Rumen fermentation and nitrogen balance of lambs fed diets containing plant extracts rich in tannins and saponins, and associated emissions of nitrogen and methane
Rumen fermentation and nitrogen balance of lambs fed diets containing plant extracts rich in tannins and saponins, and associated emissions of nitrogen and methane
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DOI：
10.1080/00039420215633
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发表时间：
2002-12-01
影响因子：
2
通讯作者：
Machm端ller, A
中科院分区：
文献类型：
--
作者：
Sliwinski, BJ;Kreuzer, M;Machm端ller, A
试验饲粮中分别添加1和2 mg/kg DM水平的单宁（水解单宁；番栗木提取物）和2和30 mg/kg DM水平的皂苷（菝葜皂苷；丝兰提取物）。这些水平远低于对反刍动物有害的阈值。通过与未添加蛋白质（10%）或蛋白质充足的对照饲料进行比较，对羔羊的影响进行了测量。随着体重的增加，饲粮由干草、精料（1:1）和额外的小麦淀粉组成。不同处理的瘤胃pH、VFA浓度、原生动物数量、有机物和纤维表观消化率均无显著差异。与高剂量的皂苷相比，低剂量的单宁显著减少了细菌数量。添加皂苷和高剂量单宁对降低瘤胃氨浓度有一定的作用。这与尿氮排泄（仅单宁）和粪便氨排放的微弱趋势有关。与未添加单宁的对照相比，低单宁剂量增加了甲烷释放量。饮食对产热的影响不具有系统性。综上所述，富含单宁或皂苷的提取物在增加体内氮潴留或减少氮排放方面仅表现出轻微的迹象。然而，饮食中蛋白质缺乏的影响可能更大。
Tannins were added to experimental diets at levels of I and 2 g/kg DM (hydrolysable tannins; Castanea sativa wood extract) and saponins at 2 and 30 mg/kg DM (sarsaponin; Yucca schidigera extract). These levels were far below thresholds expected to be adverse in ruminants. Effects were measured in lambs by comparison with unsupplemented control diets calculated to be either deficient (10%) or adequate in protein. The diets consisted of hay, concentrate (1:1) and extra wheat starch with increasing body weight. Ruminal pH, VFA concentration, protozoa count and apparent digestibilities of organic matter and fibre did not differ among treatments. The low tannin dose significantly decreased bacteria count compared to the high saponin dose. Saponin supplementation and the high tannin dose showed some potential to reduce ruminal ammonia concentration. This was associated with weak trends towards lower urine N excretion (only tannins) and ammonia emission from manure. Methane release was increased by the low tannin dose compared to the unsupplemented control. Diet effects on heat production were not systematic. In conclusion, the extracts rich in tannins or saponins gave only slight indications for either increased body nitrogen retention or reduced nitrogen emission. However, effects might have been larger with more pronounced dietary protein deficit.