However, farmers have a major controlling influence on submission rate, which is one of the key drivers of the 6-week in-calf rate. Each 10% increase in the 3-week submission rate translates to a 2-7% increase in the 6-week in-calf rate.
Farmers with great heat detection skills will achieve a 3-week submission rate of 90%. To achieve this rate in a 400-cow herd would mean detecting an average of 17 cycling cows a day and submitting to AB. Nationally, there is much room for improvement with the average submission rate at 80%, which is almost 10% less than the target.
So, how can the submission rate be maximised?
Accurate heat detection and identifying non-cycling cows before mating have a huge influence on submission rates.
Heat detection is the most important task on the farm during the mating period. Each missed heat represents the loss of a complete oestrus cycle of approximately 21 days. In a seasonally calving herd this represents lost potential production, so each missed heat has a significant financial consequence – at least $200 a time.
A good way to check heat detection skills is to obtain the three-week submission rate for early-calved, mature cows from the heat detection indicator on your 2013 InCalf Fertility Focus report.
Accurate heat detection and identifying non-cycling cows before mating have a huge influence on submission rates.
If that submission rate was less than 85% there could be a problem with heat detection. It is important to remember when doing this check that a large number of non-cycling cows at mating can also generate a submission rate less than 85% in this group of cows.
Another heat detection indicator is the Return Intervals Analysis report which helps assess the risk that too many cows may have been inseminated when not on heat.
Pre-mating heat detection 4-5 weeks before the start of the herd’s planned start of mating can help improve submission rates. Many farmers do this but some see it as extra work and prolonging the effort.
Recording pre-mating heats and assessing the herd’s pre-mating cycling rate gives you options if you notice a problem as mating approaches. If pre-mating heats aren’t done then you may not become aware of a non-cycling issue until several weeks into mating. The sooner non-cycling cows are identified the sooner action can be taken.
Carrying out pre-mating heat detection has the additional benefit of refreshing everyone’s knowledge of the signs of heat and gain confidence before it comes to the crunch time of mating.
The best heat detection programmes start with careful timing, good observation, and the effective use of detection aids. The ability to distinguish and interpret cow behaviour and other signs are critical – so are good record-keeping and training for the people responsible for heat detection.
‘Mating is crucial to farming businesses, but its importance is often not communicated thoroughly to everyone who is involved.’
First, review the heat detection skills of your staff – are they up to scratch? Does everyone involved know exactly how to identify cows on heat?
There are two types of errors that can happen during heat detection. You can miss a cow that is actually on heat or you can misinterpret the signs shown by a cow and think she’s on heat when she’s not.
If you miss a lot of heats, the submission rate of your herd will be low. The submission rate helps determine the numbers of cows in the herd that you have detected on heat and inseminated. You are aiming for high submission rates, but you don’t want to achieve this by inseminating cows that are not on heat.
Secondly, designate one or two experienced people with responsibility for observation. Others may be involved in the detection programme, but they should report their observations on a specific form or to the individuals responsible.
Thirdly, determine which aids you will use. Remember, farmers with the best heat detection results use a combination of observation and heat detection aids. No one method is perfect. Be prepared to test several combinations of options to identify the one most suitable to your herd.
Finally, keep an eye on the detail. Schedule specific times each day to check cows and regularly monitor the success of the programme. This information is critical if you want to spot trends early. A successful heat detection programme relies on monitoring and fine-tuning all through the mating period.
Mating is crucial to farming businesses, but its importance is often not communicated thoroughly to everyone who is involved. The knowledge, experience, and expectations of your mating programme should be clear. All staff members should know they play an important role in the overall reproductive performance of the herd, whether it’s performing the inseminations, drafting cows with activated heat detection aids during milking, spotting cows in heat in the field, or noticing other signs of oestrus while the cows are in the yard.
DairyNZ is hosting a series of heat detection workshops during September and October. These workshops include a session on lifting heat detection performance and putting plans in place for the team to help reach reproduction targets.
For more information on a workshop in your region visit dairynz.co.nz/heatdetection.
If you want to maximise your herd’s reproductive performance, the InCalf resources are a great place to start and if you want assistance there are a number of InCalf trained advisers available to help. For more information on InCalf visit dairynz.co.nz/InCalf.
