DairyNZ team leader – reproduction, Chris Burke, explains.
“When detecting heat, the two mistakes commonly made are missed heats and cows not actually on heat. If heats are missed, the submission rate (SR) of a herd will be low and since SR is the key driver of six-week in-calf rate, then this too will be reduced,” says Chris.
“Conversely, it is not wise to achieve good submission rates by inseminating cows not on heat, as ultimately the herd’s conception rate and the number of cows pregnant will be reduced.”
Accurate heat detection is important to herd reproductive performance and farm profitability.
Use records to evaluate heat detection
A good way to check heat detection skills is the heat detection indicator in the InCalf Fertility Focus Report. Farmers with great heat detection will achieve 95 percent.
If three-week SR is less than 90 percent, heat detection could be a problem. Another cause is an excessive number of non-cyclers before the planned start of mating date.
Signs of heat
A cow is most likely to be on heat if she is standing to be mounted by other cows, tail paint is removed or the heat mount detector has been triggered.
Other signs include mounting other cows, poor milk let down, she is restless and bellowing, mucus around the vulva or mud marks on the flanks.
Record all observed heats. This ensures non-cycling cows can be identified and treated. Heat detection should be considered a high earner, so prioritise the task during artificial breeding (AB), rather than being just another job to do.
Increasing heat detection effectiveness
Most improvements to heat detection involve a change in how things are done.
The best programmes start with careful planning, good observation and the effective use of detection aids. Being able to distinguish and interpret cow behaviour and other signs is critical – so is good record-keeping and training.
- Step one
Review heat detection skills on-farm – are they up to scratch? Does everyone involved know exactly what to look for when detecting cows on heat? It’s important that staff responsible for heat detection know what to look for and how to record information.
- Step two
Designate one or two experienced people with responsibility for observation. Others may be involved, but should report their observations on a specific form or to the individuals responsible.
- Step three
Determine which aids to use. Remember, farmers with the best heat detection results use a combination of observation and heat detection aids. Be prepared to test several combinations to find the most suitable.
- Step four
Finally, schedule specific times each day to check cows and regularly monitor the success. This information is critical to spot trends early.
This article was originally published in Inside Dairy September 2016