Please note this website requires cookies in order to function correctly. They do not store any specific information about you personally.
You may delete and block all cookies from this site, but parts of the site may not work. To find out more about cookies on this website, see our Privacy Statement.




Choose your Country

Get Started

Production & Health Breeding Values

Breeding values provide an indication of the genetic merit of an animal for a specific trait; they are calculated using information which is collected on-farm. Cows which are routinely measured through herd testing, herd weighing and TOP assessment will have more reliable breeding values then those which are not. Similarly, the reliability of a bull’s breeding values increase as more of his daughters are measured.

There are currently seven traits included in the Breeding Worth index; these traits have been selected as they have an economic value to a New Zealand dairy farm, and they are able to be measured.

In the lists below, click on a specific trait to learn more:

 
Production Breeding Values
 

Milkfat is a moderately heritable (30%) trait. You should aim to increase milkfat breeding value over time. In New Zealand, genetic gain has been pretty consistent at around 1kg/year, irrespective of breed. On average, Friesians have the highest milkfat breeding value.

Protein is a moderately heritable (28%) trait. You should aim to increase protein breeding value over time. In New Zealand, genetic gain has been pretty consistent at around 1.1kg/year, irrespective of breed. On average, Friesians have the highest protein breeding value.

Milk is a moderately heritable (34%) trait. You should aim to increase or maintain milk breeding value over time. In New Zealand, genetic gain has been pretty consistent at around 19 litres/year, with the greatest rates of genetic gain in Friesians. On average, Friesians have the highest milk breeding value.

Somatic Cell Count (SCC) is a low to moderately heritable (15%) trait. You should aim to lower SCC breeding value over time. SCC breeding values are slowly decreasing over time at a rate of 0.02/year since 2004, when they were introduced in BW. On average, Ayrshires have the lowest SCC breeding value.

 
Health Breeding Values
 

Fertility is a low heritability (9%) trait. You should aim to increase fertility breeding value over time. In New Zealand genetic losses were observed from 1990 to 2000, but genetic gains have been made since 2002 when the fertility breeding value was first included in BW.

On average, Jerseys have the highest fertility breeding value. Fertility breeding values (percentage of calving within 42 days of the start of calving) are calculated from information derived from herd recording software, herd testing and TOP assessments. Eight individual predictor traits are currently used to estimate the fertility breeding value:

- Presented for mating within 21 days of the planned start of mating (PM21) in lactation one, two and three

- Calving rate in the first 42 days after the planned start of calving (CR42) in lactation one, two and three

- Volume in a cows' first lactation

- Body condition score (BCS) in a cows' first lactation at 60 days in milk

All these traits are included as they are correlated (negatively or positively) with overall fertility. For instance, cows with genetically higher BCS have improved fertility, cows with genetically higher milk volumes have poorer fertility, and cows that are presented for mating within 21 days of the planned start of mating have improved fertility. Information from all these predictor traits are then run through a multi-trait model, where each animal is compared relative to her contemporary group (all animals with the same age (e.g. lactation one, two , three, four, five, six or six plus), year and season of calving) with other main adjustments including permanent environmental effect (e.g. effect of rearing to two years of age), age and hybrid vigour. Again, the method to estimate breeding values also includes the genetic relationship between individuals in his or her pedigree who may have left better or worse than average progeny for fertility performance.

The breeding value for longevity is calculated from information derived from herd testing, herd recording software, and TOP assessments. Four direct and nine predictor traits are currently used to estimate the longevity breeding value:

Direct

- Survival from first to second, first to third, first to fourth, first to fifth lactation

Predictor

- Protein yield in lactation one

- Somatic cell score in lactation one

- Body condition score in lactation one

- Calving rate in the first 42 days after the planned start of calving (CR42) in lactation two

- Owner opinion in lactation one

- Milking speed in lactation one

- Leg conformation in lactation one

- Dairy conformation in lactation one

- Udder overall in lactation one

These traits are included as they are correlated (negatively or positively) with longevity. For instance, cows with genetically higher owner opinion, dairy and udder conformation have improved residual longevity. Cows with genetically higher somatic cell score have reduced longevity.

Residual survival is a low heritability (6%) trait. You should aim to increase residual survival breeding value over time. Residual survival breeding values are slowly decreasing over time at a rate of 1 day/year, but have declined at a faster rate in Friesians. On average, Ayrshire and Guernsey have the highest residual survival breeding value.

Residual survival (defined as "herd life after accounting for the genetic effects of production, liveweight, fertility and somatic cells on herd life") breeding values are estimated from the longevity breeding value minus the components above using the following equation:

EBV(Longevity) - [5.434*EBV(Milkfat) + 4.408*EBV(Protein) - 0.03815*EBV(Milk) - 0.489*EBV(Liveweight) + 27.847*EBV(Fertility) - 65.131EBV(SCS)]

Body Condition Score is a moderately heritable (~25%) trait; you should aim to increase body condition score over time.  Historically genetic gain in this trait has been minimal, but this is predicted to increase following the inclusion of the BCS in Breeding Worth (Feb, 2016).

The body condition score breeding value is calculated using records collected on two year old heifers. These records are collected in early lactation, and the majority of them come from CRV and LIC progeny test herds.

Raw scores are converted into a day 60 lactation equivalent, and then enter the AE model. 

As a result of a recent review (see below) a ‘breed neutral’ adjustment has been applied to this breeding value. This means that the breed average for this trait is 0 across all breeds.

Gestation length breeding values are estimated from the difference from a progenies planned calving date and her actual date of calving. Sires with negative gestation length breeding values will ensure that gestation lengths of progeny born are shorter than 282.5 for males and 281.2 days for females. Gestation length breeding values are changing little over time.

Calving difficulty breeding values are estimated from calving assistance information collected in progeny test herds and via data recorded in herd management software. Sires with negative calving difficulty breeding values will produce progeny that cause less calving difficulties than average.

Holstein-Friesian Average (Std Dev) 2.27 (2.26)
Easy <0.01
Difficult  >4.53

Source: LIC AEU (April 2016)

Liveweight is a moderately heritable (35%) trait. You should aim to maintain liveweight breeding value over time. Liveweight breeding values are slowly increasing over time. On average, Friesians have the highest liveweight breeding value.

Source: http://www.dairynz.co.nz/animal/animal-evaluation/interpreting-the-info/breeding-values/

Choose your Country

Find a variety of information and contact details specific to your area.