With the calving season now ceased on many spring calving suckler herds around the country, the focus has turned to breeding.

Stock bulls are used for the majority of the suckler herd, with less than 20% served to AI. Much of this AI is carried out during the late autumn and winter months, when cows are housed and AI can be carried out quickly and efficiently.

Although the cold weather had slowed the breeding process early last week, warmer temperatures and better weather later in the week has helped breeding along.

Herds that have a compact calving spread (10-12 weeks) can have 80-90% of cows submitted for bulling in the first six weeks of the season. This places huge demands on the stock bull.

A mature bull that is fit and healthy should be limited to groups of 40 cows or less. Where cows are grazed in an extensive system, consider reducing the cow-to-bull ratio, as much more movement of the bull will be required.

A young bull should be limited to a group size of less than 20 cows. When using a young stock bull in his first season, farmers will often pay particularly close attention to how the bull mounts and serves the cows. Ideally, he should be placed with a heifer or a young cow showing signs of heat in isolation and given time to perform.

Get cows cycling!

Suckling inhibition can increase the anoestrus period during which cows are not cycling after calving. Some farmers will on-off suckle the calves to bring cows in heat more quickly, but this is not very common in spring.

Some farmers will also tail-paint cows for three to four weeks prior to letting the bull with them to identify cows that are not cycling. These can get veterinary intervention before the onset of breeding, to get them cycling and avoid late calvers or empty cows.

Record keeping is essential. Even though some farmers opt to have a bull's fertility tested prior to the start of the breeding season, this is not a guarantee that he will be fruitful.

The only real way to ensure that a bull is working to his optimum is to keep accurate records of what cows were served on what date and checking for repeats three weeks later. Where there are a number of repeats, farmers with large herds may alternate bulls mid-season, carry out AI or source a replacement bull to avoid the risk of running a high empty rate.