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A study on ghrelin and LH secretion after short fasting and on ghrelin levels at perioestrual period in dairy cattle
- Source :
- Reproduction in domestic animals = Zuchthygiene. 54(1)
- Publication Year :
- 2018
-
Abstract
- In two experiments, we studied (a) the changes of LH secretion in heifers under different feeding schedules and (b) total ghrelin concentration at oestrus in cows and heifers. In experiment one, synchronized heifers were allocated in three groups (R, regularly fed controls; F, fasted; and F-F fasted-fed). One day after the completion of the oestrous induction protocol, group F and F-F animals stayed without feed for 24 hr; thereafter, feed was provided to R and F-F cattle; 2 hr later, GnRH was administered to all animals. Blood samples were collected for ghrelin, progesterone, LH and cortisol concentrations. Fasting caused increased ghrelin concentrations in groups F and F-F, while in response to GnRH, LH surge was significantly attenuated in groups F and F-F compared to R. In experiment 2, lactating cows and heifers were used. On day 9 of a synchronized cycle, PGF2α was administered, and blood samples were collected twice daily until the third day after oestrus and analysed for progesterone, estradiol, ghrelin, glucose and BHBA concentrations. No difference was recorded between groups in steroids and BHBA concentrations. In comparison to mid-luteal values, ghrelin concentrations significantly increased at perioestrual period in cows, but not in heifers. This study provides evidence that starving-induced elevated ghrelin concentrations can have suppressing effect on LH secretion, even after ghrelin's restoration to basal values and that during oestrus, ghrelin secretion is differently regulated in cows and heifers, likely being independent from oestradiol concentrations. Further research is required to identify the determining factors that drive the different regulation of ghrelin secretion in cows and heifers.
- Subjects :
- medicine.medical_specialty
Period (gene)
Biology
Dinoprost
Gonadotropin-Releasing Hormone
03 medical and health sciences
Total Ghrelin
Basal (phylogenetics)
0302 clinical medicine
Endocrinology
Estrus
Internal medicine
medicine
Animals
Lactation
Dairy cattle
Progesterone
Estrous cycle
030219 obstetrics & reproductive medicine
Lh secretion
Estradiol
digestive, oral, and skin physiology
0402 animal and dairy science
04 agricultural and veterinary sciences
Luteinizing Hormone
040201 dairy & animal science
Ghrelin
Animal Science and Zoology
Cattle
Female
Food Deprivation
hormones, hormone substitutes, and hormone antagonists
Ghrelin secretion
Biotechnology
Subjects
Details
- ISSN :
- 14390531
- Volume :
- 54
- Issue :
- 1
- Database :
- OpenAIRE
- Journal :
- Reproduction in domestic animals = Zuchthygiene
- Accession number :
- edsair.doi.dedup.....73ad3b2d44415790119ae3eafa962175