Franklin Vets is able to assist in all areas of bull soundness and fertility to ensure that bull performance is not the limiting factor on your farm.

We can advise you on the following areas:bull

Bull numbers

Do not assume you have enough bulls for the likely number of empty cows at the end of artificial breeding.

The table below shows the number of bulls required based on herd/mob size and expected number pregnant at the end of AB. If you are unsure of likely number pregnant at the end of AB, give us a call and we can discuss based on AB length, submission rate, calving spread and cow condition.

The numbers stated are for bulls in with the herd on a daily basis. Dairy NZ suggests you should have the same number resting, with bulls doing two days on, two days off, to maintain body weight, feet and libido.

No. Cows in milking herd Likely % of herd pregnant at the start of bull mating
 Very Low < 40 %Low 40-50 %Moderate 50-70%High >70 %
1002 to 42 to 322
2005 to 64 to 52 to 32
3007 to 864 to 53
4009 to 117 to 85 to 63 to 4
50012 to 139 to 1074 to 5

Bull fertility

Careful bull selection can reduce the risks of selecting subfertile bulls however it is better to test them to save costs should they not perform. The exam we offer checks:

  • Palpation and measurement of testicles
  • Palpation of internal sex glands
  • Collection of semen and examination of the penis
  • Examination of sperm for motility (on farm)
  • Examination of sperm for morphology (in the lab).


Bull soundness

We can assess the overall appearance of the bulls for deformities, condition, aggressiveness and legs and claws for walking.

Bull management

To get the most out of your bulls they need to be managed correctly. Remember to observe bull activity at the start of mating. Serving ability and willingness to serve are not part of a breeding soundness examination and should be done during mating. Be quick to identify bulls with lameness and replace them with sounds ones.

Bull BVD

BVD is easily spread among the herd and can have devastating effects. Ensure that all bulls are blood tested before they join the cows. Bulls should also receive two shots of BVD before they are mixed with the herd or heifers.

It is important to plan ahead and ensure that you have enough sound mating and healthy bulls on the farm well ahead of mating. Talk to your Franklin Vets team for advice and to find out more about Dairy NZ InCalf bull selection tool.