Tannin Extracts Abate Ammonia Emissions from Simulated Dairy Barn Floors
- J. M. Powell *a,
- M. J. Aguerreb and
- M. A. Wattiauxb
Feeding more tannin and less crude protein (CP) to dairy cows may have synergistic impacts on reducing NH3 emissions from dairy barns. Three trials using lab-scale ventilated chambers with concrete floors were conducted to determine the impacts on NH3 emission of tannin and CP feeding, tannin feeding on urease activity in feces, and tannin application directly to the barn floor. For Trial 1, mixtures of feces and urine from lactating Holstein dairy cows (Bos taurus) fed four levels (g kg−1) of dietary tannin extract [a mixture from red quebracho (Schinopsis lorentzii) and chestnut (Castanea sativa) trees]: 0 tannin (0T), 4.5 (low tannin [LT]), 9.0 (medium tannin [MT]), and 18.0 (high tannin [HT]); each fed at two levels (g kg−1) of dietary CP: 155 low CP (LCP) and 168 high CP (HCP) were applied to chambers. For Trial 2, urea solution was added to feces obtained from cows fed 0T, MT, and HT at HCP. For Trial 3, tannin amounts equivalent to those fed at 0T, MT, and HT were applied directly to feces–urine mixtures from 0T-HCP. For all trials, NH3 emissions were measured 1, 3, 6, 12, 24, 36, and 48 h after treatment application. For Trial 1, reductions in NH3 emission due to tannin feeding were greatest when fed at LCP: The LCP-LT and LCP-HT treatments emitted 30.6% less NH3 than LCP-0T, and the HCP-LT and HCP-HT treatments emitted 16.3% less NH3 than HCP-0T. For Trial 2, feeding tannin decreased urease activity in feces, resulting in an 11.5% reduction in cumulative NH3 loss. For Trial 3, the application of tannin directly to simulated barn floors also apparently decreased urease activity, resulting in an average reduction in cumulative NH3 emissions of 19.0%. Larger-scale trails are required to ascertain the effectiveness of tannin extracts in abating NH3 loss from dairy barn floors.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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