Website for the Revue de Médecine Vétérinaire

Detail of the article

[Back]

For articles published from January, 2000, you can reach the complete article as a pdf file by clicking on "pdf " in the column "Links" of the table.

Year : 2016
Tome : 167
Volume : 3-4
Pages : 59-64
Title : Different times of oestradiol treatment combined with the progesterone in the Heatsynch protocols at the presence or absence of corpus luteum in dairy cows
Authors : M. R. AHMADI, A. MIRZAEI, M. ALIPOUR
Summary : Estrous detection rates are often low (< 50%) in dairy herds. Several protocols have been used in recent years for synchronization of cows based on timed insemination. Synchronization of estrus and ovulation are two of the methods for improvement of the estrous detection rate in dairy farms. The objectives of the study were to evaluate the time effect of oestradiol benzoate (OB) injection on the pregnancy rate in the Heatsynch (HS1; 24h and HS2; 48h after prostaglandin injection) and Intravaginal progesterone-releasing devices -Heatsynch (CIDRHS) protocols and to determine the efficiency of these protocols in the cows with and without corpus luteum (CL) in first and second parities. There was no significant difference between conception rate of cows that received estradiol injection at different time (37.9 vs 34.2 % for 24 and 48h after prostaglandin treatment, respectively; P = 0.15). Cows inseminated in winter had a higher conception rate compared to those inseminated in other (fall, spring and summer) seasons (P < 0.05). Conception rate of HS2 group was significantly greater than cows in CIDRHS1 group of primiparous cows; while greater conception rate of CIDRHS1 cows compared to HS2 group was found in cows with parity two (P < 0.05). In parity one, the result showed greater conception rate in HS2 group compared to cows in other groups (P < 0.05). Tendency to significant differences were observed in conception rate of cows in HS1 compared to that of cows in CIDRHS1 (35.4 vs 43.1%; P = 0.06). The results showed that time of oestradiol did not affect conception rates irrespective of parity. In conclusion, the present study showed that OB injection 24h after prostaglandin in cows with or without CL combined with CIDR can be responsible for acceptable pregnancy rate in cows had second parity. While, OB injection 48h after prostaglandin can be improved pregnancy rate in cows had first parity.
Keywords : Heatsynch; CIDR; Synchronization; conception rate; dairy cows
Correspondence : M. R. AHMADI
Adress : Department of Clinical Sciences, School of Veterinary Medicine, Shiraz University, Shiraz, Iran. rahmadi@shirazu.ac.ir
Link : pdf

[Back]