News indexrun April 2018

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2018
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The following changes were implemented for the national breeding value estimation:

  1. NVI for milk goal and dual purpose
  2. Composites conformation dual purpose
  3. Longevity
  4. Genomic breeding value estimation
  5. Update base differences calving traits

1. NVI for milk goal and dual purpose

Following the discussion about the breeding goal conducted by GES and the studbook, the NVI will be adjusted. There will be an NVI for milk goal for animals that are published milk goal base black and milk goal base red. In addition there will be an NVI for dual purpose.
The current NVI is:
NVI = 0,35*Inet +0,09*lon +5,2*UDH +5,2*FER +5,2*Udder +6*F&L +2*Cal

Claw health will be part of the NVI for animals that are published milk goal base black and milk goal base red. Furthermore feed intake will be added to the NVI as resultant of extra feed that is needed for maintenance.

The new NVI for milk goal is:
NVImd = 0,4*Inet +0,08*lon +4,7*UDH +6,3*FER +1,8*Udder +3,6*F&L +1,8*Cal +2,7*CLW + 0,23*SFC

BVK = saved feed costs maintenance during lactation (in euros).
For animals that are published on dual purpose or Belgian blue base the meat index will be added to the current NVI, creating an NVI for dual purpose.

The new NVI for dual purpose is: NVIdd = 0,35*Inet +0,09*lon +5,2*UDH +5,2*FER +5,2*Udder +6*F&L +2*Cal + 5,2* MI

2. Composites conformation dual purpose

There is a need for adjusting the breeding values for general characteristics to the breeding goal for dual purpose.  An important adjustment is the addition of the trait muscularity to the trait Type.
Formulas to calculate the composites for dual purpose of Belgian blue are:
Frame: 0,30 x  (BVST – 100) +0,40 x (BVCWa – 100) + 0,40 x (BVBDa – 100) + 0,40 x (BVRAa – 100) + 0,50 x (BVRWa – 100) + 100

Type:                    -0,0258 x (BVCWb – 104)2 – 0,0258 x (BVBDb – 104)2 + 0,31 x (BVAN – 100) + 0,42 x (BVBC – 100) + 0,31 x (BVRW – 100) + 0,31 x (BVMUSC – 100) + 101

Udder:                 0,27 x (FWFUA – 100) + 0,27 x (FWFTP – 100) – 0,0075 x (FWTLb – 100)2 + 0,36 x (FWUD – 100) + 0,36 x (FWRUH – 100) + 0,36 x (FWUS – 100) + 0,0075 x (FWRTPb– 104)2 + 100

Feet & Legs:       0,32 x (FWRLRV – 100) – 0,0267 x (FWRLSVb – 102)2 + 0,16 x (FWFA – 100) + 0,78 x (FWLOC – 100) + 100

Where:
a top off breeding values larger than 104 for BD and RW, larger than 106 for CW and larger than 108 for RA
b Weigh breeding values as optimum with quadratic function, optimum is 100 for TL, 104 for CW, BD and RTP, and 102 for RLSV, where breeding values that deviate with more than 12 points from the optimum are also set to 12 points deviation.

3. Longevity

The breeding value estimation for longevity has been renewed using a new model. Purpose of the adjustments is to stabilize the breeding values of bulls in the long run.
The most important adjustments are:

  • The approach to the trait longevity is different in the breeding value estimation. In the current model longevity of a cow stays the same during her whole life, while the new model treats the longevity in the first lactation as a different trait compared to the longevity in the fourth lactation.
  • The new breeding value estimation is based on the animal model. From now on cows will also directly get a breeding value from this breeding value estimation.
  • The calculation of the reliability has improved and represents how much information is available to estimate longevity.
  • The daughters that are culled before the first mpr will be included in the breeding value estimation of the bull.

The way of presenting the breeding value for longevity has not changed. The breeding value is still expressed in amount of days.
There is a new base adjustment. The base differences between bases milk goal black (Z), milk goal red (R) and dual purpose (D) are:

Z à R Z à D R à D
 Longevity 50 280 230

 

4. Genomic breeding value estimation

In the breeding value estimation for genomics, cows will be used in the reference population for the first time. The effect of this adjustment is that there is more variation in the genomic breeding values of the bulls.

5. Update base differences birth traits

There is an update of the base differences for the bases milk goal black (Z), milk goal red (R), dual purpose and Belgian blue.

Z=>R Z=>D Z=>B R=>D R=>B D=>B
  Direct calving ease 0 -1 34 -1 34 35
  Maternal calving ease 1 0 32 -1 31 32
  Gestation Length -2 -1 -6 1 -4 -5
  Birth weight 0 2 -35 2 -35 -37