The latest NAV routine evaluation for yield, fertility, type, udder health, other diseases, calving traits, milk ability, temperament 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).

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

News in relation to NAV genetic evaluation

Calving and birth traits for Jersey

Breeding values for calving and birth traits for Jersey are estimated from a model similar to the model, which is used for RDC and Holstein. Altogether, twelve traits – Survival, Calving Ease, and Size of Calf for first and later lactations with a maternal and direct effect each – were simultaneously analyzed. So far only Danish data are used for Jersey.

Table 2. Calving Traits in the three Nordic countries

The EBVs for the four direct traits – survival 1^st, survival later calving, calving ease 1^st, and calving ease later calving are weighted together in a Birth index. The EBVs for the four maternal traits – survival 1^st, survival later calving, calving ease 1^st, and calving ease later calving are weighted together in a Calving index. The economic weights are based on results from the NAV Total Merit Index project. Maternal and direct effect of size of calf is used as an information trait only. Beside the EBVs for maternal effects EBVs for Maternal grandsire (MGS) effects are expressed. MGS effects include beside the maternal effect also 50% of the direct effect. Correlations between EBVs from the new and old Jersey model are about 0.90 for both the birth and the calving trait.

No changes for all other traits

Interbull evaluation

The international evaluation takes place for the different traits according to table 3.

Table 3. International evaluation

International EBVs for milk ability and temperament were estimated for the first time in January 2009. The international EBVs for milk ability and temperament are included in the NTM index for females and bulls following the same rules as other Interbull EBVs

Genetic base

EBVs for bulls and females are expressed on the same cow base. This genetic evaluation included cows born from 15.05.2004 to 15.05.2006 in the genetic base (average 100).

For functional traits, sire models are used and EBVs for cows are not estimated. For functional traits, the genetic base includes bulls, which are sires of present cows – see table 4.

Table 4. Definition of genetic base for cows and bulls

NTM – Nordic Total Merit Index

NTM - Nordic Total Merit - is the name of the total economic index for dairy cattle in Finland, Sweden and Denmark. This means that bulls and cows in all three countries have a NTM breeding value calculated the same way. It also means, for example, that a bull which is used in more than one country will have exactly the same NTM, independent of whether he is used in Finland, Sweden and Denmark. Table 5 - 8 give the weight factors for the different breeds used when calculating NTM. Weight factors are slightly different for cows and bulls due to an approximate multi trait method used for cow NTM.

Pedigree index

A pedigree index is calculated for all traits without an official EBV based on daughter or own records for both cows and bulls. The pedigree index is calculated as an average of sire and dam EBVs for both bulls and females - starting from the oldest animal

Pedigree Index = ½ EBV_sire + ½ EBV_dam

The pedigree index is calculated based on all information in the pedigree as illustrated for fertility for a female in figure 1. When the pedigree index is traced back to an unknown animal the EBV is set to a birth year mean. Birth year mean is calculated per country breed. This method is applied for all traits. The principles are illustrated in figure 1 for a female for fertility.

Table 5. Weights factors for bulls and cows in NTM for Holstein

Table 6. Weights factors for bulls and cows in NTM for RDC

Table 7. Weights factors for bulls and cows in NTM for Jersey

Table 8. Weights factors for bulls and cows in NTM for Red Holstein

Publication of NTM

A bull gets an official NTM, when the bull has official EBVs for yield, type and mastitis. For traits without an official EBV, a pedigree index is used.

NAV – frequency and timing of routine runs

NAV performs 6 evaluations per year for all traits. The NAV evaluations are timed in a way so NAV can deliver updated EBVs to all the international evaluations. In Table 9, the current and future NAV and Interbull release dates are shown.

Table 9. NAV and Interbull release dates in 2009. EBVs released at NAV dates in bold will be delivered to international genetic evaluation. Note the publication date in August is 18th.

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@landscentret.dk,

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

Sweden: 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 Breeding, Ph +358-(0)207472071 jukka.poso@faba.fi