas significantly increased DM, OM and CP content of treated silage in comparision to control silage. Ruminal degradability of DM, CP and NDF were significantly affected by acid, level of acid and their interaction. Treated silages had higher ruminal degradable dry matter, lower ruminal degradable CP in comparision to control silage. Treating with organic and inorganic acids improved the quality and increased ruminal degradable dry matter and NDF and decreased ruminal degradable CP, and totally the increased nutritive value of silage.Keywords: Iranian Clover Silage, Quality Characteristics, Ruminal Degradability
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Pages 80-87In order to design, manufactur and use chewing activity automatical recorder and more accurate assessment of livestock nutrition from 8 Holstein dairy cattle were used with similar production, weight, age, breed and health in change over design 2×2 in two 21-day periods (2 weeks to adapt to the diet and 7 days for sampling). Treatments were 2 diets with the same chemical composition and different alfalfa hay particle size. The geometric mean of coarse and fine alfalfa hay, and geometric mean of two experimental rations were 3.09, 4.65, 2.91, and 3.6 mm, respectively. Animal chewing activity was recorded with visual observation and chewing activity automatically recorder. Rumination time in cows fed fine particle size was lower (P= 0.0159). Eating time was not significant different by visual observation and chewing activity automatical recorder. The jaw displacement during each a rumination meal was 334.34 and 295.47 cm for fine and coarse diet, respectively (P= 0.0001). The each rumination time In this study was ranged from 68.93 to 55.33 seconds for diets containing fine and coarse particles (P= 0.0001). The chewing of a rumination meal was reduced by increasing of particle size. The movement of jaw in one second of rumination was 4.86 and 5.34 for diets containing fine and coarse particles, respectively (P= 0.1706). The degree of displacement in a jaw movement of one minute of rumination did not change with increasing feed particles size (P= 0.1706). The jaw movements in resting time between each meal of rumination were 4.61 and 4.46 seconds for fine and coarse diets. In current experiment, In addition to evaluating the chewing activity automatical recorder was confirmed accuracy and the precision of its operation.Keywords: Alfalfa hay, Chewing activity, Holstein, Particle size
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Pages 88-92Transcription factor 7 gene (TCF7) is located on genomic candidate region for fat traits on sheep chromosome no. 5 and it is excepted to affect fat traits. In the present study, blood samples were collected from 164 Lori-Bakhtiari sheep in Shouli breeding station located at Shahr-e-Kord city, and 113 Zel sheep in Shirang breeding station located at Gorgan city. DNA was extracted from blood samples using modified salting out method and polymerase chain reactions were performed for amplification of 643 bp fragment of exon 2 of locous TCF7 gene. Determination of genotype patterns of sheep were obtained according to result of vertical electrophoresis and AA, AB and BB genotypes were revealed. In Zel breed, AA and AB genotype patterns were observed with frequency of 71 and 29 percent respectively and in Lori-bakhtiari breed, AB and BB genotype patterns were observed with frequency of 10 and 90 percent. There was no significant effect of genotype patterns on fat traits In Zel breed but it was significant effect in Lori-Bakhtiari breed. AB genotype had the greatest impact on fat-tail weight and blood cholesterol and BB genotype had considerable effect on blood triglycerides.Keywords: Blood cholesterol, Blood triglycerides, Fat, tail weight, PCR, SSCP, Sheep, TCF7 gene
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Pages 93-98In this study, estimation of genetic parameters of Lameness and genetic and phenotypic correlations between Lameness and milk, fat and protein yield were performed. The data obtained from 63403 Holstein cows were collected from the Animal Breeding Center of Iran between 2001 to 2013 Estimation of genetic parameters for lameness was performed by univariate animal and Threshold models. Also, estimation of genetic and phenotypic correlations between Lameness and production traits was performed by bivariate animal model by using the ASREML Software. Results showed that heritability of Lameness with Animal and Threshold models were 0.02 and 0.057, respectively. Estimated heritabilities with two methods were low, but with Threshold model were more than linear model, also genetic correlations between Lameness and persistency of milk, fat and protein yield were 0.31, 0.23 and 0.27, respectively and phenotypic correlations between Lameness and persistency of milk, fat and protein yield were 0.048, 0.037 and 0.029, respectively. Positive correlations between Lameness and production traits show that long term selection for production traits could be the most important factor for culling by Lameness disorders.Keywords: Correlation, Heritability, Holstein cattle, Lameness, Production traits
