Monday, 05 September 2016 23:55

BCS records system changing

Written by 
Jeremy Bryant. Jeremy Bryant.

A change will be made this month to the way body condition score (BCS) records are treated before they enter the animal evaluation (AE) system.

A new process will apply more stringent limits to BCS data that flows into the AE system and will also allow multiple BCS records for an individual cow rather than just one record per season.

New Zealand Animal Evaluation Ltd (NZAEL) manager Jeremy Bryant says the changes will mean a bull's breeding value will more closely reflect the BCS genetics he is passing on to his daughters.

The need for this change was uncovered during the AE Transition, an industry-led project which transfers the operation of the AE system from LIC's animal evaluation unit (AEU) to NZAEL, a DairyNZ subsidiary.

"This has created the chance to intensively review all aspects of data processing, looking for causes of discrepancies between NZAEL and AEU's evaluation results," says Bryant. "In this case NZAEL, with LIC, saw an opportunity to enhance BCS data processing.

"By implementing this as a part of the August AE run (released August 20), farmers can make immediate use of improved breeding values."

The early phases of the transition involved rewriting data processing methods to produce results closely aligned to those now produced by AEU. NZAEL's animal evaluation system has been tested for many months, running in parallel with AEU so the results can be directly compared.

In a similar scenario, a revision of fertility data processing was implemented in February.

"The impact of this change will be small, with 95% of dairy sires moving up or down less than $4 for breeding worth (BW)."

BCS breeding values are calculated using the BCS records of two-year-old cows in progeny test herds. Two-year-olds are often assigned more than one BCS record over the season, scored when they are inspected for 'traits other than production' (TOP) and again when their liveweight is measured.

Current system

The current pre-processing of BCS data only allows one record into the system. If a cow has multiple BCS records collected over the season, these are not included in AE.

Some of the BCS records collected onfarm are very low or high (2.0 and lower, or 7.5 and greater) which may indicate ill health, data entry errors or special management of an animal. The current system does not exclude these outlier scores and so they are allowed to flow into the model.

Dairy sires often have only small numbers of daughters scored for BCS and so one outlier (high or low BCS) can have a large impact on their overall evaluation.

New system

The new pre-processing method will use multiple records by producing an average of all the BCS data collected over the season.

In addition to this, the validation of BCS records has been increased, so that very low (2.0 or lower) and very high (7.5 or greater) records will not enter the AE model.

More like this

Have your say on emissions pricing

OPINION: We’re kicking off 2022 with a road show across the regions in February so farmers can have their say on how agricultural emissions will be priced from 2025.

Planning key to combat higher costs

Strong financial management, grazing management and people management skills will help dairy farmers buffer rising input costs and produce milk more efficiently.

Levy bodies advocacy questioned

North Otago farmer Jane Smith says she remains concerned that levy organisations appear to have little appetite for gaining full and transparent farmer mandates before taking their advocacy positions.


Plan makes co-op competitive

Fonterra's proposed capital structure will allow the co-operative to compete with other processors based on its milk price and overall…

Elite herd offered online

An elite Southland Friesian herd is set to become the biggest single livestock offering sold online so far.

Machinery & Products

Solution for rowdy cattle

Having walked away with a Fieldays Innovation Award and a useful cheque back in June, Springarm Products has recently signed…

Next generation swathers

Claas' latest generation of seven, dual-rotor central LINER swathers are said to offer numerous innovative features and functions to ensure…

Below ground fert server

Bavarian fertiliser spreader manufacturer Rauch is testing a prototype unit for depositing fertiliser in row crops to depths of 10…

Press screw separator

Probably best known for its chopping units that form an integral part of many manufacturers’ umbilical effluent spreading and injection…

Hydrogen power to cut emissions

While the automobile industry heads full tilt down the electrification route, heavier industries such as trucking and construction appear to…

» Latest Print Issues Online

Milking It

Seaweed saviour

OPINION: Scientists in Ireland are going underwater to solve their dairy sector’s methane conundrum.

Due recognition

OPINION: National's new leader Christopher Luxon’s first speech after his elevation to the top job included one important line about…

» Connect with Dairy News

» eNewsletter

Subscribe to our weekly newsletter