Optimising oestrus detection

Reproductive management technicians are highly skilled in oestrus detection and are  specially trained to identify primary and secondary signs of oestrus. Photograph: Columba O'Hare, Fotacol
Reproductive management technicians are highly skilled in oestrus detection and are specially trained to identify primary and secondary signs of oestrus. Photograph: Columba O'Hare, Fotacol

Efficient oestrus detection leads to higher pregnancy rates and higher 21 day pregnancy rates results in more pregnant cows, fewer days open and more potential profitability for dairy farms.

With submission rates in non seasonal dairy herds ranging widely and estimated to be on average between 36% and 42%, it comes as no surprise to see farms investing in management solutions to achieve accurate and reliable oestrus detection. Many studies have demonstrated today’s cows are likely to show fewer signs of oestrus and for shorter duration.

Some cows may even express signs of oestrus for less than three hours, but on average for seven-nine hours, during which they may receive up to 10 mounts with many of these mounts lasting less than two seconds. If your 21 day submission rate is less than 60%, it is likely you could make improvements on your farm.

When considering new or upgraded means of oestrus detection it’s important to weigh up whether the expected increase in reproductive performance will be worth the initial investment. No matter which oestrus detection method you employ on your farm, finding ways to improve oestrous expression prior to reconsidering current methods or upgrading systems is critical. Good mobility, sound footing, loafing space, well grooved concrete, balanced rations, great transitioning from dry pens to milking pens, are all critical and will benefit all oestrus detection methods and systems.

Visual observation remains the most common method of oestrus detection with the use of various tools to facilitate identification. These include tail paint, tail chalk, heat mount detectors attached to the tail head. All of these oestrus detection aids have been shown to be effective when used in conjunction with visual oestrus detection, however they also require dedicated time to observe and skilfully interpret.

Many farms worldwide, particularly on today’s large dairies, have dedicated reproductive management teams, either “in house” or contracted to third parties such as Genus ABS’ RMS system. These teams are specifically trained to identify primary and secondary signs of oestrus. This is through the use of detailed computer records, tail chalking and observing cows, their behaviour and their environment, and working with the farm team. These individuals are highly skilled in oestrus detection and artificial insemination with good knowledge of reproductive efficiency and be driven by improving submission and pregnancy rates on farm.

In the last decade we have also seen the rise of automated oestrus detections systems, utilising wearable cow technology such as pedometers, neck collars, ear tags and rumen boluses. As technology evolves we will continue to see further “add-ons” such as we have already - standing and lying times, rumination monitoring and more latterly interactions with feed face technologies.

When considering investment in automated oestrus detection, there are several aspects to consider including: the method of data transfer from cow device to receiver, the ease of putting on and taking off the device, the number of devices required and their battery life.

Consider if the system can be updated easily and whether the algorithms within the system can be optimised to your farm. This may be particularly important for grazing herds. It is also worthwhile investigating the technical and ongoing support and whether the system can interface with existing technology on your farm.

More recently we have seen the use of progesterone testing to assist oestrus detection through robotic milking systems. When a cow is in oestrus her progesterone levels drop, this can be detected in milk. Using milk progesterone testing can reduce the amount of false positive oestrus events detected by up to 6%, and has an overall oestrus detection rate of close to 100%. Uptake has been relatively slow to date, due to the expense involved, however as with most technology this is likely to become more cost effective over time.

In summary, there are many means of detecting oestrus in dairy cattle and these have and will continue to evolve. Quality and availability of labour, and time, has led to a rise in contracted dedicated reproductive management services and automated oestrous detection systems.

As further exciting choices become available in reproductive management solutions you should also consider if investment is best made upgrading your existing oestrus detection system or optimising the farm environment to improve oestrus expression.