The document discusses estrus cycles in cattle and buffaloes, describing the phases and signs of estrus as well as factors that can cause silent or sub estrus. Silent estrus occurs when an animal does not display behavioral signs of estrus despite physiological changes, and can be caused by environmental stressors, nutritional deficiencies, or hormonal issues. Methods for detecting estrus discussed include the use of teaser animals, activity monitors, and testing vaginal fluid conductivity or milk progesterone levels.

1. SUB ESTRUS OR SILENT ESTRUS IN CATTLE
AND BUFFALOES
Submitted by:- Rauful Hassan
(J-12-BV-730)

2. Estrous cycle:- After puberty, female enters period
of reproductive cyclicity called estrous cycle.
In other words, estrous cycle consists of a series of
predictable reproductive events beginning at estrus
and ends at the onset of subsequent estrus.

3. PHASES OF ESTROUS CYCLE
1.FOLLICULAR PHASE
a. Proestrus b. Estrus
2. LUTEAL PHASE
a. Metestrus b. Diestrus
ESTRUS :- This is the period during which female allows copulation.
This is most recognizable stage characterized by visible
behavioral symptoms such as sexual receptivity and mating.

4. SIGNS OF ESTRUS
The estrus signs are divided to primary and secondary.
 PRIMARY SIGN
 A cow standing to be mounted is the most accurate sign of
estrus. Standing heat is the most sexually intensive period of
the estrous cycle. During this period, cows stand to be
mounted by other cows. During standing heat, animal
shows characteristic posture called lordosis. The expression
of heat is due to the elevated level of estrogen in the blood
when progesterone is very low.
 An estrus cow usually stands to be mounted
20 to 55 times during her estrus period with
each mount lasting for 3 - 7 seconds

5.  SECONDARY SINGS:- These signs may occur
before, during, or after standing heat and are not
related to time of ovulation. Dairy producers
should use these signs as clues or watch the
specific cow more closely for standing behavior.
To determine whether cows exhibiting secondary
signs will stand to be mounted, they may be
isolated with a sexually active cow or teaser
animal.
 MOUNTING OTHER COWS.

6. MUCUS DISCHARGE
SWELLING AND REDDENING OF THE VULVA

7.  BELLOWING, RESTLESSNESS.
 CHIN RESTING AND BACK RUBBING.

8.  SNIFFING GENITALIA.
 HEAD RAISING AND LIP CURLING.
 DECREASED FEED INTAKE AND MILK YIELD.

10. It is the condition in which animal will
not show behavioral signs of estrus
although the physiological symptoms of
heat will be present.
Silent heat is generally not a problem and
usually is manifested by unobserved heats by
owner.
SILENT/SUBESTRUS

11.  The general pattern of sexual behaviour is almost similar in
cattle and buffaloes but the intensity of expression of
behavioral signs in buffaloes is less due to following
reasons.
I. The lower number of primordial follicles varying 10000
to 19000 compared to cattle 150000.
II. Shy breeder .
III. No homosexual behavior.

12. Buffaloes are more susceptible to heat stress due to following
reasons:-
a. Thick black color skin that absorbs more solar radiations.
b. Sparse hair coat, considered inadequate to insulate the
buffaloes from high temperature.
c. Buffalo skin has fewer (almost 1/6) sweat glands in the skin
than Zebu, situated deep in the skin.

13. FACTORS RESPONSIBLE FOR SUB ESTRUS
 ENVIRONMENTAL FACTORS
 Animals which are not allowed for grazing.
 Concrete floor.
 Over crowding.
 Heat stress

14. Heat stress can causes an increase in cortisol secretion which
has been reported to block estradiol and reduce estrus
behaviour.
Cortisol increase the conc. of progestrone in the blood
resulting in negative feed back on the hypothalamus, which
decrease GnRH and in turn reduces LH and estradiol.

15. NUTRITIONAL FACTORS
1.Beta-carotene
2.Phosphorus
3.Copper
4.Cobalt
DEFICIENCIES OF

16.  The concentration of estrogen determines the behavioral
signs of estrus which is low in high yielding dairy cows.
 Lower concentration of estrogen may be either due to
higher metabolism and clearance with high metabolic
load or sub optimal follicular growth.
 The probable cause of silent estrus is sub optimal
secretion of estradiol by mature follicle or higher
threshold of estrogen in the nervous system to display
the signs of estrus in that particular animal.
HORMONAL FACTOR

17.  In heifers, the estrus associated with first ovulation is
usually silent.
 The first postpartum ovulations frequently are not
accompanied by behavioral signs of estrus and are thus
truly “silent estrus”
 The slight amount of progestrone is required for estrus
sign showing. During second ovulation, progesterone from
regressing corpus luteum act synergistically with estrogen
to produce estrus symptoms .

