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Review
11.
Synchronization of
estrus in cattle: A review -
R. Islam
Vet World. 2011; 4(3): 136-141
doi:
10.5455/vetworld.2011.136-141
Abstract
Numbers of estrus synchronization programmes are
available in cattle based on the use of various
hormones like progesterone, prostaglandin F2a and
their various combinations with other hormones like
estrogen and Gonadotrophin Releasing hormone (GnRH).
Selection of appropriate estrus synchronization
protocol should be made on the basis of management
capabilities and expectations of the farmer.
Synchronization of oestrus can be accomplished with
the injection of prostaglandin F2a alone, but it
needs proper detection of the ovarian status of the
cows as prostaglandin F2a is active in only
functional corpus luteum in between 8 to 17 days of
estrous cycle. Progesterone may reduce fertility up
to 14 percent, but short time progesterone exposure
(less than 14 days) is beneficial. Addition of GnRH
in the Progesterone or Prostaglandin based
synchronization programme is helpful for more
synchrony in estrus as GnRH may be helpful to
synchronize the oestrous cycle in delayed pubertal
heifers and post partum cows (Post partum anoestrum)
and further a single, timed artificial insemination
is possible with this method. New methods of
synchronizing estrus in which the GnRH-PG protocol
is preceded by progesterone treatment offer
effective synchronization of estrus with high
fertility.
Keywords: Estrus, Synchronization,
Hormone, Prostaglandin, Progesterone, Anoestrus,
Estrogen, Gonadotrophin Hormone.
