This document discusses various hormonal causes of infertility in cattle, including ovarian atrophy, follicular atresia, silent heat, delayed ovulation, ovarian cysts, and persistent corpus luteum. Ovarian atresia occurs when follicles fail to grow and ovulate due to hormonal imbalances. Ovarian cysts develop from unovulated follicles and can cause anestrum. Persistent corpus luteum refers to the corpus luteum persisting beyond its normal lifespan, also resulting in anestrum. Diagnosis and treatment options aim to induce ovulation or luteinization and reestablish normal estrus cycles. Left untreated, these hormonal issues can increase costs through extended calving intervals and reduced fertility.

1. Hormonal Causes of Infertility
By
Dr. Atef Abdel-Hai Khalil Selmi
Professor of Obstetrics, Gynecology, & A.I.
Faculty of Veterinary Medicine
Zagazig University
( 2 )

2. Hormonal Causes of Infertility
1-Ovarian Atrophy
The condition was manifested clinically by a history
of prolonged period of anestrum in the affected
females.
 It is usually diagnosed in association with chronic
debilitating diseases or in aged cows over 15 -20 years
of age.
The condition was found affecting both ovaries
(small, smooth, and firm in consistency), and the
genital tract was found reduced in size.
The prognosis is poor and the affected female should
be discard from breeding or replaced.

3. 2- Follicular Atresia
The condition means regression of the growing follicles caused
by insufficiency of proper gonadotropin stimulation or due to
hormonal imbalance.
The atretic follicles fail to grow beyond its size, looses its
turgidity, and never ovulate.
 The condition was manifested clinically by a history of
anestrum in the affected females.
Histopathological examination of atretic follicles revealed that
the granulosa cell layer was found reduced in thickness and
appeared degenerated or detached. The antrum appeared
collapsed and the oocyte with the surrounded cumulus
oophorus appeared degenerated and loosely detached in the
antrum . Degenerated tissues are further replaced by fibrous
formation with complete antrum obliteration in advanced
follicular atresia.
The condition could be controlled by feeding (concentrate
ration supplemented with vitamins and minerals) together with
GnRH administration.

4. Tertiary follicle
Primary follicle
Tertiary
follicle
Egg nest
Secondary
follicle
Atretic follicle
Corpus albicans
Corpus luteum
Corpus
hemorrhagicum
Ruptured follicle
)ovulation(
1
2
3
4
5
6
7
4”
Folliculogenesis and corpus luteum formation

5. 3- Silent heat
4- Subestrum
5- weak estrum
6- Short Unobserved heat
 These conditions are characterized clinically by that the
affected females fail to express the behavioral signs of estrum or
exhibited a marked reduction in the heat period despite the
presence of cyclic estral changes in their genital organs.
 Signs of short unobserved heat could not be clinically
differentiated from those of silent heat, subestrum, or weak
estrum.
 Silent heat can be classified as functional anestrum and
constitute 90% of all anestrus cases especially in hot climate.
 Functional anestrum increases open days and causes severe
economic losses that could be calculated as 100 pound per open
day.

6. The possible etiological factors:
1- These conditions occur more frequently during
the next 60 days postpartum because incidence of
silent heat was found high in the first postpartum
estrus (77%), then decline to 55% and 35% by the
second and third postpartum estrus.
2- These conditions are observed more frequently
in foreign breeds especially when lived under hot
stressful humid environment.
3- These conditions occur more frequently in
nursed than in milked cows. Moreover, the
interval from calving to first postpartum estrus in
nursed cows was found 30 days longer than in
milked cows.

7. 4- The physiologic bases of these condition is not
clearly defined, but the central nervous system may be
less sensitive in those cases or requires a higher
concentrations of estrogen to produce the behavioral
signs of heat and consequent acceptance of the male.
5- Hereditary predisposition: High incidence of silent
heat was observed in a certain sire line in a herd of
Holstein breed, where daughters of silent dams may
developed silent heat.
6- Cows in advanced age, arthritic cows, cows with foot
rot or untrimmed feet, or affected with painful diseases
may fail to express signs of heat.
7- High lactating cows or fatty cows may also acquire
silent heat or quite ovulation.

8. Diagnoses and treatment:
 These conditions can be diagnosed by the following
application:
1-Close observations to the herd to detect estrus cows.
2-Application of heat detecting device or aids…………………
3-Careful clinical examination for prediction of heat.
4-Good keeping records.
 Treatment of those condition can be practiced more
easily by:
1-Improve managemental practices(feeding, housing,
medical care, and education of laymen).
2-Application of estrus synchronization in the affected herd.
3-Regular watching of cows during feeding or milking.
4-Selection against those conditions and replacement of
chronically recurred cases.

