Deliberately postponing the time of first insemination of a dairy cow is a herd management strategy, which potentially may benefit cow health, farmer economy and greenhouse gas emission.
Many cows can maintain a high milk yield throughout lactation. Delaying pregnancy improves both persistency and reproductive performance. However, young cows may experience trouble in the lactation after the extended lactation.
Data from 48 Danish dairy herds from 2020 to 2023 are available. In each herd, a subset of 40 cows were selected for either extended lactation or for control. We would like to investigate how extended lactation affects production and animal health of cows in their second lactation after having gone through an extended lactation in their first lactation. Among other things, we wish to know what extended lactation means for milk production, conception rate, disease, and body condition in the subsequent lactation.
To be decided in agreement with the supervisor.
Department of Animal- and Veterinary Sciences, AU Campus Viborg - Blichers allé 20, DK-8830 Tjele.
30, 45 or 60 ECTS thesis as appropriate. The MSc student may be invited to co-author a scientific publication
Prerequisites: an interest in data analysis is required. The MSc-student will become part of a research team in a collaborative project involving Dept. of Agroecology (AU) and SEGES.
Rasmussen, A. E., Båge, R., Holtenius, K., Strandberg, E., Brömssen, C. von, Åkerlind, M., & Kronqvist, C. (2023). A randomized study on the effect of an extended voluntary waiting period in primiparous dairy cows on fertility, health and culling during first and second lactation. Journal of Dairy Science, 106: 8897-8909.
