How Good Are You At Spotting Bulling Cows?

James Shenton (Sherborne)

Fertility remains one of the major areas of underperformance in many of the high yielding dairy herds we see. What are the causes? Without doubt poor fertility is a result of many factors; health, nutrition, genetics and management. One of the questions we often ask is "are we spotting all the bullers?" to which invariably the answer is "yes most of them, we are fairly good". Is this accurate? Consider the following:

  1. 60% of heats occur at night
  2. Only 50% of cows display standing heat
  3. The heat period of many cows lasts less then 12 hours with many displaying heat symptoms for less than 4 hours.

The odds are stacked against you. Be honest, how much time do you spend watching for bulling animals? The theory is three 20 minute blocks, resulting in a total of 1 hour spent watching for bullers per day. Make sure everybody is well trained in spotting bulling signs. It is well worth sitting everybody down in front of the television to watch the Dairy Co Spotting Bulling DVD. The table below shows bulling signs and their relevance. If you are unable to spend this amount of time (and many are not), use all the aids available to you, e.g. kamar, tail paint, heat time, pedometers, marker bull etc. One of the major ways of improving your fertility may be admitting you can’t spot bullers as well as you would like.


Bulling cows

A cow scoring 50 to 100 points in 24 hours is very likely to be in heat. If she scores more than 100 points, then she’s almost certainly in heat. Serve a cow twelve hours after deciding she is in heat.

Bulling string

3 points


5 points

Being jumped on by others, not standing still

10 points

Sniffing and licking the vulva of another cow

10 points

Resting chin on the rump of another cow

15 points

Jumping other cows

35 points

Jumping front end of other cows

100 points

Standing heat

100 points


For more information please contact James Shenton