1. CLINICAL MANAGEMENT OF ANESTRUM
IN COWS
By
Dr. Atef Abdel-Hai Khalil Selmi
Professor of Obstetrics, Gynecology, & A.I.
Faculty of Veterinary Medicine
Zagazig University
( 4 )

2. CLINICAL MANAGEMENT OF ANESTRUM
IN COWS
Anestrum is the principal symptom of many conditions that
causing infertility in cows. The affected cases fail to express
the behavioral signs of heat.
It is frequently observed in heifers as a herd problem,
especially during the period of reduced feed intake. Whereas,
anestrum in cows is observed mainly after parturition or after
service ( when conception does not occurs).
 Increased incidence of such syndrome in a herd might
reflect a managemental and/or nutritional problem.
Therefore, an accurate herd survey together with careful
clinical examinations is required to diagnose and treat the
possible cause(s) of such syndrome.

3. Classification of Anestrnm
Following careful clinical examination, anestrum cases
are grouped according to the absence or presence of
a functional corpus luteum on their ovaries into :
1 -Anestrum cases exhibiting no corpus luteum on the
ovary:
A-Hereditary conditions:
Bilateral ovarian aplasia, Bilateral ovarian
hypoplasia,
Freemartins, Hermaphrodites.
B-Ovarian inactivity:
Small smooth inactive ovaries and Ovarian atrophy.
2 -Anestrumcases exhibiting a functional corpus luteum
on the ovary :
A- Pregnant cases.
B- Functional anestrum (silent heat, subestrum).
C- Persistent corpus luteum.

4. 1.A:Anestrum due to hereditary conditions:
Anestrum due to hereditary conditions can be suggested
in phenotypically steer like heifers that never come in
heat despite reaching or passing age of puberty.
Application of Fincher Pencil Test is used to differentiate
Freemartins from those affected with bilateral ovarian
aplasia or bilateral ovarian hypoplasia (infantile
genitalia), or hermaphrodits (HCG challenge test).
The affected cases fail to reproduce because they are
almost sterile (hereditary).
Therefore, cases exhibiting anestrum due to hereditary
conditions should be discarded from breeding.

5. 1.B: Anestrum due to ovarian inactivity:
The adverse debilitating conditions that causing
ovarian inactivity and absolutely suppress or
even stop estrous cyclicity are:
1-A low plane of nutrition:
Lack of sufficient intake of carbohydrates,
proteins, fats, and other elements necessary to
maintain body weight may be the immediate
cause leading to delayed onset of puberty or
suppress estrous cycle following parturition.

6. 2-Seasonal influence:
Ovarian activity tends to be seasonally affected by
changes in the day light length and the environmental
temperature. However, heat stress might interfere
with the appetite of the animal and consequently
causing anestrum owing to reduction in body weight
and loss in body condition score.
3-Aging or senility:
Loss of teeth or sharp teeth owing to aging causing
inability to masticate food properly and consequently
indigestion. Indigestion, on the other hand, is
associated with reduced body weight, loss of body
condition score and ovarian inactivity with the
resultant anestrum.

7. 4-Chronic debilitating diseases:
These include severe mange, traumatic gastritis,
chronic pneumonia, Johnes disease, actinomycosis,
heavy infestation with parasites, advanced
tuberculosis, anaplasmoses, and suppurative
arthritis. These diseases reduced the appetite and
consequently reduced body weight with the
resultant ovarian inactivity.
Treatment of ovarian inactivity depends upon the
cause(s). Whereas, improving body condition score
is the key component in the treatment strategy.
While as, aged cows exhibiting progressive senile
changes or those affected with chronic debilitating
diseases should be culled or replaced.

8. 2. A: Anestrum due to pregnancy
History of the owner may be misleading and may request
treatment for anestrum.
Treatment of anestrum should be postponed in such a cow,
especially when the clinical examination reveals the presence
of a functional corpus luteum on the ovary in the absence of
any detectable changes in the genital tract.
Re-examination should be advisable for such a cow after 2-4
weeks later to exclude pregnancy.
Detection of progressive changes characteristics of pregnancy
indicate that the cow is pregnant.
Such a cows should not receive any medication to avoid
interruption of pregnancy.

