Potential use of tannin containing legumes in ruminant and monogastric nutrition

Recent studies have demonstrated that forage legumes with moderate levels of condensed tannins (CT) can be favourable for animal nutrition. The nutritional benefits included faster growth rates, higher milk production, increased fertility, improved nitrogen (N) utilization and reducing greenhouse gas and N emissions. The main objective of the present thesis was to investigate how CT from legumes, in particular Birdsfoot trefoil (BT) and Sainfoin (SF) can improve protein utilization of ruminant and monogastric and by that improve their performance and the quality of the final product. The effects of CT from BT was first investigated in Chapter 2. In particular, we focused on the potential of CT to reduce the formation of the compounds responsible of the “pastoral flavour” on lamb meat as well as their ability to protect dietary PUFA from ruminal biohydrogenation enhancing their availability in the small intestine. The influence of BT on intake, digestibility and N balance of lambs fed diets differing in CP level was investigated in the Chapter 3. In this study, special emphasis has been given to the fate of CT by monitoring possible changes in CT concentrations as well as soluble, protein and fibre bound CT fractions after the passage through the digestive tract. Finally, in the Chapter 4 we investigated the impact of increasing levels of CT from SF on growth performance, carcass characteristics and meat quality of 48 entire male (EM) with special focus on the potential of CT to reduce the formation of the boar taint related compounds.