FINAL EXAM: Managing Mare for Breeding Flashcards
1
Q
The mare is _____
Which means _____
A
Seasonally polyestrous
ovarian activity changes during the year
2
Q
Winter
A
Anestrus; small ovaries, no activity
3
Q
Early spring
A
"transitional" ovarian activity increases begins 6-8 weeks after day length increases lasts ~6-8 weeks first ovulation April 7 +- 9 days
4
Q
Late spring/early summer
A
regular cycles
“polyestrus”
5
Q
Fall
A
“transitional”; ovaries decreasing activity
6
Q
Length of estrus cycle
A
~21 days (18-23)
7
Q
How to manipulate the breeding season
A
Day length
- begin 16hr light/8hr dark in early december; will begin regular cycles sooner (february)
1. barn/stall
2. lighted paddock
3. mask
8
Q
2 phases of the estrous cycle
A
- Diestrus
2. Estrus
9
Q
Diestrus
A
Not receptive to stallion, longest period of cycle (15d), cervix closed
10
Q
Estrus
A
Receptive to stallion; ~6 days (4-9d) ovulation
11
Q
When does ovulation usually occur?
A
24-48 hours before end of estrus
