FlashMate Heat Detectors

Finding the reproductive sweet spot


Increasing input costs on farm are topical.  But it’s well-accepted that reproduction really is a key moment in the farming calendar.  Time, effort and money must be invested to set future production up.  We all want to reduce cost where we can, yet we also want to hit the `sweet spot’ and capture the highest returns at the lowest effort and cost.

Coming straight out of calving there is so much on the plate.  As pre-mating looms, farmers can be forgiven for not wanting to think too hard about reproduction or make any changes.  But the time to think about this is right now, before you get your head down again!

Detection of heat is often considered the major limiting factor in the success of reproductive programmes.  According to DairyNZ, every accurately detected heat can gain you an average 25kg of milk solids, as well as avoiding late-calving which can impact the following season.

The primary sign of heat is where a cow stands to be mounted by another cow.  This is the gold standard for heat detection.  Secondary signs such as increased walking are those that can also be caused by events other than heat and are more loosely associated with the timing of ovulation.  It is primary standing behaviour that is hard-linked to ovulation occurring around 25-32 hours from the onset of standing.

Decades of excellent studies have established the timing for when the farmer should submit the cow for breeding, because waiting for standing more than doubles the conception rate compared to a cow that is still coming into heat and is yet to stand.  It is a common misconception with New Zealand Farmers, that because sperm can survive 24 hours or more, that breeding early doesn’t have an impact on conception rate.  The effect is profound.  Breeding too early can cost you 25kg milk solids due to the lower chance of success and creates high odds you’ll have to wait for her next cycle.

The goal is to use tools that accurately call both the heat and the optimal timing for insemination to maximise success.  The decision of whether to breed `today or tomorrow’ in a once-per-day insemination regime is critical.  Getting this right can yield significant improvement in conception rates.

“We essentially ‘hire’ something to get a job done. If it does the job well, when we are confronted with the same job, we hire that same product again.  And if the product does a crummy job, we ‘fire’ it and look around for something else we might hire to solve the problem.” Clayton Christensen observed this some years ago and it certainly applies to dairy reproduction in 2023.  Farmers need to take the time to ask if an option they are evaluating truly addresses their real needs and if it does that job well.  That means reviewing hard evidence and performance data that is specific and relevant to you, and not getting distracted with features that are not so important for your operation.

Being profit-based, return on costs must stack.  This means looking beyond what is simply cheapest if the performance of that option costs you lost production.  Opportunity-cost in any given reproduction programme can be huge, so it really is worth asking hard questions and getting firm evidence for your chosen approach.

The range of heat detection approaches come with different cost and performance parameters to best fit your goals.  Money needs to be spent wisely and you need to consider any `hassle-factors’ of change, the value of staff time and training requirements, technical support, resilience, and flexibility as well as any other upfront or ongoing costs to strike a balance for your system.  We all want to put our money where the returns are greatest.

Add up your reproduction-related costs and divide that number by the total number of pregnancies, or perhaps even go a step further to look at the cost of reproduction per calf.  You can quickly model out where you think valuable gains can be made at little additional cost and effort in the first instance.  This can help you find your `sweet spot’ for your operation and help focus on extra return that can be gained for little additional cost.  Beef breeding operations in the USA focus on `cost per wear’ for heat detection, dividing the costs of heat detection by the number of days it is required.  While this may seem outside our experience in New Zealand, fresh thinking can help during times of high input costs.

In 2015 Roelofs wrote `Estrus detection tools and their applicability in cattle’ looking at a range of options from visual observation, paint, and patches, through to activity systems in the Netherlands.  The range of results indicate that skilled operators in many cases outperformed the most expensive options, but clearly with some effort.  If maximising production on a smaller operation is your goal, you may take a very different approach to large scale farms that may opt for a more repeatable (but lesser) results to accommodate available skill-level.

Similarly, Holman in `Comparison of oestrus detection methods in dairy cattle’ noted that in the UK it was the combination of staff skill and technology that gave the best results and skilled staff were again able to outperform.  So, attention may still be required and there are few `silver bullets’ out there as any vendor should tell you.  In the end it’s about getting the right fit.

For your evaluation discussions, sensitivity is about calling true heats and ideally not missing anything.  You know they’re true, because the cow got pregnant to that insemination or alternatively, blood progesterone confirmed the heat within a study.  The flipside is calling heats that aren’t real at all, which can lead to insemination-induced embryonic loss later in mating.  That’s why you need to know about specificity as well.  Higher specificity means less false positive alarms and risk of loss.  To better understand what you’re buying, you need to be discussing these key parameters, because poor selection can set you back for multiple seasons. In the end, with reproduction, it’s simply actionable insight you’re after at the right cost.  `Cost’ can also mean effort, change, time, complexity, training, and many other factors that together ensure the right returns materialise for your operation, as you plan and hit your reproduction goals.