Efficacy of Intravaginal Progesterone Administration as an Additional Treatment on Two Types of Timed AI Protocols in a Commercial Herd of Holstein Heifers

Abstract

ABSTRACT. Reproductive performance of two types of timed artificial insemination (TAI) protocols with or without intravaginal progesterone insert (CIDR) was investigated in a commercial herd of Holstein heifers. A total of seventy-four heifers with 14.4 months of age were allocated to two groups; Ovsynch (n=44) and estradiol benzoate (EB) used Heatsynch (EB-Heatsynch, n=30), and each group was additionally divided into two subgroups with CIDR insertion from day 0 to 7 (n=36) and without CIDR group (n=38). Blood was collected for progesterone (P 4 ) analysis and ovarian finding was monitored with ultrasonography. Heifers in CIDR-treated group resulted in higher pregnancy rate as compared to No-CIDR-treated group (63.9% vs 21.1%, P<0.01). Heifers with functional corpus luteum (CL) on day 0 resulted in significantly higher pregnancy rate in CIDR-treated group than No-CIDR-treated group (day 0: 67.9% vs 13.0%, P<0.01). CIDR insertion suppressed the intermediate ovulation during the first 7 days and the period from the second GnRH or EB administration to TAI as compared to No-CIDR-treated group (first 7 days: 33.3% vs. 52.6%; P<0.05, before TAI: 11.1% vs. 37.0%; P<0.05). In conclusion, the selected TAI protocols with CIDR provided acceptable pregnancy rate and contributed to the economical improvement by shortening the average age of first calving approximately for 2.5 months as compared to the previous management without TAI protocols.

Comparison of synchronisation protocols on pregnancy rate in dairy cows and heifers: A systematic review and network meta-analysis

“…In the sensitivity analysis, there were not any discrepancies neither in the differences between treatments nor in the hierarchy of treatments. Also another sensitivity analysis was performed by excluding those studies, or subgroups within studies, which are conducted with heifers and we did not observe any notable difference in results (King and Robertson, 1974;Stevenson et al, 2000Stevenson et al, , 2008Iwakuma et al, 2008;Karakas et al, 2009;Nak et al, 2009;Gordon et al, 2010). In another sensitivity analysis that we performed excluding the studies published in Turkish journals in Turkish language, we did not encounter any different results compared to the primary model (Aksu, 2010;Bülbül and Ataman, 2005;Kaçar, 2008).…”