After three weeks of breeding, there should be at least 90% of the cows served and one would be hoping that about 60% of these will be in-calf with a viable pregnancy.

A couple of percent, usually around 5%, will be pregnant, but, unfortunately, will not have a viable pregnancy and will probably come cycling at a later date.

Because the amount of bulling activity in the next few weeks will be much less than the previous weeks, it may be harder to pick up on cows in heat.

Congregate

For example, if there are three or four cows bulling on the one day, they will usually congregate together and be mounting each other.

But if there is only one cow in heat on a day, there are fewer hormones in the air and she will, in all likelihood, be mounted less often than if there was more than one cow bulling.

Some farmers find that letting off a vasectomised bull helps to identify these cows better, as the bulls will be looking for cows in heat.

Worn out

It’s important not to let off the teaser bull too soon or he will be worn out too soon in the season.

Letting them out with cows from the third week on is a good policy.

Some farmers attach chin ball markers to the bulls, whereas others just keep topping up the tail paint or other heat detection aids.

On large herds, more than one teaser bull will be required and it may be worth using teaser bulls in teams to give them a rest.