9. 7-Delayed Ovulation
The condition means that the process of ovulation occurs
in cows after the proper time (beyond 12 hour after the
end of heat signs).
Delayed ovulation is usually associated with aging of
both gametes (sperm and ova) and results in reduction of
their fertilizing capacity. Therefore, delayed ovulation is
usually associated with failure of fertilization.
The affected females exhibiting prolonged estrus phase
and developed cyclic non-breeding syndrome ( regular
repeat breeder) despite mating in the proper time ( meddle
of estrum).
The condition can be diagnosed by the history and
clinical examination (persistence of mature Graffian follicle
on surface of the ovary for 1 or 2 days later).
The condition can be controlled either by:
1-Application of second insemination by the next day.
2-Administration of GnRH or LH at the time of breeding.

10. 8- Ovarian Cysts (Cystic Ovary)
Ovarian cysts can be defined as follicular structures of
2.5 cm in diameter or more that persist on the ovary for
at least 10 days up to several months.
This syndrome affects all cows ages especially after
their 2nd
to 5th
parturition, and develops most commonly
during the second to the seventh week after calving.
Four types of cysts can be detected on the ovary(ies) of
the affected cases ( follicle theca cyst, or follicle lutein
cyst, or corpus luteum cyst, or small cystic ovarian
degeneration ).
Behavioral signs of nymphomania ( follicle theca cyst )
or anestrum ( other types of cyst ) were found associating
cystic ovarian degeneration in the affected cows.

11. The possible causes of cystic ovarian degeneration:
1- Hereditary causes:
A- Incidence of cystic ovarian degeneration was found to be
higher in dairy breeds (5.6-18.8%) than in beef breeds.
B- It was found to be closely related to the rate of milk
production ( commonly in high producing cows ).
C- It was found to be closely related to the amount of fat
contents in the milk (commonly associating high contents).
D- It is also higher in daughters of caws that had ovarian cyst
(26.8 %) than in daughters of caws that had no history of
ovarian cyst (9.2%).
E- Incidence of cystic ovary was reduced from 10.8 to 3 %
following selection of cows against cystic ovarian degeneration
(culling of cows developed cystic ovary and replacement of
their daughters).

12. 2-Nutritional and Managemental causes:
A- Feeding high concentrates ration necessary
for milk production (urea concentration was
found increased in the follicular fluid of cystic
follicle).
B- Reduced amount of green feeds in the ration
(vitamin A was found reduced in the follicular
fluid of cystic follicle).
C- Incidence of cystic ovary was high in stabled
cows (lack of exercise, lameness, stress of
lactation, reduced exposure to sun light,
reduced aeration, crowdedness and heat stress
together with postpartum uterine infection).

13. 3- Hormonal causes:
A- Increased secretion of prolactin and growth
hormone necessary for high lactation:
prolactin causes direct inhibition to granulosa
cells to secrete progesterone with a consequent
increase in estrogen secreation and
development of follicular atresia that followed
by development of follicle lutein cyst or
development of cystic CL (with a consequent
development of anestrum).
B- An endocrine imbalance:
1-Excessive amounts of FSH that over
stimulating follicular growth.

14. 2-Subnormal availability of LH to induce ovulation (anti-
LH).
3-Failure in the mechanism controlling LH secretion
(GnRH administration).
4-Deficiency in synthesis or release of GnRH was also
suggested (GnRH administration).
5-Reduced pituitary-hypothalamus responsiveness to
estrogen during the immediate postpartum period
(progesterone dominance during pregnancy,
supraphysiological concentration of estrogen shortly
before calving, most cases develops cystic ovary within
45 days after calving, spontaneous recovery of the cyst,
and responsiveness of pituitary and hypothalamus was
found to be returned by 4-6 week postpartum).

15. Classification of ovarian cysts:
1- Location of the cyst on the ovary:
A- Central cyst. B- Peripheral cyst.
2- Number of the cyst on the ovary:
A- Single cyst. B- Multiple cysts.
3- Origen of the cyst:
A- Unovulated follicle:
a- Follicle theca cyst ( nymphomania ).
b- Follicle lutein cyst ( anestrum ).
B- Corpus luteum: Cystic CL ( anestrum ).
4- Clinical manifestation:
A- Nymphomania. B- Anestrum.

16. Symptoms and clinical findings:
1- Follicle theca cyst (75 %):
A-Behavioral and phenotypic changes:
a-Frequent, irregular or continuous heat and bellow
frequently
b-Nervous, restless, sexually aggressive, acquires
masculine behavior, and mount other cows ( Nymphomania).
c-Lose weight and the voice changed to masculine pitch.
d-Relaxation of the pelvic ligaments with the consequent
development of sterility hump (elevation of the tail rote).
e-Edema in the vulva and tail folds together with signs of
pneumovagina and presence of grayish white secretion.
f-Sharp decrease in milk production rate due to elevated
concentration of estrogen together with reduced appetite.

