Use this page to learn how BW, PW and LW can be used, benchmark your herd or individual cows and check out how the genetic merit of the national herd is trending over time.
-
How to Use BW, PW and LW
Cow indices are available to help farmers make decisions about their cows.
Information that is collected on farm, such as herd testing, mating and calving data is incorporated into each index.
BW and PW are reported with an associated reliability: this gives an indication of how accurate you should expect the number to be.
$82/55 = BW of $82, with a reliability of 55%
Heifer replacements will typically have BW reliabilities of around 40%, this will increase as they enter the dairy herd and begin to accumulate records in their own right.
BW (Breeding Worth)
This index measures the expected ability of the cow or bull to breed replacements which are efficient converters of feed into profit.
read more here
Reliability
BW and PW are reported with an associated reliability: this gives an indication of how accurate you should expect the number to be.
read more here
PW (Production Worth)
This index measures the ability of the cow to convert feed into profit over her lifetime.
LW (Lactation Worth)
This index measures the expected ability of the cow to convert feed into profit in the current season.
-
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.
Click here to download the Updated Animal Evaluation Statistics