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Pages 99-106Meat quality and carcass composition are the most important economic traits in sheep. Body fat and fat-tail are key factors affecting carcass quality and meat production in each breed, and mutations in sequences of the genes that control these traits can affect the animal performance and therefore the breeding value. The aim of this study was to investigate the polymorphism in some regions of SAR1B, SEC24A and VDAC1 genes in candidate genomic regions for fat traits on ovine chromosome 5. Blood samples were collected randomly from 300 Lori-Bakhtiari and 100 Mazandaran sheep and DNA was extracted using modified salting out method. Polymerase chain reaction (PCR) was performed for amplification of 478, 579 and 348 bp fragments of studied genes using specific primer pairs and genotyping of samples was done by SSCP technique. The obtained results showed three banding patterns of A, B and C for SAR1B marker site in Lori-Bakhtiari sheep but it was monomorph in Zel sheep. For SEC24 gene, three banding patterns of A, B and C were observed in both sheep breeds, but VDAC1 was monomorph in both sheep breed. The effect of banding patterns of SAR1B gene on fat-tail characteristics were significant (PKeywords: Fat, tail traits, SAR1B, SEC24A, Sheep, VDAC1
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Pages 107-114The present study aimed to estimate the genetic for parameters of biometric traits in Iranian Moghani-sheep breeds. The data set consisted 15115 biometric records from 3702 individual progenies of 499 male and 3203 female, involve for a 15 years period (1996 to 2011). obtained from Moghani sheep breeding and raising station. Variance components and genetic parameters were estimated using restricted maximum likelihood (REML)-methods by WOMBAT software. Six different animal models were fitted and the best model for each trait determined by Akaike Information Criterion (AIC). All traits were significantly (PKeywords: Biometric traits, Genetic correlations, Heritability, Moghani sheep breed
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Pages 115-121This research was carried out in order to detect the polymorphisms in four sites of PEPCK-C gene by PCR-RFLP method in a commercial layer and broiler strains and breeder hens of Mazandaran native fowls breeding station. Blood samples were collected randomly from 150 birds from a three populations and DNA was extracted using modified salting out method. Using polymerase chain reaction (PCR) and specific primers pairs a region with the length of 3792 bp from position -1723 to exon 4 from PEPCK-C gene was amplified. In RsaI marker site two alleles of A (33%) and B (67%) were detected in Mazandaran native fowls, A (34%), B (66%) in commercial broiler and A (24%) and B (76%) in commercial layer population. Two genotypes of AB and BB were detected with the frequency of 66 and 34% in Mazandaran native fowls 68 and 32% in commercial broiler and 48 and 52% in commercial layer hens. In BstEII marker site two alleles of A (28%) and B (72%) were detected in Mazandaran native fowls population, A (19%), B (81%) in commercial broiler and A (59%) and B (41%) in commercial layer lines. Three genotypes of AA, AB and BB were detected with the frequency of 2, 52 and 46 in Mazandaran native fowls, 2, 34 and 64% in commercial broiler and 42, 34 and 24% commercial layer. In PstI marker site two alleles of A (43%) and B (57%) were detected in Mazandaran native fowls population, A (52%), B (48%) in commercial broiler and A and B (50%) in commercial layer samples. Three genotypes of AA, AB and BB were detected with the frequency of 16, 54 and 30% in Mazandaran native fowls, 18, 68 and 14% in commercial broiler and 6, 88 and 6% in commercial layer population. In BstEII marker site (position to 흍) the results showed that all samples from different strains had the same banding pattern with monomorphic BB genotype. Among 3 observed SNPs 2 were in the promoter site and 1 in intron 2 region. As a result of finding polymorphism in this marker site and also its major effect on production traits such as egg for production, feed conversion ratio and growth rate it can be considered as a candidate gene in detection of QTL related to these traits in poultry industry.Keywords: Polymorphism, PEPCK, C, Chicken, PCR, RFLP
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Pages 122-129A paternal half-sib design was implemented to identify QTL on chromosome 2 affecting growth traits in Japanese quail. Using a reciprocal cross between two strains, white (laying) and wild (broiler) of Japanese quail, 34 birds were obtained in F1 generation and 422 offspring related to 9 paternal half-sib families in 5 consecutive hatches were generated. Progeny from 9 paternal half-sib families were measured for growth traits, and genotyped for four microsatellite markers on chromosome 2. QTL analysis was performed with least squares interval mapping method based on regression in across and individual paternal half-sib families. In addition to the QTL responsible for Kleiber ratio, other QTLs related to growth in positions 13, 51, 53, 54 and 55 cM, (PKeywords: Growth traits, Japanese quail, Paternal half, sib designs, Quantitative trait loci, Kleiber ratio
