Equine Breeding Programs Flashcards
What is a stallions book?
list of mares that will be bred to him in a given year
What is a cover
when a stallion breeds a mare naturally
what is a mount/phantom/dummy
fake mare that allows us to collect semen for AI when stallion mounts it
what is an artificial vagina
what we use to collect semen from a stallion
what are the four methods of mare breeding
-natural service
-on farm AI
-shipped fresh chilled AI
-frozen semen AI
what is the only approved method of breeding in thoroughbreds to obtain a registered foal?
Natural cover
advantages of natural cover breedings (5)
-Minimal equipment expenses (no lab etc)
-Obvious when mare is in heat
-No knowledge of semen handling required
-No semen shipments lost
-High conception rate
disadvantages of natural cover breedings (4)
-Risks of injury to horses and handlers
-One mare bred per ejaculation
-Mares must travel to stallion (often with new foal)
~assoc. risks and costs
-Some mares will not accept a stallion even when in estrus
What needs to be done in natural cover programs to assure no disease transmission occurs?
-Pre-breeding culture swabs
-Clean breeding practices
advantages of AI (5)
-Mare & foal stay at home
-Efficient
-Many mares can be bred with a single collection
-Fresh-chilled semen lasts about 48+ hours when diluted with semen extender
-Frozen semen - stallion continues performance career without interruption
disadvantages of AI (2)
-Increased expenses
◦ Laboratory costs
◦ Semen shipping cost
◦ Veterinary costs of mare management
-Considerable knowledge in semen handling
advantages of frozen semen (4)
-Permanent storage
-Semen available anytime
-Stallions continue performing
-Improved genetics – use of stallions around the world
disadvantages of frozen semen (1)
-Higher costs
◦ Semen collection, freezing, storage, transport
◦ Very intensive mare monitoring required
◦ Requires specialized equipment and expertise
characteristics of anovulatory season (dec-feb)
◦ Variable behavior
~Usually uninterested in stallion – “meh”
◦ Small ovaries, small follicles <10 mm
◦ Flaccid uterus, no edema
◦ Cervix – pale, tight or relaxed
levels of GnRH, FSH, LH, estrogen and P4 in winter anestrus
-decreased GnRH and FSH
-no LH, estrogen or P4
What environmental factor triggers the resurgence of ovarian activity?
Increased daylength
What hormone is released in response to increased daylength?
GnRH
What happens to FSH levels during the resurgence of ovarian activity?
it increases
What is notable about the follicles during spring transition?
Follicles start to grow but do not produce much estrogen
What is the status of LH during the resurgence of ovarian activity in spring transition?
There is low bioactive LH and no LH receptors, so ovulation does not occur
Describe the characteristics of the ovaries during the spring transition
The ovaries are large with multiple follicles
What changes occur in the uterus during spring transition?
The uterus is flaccid with variable edema
What is the typical state of the cervix during the resurgence of ovarian activity?
The cervix is usually relaxed and may appear pale to pink