Reproductive
Failure:
Anatomy & Physiology
Animal Breeding
Pensacola Jr College
Common Aspects of
Reproductive Failure
w Development problems
w Reproductive tract injuries
w Cysts
w No cycling
w Disease (next lecture)
Development
Problems
w Freemartin
w Infantile reproductive
system
w Incomplete or blocked
structures
w Hermaphroditism
w Cryptorchidism
1. Freemartin
w The female of male-female
twins (esp. in cattle)
Embryonic membranes of twins
fuse before reproductive organs develop
Cell mixing brings some Y
chromosomes into female
Oviducts, uterus, and cervix
do not form correctly
Always sterile
Cause of
Freemartin
2. Infantile reproductive
system
w Failure to develop to
maturity
w Most often seen in underfed
female animals
w Generally reversible
3. Incomplete or
blocked structures
w In females: permanent
defects in oviducts, uterus, cervix, or vagina (still cycle)
w In males: permanent defects
in vas deferens or urethra
w Genetic cause (inbreeding)
w Usually sterile
4. Hermaphroditism
w Presence of anatomical
structures of both sexes
w True hermaphrodite:
Has both male & female
gonads (separate or as ovotestes)
Genetic defect (XXY or XO)
4. Hermaphroditism
(contd)
w Pseudohermaphrodite
Has either testes or ovaries
(determines sex classification)
Has combination of other
male and female reproductive tract structures
Caused by hormone or enzyme
deficiencies
Ovotestis in true
hermaphrodite
w
Pseudo-hermaphrodite
w male cat
Male dog
pseudohermaphrodite
5. Cryptorchidism
w Testes fail to descend into
scrotum through inguinal canal
w Genetic defect
w Unilateral cryptorchid
only one testis descends,
reduced fertility
w Bilateral cryptorchid
Neither testis descends,
sterile
Cryptorchid dog
tumor (top)
Reproductive Tract
Injuries
w Uterine or vaginal tears
w Prolapsed uterus
w Broken penis
1. Uterine or
Vaginal Tears
w Usually occurs during either
assisted delivery or manual removal of retained placenta
w Small tears in normal
delivery do not usually block reproduction
w May require surgical
correction
2. Prolapsed
Uterus
w Uterus moves partway or
completely through vaginal canal
w Generally occurs following
parturition due to:
Dystocia
Retained placenta
High estrogen pasture/grazing
Prolapsed Uterus -
cow
3. Broken Penis
w Penis bent and blood vessels
ruptured during copulation at a sharp angle
w Most common in species with
fibroelastic penis (less erectile tissue to provide resistance to breakage)
Cystic Ovaries
w Ovaries form abnormal
fluid-filled sacs
Caused by ovulatory failure
w Follicular cysts:
Thin-walled cysts
Produce estrogen
May cause chronic heat
Rupture w/hormone treatments
Follicular cyst
Cystic Ovaries
(contd)
w Luteinized follicles:
Thick-walled cysts
Produce progesterone
May develop FROM follicular
cysts
Cause anestrus
Regress with hormone
treatments
Ultrasound
luteinized follicle
Lack of Cycling
w Anestrus = absence of estrus
w Most common cause =
pregnancy!!!
w Other common causes:
Postpartum anestrus
Lactation
Seasonal anestrus
Anestrus as
Reproductive Failure
w Physical problem
w Disease problem
w Poor nutrition (especially
low calorie intake)