Beef Bull Condition score and beef assessment guidelines

Bull condition score

Body condition score is a key factor when monitoring the general health and nutritional well-being of bulls. It is also a means of assessing whether young bulls have been overfed before purchase and may fail semen and serving ability tests.

Aim to keep the condition scores of British breed bulls within the following ranges at start of mating, and then during mating:

• Minimum condition score 2.0

• Maximum condition score 3.5

Options for adjusting the condition scores of bulls include:

• Checking bull soundness at least two months before the start of mating. This allows nutritional adjustments to start with sufficient time to ensure target condition score and testicular size responses are met;

• Increasing or decreasing pasture available and or pasture quality for bulls before mating;

• Supplementary feeding with a diet containing at least 11.5 megajoules per kilogram when condition score is less than 2.0, and considering protein supplements to stimulate testicular development before mating; and

• Replacing bulls if condition score is below the suggested limit at the start of mating.

Bull physical soundness

Bulls that are about to be mated need to be assessed as being physically sound, not carrying reproductive infectious diseases, and having acceptable levels of libido and semen quality. Refer to the box below for bull assessment guidelines.

Bull assessment guidelines

Bulls must pass all physical tests specified in the Australian Association of Cattle Veterinarians’ publication, ‘Evaluating and Reporting Bull Fertility’. The physical attributes evaluated include:

• Front and hind feet claws and soles

• Angle of pasterns in front and hind legs

• Hind limb conformation from the side (normal, sickle hocked, post legged, swollen or puffy hocks)

• Hind limb conformation from rear (normal, bow legged, cow hocked)

• Stance and gait abnormalities

• Spine and limb defects

• Head examination from front and side for alignment, absence of swellings and normality of eyes

• Scrotal skin pliability, thickness and inflammation

• Scrotal palpations for fat, freedom of movement, head, body and tail of epididymis, shape of testes, hernias

• Prepuce, sheath and umbilicus

• Penis, including palpation through skin, protrusion of penis and examination of erect penis; there are a potentially large number of penile and prepuce abnormalities

• Infectious disease assessment as set out by the Australian Association of Cattle Veterinarians

Serving ability

It is important to know the serving ability of each bull. The serving ability test is a useful procedure, but it does require a trained person to use careful application of animal husbandry skills to obtain a meaningful result. It is recommended that a local veterinarian carry out the test under approved guidelines.

Guidelines to serving ability:

• Minimum serving ability – 2 or 3 servings in 10 minutes

• Minimum time since bulls exposed to excessively hot conditions – 60 days before mating

Preparation of bulls for mating should include:

• Mating bulls of highest serving ability to heifers so that they get in calf at their first joining. Cows that calve early in their first season tend to be early calvers for the rest of their lives.

• Selecting bulls for mating that meet the specifications set out in the AACV publication, ‘Evaluating and Reporting Bull Fertility’;

• Ensuring access to at least one replacement bull (more in larger herds) from four weeks before mating begins;

• Planning mating groups eight weeks before joining and running bulls together before mating to allow social groupings to establish (mixing bulls either shortly before or during mating can reduce conception rate due to distraction when fighting, and possible injury to bulls);

• Vaccinating bulls with appropriate vaccine to keep the herd protected against diseases that affect fertility

What to measure and when

• Ratio of bulls per 100 cows before mating each year;

• Body condition score weekly from eight weeks before mating until the end of mating;

• Physical and health check-up at eight to four weeks before and at start of mating; and weekly during mating;

• Semen examination at eight and four weeks before, and then at mating when infertility is suspected;

• Libido tests completed once at eight to four weeks before mating;

• Calving histogram prior to mating.