Reproduction In Sheep Flashcards
What does seasonal polyestrous mean?
Length of the breeding season varies with breed and daylength
What happen to sheep and goats in tropical environments?
They can breed through out the year
Why does the Dorset and Merino breeds have longer breeding seasons?
They originated near the equator
What happens to the ewe follicles in the summer?
They develop and secrete E2 in the anestrous
What changes the frequency of LH in the ewe?
The response of negative feedback in E2 and suppresses LH in the summer but can’t during the breeding season
When are Melatonin levels greatest?
In the dark
What does Melatonin do?
Mediates the response to changes in photoperiod
During what months can ram breed?
They can throughout the year but day length will stimulate secretion of LH, FSH and testosterone.
What is melatonin?
A derivative of the animo acid tryptophan
Where is melatonin made?
Pineal gland
What two factors influence the onset of the breeding season?
Photoperiod and temperature
How is info transferred from the retina of the eye to the SCN?
Nerve tract