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Pages 130-139This study was carried out to investigate different data transformation methods on homogeneity and heterogeneity of variance components. Data included 305-day lactation records for protein yield from the first three lactations of Iranian Holstein cows collected from 1983 to 2014 by the Animal Breeding Center and Promotion of Animal Products of Iran. Data included 141670 records for 1st lactation, 115395 records for 2nd lactation and 82529 records for 3rd lactation. Records were categorized to 3 classes according to the average of herd-year production. For testing the heterogeneity of variance components Bartlet test was used and it was significant among all three lactations. A pre-correction method and two different data transformation methods including Box-Cox and Square root were used to correct for heterogeneity of variance. Genetic parameter and heritability estimates were estimated by VCE program, under an animal model. Spearman correlations and proportion of animals selected before and after data transformation were also estimated. Application of the Visscher adjustment method resulted in slightly higher heritabilities, which may be due to the more accurate estimation of additive genetic effects when heterogeneity is considered. Heterogeneity of variance had a significant effect on re-ranking and selection of 5% top sires and 1% of top dams. Pre-correction, Box-Cox and Square root method caused a proportion of 4%, 19% and 10% of top sires and 10%, 21% and 7% of top dams, respectively, to be excluded from selection when compared to the homogenous variance scenario. The results of this research indicate that the variance between different levels of herd-year production is not homogeneous and may influence the ranking and genetic evaluation of top cows.Keywords: Data transformation, Holstein, Protein, Variance Heterogeneity, Re, ranking
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Pages 140-148In the present study for evaluation of genetic variability within and between Iranian native fowls, thirty nine blood samples were randomly collected from native fowls breeding stations of west Azarbayjan, Khorasan, Fars, Mazandaran, Yazd and Esfahan provinces. Inorder to compare the obtained results with other Asian, African and European breeds the D-loop sequences of mtDNA taken from GenBank. Total DNA of the samples was extracted by salting out procedure and was used as a template for amplification and sequencing of D-loop region of mtDNA. Sequence analysis of the 1231-2 bp D-loop region in all samples revealed a total of 16 haplotypes with 14 polymorphic sites. Analysis of molecular variance (AMOVA) was carried out based on Kimura method .The Fixation index values using kimura-2 parameter method ranged from -0.157 to 0.37763. The variation within and between the populations was estimate as (81.05 and 18.95, respectively). The genetic distance between Esfahan and West Azarbayejan, Esfahan and Fars, Esfahan and Khorasan, Esfahan and Mazandaran, Esfahan and Yazd, Fars and khorasan, Fars and Yazd populations were significantly different (pKeywords: Genetic diversity, Genetic distance, Iranian native chickens, mtDNA, Phylogenic
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Pages 149-156The objective of this study was to investigate genetic and phenotypic parameters of body weight of shall lambs in different ages. Records of growth traits obtained from 6,692 lambs (progeny of 195 rams and 1,288 ewes) were used. The records of birth weight, BW (6,690 records), 3-month weight, W3 (6,654 records), 6- month weight, W6 (6,662 records), 9-month weight, W9 (6,599 records) and 12-month weight, W12 (6,528 records) collected between 1997 and 2013 in Shal Breeding Station in Ghazvin province were used. Genetic parameters were estimated applying restricted maximum likelihood method fitting an animal model using WOMBAT program. Test of significance for the fixed effects was carried out using SAS 9.2 software. The mean ± standard deviation of BW, W3, W6, W9 and W12 were 4.31±0.92, 20.90±3.46, 34.13±3.92, 47.42±4.21, and 60.46±4.28 kg, respectively. Direct heritability estimates were 0.13±0.02, 0.57±0.05, 0.52±0.05, 0.79±0.04 and 0.73±0.05 for BW, W3, W6, W9 and W12 respectively. The highest maternal heritability was estimated for W9 (0.32±0.02).Keywords: Growth traits, Genetic parameters, Heritability, Shall sheep, Variance components
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Pages 157-167Longevity records of 26991 Mehraban lambs born from 405 sires and 8114 dams which collected by the Agricultural Organization of Hamedan Province during 1981 to 2011 were used in this study. To determine the fixed effects fitted in statistical model (birth year, birth month, type of birth, age of dam, flock, lamb sex and lamb birth weight and their interactions), the GLM procedure of SAS software was used. Interaction between birth year-lamb sex and all fixed effects except for birth type, dam age and linear covariate variable of lamb birth weight was significant on longevity (PKeywords: Bayesian analysis, Genetic parameters, Gibbs sampling, Longevity, Sheep
