Set 1 Flashcards
Freemartin
- disease that limits performance
- heifer is born co-twin to a male
- > 90% are free martin
- female sex characteristics androgenized
- abnormal external and/or internal genitalia
- 95% sterile
Lactation period lasts how many days
~305
Dry period lasts how many days?
~60 days
How long is a cow in gestation?
~283 days
Time to complete parturition in the following species:
- mare
- heifer
- cow
- ewe
- sow
mare= 10-20 mins heifer=2-4 hours cow= 20 min - 2 hours ewe 30-60min sow= 20 min between piglets(often in pairs)
Stage 1 of parturition
relaxation of the pelvic ligaments(tail head up)
relaxation and dilation of the cervix
fetus changes position
placental membranes push against cervix by rhythmic contractions of the uterus
can take 2 to 3 days for this stage to complete
Stage 2(20 min to 2 hours)
-allantois ruptures
-amniotic sac ruptures
-fetus is expelled from uterus by
abdominal contractions
uterine contractions
fetal movement
Stage 3 of parturition
expulsion of fetal membranes
Dystocia(difficult birth)
- failure of the cervix to dilate
- obstruction of vagina
- failure of vulva or vagina to dilate
- uterine torsion
- uterine inertia
- maternal-fetal disproportion
- abnormal presentation
- twins
- malformed fetus
Consequences of dystocia
death of fetus vaginal tears uterine tear obturator nerve paralysis sciatic nerve paralysis muscle damage due to being down
Retained placenta
-failure to expel fetal membranes by 24 hours post calving
Risk factors with retained placenta
- dystocia
- twins
- abortion
- milk fever
- caesarian section
- induced delivery
- immune function greatly reduced
- major risk factor for subsequent metritis
Postpartum involution
process of restoration of reproductive tract to support subsequent pregnancy
-shrinkage and repair of uterus and cervix
-sloughing of endometrium(lochia)
-clearance of bacterial contamination within 3 weeks
restoration occurs in parallel with return to cyclicity
Postpartum anestrus
-20-25% of dairy cows may not cycle by 60 DIM
Metritis
acute, bacterial uterine infection (39.5, off feed, toxemia)
- may or may not have RP
- uterine discharge is watery, red-brown and foul smelling
- largely a problem of postpartum immune function
- systemic antibiotics to treat
Endometritis
infection/inflammation of uterus; no systemic signs(>21 DIM)-localized infection
-characterised by delayed involution
-development depends on the immune response of the cow
-treat with IU antibiotics 4-6 weeks postpartum
-clinical signs include
purulent discharge 15-20%
cytological endometritis 15-20%
Cost of metritis
Economic loss for each cow: -antibiotic treatment 53-109/case -culling and death 85/case -milk loss 83/case -reproduction 109/case total being ~ 329-386
Almost all cows have bacterial contamination of the uterus after calving, the difference of becoming infected or not lies in?
- magnitude of infection
- regulation
- duration
- effectiveness of the response
Cystic Ovarian Condition
-ovarian follicle that fails to ovulate or regress and grows to abnormal(>2.5 cm diameter)
-ovum in a cyst will age and be infertile
-may impair reproduction short-term
-over-diagnosed and generally overrated as a problem
-treatment
induce LH surge
+/- supplemental progesterone
Non-infectious abortion
- early embryonic loss(15-25% of pregnancies diagnosed at 28 days are lost by 60 days)
- twins
- heat stress
- fetal genetic acomalies
- iatrogenic
Infections abortion- non contagious
-disease agent may be introduced by circulation or up repro tract
-sporadic abortion(~3-5%)
-fungal
-opportunistic bacteria
other maternal disease, inflammatory response may cause abortion Ex ecoli mastitis
Infectious abortion- contagious
agents are contagious and have predilection for causing abortion
- IBR
- BVD
- Leptospirosis
- neospora
Neospora Caninum
- coccidian parasite
- infects cattle, dogs
- subclinical in infected adults
- infection is life long
- manifestation is abortion(4-7 months)
- if fetus not aborted calf very likely to be infected (PI)
- no effective treatment
