NAV published the methane index for Holstein AI bulls in May 2025. The next step is now taken, with the methane index also being published for Holstein females, as well as for both bulls and females in RDC and Jersey. The methane index is included in NAV Bull search.
Methane is currently an information trait and is not part of NTM. At present, methane has no defined economic value, and therefore it is not relevant to include methane in NTM.
Read more about methane index:
The second NAV routine evaluation this year took place as scheduled. The NAV Bull Search has been updated with the new EBV’s and GEBV’s. NAV Beef Search is also updated with new beef x dairy breeding values.
In this evaluation, the weight of saved feed in NTM was adjusted for all breeds. In the February 2025 evaluation, a new Saved feed index was introduced. Saved feed is based on dry matter intake (DMI), production (ECM) and weight change over the lactation. Due to changes in the saved feed evaluation, its economic value was also updated. Based on this revised economic value, the weight of saved feed in NTM also needed adjustments. For all breeds, the weight of saved feed has increased, as well as the correlation between NTM and saved feed. The correlations between old and new NTM are still very high, meaning that only minor reranking in a year group is seen.
In the May 2025 evaluation, NAV published the methane index for Holstein AI-bulls. Now it is time to publish methane index for Holstein females, as well as for both bulls and females in RDC and Jersey. Methane index is also included in NAV Bull search.
Read more about the changes: