How to use BW and PW

Use this page to benchmark herds, cows and dairy sires, and check out how the genetic merit of the national herd is trending over time.

BW (Breeding Worth): This index indicates the expected ability of a cow or bull to breed replacements which are efficient converters of feed into profit. Click here to read more.

PW (Production Worth): This index indicates the ability of a cow to convert feed into profit over her lifetime. PW includes factors like hybrid vigour, which cannot be passed on to progeny.  

Reliability: BW and PW are reported with an associated reliability. This a percentage figure and gives an indication of how likely a BW or PW is to change as new data is added. For example, a BW of 150/99 should be stable, where a BW of 150/35 is highly likely to change.

• Genetic Trends in the National Herd

  On average, milk solids production has increased by about 50kg/cow over the past ten years. It is estimated that around 42% of those production gains are a direct result of farmers commitment to genetic improvement.

  Alongside these production gains, the genetic merit of the national herd has also improved or held steady across a wide range of economically important traits.

  The graphs below show how the genetic merit of cows in the national herd is trending for individual traits.

  Breeding Worth: $8.73/year (10 yr), $9.70 (5yr)

  The rate of genetic gain in Breeding Worth is increasing over time and currently sits at around 1.38% per year. The following graph shows the average BW of cows by year born. The 10 year average rate of gain is $8.73/year. The 5 year average rate of gain is $9.70/year.

  

  Production Efficiency

  Protein: 1.11kg/year

  

  Fat: 1.04kg/year

  

  Milk volume: 20.5l/year

  

  Liveweight: 0.45kg/year

  

  Robustness

  Somatic cell score: -0.014 score/year

  

  Fertility: 0.1%/year

  

  Longevity: 14.7 days/year

  

  Body condition score: 0.001 score/year

  

  Traits other than Production

  Udder overall

  

  Dairy/Body conformation

  

  Note: Genetic Trend data is current as at June 2016. All cows born in each year are included in the averages, with the exception of animals who do not have any calvings or matings recorded by the age of three years old.