We know that the calving pattern has a huge impact on herd production and sustainability.
Effective management of non-cycling cows is a key lever in maintaining (or improving) your calving pattern. The goal is to unlock the greatest cost benefit from any intervention.
A non-cycling cow is a cow that has not had an observed heat and is more than 6 weeks post calving; some of these cows will be cycling with no visible heat and some will have ovaries that have not started cycling
Checking and marking your cows on heat at least 5 weeks prior to the planned start of mating (PSM) will give you information about how ready your herd is for mating. This can be done by tail painting or using wearables data. Even if you don’t plan on doing a non-cycler treatment programme, knowing which cows have heats will give you information on what to expect for mating.
Ten days prior to mating you will have an idea about how many early calving cows are cycling. These are the most valuable cows in your herd. Ensuring that they are mated early will provide you with the best return.
The industry target is to have 75% of cows cycling 10 days before PSM. If you have less than 65% of the herd cycling 10 days prior to PSM you will struggle to get a good 3-week submission rate and have a poorer 6 week in-calf rate.
Switching your non-cycling cows to once a day at this stage has not been shown to help in getting them cycling in time. If the cows are moved to once a day, it is not recommended to move them back to twice a day for the rest of the season (I have seen disastrous results when this was done during mating).
There are a few different non-cycling cow treatment options which you can discuss with your vet. Most non-cycler programmes will take 10 days. New trial work has shown an extra 5.6% improvement in conception rates from a 13-day programme with an extra prostaglandin shot given 3 days before the CIDR is inserted.
After pregnancy testing this year, I collected the data from some of our farms which used CIDR programmes pre-mating and had an early/accurate aging pregnancy test. From this data I had 769 cows that were treated prior to PSM, with a 10-day CIDR programme that included Novormon eCG with the prostaglandin injection at day 7.
The average conception rate for these non-cycling cows was 51%. The average conception rate for Vetora farms in the first 3 weeks was 58% last season. This was a great result considering we expect non cycling cows to have lower conception rates than normal cycling cows.
Contact your vet for a reproduction consult and get ready for mating this season!
