The national Dutch/Flemish breeding value estimation has been changed in the following ways:
- Starting April 2017, the calculation of production breeding values will include testdays from the first five lactations of an animal. Up until now, three lactations were used. Furthermore, the calculations will be based on information of the first 420 days per lactation. This used to be the first 335 days. Lastly, the heritabilities and other parameters have been re-estimated. Starting April 2016, new bases differences will apply for the production traits:
- The data used for the breeding value estimation for mastitis will be expanded by the use of mastitis cases registered by farmers in the management program UniformAgri. This data is added to the data from program CRV veemanager, which was introduced into the breeding value estimation in April 2016. This change had added 1,5 million records of lactation data of cows having/ or not having mastitis, resulting in an increased reliability for the clinical mastitis and udder health index breeding values.
- The genetic parameters (heritabilities and correlations between traits) have been updated for the calving traits; direct calving ease, maternal calving ease and livability.
- The genetic parameters have also been updated for temperament and milking speed.
- Mexico, HOL: First participation in Interbull breeding value estimation
- Great Britain, HOL/RDC/JER/BSW/SIM: Change of the effects in the model
- Australia, HOL/JER: Changing from old single trait model to a random regression test-day model
- Slovenia, HOL: First participation in Interbull breeding value estimation
- USA, JER: Rear teat placement added as a new trait to replace the previously used substitute trait front teat placement
- Great Britain, HOL/RDC/JER/BSW/SIM: Participating with mastitis data for the first time
- Norway, RDC: First participation in Interbull breeding value estimation
GMACE, conversion of genomic breeding values
The Interbull conversions for genomic breeding values has seen a refinement in methodology. The changes take into account an overlap of bulls in the used referencepopulations of various countries better. The consequence are a slight drop in reliabilties for all the converted breeding values and a slightly lower variation for some traits.
Changes per country:
- Germany: First participation for temperament
- Italy: First participation for milking speed
- France: First participation for heifer fertility