Bull Testing

It has been found that in most commercial operations, up to 20% of the mixed age bull team is unsound for mating. In single sire mating systems or when there is a defective dominant bull, this can have a massive impact on the herd’s reproductive performance.

Before the bull team goes out, its important you have the confidence the boys are up to the task. Tests should be done in the months leading up to mating so any issues can be identified, and replacement animals sourced.

Capability Test – What’s involved

• A heifer or cow is selected to match the size of the bull and tethered or bailed. In some case she is injected with prostaglandin the day before to bring her on heat.

• The bull is introduced and as he mounts his penis is checked for any abnormalities (injuries, warts, shape, color, length).

• An artificial vagina then steers the bull’s penis away and the semen is collected (the sample needs to be kept at body temperature and away from sunlight).

• The cow or heifer is only served once by each bull and her welfare needs to be assessed along the way.

• During the process, the bull’s ability to mount is evaluated, any structural issues are identified, scrotal size is measured, and temperament is assessed.

• The semen is then sent away for evaluation and detailed quality report is generated based on density, mortality, and deformities (75% alive and normal is a good result). Most vets will offer this service.

Bull Health

• Any small disease or injury can cause a bull to be infertile for a period of time as anything that raises the body temperature can damage sperm.

• Monitor bulls closely during mating to make sure they are doing their job. Check them twice a week and observe them walking, and if possible, watch them mate.

• Treat injured bulls promptly and allow plenty of time for them to recover. Have spare bulls on farm to swap out if one becomes lame or injured.