Synchronization of estrus and it's protocols in animal husbandry

1. DR. Jagdesh Chauh

2. The operation or activity of two or more things at the same time or rate.
Two or more than two actions happens at the same time.
SYNCHRONIZATION:

3. • Time of increased sexual desire, activity and receptivity
• In heat
• Sexually active
• Highly receptive
• During estrus female will stand and accept male. At other times, female
rejects mating advances of male.

4. • Sequence of events between two cycles.
Beginning of
second estrus
Inter-estrus
interval
Time
Beginning of one
estrus

5. • The time between these two estrus events averages 21 days
but can vary between 17 to 24 days. The estrous cycle has
four stages: Estrus, Metestrus, Diestrus, and Proestrus.
• The most obvious and visual of these stages is estrus.
• During estrus, the female is in standing heat, which means
she is visually receptive to the male and stands still to be
mounted.

6. A management technique that makes use of
hormones to control or reschedule the estrous
cycle
Many cows
Artificial hormones
/ chemicals
In heat
(estrus)
Many young
ones
Fertilization
Inseminatio
n

7. • Bringing a large numbers of animals in estrus at nearly the
same time.
• Saving labor – avoiding estrus detection
• Planned matting – timed insemination
• Planed calving
• Uniformity of calves for the future replacement of in farm
• shorten the breeding period to less than 5 days, instead of
females being bred over a 21-day period.

8. • To control the timing of the onset of estrus by controlling the length of
the estrous cycle.
• The various approaches for controlling cycle length are:
Progesterone or
synthetic progestin
administration to
suppress ovarian activity
temporarily.
Administration of
Prostaglandin to regress
the corpus luteum (CL)
of the animal before the
time of natural luteolysis.
A newer way of creating
estrous synchrony is by
using gonadotropin-
releasing hormone (GnRH)
or an analogue, which
causes ovulation of a large
follicle, This help in
synchronizing estrous cycle
in an estrous

9. • 1. PROSTAGLANDIN:
Naturally occurring hormone that causes regression of the
CL (luteolysis) and decreases progesterone secretion
which results in a return to estrus
Can expect estrus within two days following injection
The oldest way to synchronize estrus is by using
luteolytic agent such as Prostaglandin F2α or
analogue which cause the regression of CL.
Protocols include PGF one-shot method and PGF
two-shot method

10. • In this method a single injection of prostaglandin is given to cyclic
females, and then these females are bred as they express estrus.
• ADVANTAGES:
• This represents the
greatest savings in cost
and labor associated with
treatments because only
one injection is given.
• Useful for detection of estrus in
heifers and cows
• DISADVANTAGES:
• The disadvantage of this
program is that one-third
of the females do not
respond to the injection.
• 10-25% of females may not be
detected in estrus during days
0 to 10
• Must have CL
• Abortion

12. • In this method two injections of prostaglandins are given at
an interval of 10–14 days once the stage of estrous cycle in
the cows is unknown.
• ADVANTAGES:
• Useful for detection of estrus in
heifers and cows.
• Detection of estrus is not
required before or between
injections.
• All cycling cows should
respond to the second injection
regardless of what stage of the
estrous cycle they were in
when the first injection was
administered.
• DISADVANTAGES:
• Females must have functional
CL
• Administration of PGF will
cause abortion in pregnant
animals

14. • Synchronization of estrus with progestin maintains high
levels progesterone in the female’s system, even after the
regression of the corpus luteum.
Melengestrol acetate
(MGA) (oral feeding),
Syncro-Mate-B (SMB)
(ear implant), and
CIDR (intravaginal
device)
These are the commercial products which fall into this category.

15. • A. MGA FEEDING:
•
• MGA was added to feed combined with PGF2α, such that females received
0.5 mg/head/day for 14 days and if MGA was administered, cyclic females begin to
show estrus.
• This estrus is sub fertile and not recommended to breed.
• Females should be bred on the second estrus observed after 96hrs following MGA
removal and bred artificially after 12 hrs.

16. • Synchromate B is an ear implant which contains
synthetic progesterone and also an injection that contains
synthetic progesterone with a synthetic estrogen.

17. • The implant is placed in the ear for nine days. At the end of the nine day
period the implant is removed and the injection is given. The cows or heifers
will start to show heat about 48-60 hours after plant removal.

18. • CIDRs are inserted intra-vaginally using a specialized applicator
• Once inserted, CIDRs provide slow-release administration of
progesterone, which artificially extends the luteal phase
• Plasma progesterone levels rapidly increase upon insertion, when
removed the progesterone levels decrease rapidly
• This is normal and does not impact the effectiveness of the device or
the animal’s performance

20. • Naturally occurring hormone that stimulates the release
of LH and FSH that stimulates follicular development
• Protocols include Ovsynch and Cosynch

21. • In CO-Synch program, an injection of GnRH on day 1, an
injection of prostaglandin on day 8, and then a second
injection of GnRH with breeding on day 10 are given.
• 1 7 2
GnRH PGF2 α
GnRH &
inseminatio
n

22. • There are two main variations of Ovsynch; they differ only in the timing of
the final injection.
OVSYNCH 48
It requires an injection of GnRH on day
0 and an injection of PGF2α 7 days
later.
A second injection of GnRH is
administered 48 hours later, and the
cow is inseminated 24 hours after the
final injection of GnRH.
OVSYNCH 56
This protocol also starts with an
injection of GnRH on day 0 and an
injection of PGF2α on day 7
In Ovsynch56, the GnRH is
administered 56 hours after the PGF2α
and TAI is performed 24 hours later

23. • OVSYNCH 48
• 7 2 1
• OVSYNCH 56
• 7 2½ 1
GnRH PGF2 α GnRH
Inseminati
on
GnRH PGF2 α
Inseminati
on
GnRH

24. • M. Hashemi , M. Safdarian & M. Kafi (2006). Estrus
response to synchronization of estrus using different
progesterone treatment outside the natural breeding
season.
• Prassana pal and Muhammad Rayees dar (2020), review
paper on induction and synchronization of estrus.