Bull management

Bulls: power up!

After hundreds of discussions on bulls, InCalf can confidently say not having enough bulls is still the number one issue. It is easier than ever to make sure you have enough bulls by using InCalf's Bulls: power up!

Rule of thumb

  • Seasonal/split calving herds - using AI & bulls 
    3 bulls for every 100 cows at mating start date/start of AI or 4 per 100 if mating synchrony is used 
  • Year-round calving herds - no AI
    2 bulls for every 100 milking cows
Write down the number of bulls needed for your herd on the reminder card and pin it up in the dairy. 

Not planning to use AI this year?

You'll need a bull team of 6 bulls for every 100 cows, this includes spare bulls for rotation.

Tips to keep your bull team in top shape

  1. Have the bulls on the farm by mating start date
  2. Rotate the bulls frequently – e.g. run half the bulls with the herd at any one time, spell the rest, rotate the group at least weekly
  3. Avoid fighting by grouping bulls of similar size, age and temperament
  4. Always run a minimum of two bulls with a small mob
  5. Use bulls aged between 15 months and 4 years
  6. Vaccinate, especially for Vibrio and Pestivirus (BVD)
  7. Get your vet to check for Pestivirus (BVD) and discuss ways to manage it

More information

Bull management - The InCalf Book (chapter 12) (PDF, 204KB)

Sections include:

  • Growing bulls
  • Selecting the best bulls to use
  • Managing working bulls
  • Assessing bull performance
  • Using sufficient bull power

Bulls: power up! Adviser handbook (PDF, 698KB)

If you're an adviser the resources in this kit will help you start a conversation with your clients about their bull management. Not only does it add value to a farm visit, it could easily reduce the number of empty cows they have, increase production and help make their business more profitable.

Bulls: power up! fact sheet (PDF, KB)

Having enough ‘mop-up’ bulls on hand is a simple, cheap and effective way to improve dairy herd fertility. Many dairy farms don’t use enough bulls. With InCalf’s Bulls: power up! it is easier than ever to make sure you have enough bulls for the coming mating season.