Annual bull management checklist

1. Current herd bulls

Bull health

There are several diseases that impair bull fertility either as true venereal diseases or by being adversely affected by the pathogen during the mating period. Many of these diseases can be controlled or managed by an effective vaccination program before the breeding season.

An annual vaccination program should include: botulism, vibriosis, clostridial diseases (5-in-1 vaccine) and ephemeral fever (3 day sickness). Tick fever vaccination may be required in specific circumstances.

Infection of a bull, particularly during a short mating season, can have a serious effect on the herd conception and subsequent branding rates.

Also test bulls for worms and treat if required.

Body condition

A body condition score of 3 (out of 5) is ideal for maximum sperm production.

Over-fat bulls can be sub-fertile and excess strain can be placed on their legs and spine.

Structural soundness

Legs, joints and feet should be checked for injuries, stiffness and cuts/swelling.

Breeding soundness

BULLCHECK® or a Veterinary Bull Breeding Soundness Evaluation (VBBSE) covers scrotal and physical examinations, semen motility, sperm morphology, and serving capacity (if required).

A vet should perform an annual VBBSE, before joining, to identify bulls that are declining in fertility. This is particularly important for single sire herds.

Bull age

To justify retaining an older age bull in the herd the bull must be fertile, structurally sound and also equal to, or better than, the most recent bull replacements for all genetic traits used in selection.

Bull percentages

Have you got enough or too many bulls?

The ‘Bull Power’ project found that when bulls met the minimum requirements of a VBBSE, bull percentages of 2.5% did not jeopardise branding rates on large pastoral holdings where waters were spread out and in large paddock sizes.

2. If you need to purchase bulls

Look at your breeding objective

Identify the traits that are most economically significant, which could be carcase traits, growth or fertility traits.

Click here to find out more about breeding objectives.

Research

Refer to sire summaries and sale catalogues and talk to your supplier about your requirements (e.g. VBBSE certificate).

Selection

Look at BREEDPLAN EBVs and $Indexes to select bulls that match your criteria.

Work through your bull cost per calf and set your price limit and stick to it!

Look at your list of selected bulls and assess/rank each bull or structural and reproductive soundness (based on the VBBSE), temperament and BREEDPLAN EBVs.

Make your purchases.

Extra resources for purchasing bulls

At home

Give your new bulls enough time to adapt to their new environment. Ensure bulls are working condition before joining, particularly if they were in sale or show condition.

Bulls coming from very different geographic and climatic environments should be relocated much earlier than those animals bought from a similar environment to your herd. Even within genotypes, some bulls adapt to more stressful environments more readily than others (the latter being more likely to have their semen quality affected). Where possible, in-coming bulls should be kept with animals of similar age.

Check the vaccination history of purchased bulls and vaccinate if necessary.