Farmers are evaluating what they can do on a management level to avoid this tail.
All I can say is that differences in the above between farms seem to make no major difference to the 5pc figure for late calvers.
I would speculate that weather impacts - and potentially spring as much as summer - may be the most likely common denominator.
I believe that the main way to avoid late calvers is to adjust the length of the mating period. My general advice is to mate for 10-12 weeks from the day you start the cows - with the bull removed from heifers up to two weeks prior to the end of mating the cows.
A late calving heifer is of no benefit to anyone. But removing the bull or AI before 10 weeks often comes with notable and increasing financial penalties, while mating longer than 12 weeks will definitely result in May calvers which is no use to anyone in the spring calving game.
For me 11 weeks breeding works well in any one given year.
What can you say about bull calves?
There's been a huge focus on the Jersey bull calf this year. But let's be clear - all bull calves have in general made poor money this year.
So, while as an industry we need to be sustainable and have high welfare and ethical practices, blaming this year's calf issue on the Jersey-cross breeding seems somewhat unfair.
Whether Friesian, Hereford or Angus, the time, milk and money poured into rearing the bull calf seems to generate no monetary return compared to milk sold. The sooner the male leaves the farm, the better the outcome on a spring-calving unit.
The other reality is that we have to mind and protect the business we are in - milk.
In an ideal scenario, we would generate a by-product of value to the beef sector, but when it comes to breeding decisions we must protect the traits that add value to our business.
The first priority is compact calving, because this generates days in milk and ultimately kgMS/cow, the main commodity on which we're paid.
Achieving greater than 90pc calved at six weeks isn't happening by accident.
The majority of dairy AI bulls chosen for spring calving herds are negative for gestation length, which means calving before the standard 283 days.
The second priority is calving ease, with <2 ideal.
A dairy cow must heal and be up and running rapidly after calving.
Bulls with increasing calving difficulty are more likely to result in a cow losing greater body condition post calving, a higher incidence of health issues, a longer anoestrus period and a loss in milk productivity. The main focus is to protect the cow so she can milk to her best ability, rather than focusing solely on adding value to the calf.
The third priority is to generate enough replacements and achieve a desired cow type. Adding increasing value to the traits of a herd, in EBI, is a more important focus than the-surplus-to-requirement bull calf.
However, establishing what stock numbers you want on the farm, and replacement rates therefore required, will help in working out how many weeks of dairy AI should be used, and the selectivity you wish to impose.
Personally, while running a tight ship is ideal, having a certain amount of tolerance in the system to cover risks such as an unbalanced bull to heifer ratio, a TB outbreak, or a lower than expected in-calf rate, should be considered. While we need solutions to the bull calf issue, each farmer must consider the gains they need for dairying when making breeding decisions.
The beef industry must identify some reliable independent model for delivering profitability; it cannot depend on dairy farmers because the dairy bull calf will remain a secondary consideration for milk suppliers.
Mary Kinston is a discussion group facilitator and consultant, and farms with her husband in Co Kerry.