Exam 3 - Non-infectious Infertility Flashcards
what is the most common cause of anestrus/low pregnancy AI rates in cattle?
inaccurate estrus detection - occurs 90% of the time, usually no pathology & they are usually in diestrus with a CL
how is non-detected estrus diagnosed?
repeated exams - include exams for cows that are ‘in heat’, & make sure you keep accurate records
how can temperature cause anestrus in cattle?
very hot or very cold can reduce activity
how can size & location of the yard cause anestrus in cattle?
not truly anestrus, but it is too big so the cows never see their friends with benefits
what are some methods in which heat detection is improved for cattle?
KaMar paint patches - placed at tail base & splatter when they are mounted
grease pencil thing - cheaper than the paint ones, & it looks like slicked back hair when they are mounted
how do pedometers help with estrus detection in cows?
cows in estrus will walk more/show more activity
are teaser animals more commonly used in the dairy cattle or beef cattle industry?
more common in beef cattle
what is the most important thing to improve estrus detection in cattle?
OBSERVATION
how is PGF2a used to improve estrus detection in cattle?
when given, it concentrates the number of cows going into heat at one time when given to a sexually active group of cows (need to have a CL & be in diestrus to respond to this)
what is a gomer bull?
bull that has a deviated pp or pp problem that can’t actually breed a cow, but it can be used for detecting cows in estrus
what is a physiologic cause that is often forgotten as a cause of anestrus in cattle?
pregnancy!!!
what are the most common pathologic causes of anestrus in cattle?
uterine distension from pyometra (persistent CL), mucometra, & hydrometra
why do cows get a pyometra from a retained CL causing anestrus? what cows are often affected by this?
they are unable to release PGF2a from their endometrium, so the CL stays & wrecks shop
commonly occurs in postpartum cows
what is the biggest difference between mummified fetuses in cattle & macerated fetuses in cattle?
prognosis - mummified fetuses carry a better fertility prognosis
macerated has a poor fertility prognosis
when do mummified fetuses occur in cattle? what pathology is seen?
3-8 months into gestation - fluid resorption & sterile environment
when do macerated fetuses occur in cattle? what pathology is seen?
any stage of gestation but usually after bone formation!!!!!
vaginal discharge & probably stinky and smelly
which one is macerated & which one is mummified?
mummified - top photo, dried up fetus
macerated - bottom picture, infected & gross
T/F: cystic ovarian disease affects 10-30% of dairy cows & is less common in beef cattle (unless they are frequently superovulated)
true
what is cystic ovarian disease in cattle?
follicle-like structures that fail to ovulate - follicular cysts
or partially lutenized cysts with thicker walls that are usually single - luteal cysts
what are the differences between follicular cysts & luteal cysts in cattle?
follicular - > 25mm in diameter, thin-walled
luteal cyst - thicker walled, usually single
what is the mechanism of cystic ovarian disease in cattle?
inadequate LH release or lack of LH receptors
stress near calving/hereditary predisposition
T/F: cystic ovarian disease in cattle is more common at or after the 3rd lactation
true
what are the clinical signs associated with cystic ovarian disease?
70-80% anestrus
20-30% nymphomania - mounting other cows constantly or sterility hump with a prominent tail head
occasional masculinization
this is a sterility hump - what condition is this appearance associated with?
cystic ovarian disease
how is cystic ovarian disease diagnosed in cattle?
history & clinical signs
palpation/ultrasound
uterus is flaccid!!!!!!!
why is no treatment sometimes used for cystic ovarian disease in cattle?
none due to spontaneous recovery - 60% before 1st postpartum ovulation & 20% after 1st postpartum ovulation
what treatment is used for follicular cysts in cattle?
GnRH - stimulates LH release from AP, gets them to estrus in 3 weeks
hCG - LH activity, normal cyclicity in 3 weeks with 65-80% responding to a single dose, but if no response to the 3rd treatment, bad news
what treatment is used for luteal cysts in cattle?
PGF2a given 9-10 days after GnRH or hCG
estrus in ~3 days, so estrus from treatment takes 12 days instead of 3 weeks
T/F: it is cost effective to exam cows for cystic ovaries 50-60 days postpartum to determine if treatment is needed & then treating what is necessary
true
T/F: manual rupture of luteal cysts is an okay treatment option for cystic ovarian disease in cattle
false!!! very bad - risk of hemorrhage especially with luteal cysts
how do freemartins happen in cattle?
anastomosis of fetal vessels of twin baby cows - male differentiation occurs earlier than female differentiation, so there is a transfer of the H-Y antigen which inhibits female gonadal development
T/F: >90% of twin calves are affected by freemartinism
true
what animals are affected by freemartinism?
female co-twin of male calf