18. Diagnosis
Diagnosis is based on
 Clinical history
 Rectal palpation of genital system

19. TREATMENT
MANAGEMENTAL
IMPROVEMENT
HORMONAL

20. MANAGEMENTAL IMPROVEMENT
1. By allowing the animals for grazing or left them loose
for few hours where the animals have been tied.
2. There should be provision of non-slippery or kuccha
floors to facilitate the mounting activity of the cows that
are in estrus.
3. In summer season the water should be sprinkled over
the body of the animals for 5-10 minutes twice or thrice
daily.

21. 4. Allow the animals to wallow for 2 hours daily in morning
and in evening to alleviate the impact of heat stress.
5. At large organized dairy farm cooling system
installed inside the shed is found to be very effective in
maintaining normal estrus behavior of buffaloes and cross-
bred cows.
6. If the roof is made up of asbestos or iron sheet then
spread some paddy straw over it make wet by sprinkling of
water.
COND…

22. 7. Animals should be fed green fodder and the feeding
must be done during cool hours of the day.
8. During summer the feed intake of the animal is
reduce so the quality of the ration should be improved
in order to fulfill their physiological needs.
9. Visual observation should be performed by trained
person during cooler hours especially during early
morning and late evening.
COND…

23. OESTRUS DETECTION METHODS
Detection of mounting
Indirect detection
Activity monitors
Conductivity of vaginal fluids
Heat detector animals

24.  Teaser animal can be used as heat detector animal
which could be androgenized female or vasectomized
bull.
 Chin ball is strapped on the underneath side of the
chin of the teaser animal. The device causes colored
paint, dye, on the back of the cow that is mounted.
 The ratio of cows to teaser
should be not greater than 40:1.
Heat detector animal

25. DETECTION OF MOUNTING
Tail paint Heat mount detectors

26. Radio- telemetry
 This include use of a battery powered, pressure-
sensitive transmitter. The transmitter is secured in a
durable pouch. This pouch is glued to the sacrum
region just anterior to the tail head with contact type
adhesive. Transmitter is activated by a continuous
pressure with duration of 1second from the weight of
mounting animal.
 CCTV.

27. Activity monitors (Pedometers)
 The cow become more active when they are in estrus,
activity monitoring through the use of pedometers is a
potentially valuable. It is applied just above the fetlock.
The amount of activity/ walking is recorded by the device
which is read by a scanner each time the cow enters the
milking parlor.

28. CONDUCTIVITY OF VAGINAL FLUIDS
 This method is based on the concept that the electrical
resistance of vaginal fluids decreases during pro estrus
and through the estrus due to increase in the volume and
ionic composition of cervical and vaginal fluid. The estrus
probe is designed to monitor these changes wherein low
probe readings in associated with estrus.
 Fern pattern
detection.

29. INDIRECT METHODS
Inline progesterone
measurement
Mechanical nose
 Mechanical nose :- the physical principle is based on
detection of sex pheromones that are secreted by cow
exclusively during estrus.
 Inline progesterone measurement :- milk progestrone
level will be lowered during heat period . If it decrease level
persists for 2 to 3 days, on third day animal my be served. ELISA
test should be done to check progestrone level in milk during
each milking time.

30. Number of observations made and
their efficiency.
No. of observation period %Cows seen in Heat
Once-a-day 60%
Twice-a-day 80%
Three-times-a-day 90%
Generally estrus in buffaloes commences towards late evening with peak sexual
activity between 6PM to 6AM. So the observation should be made during these
hours.

31. Nutritional supplement.
 Feeding of UMMB.
 Feeding of black gram.
 Vitamin A and C.
 Phosphorus, cobalt and copper.
A block of 5kg may last for 7-8days,

32. HORMONAL TREATMENT
 If a mature CL is present, PGF2alpha is given followed
by FAI. If CL is at refractive stage, double inj. of PG
regime at 11 days interval.
 PRID or other PG implants can be used followed by
FTI.
 After 16-18hrs AI is done.

33. Reference
 Reproduction in farm animal by E.S.E. Hafez. B.
Hafez
 Tanuvas e learning.
 Internet.