Effect of CIDR-based protocols for timed-AI on the conception rate and ovarian functions of Japanese Black beef cows in the early postpartum period》.pdfVIP

Theriogenology 64 (2005) 1197–1211 /periodicals/the Effect of CIDR-based protocols for timed-AI on the conception rate and ovarian functions of Japanese Black beef cows in the early postpartum period M. Sakase a,b, Y. Seo a, M. Fukushima b, M. Noda b, K. Takeda b, S. Ueno b, T. Inaba a, H. Tamada a, T. Sawada a, N. Kawate a,* a Department of Advanced Pathobiology, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan b Northern Center of Agricultural Technology, General Technological Center of Hyogo Prefecture for Agriculture, Forest and Fishery, Wadayama, Hyogo 669-5254, Japan Received 21 June 2004 Abstract Our objectives were to compare: (1) conception rates (in early postpartum Japanese Black beef cows) to timed-artificial insemination (timed-AI) among Ovsynch and Ovsynch plus CIDR protocols, and a protocol that used estradiol benzoate (EB) in lieu of the first GnRH of the Ovsynch plus CIDR; and (2) the effects of these protocols on blood concentrations of ovarian steroids. Cows in the control group (Ovsynch; n = 35) underwent a standard Ovsynch protocol (GnRH analogue on Day 0, PGF2a analogue on Day 7 and GnRH analogue on Day 9), with timed-AI on Day 10, approximately 20 h after the second GnRH treatment. Cows in the Ovsynch + CIDR group (n = 31) received a standard Ovsynch protocol plus a CIDR for 7 days (starting on Day 0). Cows in the third treatment group (EB + CIDR + GnRH; n = 41) received 2 mg of EB on Day 0 in lieu of the first GnRH treatment, followed by the same treatment as in the Ovsynch + CIDR protocol. The conception rate tended to be greater in the Ovsynch + CIDR group (67.7%, P 0.15) and was greater in the EB +