18. B- Rectal and vaginal examination:
a-Presence of 1 - 4 thin walled cyst on one or both
ovaries( 2.5 - 10 cm in diameter).
b-Fallopian tubes are enlarged an relaxed or flaccid.
c-The uterus is enlarged, edematous and flaccid.
d-In longstanding cases, the uterine wall became
thin and the lumen became distended with mucoid
fluid (hydrometra or mucometra).
e- Endometrial glands exhibite cystic degeneration.
f-Bartholin glands and Gartner ducts became cystic
too.
g-Portio vaginal is enlarged, dilated and relaxed
together with presence of grayish white mucous.

19. C-Histopathological changes and fate:
a-Degenerative changes together with partial
luteinization occurs in the granulosa cell layer
of follicle theca cyst.
b-Progesterone production is increased and
estrogen production is reduced.
c-The affected cow went anestrum and the
condition might spontaneously recovered .

26. 2- Follicle lutein cysts (22%):
It comprises about 23% of the cows affected
with cystic ovarian degeneration, but the
percentage would be higher than this value
because the condition is not associated with
abnormal sexual behavior as in follicle theca cyst
(nymphomania).
Affected cases are anestrum, but spontaneous
recovery may occurs.
The cyst is firm, less fluctuating than follicle
theca cyst, and persists on the ovary without any
cyclic changes.

28. 3- Corpus luteom cyst ( 2.5%):
It develops from an
ovulated follicle, but
luteinization is not
complete that leading
to formation of central
lacuna filled with
serous fluid.
It is associated with
absence of cyclic
ovarian changes.
The affected cow
exhibits anestrum.

29. 4-Small cystic ovarian degeneration(0.5%):
The affected cases exhibited the presence of
small multiple growing follicles on the ovarian
surface ( 0.5 – 1 cm in diameter), that makes the
ovary likes mulberry.
The condition may be due to arrested
follicular growth owing to deficiency in FSH
secretion or improper gonadotropin stimulation.
Follicular degeneration and atresia can be
detected in those cysts.

30. Diagnosis:
A- History. B-Symptoms. C-Clinical examination.
Prognoses:
The prognosis is favorable when the affected cases
were early diagnosed and treated.

31. Treatment:
1-Induction of ovulation or luteinization either by
squeezing of the cyst or by IM injection of GnRH
(twice the dose) or HCG, then followed 8 days later
by a single IM injection with a luteolytic dose of
PGF2α to reestablish normal estrus cyclicity.
2-Recurred cases should be replaced or discarded
from breeding.
3-Injection of a prophylactic dose of GnRH at the 12th
to 14th
day postpartum will reduce the incidence of
cystic ovary.
3-Selsction against such syndrome (male and
female).

32. Economic importance:
Increased incidence of cystic ovarian
degeneration (especially those associated with
signs of nymphomania) in cows causes severe
economic loss through the following:
1-Increases open days.
2-Causes sharp decrease in milk yield.
3-Reduces body condition score.
4-Increases the possibilities of infectious
illness.
5-Increases coast of medical treatment.
6-Increases the possibilities of dissemination.

33. 9-Persistent corpus luteum
True persistent corpus luteum means
persistence of CL on the ovary beyond its normal
life span without any detectable changes in the
genital tract as that recorded in the following
conditions:
1-High lactating cows.
2-Hereditary deficiency of endometrial glands.
3-Marked decrease in the endometrial caruncles
(hereditary or pathological).
4-Marked reduction in endometrial glands due to
repeated uterine infection or chronic degenerative
changes in the endometrium.

34. False persistent CL is the corpus luteum
observed most commonly after breeding and
conception. It is associated with uterine changes
as that detected in the following condition:
1-Normal pregnancy (exhibits progressive uterine
changes according to the stage of pregnancy).
2-Following embryonic or fetal death due to trauma or
genital infections (develops fetal resorption, abortion,
closed pyometra, macerated fetus, or mummified).
3-Uterine distention (hydrometra, mucometra &
pyometra).
4-White heifer disease(segmental aplasia of the
Mullarian ducts, uterus unicorns, or persistent hymen).

35. Symptoms and diagnosis:
Retained corpus luteum on the ovary is
always associated with anestrum and the
affected cases never cycles.
Its diagnosis requires two successive
examinations at two weeks intervals and
depends upon the detection of that CL on the
same ovary, with the same size, without any
detectable changes in the genital tract.
Retained CL becomes deeply embedded,
more centrally located, and could not be
palpated easily, especially in longstanding cases.

36. Treatment:
In order to avoid interruption of pregnancy, a
careful clinical examination should be done to
excluded pregnancy before any medical
interference.
A luteulytic dose of PGF2α will involutes such a
retained CL together with reestablishment of estrus
within 3 – 5 days (followed by evacuation of
uterine contents).
Culling of recurred cases ( after receiving two
successive treatments) because of degenerated
endometrium or hereditary deficiency of
endometrial glands are suggested in those cases.

37. Heifers exhibit persistent CL due to hereditary
causes are culled too.
Avoid enucleating deeply embedded retained CL
detected in association with pyometra.