Science Links Japan | Analyses of Mechanisms of Improved Conception by Newly Developed Methods of Synchronization of Ovulation and Timed-AI in Japanese Black Beef Cows

Analyses of Mechanisms of Improved Conception by Newly Developed Methods of Synchronization of Ovulation and Timed-AI in Japanese Black Beef Cows

Accession number;05A1044255

Title;Analyses of Mechanisms of Improved Conception by Newly Developed Methods of Synchronization of Ovulation and Timed-AI in Japanese Black Beef Cows

Author; KAWATE NORITOSHI (Univ. of Osaka Prefect.) SAKASE MITSUHIRO (Hyogokennorinsuisangijutsusogose Hokubunogise) NAKAGAWA CHIKARA (Univ. of Osaka Prefect.) TAMADA HIROMICHI (Univ. of Osaka Prefect.) SAWADA TSUTOMU (Univ. of Osaka Prefect.)

Journal Title;Shokuniku ni kansuru Josei Kenkyu Chosa Seika Hokokusho

Journal Code:X0296A

ISSN:

VOL.23;NO.;PAGE.6-12(2005)

Figure&Table&Reference;FIG.3, REF.10

Pub. Country;Japan

Language;Japanese

Abstract;In order to clear mechanisms of improved conception by CIDR-based protocols for timed-AI in suckled Japanese Black beef cows at early postpartum period, we examined preventive effects of CIDR on 1) premature ovulation before AI when the program is started in the latter period of luteal phase (Experiment 1) and 2) enhanced production of luteolytic factor from uterus in the luteal phase after the synchronized ovulation in non-cycling cows (Experiment 2). In the experiment 1, cycling cows in the control group underwent Ovsynch protocol (GnRH on Day 0, PGF2.ALPHA. on Day 7 and GnRH on Day 9), with timed-AI on Day 10. Cows in the Ovsynch +CIDR group received the Ovsynch protocol plus a CIDR for 7 days (starting on Day 0). Cows in the EB+CIDR+GnRH group received EB on Day 0 in lieu of the first GnRH treatment, followed by the same treatment as in the Ovsynch+CIDR protocol. Ovarian structure was observed by ultrasonography and blood was taken, daily from Day 0 to 11. Concentrations of progesterone in plasma were determined by RIA. In experiment 2, non-cycling cows were divided into three treatment groups and each group was treated with one of the same protocols (Ovsynch, Ovsynch+CIDR or EB+CIDR+GnRH; starting on Day 0). Oxytocin stimulation test was performed on Day 24 to examine secretion of PGE2.ALPHA. from uterus. Blood sample was taken every 15 min from-60 to 180 min after oxytocin treatment. Concentrations of 13, 14-dihydro-15-keto-PGF2.ALPHA. (PGFM) in plasma were determined by RIA. The results in the experiment 1 using cycling cows showed that both protocols using CIDR prevent premature ovulation before timed-AI observed in Ovsynch protocol when stared a few days before luteolysis, by maintaining progesterone level in blood high.... (author abst.)

Related Articles;