Profitable dairying

Mating management and heat detection

Mating management and heat detection is one of the most important functions on the farm.  Regardless of dairy payout, stock values or farm costs, your ability to get the herd in calf to a tight calving pattern will directly impact your bottom line – for better or worse.

Let’s go back to basics on this essential farm skill.

A non-pregnant cow should come on heat / into oestrus every 18-24 days with the average cycle being 21 days.  To cycle regularly and have the best possible chance of maintaining a pregnancy, she needs to be healthy and well-grown, consistently fed and managed to be at a body condition score of 4.0 at the planned start of mating and have had sufficient time between calving and mating to return to her normal reproductive state.

At least three weeks prior to the planned start of mating, you and your staff should actively monitor and record cows coming into heat to identify any anoestrous or non-cycling cows early.  The best heat detection programmes, both before and during mating, combine planning and observation with effective heat detection aids.  Estrotects or tail paint should be applied to all cows to give you and your staff the best possible chance of identifying and recording cows in heat.  After the cow has come on heat and been recorded, a different colour Estrotect or tail paint is applied.  At the end of three weeks it will be very obvious which have not cycled and need to be referred to your vet for further investigation if they are to stay within a concentrated calving pattern.

But do you know how to pick a cow that is in heat?  Yes?  Fantastic.  But how about your staff?  Let’s refresh ourselves on the symptoms of cows in heat so that everybody can keep an eye out:

Prior to and following a standing heat – the ideal time to inseminate for best results - cows may be restless and noisy.  They may smell and ride other cows but will not stand to be ridden themselves.

Cows in heat will stand out as restless and active, often gathering in small groups of continually milling animals.  You will notice this behaviour best in the paddock – quietly move among the cows a couple of hours after milking and taken note of these animals as they may not be evident in the yard or moving around the farm.  Cows in heat will stand to be ridden which will rub skin and hair off the top of the tail as well as triggering heat detection devices.  The coating of Estrotects will be rubbed off, revealing the vivid and easily seen alert colour beneath or tail paint will be rubbed off.  As a result of riding, you may also see scuff or mud marks or saliva down the flanks of the cow on heat caused by mounting animals.  Less reliably, cows on heat may hold their milk or come into the shed in a different order than usual, often at the front or back of the herd.

Cows on heat should be artificially inseminated as soon as practical after this time, separate them from their herd mates, ready for insemination after milking and, when the cow has stopped standing to be ridden, reapply a fresh Estrotect or coat of tailpaint in a different colour to signal that she has been mated.

It’s expensive when you are surprised by high empty rates at the end of mating so keep an eye on how things are going.  You should be aiming for a submission rate (cows coming up for AI) of at least 82% in the first three weeks and pregnancy scanning will keep you informed of in-calf and empty rates to enable decision-making later in the season.  Keep in touch with your AB company and vet – they can offer solutions including synchrony, short-gestation bulls or other ideas to minimise current losses and set you up for continual improvement and more profit next year.

Mating management and heat detection falls at a busy time of year following the trials of calving.  However, an effective strategy at this end of the season can not only make next season easier but more profitable too.