Estrous Cycle Comparison Flashcards
How long is the typical estrous cycle of bovine?
21 days
How long is estrus of bovine
12 to 18 hrs
Avg size of dominant follicle in bovine?
9-13mm
How many follicular waves do lactating holstein tend to have?
2 waves/cycle
How many follicular waves do beef and dairy heifers have?
2 or 3 waves/cycle
What does the # of follicular waves determine?
Estrous cycle
What does a peak in FSH proceed?
Follicular wave - each FSH peak indicates a follicular wave
How long is the porcine estrous cycle?
21 days
How long is estrus in porcine?
50hrs
Do pigs have follicular waves?
No, every day during estrous you have the formation of new follicular wave
What occurs on day 15 and 16 of pig estrous?
40% of follicles present will undergo atresia or degeneration before LH surge
What is ovulation rate in pig affected by>
Age
Breed
Nutrition
What type of estrous cycle do equine have?
Seasonal polyestrus (long day)
How long is estrous cycle in equine?
21 days
How long is estrus in equine?
7 days
3 Characteristics of mare estrous cycle
- Prolongation of LH secretion
- Rather than a surge in the LH secretion, LH increase is more gradual
- FSH has a long lifespan
What type of estrous cycle do ovine have?
Seasonal polyestrus (short Day)
Estrous cycle length in ovine?
17 days
Duration of estrus in ovine?
30hrs
What things influence estrous cycle in ovine?
Breed
Age
Season
Presence of male
Length of estrous in bitch
6 months
Length of estrus in bitch
9 days
When does ovulation occur in bitch?
48-60hrs after LH surge
What does proestrus end with in bitch?
Receptivity of female
How long can sperm survive in utero in bitch?
7 days
How do progesterone levels compare between pregnant and non-pregnant bitch?
P4 levels are similar
How often does the queen enter estrus?
Every 17 days
How long is estrous in caprine?
20-21 days
How long is estrus in caprine?
22-60hrs
How many ovaries do chickens have?
1
How often can chicken produce an egg?
1/day
How does progesterone act in chicken?
Like estradiol
It will influence the surge center to release GnRH when a threshold is reached