9. 2.B :Anestrum due to functional anestrum
Silent heat and weak estrum or subestrum occurs most
commonly in cows after parturition (during the next 60
days postpartum). However, older cows (over 15 year
of age) tended to show longer intervals between
parturition and estrum than did the younger cows.
Postpartum silent heat occurs more frequently in
nursed than in milked cows . Moreover, the interval
from calving to first estrus is 30 days longer in nursed
cows than in milked cows.
High lactating cows or fatty cows may acquire silent
heat.

10.  Cows in advanced age, arthritic cows, cows with foot rot or
untrimmed feet or those exhibited painful diseases may fail
to show signs of heat.
 Hereditary predisposition for subestrum or weak heat is a
character of certain breeds. Holstein cows from a certain
sire lines exhibited high incidence of silent heat.
 The physiologic basis for silent heat is not clearly defined,
but the central nervous system in the affected cases may
be less sensitive and requires a high level of estrogen to
produce the characteristic symptoms of estrum. Another
explanation is that the adipose tissues in fat cows adsorb
estrogen and the available level of estrogen is not enough
to induce the nervous manifestation of heat.

11.  Silent heat is characterized clinically by absence of heat
signs or failure of estrum, but some cases may develop mild
signs of estrum especially in subestrum cows.
 The clinical signs of short unobserved heat are difficult to be
differentiated from those of silent heat, weak heat or
subestrum.
 Close observation, application of heat detecting device or
using a teaser bull can be of significant value in detecting
those cases.
 Regular gynecological examination reveals cyclic changes in
the genital organs. Therefore, prediction of heat will be
useful in managing those conditions.
 Synchronization of estrus would be helpful and can be
practiced more easily than any other treatment in managing
those cows.

12. 2.C :Anestrum due to persistent corpus luteum
False persistent CL is observed most commonly after
breeding and conception and then after 10 to 90 days
following embryonic or fetal death (pregnancy,
pyometra, mucometra, fetal maceration, and fetal
mummification).
 Persistent corpus luteum can be detected on the
ovary corresponding to a missing horn (uterus
unicorns).
True persistent CL is not associated with any
detectable genital changes (high lactation, lack of
caruncles or deficiency of endometrial glands).

13. In long standing cases the corpus luteum become centrally
located, deeply embedded and may be difficult to be diagnosed.
Clinical examination of the uterus or evaluation of
endometrial biopsy may declare the possible cause of CL
persistence.
Occasionally, persistent corpus luteum may be recovered
spontaneously, but most cases would be existed for several
months without estrum unless diagnosed and treated.
Following repeated clinical examination and exclusion of
pregnancy, a luteolytic dose of PGF2α is indicated (when the
corpus luteum is still within the same size and persists on the
same ovary without any detectable clinical changes in the
genital tract).

14. Manual removal of persistent corpus luteum
is not recommended to avoid traumatic
lesions for the ovary and adhesion to the
surrounded tissues.
 When, the condition is recurred in the same
animal after treatment, a deficiency of
endometrial glands will be suggested and
culling or replacement is recommended.

15. 2.D :Anestrum due to cystic ovary
Ovarian cysts are developed most commonly during the
second to the forth month after parturition in cows.
Behavioral signs in the affected cases are variable, but
there are two main signs can be detected and used to
classify those cases into nymphomaniac or anestrum cows.
Nymphomaniac cows exhibit frequent, irregular,
prolonged or continues signs of heat. They are often
nervous, restless, and bellow frequently. The cyst(s) might
persist on the ovary for 10 days up to several months.
Occasionally, thick-walled, fluctuating luteal or luteinized
cysts may be consequently developed. These luteinized
cysts together with corpus luteum cyst are associated with
signs of anestrum.

16. Mucometra may be developed in longstanding
condition and the owner believed that the cow is
pregnant, but the clinical examination revealed no
signs characteristics of pregnancy.
Anestrum cases due to cystic ovary (follicle lutein
cyst or corpus luteum cyst) can be treated with a
luteolytic dose of PGF2α.
 However, incidence of cystic ovary in cows can be
minimized by injection of GnRH at the 10th
or 12th
day
postpartum.
Moreover, herds with high incidence of cystic
ovaries should be bred to bulls selected from those
shown to have daughters with very low incidence of
cystic ovary.