Document Detail

Night-time melatonin secretion and seasonally delayed puberty in gilts.
MedLine Citation:
PMID:  15943696     Owner:  NLM     Status:  MEDLINE    
This study was conducted to determine whether the seasonal delay in puberty in autumn is driven by individual differences in night-time melatonin secretion in domestic gilts at the attainment of puberty. A group of spring-born gilts (n = 30) were expected to reach puberty in autumn by the age of 7 months. Eighteen of these gilts were selected in pairs on the basis of matched days of birth. By the expected time, half of the animals showed oestrous symptoms (group CYCLING, n = 9) with the rest remaining silent (group SILENT, n = 9). Afterwards, all gilts were fitted with indwelling jugular catheters for frequent blood sampling. Blood samples were collected from all animals three times during the day followed by three times in the night at 2-h intervals for 48 h. The samples were analysed by a commercial radioimmunoassay (RIA). The results show a consistent 25-fold rise (on average) in night-time melatonin concentration in every animal sampled with group averages ranging from 0.28 +/- 0.04 to 0.37 +/- 0.06 pg/ml at day and from 10.20 +/- 2.16 to 10.67 +/- 0.05 pg/ml at night. Night-time group mean values between CYCLING and SILENT gilts did not differ significantly (10.26 +/- 0.67 and 10.38 +/- 0.94 for the CYCLING; 10.67 +/- 0.05 and 10.20 +/- 2.16 for the SILENT). When 10 pg/ml was used as a threshold value, six individuals did not reach it during the night (low responders). Two of these gilts were CYCLING and four were SILENT. In conclusion, the results presented imply no involvement of the level of night-time melatonin concentration in the seasonal delay of puberty in gilts.
O A T Peltoniemi; A Tast; J V Virolainen; V Karkamo; M Heinonen; M A Andersson
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Reproduction in domestic animals = Zuchthygiene     Volume:  40     ISSN:  0936-6768     ISO Abbreviation:  Reprod. Domest. Anim.     Publication Date:  2005 Jun 
Date Detail:
Created Date:  2005-06-09     Completed Date:  2005-07-22     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9015668     Medline TA:  Reprod Domest Anim     Country:  Germany    
Other Details:
Languages:  eng     Pagination:  224-7     Citation Subset:  IM    
Faculty of Veterinary Medicine, Department of Clinical Veterinary Sciences, University of Helsinki, Saarentaus, Finland.
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MeSH Terms
Circadian Rhythm*
Estrous Cycle / physiology
Melatonin / secretion*
Sexual Maturation / physiology*
Swine / physiology*
Time Factors
Reg. No./Substance:

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