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Pages 166-174In current research, two strains of Japanese quail consisting of 150 wild quail (50 male and 100 female birds) and 150 white quail (50 male and 100 female birds) were used as base population in Aghghala quail station. Four mating groups include group 1 (wild male×wild female), group 2 (white male×wild female), group 3 (wild male×white female) and group 4 (white male×white female) were used for producing progeny. Chicks were weighed and then slaughtered at 35 days of age. After slaughter and removing feathers, carcass seperation was carried out. The internal organs consisting glandular stomach, gizzard, Spleen, liver, heart, bursa fabricius and total digestive system weighed by scale with 0.01g accuracy. The fixed effects of sex, hatch and mating group were investigated. The variance and covariance components and genetic parameters were estimated using multiple animal model and restricted maximum likelihood with ASREML software. Sex and hatch had significant effects on body, carcass and breast weights (PKeywords: Body weight, Carcass characteristics, Heritability, White, wild Japanese quail
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Pages 175-183One of the main problems of multiple-trait genetic evaluation in poultry breeding is high computing costs. Principal components analysis (PCA) is a method for reducing the number of traits in correlated trait analysis. The aim of the present study was to determine the most effective principal components (PCs) of internal egg quality and some performance traits of Azarbayjan native chickens. Records were measured from 1500 native hens, including body weight at sexual maturity (BWSM), age at first egg production (ASM), egg volume (EV), yolk percent (YP), yolk width (YWI), yolk weight (YW), yolk Index (YI), yolk dry matter (YDM), yolk depth (YD), yolk pH (YPH), yolk coefficient (YC), the ratio of yolk weight to albumen weight (RYA), albumen percent (AP), Hough Unit (HU), albumen pH (APH), albumen height (AH), albumen dry matter (ADM), albumen weight (AW). Descriptive statistics, phenotypic Pearson coefficients and principal components analysis were evaluated using SAS software. The results showed that the range of Pearson correlation coefficients for phenotypic traits varied from zero to 0.98. The correlation coefficients more than 0.6 between HU and AH, YP and RYA, YW and YC, YP and YWI, YP and YW, YP and YDM, YP and YC¡ YWI and YW, YWI and YDM, YWI and RYA, YW and RYA, YI and YD, YDM and YC, YDM and RYA, YC and RYA, AP and AW, and ADM and AW were evaluated. The PCA analysis showed that the eight first principal components explained about 90.21% of the total variation of internal egg quality traits. Using PCA in internal egg quality, BWSM and ASM showed that YW, YDM, YC, YP, RYA, YWI, AP, AH, AW and HU have great impact on the total phenotypic variance. So, this method can be used for internal egg quality and performance trait analysis of native hens and can reduce computing costs and time of genetic evaluation of multiple traits.Keywords: Eigenvalue, Internal egg quality, Multiple, traits, Pearson correlation, Principal components
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Pages 194-200To determine of MEG9 gene polymorphism and its association with birth weight in Sistani cattle, the blood sample of 130 calves (male and female) were randomly collected belonging to Sistani cattle Research Center. The DNA extraction from whole blood was performed using phenol-chloroform procedure. Polymerase chain reaction was performed for amplification of 210-bp segments of exon 3 of MEG9 gene using specific primers. Detection of mutations were carried out by electrophoresis of poly-acrylamide gel 8% and silver staining using SSCP method. Association study of allele patterns with birth weight was done with fixed linear model and comparison of means was conducted by Tukey-kramer method. Results showed that three allele patterns including q1, q2 and q3 in PCR product of MEG9 gene in Sistani cattle with frequency of 37, 34 and 29 % respectively. The genetic diversity in MEG9 gene had significant correlation with birth weight (PKeywords: Birth weight, MEG9, PCR, SSCP, Polymorphism, Sistani cattle
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Pages 201-208This study was conducted to compare the feedlot performance and growth traits of Lori-Bakhtiari (n=39), Romanov × Lori-Bakhtiari (n=38) and Pakistani × Lori-Bakhtiari crossbred (n=12) lambs during two consecutive years. Lambs were weaned at the age of 90 ± 5 days. After weaning and preliminary fattening period, three groups of lambs were fattened for 90 days in the same conditions. The results showed that weaning weight in Romanov × Lori-Bakhtiari crossbred lambs were significantly higher than in Lori-Bakhtiari and Pakistani × Lori-Bakhtiari crossbred lambs. Lori-Bakhtiari and Romanov × Lori-Bakhtiari lambs were not significantly different (PKeywords: Crossbreeding, Growth, Feedlot, Lori, Bakhtiari, Romanov, Pakistani