The latest NAV routine evaluation for yield, fertility, type, udder health, other diseases, calving traits, milk ability, temperament, growth, longevity, claw health and NTM took place as scheduled. NAV carried out three evaluations per trait group:

Holstein evaluation, including data from: Danish Holstein, Danish Red Holstein, Swedish Holstein, Finnish Holstein, Finnish Ayrshire and Finn Cattle.

Red Dairy Cattle evaluation, including data from: Danish Red, Swedish Red, Finnish Ayrshire, Finnish Holstein and Finn Cattle.

Jersey evaluation, including data from: Danish Jersey and Swedish Jersey (only yield and type).

Extraction dates

Dates for extraction of data from national databases are given in table 1.

Table 1. Dates for extraction of data from the national databases

Data used in genomic prediction

Genotypes were extracted from the joint Nordic SNP data base 19th October 2011. Interbull information from August 2011 and national information according to extraction dates in table 1 were included in genomic prediction.

News in relation to NAV genetic evaluation

Genomic prediction

GEBVs are published for the first time for genotyped DRH animals for all traits in NTM and linear type traits. DRH animals are included in the Holstein reference population. The GEBVs for Body, Udder and Feet&Legs are estimated based on Holstein weights and optimum to be able to estimate GEBVs for these traits.

Claw health

Procedures for editing of Finnish data have been improved which means extra 55,000 claw trimmer registrations from Finland are used in the routine evaluation. The changes in EBVs from August to November routine run are due to the extra data somewhat larger than we normally see between two subsequent routine evaluations for bulls tested in Finland.
Genetic base

EBVs for bulls and females are expressed on the same cow base. This genetic evaluation included cows born from 02.11.2006 to 02.11.2008 in the genetic base (average 100).

Genomic EBVs (GEBVs)

GEBVs combine genomic and phenotypic information. GEBVs are estimated for all combined traits in NTM, single type traits, and NTM. Table 2 describes how different categories of genotyped animals are handled in the evaluation. All non genotyped animals get traditional EBVs.

Table 2 Publication of Genomic breeding values (GEBVs) for different categories of animals

·          EBV=Estimated breeding value based on phenotypic data only
·          IB EBV = Interbull breeding value based on phenotypic data only
·          GEBV=Genomic Enhanced breeding value – based on phenotypic data and genomic information

For animals having a GEBVs the GEBV is published as the official index instead of the EBV

NAV will in the coming months work with:

·    GEBVs for genotyped bulls with daughters
·    Genotyped cows with own records

Reliabilities

The reliability of genomic information varies between traits and breeds. Table 3 give a general picture of the reliability of the genomic information used when weighting genomic information and phenotypic information together in GEBV.

Table 3 Reliability of genomic information

Publication of NTM for Nordic and foreign bulls

A NTM is published if the bull has official EBVs (NAV EBV or international EBV) for Yield, Mastitis and Type. By official means for NAV EBVs that the NAV thresholds are met and for international EBVs (IB EBVs) that Interbull estimates EBVs for the single bull. EBVs are used in the following priority NAV EBVs, IB EBVs and Pedigree index. For traits without a NAV EBV or an IB EBV a NAV pedigree index is calculated.

For bulls with a Nordic herd book number the pedigree index follows the principles described in the October 2008 routine information. For foreign bulls without a Nordic herd book number the pedigree index is calculated in as ½(EBVsire-100) +1/4(EBVmgs-100) +100. If EBVsire or EBVmgs is not official NAV EBVs then 100 is used.  

NAV – frequency and timing of routine runs

NAV has 4 evaluations per year including all phenotypic data. In Table 4 the future NAV and Interbull release dates are shown. NAV does four extra genomic predictions to get GEBVs based on the newest information for all genotyped bull calves and females. The extra runs take place 15.3, 15.6, 15.9 and 15.12. After the extra runs GEBVs for females are published on national data bases

Table 4. NAV and Interbull release dates in 2011/2012. EBVs released at NAV dates in bold will be delivered to international genetic evaluation.

You can get more information about the joint Nordic evaluation:

General about Nordic Cattle Genetic Evaluation: www.nordicebv.info
Contact person: Gert Pedersen Aamand, Ph.: +45 87405288 gap@vfl.dk,

Denmark: www.landscentret.dk/nav
Contact person: Ulrik Sander Nielsen, Danish Cattle, Ph. +45 87405289, usn@vfl.dk

Sweden: www.sweebv.info, www.svenskmjolk.se
Contact person: Jan-Åke Eriksson, Swedish Dairy Association, Ph. +46 08-790 58 67 jan-ake.eriksson@svenskmjolk.se

Finland: www.faba.fi
Contact person: Jukka Pösö, Faba, Ph +358-(0)207472071 jukka.poso@faba.fi