The Ovsynch/TAI program for timed insemination is a means to increase herd
reproductive efficiency to first service and is of economic benefit.
Cows with a body condition score below 2.5 at first service have a lower pr
egnancy rate following a timed insemination.
Progesterone concentrations in the luteal phase following insemination are
related to embryo development. Injection of hCG (3300 IU) at d 5 after inse
mination induced an accessory CL, stimulated plasma progesterone concentrat
ions and increased pregnancy rates.
Injection of bovine somatotrophin at either the time of the initial injecti
on of GnRH or at the time of insemination increased pregnancy rates to firs
t service when utilizing the Ovsynch/TAI program.