This time of year sees many spring-calving suckler and dairy herds in the market for a new stock bull, and while some may have sourced their bulls for the breeding season already, others are still on the look out for a suitable bull for their herd.

Buying a bull is a big investment for any farmer and the bull selected has the potential to contribute up to 50% of the genetics on the farm, so will play a huge part in determining the genetic potential of the progeny from the herd.

When purchasing a stock bull, as well as the physical appearance of the bull, all relevant factors and available data should be taken into account and considered.

In a recent post on the Teagasc website, Teagasc Ballinrobe drystock advisor, Patricia Lynch reminded farmers of some key things to bear in mind when sourcing a suitable stock bull.

What do you want from your stock bull?

Different farmers want their stock bull to deliver different traits. Some farmers want a terminal bull that will deliver progeny with good beef potential while other farmers want a stock bull that will deliver good replacement heifers.

Some herds of cows will have a higher threshold for calving difficulty than other herds and this is also a factor to be considered.

The Teagasc advisor said that if the farm is not retaining heifers as replacements or selling heifers on for breeding, then the terminal traits will naturally enough be the main focus.

Lynch said: “If you are aiming to breed replacement females, then you will be targeting a balance of maternal traits.

“Suckler Carbon Efficiency Programme (SCEP) participants should be looking for four or five star on either the terminal or replacement indexes or both. Also under the requirements of the scheme, calves born on the farm must be sired by a genotyped four or five star bull.

“Another factor to consider is reliability, the higher the reliability figure is, the less likely that a bull’s breeding values will change considerably in the future. It is even better still if a bull has their genomic evaluation completed at the time of purchase.

“One of the most important figures that needs to be looked at before any purchase is made is the calving difficulty figures. If you want a bull to serve all cows and heifers on the farm, then the calving difficulty figures are critical.”

The Ballinrobe-based Teagasc advisor said: “For first-time calving heifers, check the beef heifers calving difficulty figure of the stock bull.

“Ideally select a bull with a beef heifer calving difficulty figure of less than 7.5%. For mature suckler cows, check the beef cows figure. To reduce calf mortality and labour around calving, look to source a bull with high reliability figures on calving difficulty.”