نوع مقاله : مقاله پژوهشی

نویسندگان

1 استادیار گروه علوم دامی، دانشکدۀ کشاورزی، دانشگاه گیلان، رشت‌، ایران

2 مربی پژوهشی، بخش فرآوری تولیدات دامی، مؤسسۀ تحقیقات علوم دامی کشور، کرج‌، ایران

3 دانشجوی دورۀ دکتری گرایش فیزیولوژی دام، گروه علوم دامی، دانشکدۀ کشاورزی، دانشگاه گیلان، رشت‌، ایران

چکیده

اثر مصرف ملاتونین و بروموکریپتین بر وزن بدن، ریزش الیاف، و خصوصیات کرک با استفاده از 24 رأس بز مادۀ رائینی (دو تا سه‏ساله) در چهار گروه ‏آزمایشی شاهد (C)، ملاتونین (MI)، بروموکریپتین (B)، و ملاتونین+بروموکریپتین (MIB) بررسی شد. در گروه MI، یک قرص 18 میلی‌گرمی ملاتونین در زیر پوست قرار داده شد و 40 روز بعد این عمل تکرار شد. در گروه B، 5/0 میلی‏گرم بروموکریپتین برای هر کیلوگرم وزن زنده، سه نوبت در هفته تزریق شد. در گروه MIB، ملاتونین و بروموکریپتین با یکدیگر مصرف شد. بزها به‌مدت دو ماه در شرایط طبیعی و با طول دورۀ کوتاه روشنایی (8 ساعت نور و 18 ساعت تاریکی) پرورش داده شدند. الیاف بز با شانۀ‌ چوبی در چهار مرحلۀ زمانی با فاصلۀ دو هفته از 23 بهمن تا 8 فروردین جمع‌آوری شد. وزن الیاف شانه‌شدۀ بزهای گروه C، MI، B، و MIB به‌ترتیب 3/21، 3/23، 7/15، و 0/17 گرم بود (05/0P>). میانگین قطر کرک در بزهای گروه MI (4/21 میکرون) بیش از تیمارهای C، B، و MIB به‌ترتیب 2/20، 9/19، و 8/19 میکرون بود (01/0P<). ضریب تغییرات قطر کرک بیدۀ بزهای گروه شاهد بیش از سایر گروه‌ها بود (05/0P<). نتایج نشان داد که ملاتونین و برموکریپتین موجب افزایش یکنواختی قطر الیاف کرک در بزهای مادۀ رائینی می‏شود.

کلیدواژه‌ها

عنوان مقاله [English]

The effect of melatonin and bromocryptine administration on body weight and shedding fibre of Raeini goats

نویسندگان [English]

  • Ardeshir Mohit 1
  • Mahnaz Salehi 2
  • Zeynab Khob Bakhat 3

1 Assistant Professor, Department of Animal Science, Faculty of Agricultural, Guilan University, Rasht, Iran

2 Instructor, Department of Animal Product, Animal Science Research Institute, Karaj, Alborz, Iran

3 Ph.D. Candidate, Department of Animal Science, Faculty of Agricultural, Guilan University, Rasht, Iran

چکیده [English]

The effect of melatonin and bromocryptine on body weight, fibre shedding and cashmere traits was investigated by using 24 Raeini female goats (2-3 years old) in four experimental groups: control (C); melatonin (MI) implant (18 mg at first and repeated after 40 days), bromocryptine (B) injection, (0.5 mg/kg BW per three days) melatonin and bromocryptine implant and injection (MIB). All goats were maintained under natural photoperiodic conditioned of short day photoperiod (8 h light and 18 h dark), for two months. Fibre was harvested by using wooden combs and each goat was combed four times at two week intervals, from 23th February to 8th March. Combed fibers were 23.3, 15.7, 17.0 and 21.3 percent for MI, B and MIB treated and C groups. Cashmere fiber diameter (CFD) for MI group (21.4 um) was higher than the other C, B and MIB groups 20.2, 19.9 and 19.8 um (P<0.01). The CV of CFD was significant and higher in C group compared with the other groups (P<0.05). These results suggest that melatonin and bromocryptine improve uniformity of cashmere diameter in Raeini female goats.

کلیدواژه‌ها [English]

  • cashmere percent
  • combed fiber
  • CV of diameter
  • diameter
  • length
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