Does oestrus observation work? - Success control

As in many aspects of farm management it is also worthwhile from time to time to verify objectively the subjective impression on how well oestrus observation is working in daily operations.

Noticing weaknesses

There are a few signals that could indicate weaknesses in oestrus detection:

  • Only a few fresh-lactating cows (< 45 days in milk) are identified as in oestrus.
  • Involuntarily they have a long average rest period – longer than you intend.
  • Many cows have to be re-inseminated after more than 42 to 46 days.
  • Many non-pregnant cows are found during pregnancy testing.

Oestrus detection rate

In order to ensure the quality of oestrus observation is objective, fertility professionals recommend the oestrus detection rate be determined over 24 days:

  • You make a list of all animals who calved longer than 45 days ago but which have not yet been inseminated.
  • Over the next 24 days you delete each cow that you have seen in oestrus.
  • Then you calculate how many animals in this period you have identified at least once as in oestrus.

A satisfactory oestrus detection rate starts at 80%.

Practical example

Ueli’s farm has 40 cows who calve seasonally. On 5 January 25 animals have still not been inseminated but calved more than 45 days ago. Ueli notes the names on a shed list. By 29 January he has identified 13 of these animals as in oestrus and has deleted them from the list. He calculates (13 x 100)/25= 52.

He has therefore an unsatisfactory oestrus detection rate of 52%.

Most frequent mistakes

What are the most frequent mistakes when your oestrus detection rate is too low?

  • You do not observe at regular intervals during the day
  • You observe for only a short period
  • You only observe during shed periods
  • You and others who are observing oestrus on the farm do not arrange things correctly between each other.
  • You do not note down your observations correctly
  • You do not detect the oestrus signals or you do not interpret them correctly

Oestrus monitoring tools

Using tools

Not every farm has a conveniently located yard or a sprightly grandfather who takes on the oestrus observation and can thereby easily perform the requirement for three 15 minutes oestrus observations.

Enough time?

Therefore you should question precisely and critically whether you dedicate a quarter of an hour three times a day to oestrus observation or not. Anyone unable or willing to take this time, is well advised to make use of support tools.

Quickly amortized

Systems differ in their use, acquisition costs and uniqueness.  However, they amortize quickly because the commercial consequences of a missed oestrus detection are concealed but horrendous. For example, in Switzerland the talk is of 350 Swiss Francs incurred in costs per missed oestrus.

Know the animals

All oestrus detection tools never quite replace personal observation. The farmer must know his animals!

Different systems

Tools that may be used to support oestrus observation include color markings and electronic systems such as pedometers, activity meters or continuous video surveillance.

All texts and pictures come from our partner site (french)- you will find more information an tips about fertility there.