Angus Australia


3. Fertility, Temperament & Feed Efficiency Breeding Values

Breeding values for fertility, docility and feed efficiency provide valuable information on areas which can affect the performance and efficiency of a beef operation.


Click on the individual trait you are interested in:

Days to Calving

Scrotal Size






Days to Calving (DTC)

Days to Calving EBVs are estimates of genetic differences between animals in the time from the start of the joining period (i.e. when the female is introduced to a bull) until subsequent calving.

Lower Days to Calving EBVs indicate an animal is expected to produce progeny that conceive earlier in the joining period. Females with lower Days to Calving EBVs also tend to show earlier puberty as heifers and earlier return to oestrous after calving.

DTC is expressed in day units.

Collecting Days to Calving Information 

Breeders interested in the Days to Calving EBV need to record all ‘events’ associated with the natural joining of all their females. From the start of the mating period in each breeding season through to when the subsequent calves are born.

All calves that are born as a result of the joinings need to be recorded with Angus Australia.

Record the date and reason for any female removed from the herd, particularly those present at the start of joining that are no longer within the herd by the time of the subsequent calving. The fate/disposal code information is critical to the Days to Calving analysis.



Scrotal Size (SS)

Scrotal Size EBVs are estimates of genetic differences between animals in scrotal circumference at 400 days of age.

Higher Scrotal Size EBVs indicate the animal is expected to produce sons with larger scrotal circumference as yearlings and daughters that reach puberty earlier.

Scrotal Size EBVs are expressed in centimetre units.


Collecting Scrotal Circumference Measurements 

Scrotal circumference measurements taken on bulls between 300 and 700 days of age are used to calculate Scrotal Size EBVs within Angus BREEDPLAN.

Scrotal circumference measurements should be recorded by pulling the testes firmly down into the lower part of the scrotum and placing a measuring tape around the widest point. Scrotal circumference measurements can be taken by anyone. They do not need to be taken by an accredited technician.

A variety of scrotal circumference measuring devices are commercially available from agricultural supply stores or organisations such as the Australian Cattle Veterinarians.

It is recommended that scrotal circumference is measured when bulls are reaching puberty, which will vary according to seasonal conditions and the maturity pattern of the animals being measured. In the majority of cases, the optimum time to record scrotal circumference measurements for Angus BREEDPLAN is when bulls are being weighed at 400 days.

Docility (DOC)

Docility EBVs are estimates of genetic differences between animals in temperament.

Higher Docility EBVs indicate an animal is expected to produce a higher percentage of progeny with acceptable temperament.

DOC is expressed in percentage units.


Collecting Docility Information 

Docility scores taken on calves between 60 and 400 days of age are used to calculate Docility EBVs within Angus BREEDPLAN. The recommended time  of  scoring  is  at  weaning  or shortly afterwards.

Animals can be scored for docility using either a crush or yard test:

  • Crush Test – Calves are put up a race and held in a crush or weigh scales for a minimum of 10 seconds (but not necessarily head bailed).
  • Yard Test – Calves are individually put into a small square yard and the handler attempts to hold the animal in one corner for a minimum of 10 seconds.

Docility Scores for Angus BREEDPLAN:

  1.  Docile
  2.  Restless
  3. Nervous
  4. Flighty
  5. Aggressive

Net Feed Intake (Post-Calving) (NFI-P)

Net Feed Intake (Post Weaning) EBVs are estimates of genetic differences between animals in feed intake at a standard weight and rate of weight gain when animals are in a growing phase.

Lower NFI-P EBVs indicate the animal is expected to produce progeny that eat less feed per day, relative to their weight and rate of weight gain.

NFI-P is expressed in kilogram per day units.

Collecting Net Feed Intake Information 

Net feed intake information is used to calculate the Net Feed Intake (Post Weaning) and Net Feed Intake (Feedlot) EBVs within Angus BREEDPLAN.

Collection of net feed intake information can be conducted either ‘on-farm’, or at a ‘central-test’ facility (e.g. Tullimba Research Feedlot), and involves:

  • collection of daily feed intake measurements
  • collection of regular weights to assess the weight, and rate of weight gain of animals

The use of commercial feeding systems that automatically record feed intake of individually electronically identified animals is recommended.

Those who are considering collecting net feed intake information for Angus BREEDPLAN need to be aware that the collection of feed intake measurements must be collected in a standardised way, and can be challenging, expensive, and time consuming.

  • Animals must be between 210 and 700 days of age at the commencement of the net feed intake test period
  • Bulls, steers or heifers can be tested, however only animals of the same sex should be tested in the same pen.
  • A minimum adjustment period of 21 days is recommended prior to commencement of the test to allow animals to adjust to the ration and the testing environment/equipment.
  • Daily feed intake measurements should be collected for a minimum test period of 70 days, with a minimum of 60 valid feed intake days per animal.