Submitted to: Journal of Dairy Science
Publication Type: Abstract Only
Publication Acceptance Date: July 26, 2004
Publication Date: July 26, 2004
Citation: Hymes Fecht, U.C., Broderick, G.A., Muck, R.E., Grabber, J.H. 2004. Effects of feeding legume silage with differing tannin levels on lactating dairy cattle [abstract]. Journal of Dairy Science. 87 (Supplement 1):249. Technical Abstract: Silages made from Birdsfoot trefoil (BFT) containing three different levels of condensed tannins (CT) were compared to alfalfa (ALF) and red clover (RC) silages as forage sources. Twenty-five lactating Holstein cows (5 fitted with ruminal cannulae) were randomly assigned to incomplete 5X5 Latin squares to assess the effects on milk production and N utilization. Diets contained (DM basis) 50% of ALF, RC or one the 3 BFT that contained low (LTBFT), normal (NTBFT) or high (HTBFT) concentrations of CT. There were differences in CP among silages: ALF and LTBFT were highest, NTBFT and HTBFT intermediate, and RC lowest. The levels of NDF were higher in RC and ALF than in the BFT silages. There were no differences in DM intake or in milk composition due to silage source. However, yield of milk and FCM was higher on NTBFT and HTBFT than LTBFT, which was higher than that on ALF and RC. Fat yield was 0.19 kg/d higher on NTBFT than on ALF, with the other 3 diets being intermediate. Protein yield on all 3 BFT diets, regardless of CT level, was higher than on ALF and RC, despite the fact that the BFT diets contained about 1% less CP. MUN was lower on NTBFT and HTBFT than on LTBFT, ALF and RC. Differences in milk yield may have been confounded by the BFT diets being lower in fiber (27% NDF) than the ALF and RC diets (29% NDF). However, these results suggest CT concentration was directly related to improved utilization of CP in BFT silages.