As we approach the fourth week of May, many farmers will be three weeks into their breeding season and submission rates will have to be looked at.
Some farmers may only by a week or two into the breeding season, depending on their projected calving start date, as many opt to start breeding later so cows are calving to align with grass growth and ground conditions on their farm.
However, for the farms that are three weeks into breeding, the three-week submission rate target is 90% for cows and 100% for heifers, which is crucial in order to achieve a six-week calving rate of 90%.
Achieving a high three-week submission rate is a critical driver of fertility performance in spring-calving systems and the earlier in the spring cows calve down, the more days in milk, the more days at grass leading to more milk solids produced over the lactation.
Submission rates
A 90%submission rate over the three weeks is important as if 90% of your herd are submitted at this point, we know that a number of cows will not hold to first service.
Only 55-60% first-service conception rates are likely to be obtained from the 90% that were submitted for mating, meaning in a 100-cow herd where 90 cows have been submitted, 50-55 of these cows should be in calf.
So, 45-50 cows still have to go in calf, meaning a lot of work still has to be done. This highlights the importance of maximising your submission rate in the first three weeks to ensure that the majority of the herd are in calf after six weeks of breeding.
In order to maximise the six-week in calf rate, of the cows that didn’t hold to their first service, you are only going to get one more chance to get them in calf within the six weeks.
The target six-week in calf rate should be around 75-80% for your cows and 100% for your heifers, which would mean when heifers are factored into this, you should end up with a 90 six-week calving rate the following spring.
In order to get every cow in calf in a short space of time, a farmer must start to identify non-cycling cows, and reduce the number of repeats as much as possible.
If you are using tail paint, switch to a new colour paint after cows have been inseminated to allow for easy identification, and to get an understanding of how your submission rates are progressing.
Non-bulling cows
On every farm, there will be a proportion of cows that are not displaying any behavioural heat at the start of the breeding season.
The return to normal cyclic behaviour usually occurs by 30-35 days after giving birth. The first heat is often silent and the first cycle after that is a short eight to 12 days.
Normally, cows would show behavioural heat 38-47 days after calving. When a cow fails to show signs of heat 60 days after calving, it is called postpartum anoestrus and can be due to true anoestrus or suboestrus.
Suboestrus is when a cow may be cycling normally, but displays weak or silent heats. Identifying these cows over the next number of days is crucial to determine which cows will remain in the herd.
It is also important to monitor any cows that are repeating, so you can make sure they are picked up and served again.
Farmers should get these cows checked by their vet in the next couple of days as they may need treatment or to be metrichecked.
Farmers could choose to synchronise these non-bulling cows to stimulate the resumption of cyclicity, and is the most effective and efficient way getting these cows back in calf early combined with increase energy intake.
It is important that these cows are dealt with early to try and maximise the six-week submission rate and get the cows calving down early in 2026 to turn them out to grass straight away and save on costs of production.
