Terhi Vahlsten

Look at the genetic improvement for more traits

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Nordic trend page is updated

On the Nordic trend page genetic trends for the Nordic cattle breeds are displayed for NTM and sub-indices calculated by NAV. The page has been improved to display trends also for Claw health (in graph “Health”) and Youngstock Survival (in graph “Fertility/survival”).

Genetic trends in a population is given by the average breeding value per birth year. You can choose to show the trends for different populations, sexes, and together or separately for the three Nordic countries (DFS – Denmark, Finland and Sweden).

For both RDC and Holstein cows there has been a slight genetic improvement for both Claw health and Youngstock survival over the last seven year period. For Jersey the same can be seen for Youngstock survival whereas there is no clear trend for the Claw health index.

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Reliabilities for GEBV’s

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Reliabilities on GEBV’s are published

In November 2015 NAV starts to publish reliabilities along with the GEBV for genomically tested bulls. The estimated reliabilities (%) for candidate bulls are presented per bred for the main traits in table 1. The differences in the level of the reliabilities can to a large extend be explained by the differences in size of the reference populations for the three breeds.

 

Table 1 Average GEBV reliabilities (%) for bull calves born in 2014

Traits Holstein RDC Jersey
Yield 74 67 67
Growth 60 49 28
Fertility 65 47 42
Birth 70 57 44
Calving 64 43 65
Udder health 68 57 56
Other disease 45 38 26
Claw health 43 33 –
Longevity 61 38 37
Frame 73 58 63
Feet & Legs 68 54 53
Udder 73 55 60
Milking speed 69 66 60
Temperament 62 53 27

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New weigths for Jersey’s udder index

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Jersey has changed weight in udder index

In November 2015, Jersey has introduced a new weighing of the linear conformation traits in the overall udder index. The new and the old weights are shown in table 1. The changes in weights for udder create significant reranking of cows and bulls. The correlation between the old and the new udder index for Jersey bulls is 0.84.

 

Table 1. Old and new weightings of linear udder traits in mammary. Jersey

Traits Previous New
Fore udder attachment 25 20
Rear udder height 5
Rear udder width
Udder cleft 10
Udder depth 35 25
Teat length 3
Teat thickness 12
Teat placement, front 15
Teat placement, back -10
Udder balance -10
Codes for udder 5

 

 

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