Inhibitory effects of CIDR-based ovulation-synchronization protocols on uterine PGF2alpha secretion at the following luteal phase in early postpartum non-cycling beef cows.
We investigated whether CIDR-based ovulation-synchronization protocols inhibit secretion of prostaglandin (PG) F2alpha from the uterus in the following luteal phase in non-cycling beef cows. Ten early (a month) postpartum non-cycling Japanese Black beef cows were treated with (1) Ovsynch (GnRH analogue on Day 0, PGF2alpha analogue on Day 7, and GnRH analogue on Day 9; n=3), (2) Ovsynch+CIDR (Ovsynch protocol plus a CIDR for 7 days from Day 0; n=4), or (3) estradiol benzoate (EB) Ovsynch+CIDR (EB on Day 0 in lieu of the first GnRH treatment followed by the Ovsynch+CIDR protocol; n=3). An oxytocin challenge was administered on Day 24 to examine uterine PGF2alpha secretion. Plasma concentrations of 13,14-dihydro-15-keto- PGF2alpha were lower at 30-120 min after oxytocin administration in the Ovsynch+CIDR group and 75 min after administration in the EB Ovsynch+CIDR group than in the Ovsynch group (P<0.05). Plasma progesterone concentrations were higher from Days 1 to 7 in the Ovsynch+CIDR group and from Days 1 to 5 in the EB Ovsynch+CIDR group than in the Ovsynch group (P<0.05). The progesterone concentrations were higher on Days 27 and 29 in both CIDR-treated groups than in the Ovsynch group (P<0.05). In conclusion, in non-cycling beef cows, CIDR-based ovulation-synchronization protocols inhibit uterine PGF2alpha secretion in the following luteal phase and prevent premature luteolysis as is seen with the Ovsynch protocol.
Sakase
Mitsuhiro
M
Department of Advanced Pathobiology, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Japan.
Kawate
Noritoshi
N
Nakagawa
Chikara
C
Fukushima
Moriyuki
M
Noda
Masanobu
M
Takeda
Kazushi
K
Ueno
Satoru
S
Inaba
Toshio
T
Kida
Kayoko
K
Tamada
Hiromichi
H
Sawada
Tsutomu
T
D000282:Administration, Intravaginal; D000818:Animals; D002417:Cattle / Q000502:physiology*; D015237:Dinoprost / Q000031:analogs & derivatives / Q000097:blood / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000378:metabolism; D004973:Estrus Synchronization; D005260:Female; D008183:Luteal Phase; D010060:Ovulation; D010121:Oxytocin / Q000378:metabolism / Q000494:pharmacology; D011374:Progesterone / Q000097:blood; D011863:Radioimmunoassay; D013997:Time Factors; D014599:Uterus / Q000378:metabolism*
C008228:15-keto-13,14-dihydroprostaglandin F2alpha; D011374:Progesterone; D004958:Estradiol; D010121:Oxytocin; D015237:Dinoprost