All Assorted Flashcards
What are two functions of the follicle on the ovary ?
1.Contains the ovum
2.Produces estrogen
What is the ovum caught by ? Where is it directed to? And how long does it survive ?
Caught by the - Fimbria
Directed into the - Oviduct
Will survive for - 12 hours
During diestrus the follicle on the ovary has been replaced by what? And what hormone does it produce?
Replaced by the - Corpus Luteum
And produces progesterone
If the mare is not pregnant in the final days of diestrus what hormone is released? And what is destroyed?
PGF2a is released
And the CL is destroyed
What is the natural peak time for conception in mares ?
Summer solstice
The hormone GnRH stimulates is what ?
The pituitary gland
What do the follicles secrete when they reach 20-25 mm?
Estrogen
If no embryo is present in the uterus at the end of this 12-15 day period the uterine endometrium secretes what??
Prostaglandin (PGF2a)
What destroys the CL which is producing progesterone?
PGF2a
Without________ to act as a inhibitor the FSH levels rise , and the estrous cycle repeats itself
Progesterone
List one factor that relates to poor reproduction efficiency in horses
Seasonal occurrence of estrus
What are the 2 aspects of reproductive management
- Detection of estrus
- Mating management
List 2 methods of teasing
- Pen or stall
- Tease wall
What insemination timeline leads to highest conception rates?
36 hours before and up to ovulation
List 2 factors that affect spermatogenesis is the stallion
- The hormone testosterone
- Daylight length
List one venereal disease found in horses
Contagious equine metritis
List 2 components of a breeding soundness exam
- Medical history of the stallion
- Medication history
- Behaviour history
List 4 methods of semen collection
- Condom
- Pharmacologically induced
- Use of an AV
- Manual Manipulation
What is the normal internal temperature range of the AV?
44c to 48c fill at 50c
List one advantage of pasture breeding
High conception rates
List one disadvantage of pasture breeding
Risk of injury to stallions and mares is greater
List one advantage of hand breeding
Increased control of stallion and mares resulting in fewer injuries
List one disadvantage of hand breeding
Increased labour
List one function of the semen extender
Increase the volume of the ejaculate
What is the most common ingredient found in semen extenders
Milk based
How many progressively motile Sperm should be inseminated in the mare and at what concentration/ml?
500 million and 25-50ml
How many progressively motile sperm are standard does for shipped semen
1 billion and 25-50ml
Most stallions that are considered “good coolers” will still have at least ___% to ___% of the initial Sperm motility after 24 hrs of cooling
40% to 50%
Semen is generally ordered when a follicle ___ mm to ___mm in diameter is first detected
35mm to 40mm
In order to help ensure that ovulation occurs within 24 to 48 hours after insemination mares are commonly administered either ________ or ______________________
Desorelin or Human Chorionic Gonadotropin (hcg)
A minimum of ____% progressively motility should be present post thaw for a stallion considered a “good freezer”
30%
List one common purpose for embryo transfer
To produce more that one foal in a season from a particularly valuable mare
Is embryo collection a surgical or non surgical procedure?
Non surgical
What is a intracytoplasmic sperm injection
A micro injection of a single sperm into the cytoplasm of a mature oocyte
One benefit of line breeding
Concentrates on desirable traits
List one drawback of line breeding
Also concentrates on undesirable traits
What % of blood is contributed by an ancestor in the 3rd generation
12.50%
What is linecross
Line cross is a line bred individual from one family crossed with a line bred individual from another family
A lighting program that supplies ___ hours of light to __ hours of dark provide best results for stimulation of the estrous cycle
16 & 8 hours
3 methods for pregnancy determination
- Palpation
- Ultrasound
- Observation
