On June 21, Akke Kok obtained her PhD degree with distinction (cum laude), based on her thesis ‘More milking days with lower yields. Sustainability impacts of short or no dry periods in dairy cows’
What are the effects of different dry period strategies?
Shortening and omitting the dry period are strategies to improve cow health and ease the transition period around calving. Akke’s thesis was aimed to evaluate and integrate sustainability impacts of short, or no dry periods with focus on cow welfare, cash flows and greenhouse gas (GHG) emissions.
Cows with no dry period better adapted to next lactation
In the end, the conclusion of the thesis is, that cows with no dry period seemed better adapted to the next lactation than cows with a dry period. The estimated impacts of short and no dry period on cash flows and GHG emissions were small but negative compared with a conventional dry period. Improved cow health and lifespan after a short or no dry period could compensate these impacts.
‘Thesis of excellent interdisciplinary quality’
According to the committee Akke has written a thesis of excellent interdisciplinary quality. She performed an excellent in-depth analysis of the welfare, economic and greenhouse gas consequences of “no or short dry period” in dairy cows. In each domain, welfare, economic and environment, she developed new metrics and models and applied these in experiments and modelling. She moreover showed to be able to integrate all domains at a very high level in her general discussion.
Akke’s promoters were prof. Imke de Boer, prof. Bas Kemp and prof. Henk Hogeveen and co-promoters dr. Corina van Middelaar and dr. Ariette van Knegsel
text by APS and Yvonne van Puijenbroek