AHMAdi, M. R., H. R. GHAisARi: Heat stress and different timed-Ai methods influence on pregnancy rates of dairy cows. Vet. arhiv 77, 327-335, 2007. ABsTRACT The objective of this study was to evaluate three synchronization fix timed-AI protocols throughout the year on one commercial dairy farm in a semi-arid zone. Mean temperature-humidity indices (THI) were 77.5, 84.9, 70.8 and 58.8 in spring,...

To compare 2 strategies for systematically resynchronizing ovulation, lactating Holstein cows (n = 763) at various days in milk and prior artificial insemination services were assigned randomly at timed AI (TAI) to receive the first GnRH injection of Ovsynch 26 (D26) or 33 (D33) d after TAI to resynchronize ovulation (Resynch) in cows failing to conceive. Cows in the D26 treatment received GnRH...

The aim of the present study was to study the effect of parity on the efficacy of an Ovsynch protocol in buffalo. Buffalo heifers (HE; n = 8) and cows (BC; n = 9) were used to monitor ovarian follicular dynamics and evaluate serum progesterone profiles during this protocol. A total of 385 control buffalo heifers (CHE; n = 219) and cows (CBC; n = 166) were used to compare conception rates follow...