The efficacy of the recycled CIDR on estrus synchronization in postpartum anestrum in buffalo cows

Abstract

The present study aims to evaluate the efficiency of the reused controlled-internal drug-releasing devices (CIDR) compared with the hormonal method to induce estrus in the postpartum anestrus of Iraqi buffalo’s cow. Thirty-two buffalo cows aged at least three years suffering from postpartum anestrus were randomly selected and divided into four groups (eight animals each). Ultrasound was used to assess the ovarian status. Animals with any reproductive defects were excluded. In the first group (G1), a new CIDR device was used for nine days, while in G2 animals, the device of the first group was reused for nine days; while, in the G3 group, the devices were further reused either for nine days (subgroup A) or 18 days (subgroup B, received PGF2α , at day 17; GnRH, at day 19). In the fourth group (G4), the animals received an injection of PGF2α (IM, 25 mg) followed by a dose of GnRH (IM, 500 mg) after 72h, without CIDR insertion. Blood samples were collected from the jugular vein pre and post CIDR insertion. Blood samples were utilized for the progesterone level assessment. For estrus and conception rates, animals were bred by fertile buffalo bulls, and pregnancy was detected at day 45 post-mating. Results showed that there was no variation in the rates of estrus induction and conception between the uses of the new CIDR device (G1) and the reused devices (G2 and G3 subgroup A); however, in the subgroup B and G4, only 50% of the treated animals demonstrated estrus. The duration, hormone, estrus, and pregnancy rate results revealed highly significant variations between groups. After the device withdrawal, the progesterone level in G2, G3, and G4 revealed a significant decline relative to G1. In addition, the duration was positively correlated to the progesterone level, estrus, and pregnancy rate. The progesterone level during the first and second services revealed a slight negative correlation with pregnancy. In conclusion, reusing the same CIDR up to three times for estrus synchronization is highly effective inducing estrus with high conception in postpartum anestrus Iraqi buffalo cows. Additionally, it is possible to reuse the CIDR device in 9 days without administration of GnRH in the lactating buffalo cows.