Bovine - Cystic Ovarian Disease and Anestrus Flashcards
What are some other names for cystic ovarian follicles?
Nymphomania, ovarian cysts, cystic ovarian degeneration or disease, cystic ovaries
Why are cystic ovarian follicles so bad?
Because they are a major cause of economic loss in production systems due to an increased number of open days and the drug cost is more to try and sync them
Why is an increased number of open days bad?
Because that means there are extending calving intervals and inconsistent cycling and calving
Post-calving, what is the voluntary waiting period for breeding in dairy cattle?
60 days
What is the classical definition of cystic ovarian follicles?
Presence of an anovulatory structure on the ovary more than 2.5 cm in diameter and which has persisted for at least 10 days in the absence of a corpus luteum
Why is the classical definition of cystic ovarian follicles troublesome?
Cows typically ovlate between 1.6 - 1.9 cm follicles, this definition leaves out many follicles within 19-25 mm
10 days is also in question, due to the dynamic changes follicles have - new follicles could become cystic and replace a particular follicle that may or may not have been cystic
Absence of the corpus lutea is not universally accepted
What is the ‘newer’ definition of cystic ovarian follicles?
Presence of a follicle(s) with a diameter of at least 20 mm, present on one or both ovaries in the absence of any active luteal tissue, and which clearly interferes with normal ovarian cyclicity
What is the sub-classification of cysts based on?
the degree of luteinization and progesterone concentration in blood or milk
Describe a follicular cyst.
thin walled and secretes verying amounts of estradiol
In a follicular cyst, what dictates the amount of estradiol in the follicular fluid?
the layers of granulosa cells
Describe a luteal cyst.
thicker walled than follicular cysts - the granulosa and theca cells have undergone some degree of luteinization and they secrete varying amounts of progesterone
Luteal cysts are presumed to be follicular cysts that have undergone _____ _______.
some luteinization
Do beef or dairy cattle typically get cystic ovarian follicles more?
dairy
___% of dairy cows will spontaneously recover from COF prior to their first post-partum ovulation and never be diagnosed.
60%
When is cystic ovarian follicles seen in beef cattle?
in intensely managed herds - more commonly in ART programs
Physiologically, why do cystic ovarian follicles occur?
there is dysfunction or neuroendocrine imbalance with the HPG axis causing ovulation failure
What is the primary hypothesis for the physiologic cause of cystic ovarian follicles?
there is an altered release of LH from the pituitary gland - LH surge is absent, there are insufficient amounds, or there is improper timing
What additional factors could lead to the physiologic cause of cystic ovarian follicles?
oxidative stress, NEB, liver metabolism function, or intra-follicular factors
What clinical signs are associated with cystic ovarian follicles?
extended anestrus (>80% of cows), nymphomania (~10% of cows), and sporadic and irregular patterns of estrous cycles
How can cystic ovarian follicles be diagnosed?
rectal palpation, ultrasound, and with blood progesterone
What is the most accurate diagnostic method for cystic ovarian follicles?
with blood progesterone - to be correlated with luteal wall thickness
What is the accuracy of diagnosing a follicular cyst with ultrasound?
74% - thin walled and with anechoic fluid
What is the accuracy of diagnosing a luteal cyst with ultrasound?
90% - thicker walled, cob-web strands
What treatments can be used for cystic ovarian follicles?
hormonal treatments, protocols, and mechanical
What hormones can be used to treat cystic ovarian follicles?
GnRH, HCG, LH, progesterone, and prostaglandins
What horomone does not work to treat cystic ovarian follicles?
estrogen
What protocols can be used to treat cystic ovarian follicles?
ovsynch and CIDR protocols
What are the mechanical techniques can be used to treat cystic ovarial follicles?
It is not recommended - draining, manual rupture
What conditions are associated with cystic ovarian follicles?
high milk production (debated), twinning, environment (summer months), age (older animals), BCS, and genetic predisposition (heritability is low)
1 unit increase in BCS = a _____x higher likelihood of cystic ovarian follicles.
8.4 times higher
Define Anestrus/anestrous.
refers to condition where heifer/cow has not been seen in estrus
What are the causes of anestrus/anestrous?
pregnancy, delayed puberty, and post-partum anestrous
What can cause post-partum anestrous?
too short of time since calving, negative energy balance, health issues, and lactational
Is ovarian inactivity normal after parturition?
yes for a short period of time
What is the cause of ovarian inactivity after parturition?
the elimination of progesterone and estrogens at parturition, and relatively long suppression of FSH and LH during late gestation
When does ovarian inactivity become problematic?
When it happens over an extended period of time - like during the voluntary wait period
How often does problematic ovarian inactivity postpartum happen?
the incidence is 10-30% of cows
When is the 1st FSH increase postpartum and what is the caveat associated with this?
the first FSH increase is within 3-5 days postpartum however, typically does not have other components to finish the cycle
When does the first complete cycle occur postpartum in dairy cattle?
15-45 days postpartum
When does the first complete cycle occur postpartum in beef cattle?
30-130 days postpartum
How can lactation inhibit signs of estrus?
Prolactin will suppress GnRH and therefore suppress the LH surge
Doubt this is important for this test, but in what species is lactational anestrous significant in? Non-existent in?
Significant in sows, non existent in equine and alpaca
What is the new hypothesis for why lactational anestrus happens?
The presence (nursing and mere presence) of the calf inhibits GnRH and LH frequency and surge, which establishes the negative feedback of estrogen on the hypothalamus
How is lactational anestrus treated hormonally?
Remove the calf, then do GnRH/CIDR protocols
How can GnRH treat lactational anestrus?
it may mimic the natural release from the surge center
How can pLH or HCG treat lactational anestrus?
it may mimic the LH release from the pituitary
How can progesterone treat lactational anestrus?
it may allow cows on GnRH to accumulate in surge center
