Factors Affecting Reproductive Efficiency Flashcards
What are factors affecting reproductive efficiency in a mare?
-age and # of pregnancies
-reproductive health: tract abnormalities in the vulva, vagina/vestibule, cervix, and uterus
Urine pool
when urine accumulates in the vagina
-can happen due to conformation, age, or foaling complications
Inflammation of the uterus
-multiple possible causes
-an endometrial (uterine) cytology looks for inflammatory cells
Infection of the uterus
bacterial infections or yiest/fungal infections (less common)
-can do an endometrial culture
Endometrial abnormalities of the uterus
-endometrial cysts (can see with an ultrasound)
-endometrial fibrosis (can see with a biopsy)
Endometrial biopsy’s are done…
when a mare is having trouble getting in foal or staying in foal
Category I biopsy
normal
-70-80% live foal rate
Category II biopsy
mild to moderate fibrosis/inflammation
-40-70% live foal rate (depending on if its mild or moderate)
Category III biopsy
severe fibrosis/inflammation
-<20% live foal rate
Spermatogenesis is…
a continuous process of
From initiation of sperm to maturation is how many days?
about 57 days
Time from initiation to ejaculation is about how many days?
57-63
When will you see an event that affects spermatogenesis in semen quality?
57-63 days later
How long can sperm remain in the tail of the epididymis?
for several days
Daily sperm output
of mature sperm that can be harvested each day
Daily sperm output is affect by:
-day length
-testis size/weight/volume
-stallion age
Younger stallions sperm output is…
less than older stallions
Daily sperm output for mature stallions in the spring-summer
-3-4 billion/day
Is there an advantage to collecting stallions more often than 3x/week?
no, more than 3 times per week will result in about the same amount of sperm/ejaculate
A sub-fertile stallions pregnancy rate per cycle is:
less than 30%
Possible causes of a sub-fertile stallion
-illness
-blocked ampullae
-hormonal imbalance
-behavior
-testicular degeneration
-acrosomal abnormalities
