Submitted to: American Forage and Grassland Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 3/4/2001
Publication Date: 4/22/2001
Citation: Turner, K.E., Neel, J.P. 2001. Blood urea nitrogen concentrations when lambs were offered hay diets supplemented with quebracho tannin. In Terrill, T. (ed) American Forage and Grassland Conference Proceedings, Springdale, AR 10:358-362.
Technical Abstract: Fifteen crossbred lambs (avg wt 105 lb) were randomly assigned to a replicated study to evaluate the influence of condensed tannin (CT) on protein-use in ruminants. After 14 d, lambs offered the sericea lespedeza [Lespedeza cuneata (Dum.-Cours.) G. Don; LESP] hay diet had lower (P < 0.01) blood urea nitrogen (BUN) concentrations (13.5 mg/dl) when compared to lambs offered alfalfa (Medicago sativa L.; ALF) hay diets supplemented with quebracho tannin which were all similar (mean 21.5 mg/dl). For all lambs, BUN concentrations was quadratically related to the total N: total phenolics ratio in the diet (BUN, mg/dl = -0.43x2 + 4.27x +13.77; R2 = 0.68). Further research is needed to identify grass and tannin-source combinations for ruminants that maximizes condensed tannin tolerances by ruminants yet optimizes nitrogen-use and production efficiencies.