Diurnal variation in nitrogen and marker excretion in dairy cows

In feeding and digestibility trials with dairy cows we often use markers to estimate excretion of feces and urin through spot sampling, to avoid total collections that are both labour intensive and causes more stress to the animal. However, we know that there is a diurnal variation in the excretion of some markers, which makes it important to consider both the number of samples and the timing of sampling when planning an experiment. In this master project, we want to study how this variation may affect the calculated excretion of nitrogen, by repeated collection of urine and feces from cows at Lövsta.

The project consists of 1-2 weeks of animal experiment at Lövsta, including frequent sampling also during nighttime. In addition, sample preparation and some analytical work may be included. 

This is a suitable 30 credits-project for 1-2 students, e.g. on the Animal Science master program. It is well suited for a student who is interested in nutrition and who wants a project with practical as well as analytical work. 

If you want to know more, please contact Cecilia.Kronqvist@slu.se