US Dairy Forage Research Center, Madison, WI 53706, USA.
J Environ Qual. 2011 May-Jun;40(3):907-14. doi: 10.2134/jeq2010.0492.
Feeding more tannin and less crude protein (CP) to dairy cows may have synergistic impacts on reducing NH emissions from dairy barns. Three trials using lab-scale ventilated chambers with concrete floors were conducted to determine the impacts on NH 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 () fed four levels (g kg) of dietary tannin extract [a mixture from red quebracho () and chestnut () 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) 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, NH emissions were measured 1, 3, 6, 12, 24, 36, and 48 h after treatment application. For Trial 1, reductions in NH emission due to tannin feeding were greatest when fed at LCP: The LCP-LT and LCP-HT treatments emitted 30.6% less NH than LCP-0T, and the HCP-LT and HCP-HT treatments emitted 16.3% less NH than HCP-0T. For Trial 2, feeding tannin decreased urease activity in feces, resulting in an 11.5% reduction in cumulative NH 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 NH emissions of 19.0%. Larger-scale trails are required to ascertain the effectiveness of tannin extracts in abating NH loss from dairy barn floors.
给奶牛饲喂更多的单宁和较少的粗蛋白（CP）可能会对减少奶牛场氨气排放产生协同影响。使用带有混凝土地板的实验室规模通风室进行了三项试验，以确定单宁和 CP 喂养对 NH 排放的影响、单宁喂养对粪便中脲酶活性的影响以及单宁直接应用于畜舍地板的影响。在试验 1 中，将来自泌乳荷斯坦奶牛的粪便和尿液混合物（）饲喂四种水平（g kg）的日粮单宁提取物[来自红金合欢（）和栗树（）的混合物]：0 单宁（0T）、4.5（低单宁 [LT]）、9.0（中单宁 [MT]）和 18.0（高单宁 [HT]）；每一种都以两种日粮 CP 水平（g kg）饲喂：155 低 CP（LCP）和 168 高 CP（HCP），分别应用于腔室。在试验 2 中，向饲喂 HCP 的 0T、MT 和 HT 的奶牛粪便中添加尿素溶液。在试验 3 中，将相当于饲喂 0T、MT 和 HT 的单宁量直接应用于来自 0T-HCP 的粪便-尿液混合物。在所有试验中，在处理后 1、3、6、12、24、36 和 48 小时测量 NH 排放。在试验 1 中，单宁喂养降低 NH 排放的效果最大，当在 LCP 下喂养时：LCP-LT 和 LCP-HT 处理比 LCP-0T 少排放 30.6%的 NH，而 HCP-LT 和 HCP-HT 处理比 HCP-0T 少排放 16.3%的 NH。在试验 2 中，单宁喂养降低了粪便中的脲酶活性，导致累积 NH 损失减少 11.5%。在试验 3 中，单宁直接应用于模拟畜舍地板也明显降低了脲酶活性，导致累积 NH 排放平均减少 19.0%。需要更大规模的试验来确定单宁提取物在减少奶牛场 NH 损失方面的有效性。
