THE ROLE OF CONDENSED TANNINS IN THE NUTRITIONAL-VALUE OF LOTUS-PEDUNCULATUS FOR SHEEP .2. QUANTITATIVE DIGESTION OF CARBOHYDRATES AND PROTEINS
THE ROLE OF CONDENSED TANNINS IN THE NUTRITIONAL-VALUE OF LOTUS-PEDUNCULATUS FOR SHEEP .2. QUANTITATIVE DIGESTION OF CARBOHYDRATES AND PROTEINS
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DOI：
10.1079/bjn19840055
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发表时间：
1984-01-01
影响因子：
3.6
通讯作者：
MANLEY, TR
中科院分区：
文献类型：
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作者：
BARRY, TN;MANLEY, TR
将含有总浓缩单宁46和106 g/kg干物质（DM）和游离浓缩单宁3和14 g/kg DM的初级生长营养型长柄山羊草割下，每隔1小时（750 g DM/d [d]）新鲜饲喂在瘤胃和十二指肠内安装永久性瘘管的绵羊。低单宁荷花和高单宁荷花的总氮含量分别为41.3和31.6 g /kg DM，木质素含量分别为132和152 g /kg DM。记录营养摄取量，直接收集粪便量。通过测定持续注入瘤胃的惰性Ru-菲罗啉（Ru- p）和Cr-EDTA标记物在十二指肠处的稀释度，估计十二指肠食糜流量。通过比较两种饲粮的消化情况，并将每种饲粮的消化情况与相似采食量下不含单宁的新鲜饲料的预测值进行比较，来评估浓缩单宁的影响。各营养物质表观消化率高单宁荷花低于低单宁荷花（P < 0.01）。两种形式荷花瘤胃和瘤胃后纤维素消化水平与预测值相似。与不含单宁的新鲜饲料相比，饲喂两种形式荷叶的绵羊瘤胃中消化的半纤维素和易发酵碳水化合物（RFC；可溶性碳水化合物+果胶）较少，但这两种营养物质的瘤胃后吸收增加了。低单宁荷叶和高单宁荷叶的瘤胃总氮增加量（十二指肠氮流量-总氮摄入量）分别为1.8和10.5 g/d，而在相同的总氮摄入量下，不含单宁新鲜饲料的预测总氮损失分别为3.7和2.1 g/d。低单宁荷叶和高单宁荷叶的瘤胃后非氨氮消化率分别为0.71和0.67，而同等不含单宁新鲜牧草的瘤胃后非氨氮消化率为0.76。以氨基酸形式从小肠吸收的能量为两种莲代谢能的0.29，而多年生黑麦草和白三叶的代谢能分别为0.17和0.21。与不含单宁的新鲜饲料相比，荷花中浓缩单宁的存在显著增加了瘤胃后NAN的吸收，但抑制了RFC和半纤维素的瘤胃消化。
Primary growth vegetative L. pedunculatus containing 46 and 106 g/kg dry matter (DM) of total condensed tannin and 3 and 14 g/kg DM of free condensed tannin, was cut and fed fresh at hourly intervals (750 g DM/d [day]) to sheep fitted with permanent cannulas into the rumen and duodenum. Low- and high-tannin lotus contained respectively 41.3 and 31.6 g total N/kg DM and 132 and 152 g lignin/kg DM. The 2 forms of lotus were similar in carbohydrate composition. Nutrient intake was recorded and fecal output measured by direct collection. Digesta flow to the duodenum was estimated by measuring dilution at the duodenum of inert Ru phenanthroline (Ru-P) and Cr-EDTA markers continuously infused into the rumen. Effects attributable to condensed tannins were assessed by comparing the digestion of the 2 diets, and by comparing the digestion of each with predicted values for non-tannin-containing fresh forages fed at similar intakes. Apparent digestibility of all nutrients measured was less for high- than for low-tannin lotus (P < 0.01). The levels of cellulose digested ruminally and post-ruminally in both forms of lotus were similar to predicted values. Less hemicellulose and readily fermentable carbohydrate (RFC; soluble carbohydrate + pectin) was digested in the rumen in sheep given both forms of lotus than would be predicted for non-tannin-containing fresh forage diets, but this was compensated for by greater post-ruminal absorption of both nutrients. Total N gains across the rumen (duodenal N flow-total N intake) were 1.8 and 10.5 g/d for low- and high-tannin lotus vs. predicted losses of 3.7 and 2.1 g/d for non-tannin-containing fresh forages given at the same total N intakes. Post-ruminal digestion of non-ammonia-N (NAN; proportion NAN flowing at duodenum) was 0.71 and 0.67 for low- and high-tannin lotus respectively vs. 0.76 for comparable non-tannin-containing fresh forages. Energy absorbed as amino acids from the small intestine was calculated to be 0.29 of metabolizable energy for both forms of lotus, compared with 0.17 and 0.21 for perennial ryegrass and white clover. The presence of condensed tannins in lotus markedly increased post-ruminal NAN absorption compared with non-tannin-containing fresh forage diets, but depressed ruminal digestion of RFC and hemicellulose.