Avoid disappointment. Assess bull fitness today

26 August 2016

Are your bulls fit and ready for spring joining?

It’s a question every producer with a spring-calving herd should be asking now, according to Dr Peter Armstrong, who also said a Veterinary Bull Breeding and Soundness Examination (VBBSE) makes economic sense.

“With Angus bulls averaging about $7,500, the cost of each calf (sired by that bull) is about $67 based on the average working life of bulls from 2.8 to three years,” he said.

“If the bull is sub-fertile, that cost goes up dramatically.

“A VBBSE works out to cost the producer about $1.20 to $1.50 per calf, this is cheap insurance.”

Peter, a cattle producer and a large animal veterinarian with a mobile practice based at Junee, NSW, will be walking producers through the important aspects of preparing bulls for joining at a ReproActive workshop on Tuesday, 13 September, at Condobolin, NSW.

“There is no enjoyment in waiting until pregnancy testing to find out there was a problem. Producers should conduct a full VBBSE of their bulls six to eight weeks prior to joining, on an annual basis,” he said.

Peter recommends producers follow these procedures to guarantee breeding soundness prior to joining:

Crush-side examination

  1. Structure – assess legs, feet and back for soundness and particularly note any changes in claw set as they can suggest problems higher up the limb.
  2. Penis and sheath health – look for any issues such as infections or old injuries from last joining.
  3. Scrotal palpation – a scrotal measurement is taken to ensure the bull has enough sperm output to meet the demands of the joining period. Scrotal size is highly heritable for the onset of puberty of heifer progeny. Assess tone or ‘springiness’ of testicles, which are indicators of good sperm quality. Identify any injuries or structural abnormalities.
  4. Internal sex gland palpation via rectal entry – irregularities can indicate infections.
  5. Semen testing. Poor quality sperm is rare in bulls that have appropriate scrotal size and tone, especially in southern temperate climates. It is important to test young yearling bulls being used at joining as they may have not reached puberty and in single sire mating situations.  

Peter said a high percentage of bulls culled from a VBBSE don’t make it past the crush-side exam.

Serving ability test

  1. Most important for middle-aged and older bulls.
  2. Is the most accurate integrated assessment of structure, locomotion and serving functionality. Many bulls can pass the crush-side examination but fail when put out on a serving test.
  3. Identifies abnormal serving conditions such a spiral and ventral deviations of penis (often seen in aging bulls from polled breeds), back injuries and pain. It is the only way to accurately estimate the bulls cow serving capacity.


  1. Ensure young bulls are in body condition score 3.5 to 4 (out of 5) and older bulls condition score 3 (but no more) to ensure quality sperm production and a ‘buffer’ for weight loss at joining time.
  2. The sperm production cycle is 70 days so bulls need to be on good nutrition at least 70 days prior to the bull-in date to get 65-70% of cows in calf in the first cycle.
  3. Older bulls shouldn’t get too fat (more than condition score 3), as it affects their athleticism and increases risk of injury.


  1. At a minimum, all bulls should receive a Vibriosis vaccination of two initial injections six weeks apart and then an annual booster. Peter recommended that if producers have bought vaccinated bulls but let their boosters lapse, they should start the course again.
  2. 7 in 1 vaccine to protect against Leptospirosis and clostridial diseases.
  3. Vaccinate for Pestivirus and know bulls’ persistently-infected status.
  4. Control internal and external parasites.

Out in the paddock

  1. The first 21 days are crucial to a tight joining period. Check young bulls every two to three days and older bulls at least once a week.
  2. While serving, observe bulls from the right hand side to check for any entry issues, excessive exposure of the penis post-serving and swelling.
  3. Young bulls are often very vigorous and need close observation. Replacing a young bull with a fresh bull for the second cycle may be needed if signs of injury are noticed. It is best to get the young bull out of the mob and assessed immediately if there is any indication of something not ‘quite right’. Many serious injuries in young bulls can be avoided and minimised if a prompt assessment is made. 

The ReproActive workshop, which also features presentations and practical demonstrations on critical mating weights, body condition scoring and reproductive diseases will be held on Tuesday, 13 September from 8.30am-2.30pm at the Moonbi Hall and 'Newlands', Lachlan Valley Way, Condobolin, NSW.

To register online go to http://www.reproactivecondobolin.eventbrite.com.au by 12 September for more information and directions.

More information: Dr Peter Armstrong T: 0438 404 249 E: slvs@outlook.com

Want to know more? Check out the mating guidelines in the More Beef from Pastures manual.

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