OVARIAN RESPONSE OF DAIRY COWS TO PROGESTERONE COMBINED ON
Abstract: The objective of
this study was to evaluate the response of ovaries in estrus
synchronizationprotocol using GnRH-PGF2α based protocol combined progestin in a
herd with tie-stall housing system.A total of 20 Holstein Friesian cows at
different stages of estrus cycle in a dairy herd were enrolled inthe present
study. The cows were randomly allocated into two treatment groups; with and
without CIDR(Controlled internal drug release) insertion. All cows received 100
μg of GnRH I.M. at the beginning ofthe treatment (d 0) without regard to the
stages of the estrus cycle followed by 25 mg PGF2α IM 7dayslater. Cows in CIDR
group were inserted CIDR into the vagina at the time of GnRH administration
andwere removed on the day of PGF2α administration. estrus signs were checked
twice daily starting onday-2 after initiation of the protocol, except cows in
CIDR group the estrus signs were checked startingon day-8 of the protocol. The
animals showing estrus signs were noted. Blood samples were collectedfrom all
animals on the days of GnRH and PGF2α treatments and on day-10 after initiation
of protocolfor progesterone concentration. The results of this study showed
that 30% animals in cows withoutCIDR insertion showed estrus signs prior to
PGF2α injection. Involving CIDR to synchronized estruswith GnRH-PGF2α based
protocol avoided the occurrence of premature estrus and maintained
highprogesterone concentration on the day of PGF2α administration. It is
concluded that ovarian responseafter involving CIDR in the protocol for estrus
synchronization especially using combination of GnRHand PGF2α were much
effective to synchronize the initiation of estrus in dairy cows. Likewise, the
useof progesterone avoided premature estrus.
Author: A.L. Toleng, M. Yusuf,
H. Hasbi, A.R.M. Putri
Journal Code: jppeternakangg130038