Effects of intravaginal progesterone devices reuse on reproductive efficiency of Nelore cows

Abstract

The aim of this study was to evaluate the effects of reuse of intravaginal progesterone devices (CIDR®) on reproductive efficiency of Nelore cows. The experiment was conducted at the Capim Branco Farm of Federal University of Uberlandia with the use of TAI protocol in 110 Nelore cows. In this protocol, the intravaginal progesterone devices will be reused twice. On day zero (D0), the intravaginal device containing 1.9 g progesterone (CIDR ®, Pfizer) was inserted. At the same time, 1.0 mg of estradiol cypionate intramuscular injection (ECP ®, Pfizer) was given. On the seventh day (D7), cows that had a CL detected in D0 by transrectal ultrasound were given 12.5 mg of prostaglandin (Lutalyse ®, Pfizer). On the ninth day (D9), the devices were removed and the animals were again treated with 1.0 mg ECP. On the same day the calves were temporary removed from the cows for 48 hours. On the eleventh day (D11), insemination was performed and the calves were returned. No difference was detected (P = 0.138) in conception rate of cows that were treated with the protocol (49.64%) or not (58.51%). The conception rate was similar for the new devices and reused once or twice (55.00% vs. 46.39% vs. 46.75%, P = 0.252). The number of uses of the intravaginal progesterone device doesn’t influence the conception rate of animals treated with timed artificial insemination protocol.