پارامترهای ژنتیکی اثرات مستقیم و مادری برای صفات رشد گوسفند افشاری

Subject Areas : Camel

آ. خرسند ¹ , س.ح. حافظیان ² , ا. تیموری-یانسری ³ , ا. فرهادی ⁴

1 - Department of Animal Science, Faculty of Animal Science and Fisheries, Sari Agricultural Science and Natural Resources University, Sari, Iran
2 - Department of Animal Science, Faculty of Animal Science and Fisheries, Sari Agricultural Science and Natural Resources University, Sari, Iran
3 - Department of Animal Science, Faculty of Animal Science and Fisheries, Sari Agricultural Science and Natural Resources University, Sari, Iran
4 - Department of Animal Science, Faculty of Animal Science and Fisheries, Sari Agricultural Science and Natural Resources University, Sari, Iran

Received: 2012-10-29 Accepted : 2013-01-26 Published : 2014-03-01

Keywords: صفات رشد, پارامتر ژنتیکی, گوسفند افشاری,

Abstract :

پارامترهای ژنتیکی و مولفه‌های (کو) واریانس وزن بدن در تولد (BW)، شیر‌گیری (WW) و شش ماهگی (BW6) و میانگین افزایش وزن روزانه (ADG) قبل و بعد از شیر‌گیری گوسفند افشاری با استفاده از روش حداکثر درست‌نمایی محدود شده (REML) و مدل دام در نرم افزار DFREML تخمین زده شدند. تست نسبت درست‌نمایی (LRT) برای مقایسه مدل‌ها مورد استفاده قرار گرفت. سال‌های تولد، سن مادر، جنس بره‌ها و نوع تولد اثرات معنی‌داری را روی صفات مورد مطالعه نشان دادند، بنابراین به‌ عنوان اثرات ثابت در مدل قرار داده شدند. وراثت‌پذیری مستقیم (h2) برای BW، WW و BW6 و ADG قبل و بعد از شیر‌گیری به ‌ترتیب بر‌اساس بهترین مدل برابر با 231/0، 164/0، 246/0، 118/0 و 07/0 بود. اثرات مادری به ‌طور معنی‌داری صفات قبل از شیر‌گیری را تحت تأثیر قرار دادند. وراثت‌پذیری مادری (m2) صفت BW و اثرات محیط دائمی مادری (c2) صفات WW و ADG قبل از شیر‌گیری به ‌ترتیب برابر با 219/0، 078/0 و 079/0 بود. همبستگی‌های مستقیم ژنتیک افزایشی (ra) و فنوتیپی (rp) بین صفات مطالعه شده در همه موارد مثبت بوده و به‌ ترتیب در محدوده‌های 425/0 تا 990/0 و 013/0 تا 990/0 قرار داشتند. همبستگی محیط دائمی مادری (rc) بین WW و ADG قبل از شیرگیری برابر با 984/0 بود.

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