Double Ovsynch - Is It Time to Update the Program?

Double Ovsynch - Is it time to update the program?

The Double Ovsynch synchrony and fixed time AI program has been around for many years without much change.

The benefits of the Double Ovsynch program over other similar programs such as OvSynch, PreSynch, G6G, SelectSynch, CoSynch etc has been demonstrated for several years with high ovulation rates, conception rates and pregnancy to AI rates (P/AI) across many countries and production systems.

In recent years the research focus has been on tweaking the dose rates of the PG and GnRH at various points within the Double Ovysnch program.

The research has clearly shown that the addition of a second 2 ml dose of PG as part of the program prior to AI will increase ovulation rates and P/AI in both cows and heifers regardless of the type of semen used.

The weight of evidence is now also substantial that increasing the dose of GnRH to 2 ml at the GnRH 3 time point of the program has substantial benefits in reproductive outcomes over the traditional 1 ml dose. However, as always with dairy cows, there are some subtilities that need to be understood.

• There is no benefit of increasing the dose above 1 ml at either the GnRH 1, GnRH 2 or GnRH 4 time points of the program.

• The beneficial response in P/AI  of the higher dose of GnRH is not seen when using sexed semen in cows. Heifers in general do not tend to respond positively to the increased GnRH dose regardless of the type of semen used.

So, stick with the 1 ml GnRH dose throughout the Double Ovsynch program in heifers or if using sexed semen in cows - if practical.  There are no negative effects on fertility of the higher dose in either circumstance, just no benefits.

The Double Ovysnch program we now are recommending is shown below - talk to one of our vets for more information.