Measuring polyphenoloxidase (PPO) effect on red clover rumen and intestinal digestion in vitro.

Senast ändrad: 27 november 2023
Närbild på in vitro utrustning på lab. Foto.

The aim in this degree project is to use in vitro techniques to examine the effect of polyphenoloxidase (PPO) in red clover varieties on ruminal protein degradation and intestinal amino acid digestion.

High yielding dairy cattle require protein supplementation. Rapeseed meal outperforms soybean meal but its supply is insufficient. Red clover, with its high protein content and N utilization efficiency due to high PPO activity, reduces protein supplement needs in dairy cow diets. However, imbalanced amino acid uptake in the small intestine may limit milk N conversion from dietary N. Addressing red clover limitations could allow breeding varieties with optimal PPO levels for enhanced amino acid supply for milk synthesis. This trial is part of a larger project “Improving red clover as protein source for dairy cows”. This project supports two specific degree project that are perfect for students interested in laboratory practices and sample analysis.

Project 1: “Assessing metabolisable protein in different varieties of red clover by an in vitro system.” You will be using in vitro gas production system and continuous flow analyser to estimate utilisable crude protein (uCP) based on the ammonia N concentration in incubation medium.

Project 2: “Assessing in vitro intestinal digestibility of amino acids of different red clover varieties.”
You will conduct in vitro intestinal digestion experiments based on HCL-pepsin and pancreatin digestion to evaluate amino acids digestion in different red clover varieties. Work also includes sample preparation for nitrogen analysis with elemental analyser and samples for amino acid analysis.

Both projects include experiments, sample analysis, data collection and analysis, literature review and report writing. The experimental work should be performed during February-April 2024 in Umeå. The experimental work of project 2 can be performed also during summer 2024.


Project leader:

Merko Vaga,

Project manager:

Sophie Julie Krizsan,