Feeding value of supplemented diet with black tea by-product silage : Effect of polyethylene glycol addition to the diet on digestibility of protein fractions in goats
Feeding value of supplemented diet with black tea by-product silage : Effect of polyethylene glycol addition to the diet on digestibility of protein fractions in goats
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红茶副产品青贮饲料补充日粮的饲喂价值：日粮中添加聚乙二醇对山羊蛋白质组分消化率的影响
DOI：
10.1111/j.1744-697x.2007.00083.x
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发表时间：
2007
影响因子：
1.3
通讯作者：
H. Yokota
中科院分区：
文献类型：
--
作者：
M. Kondo;Hidaka Miho;K. Kita;H. Yokota
采用离体和活体试验研究了红茶副产物青贮饲料的饲用价值。为研究红茶副产物中单宁对营养物质消化率的影响，本试验还将聚乙二醇（PEG）作为单宁结合剂饲喂山羊。关于体外瘤胃发酵，补充红茶副产品青贮基础基质在超过1%的干物质（DM）的基础上降低了氨-N（NH3-N）的浓度在介质中，表明红茶副产品抑制蛋白质降解在瘤胃。在体内消化率试验中，采用3 × 3拉丁方重复设计，分别饲喂梯牧草+豆粕（对照）、对照+红茶副产物青贮（+BTS）和对照+红茶副产物青贮+ PEG（+PEG）日粮。红茶副产品青贮饲料补充到控制饮食在5%的DM的基础上。红茶副产品青贮饲料供应显着降低粗蛋白质（CP）的消化率相比，控制饮食（63.9比67.5%），但减少消化率往往改善PEG添加（66.5%）。对照组中酸性洗涤剂不溶性N（ADIN）被轻微消化（1.5%），但+BTS中消化率为负（-19.1%）。另一方面，添加PEG明显提高ADIN消化率（2.9%）。+BTS和+PEG均未改变尿氮排出量和瘤胃液NH3-N浓度。粪氮输出量在+BTS中显著高于对照，但在+PEG中有降低的趋势。氮素存留量以+PEG处理最高，其次为+BTS和对照。本研究间接证实了红茶副产物青贮饲料中降低蛋白质消化率的化合物是单宁。有人建议，提供红茶副产品青贮饲料中的5%率在饮食中是这样一个高的水平，粪便N输出增加单宁蛋白结合分级ADIN。
The feeding value of black tea by-product silage was studied both in vitro and in vivo. To estimate the effect of tannins in black tea by-product on nutrient digestibility, polyethylene glycol (PEG) was also given to goats as a tanninbinding agent. Regarding in vitro ruminal fermentation, supplementation of black tea by-products silage to basal substrates at more than 1% on a dry matter (DM) basis decreased the ammonia-N (NH 3 -N) concentration in the medium, indicating that black tea by-products suppressed protein degradation in rumen. In the in vivo digestibility trial, six castrated goats were fed diets of timothy hay + soybean meal (control), control + black tea by-product silage (+BTS), and control + black tea by-product silage + PEG (+PEG) in a replicated 3 × 3 Latin square design. Black tea by-product silage was supplemented to the control diet at 5% on a DM basis. Black tea by-product silage supply significantly decreased crude protein (CP) digestibility compared to the control diet (63.9 vs 67.5%), but the diminished digestibility tended to be improved by PEG addition (66.5%). Acid detergent insoluble N (ADIN) was slightly digested in control (1.5%), but the digestibility was negative (‐19.1%) in +BTS. On the other hand, addition of PEG clearly improved the ADIN digestibility (2.9%). Urinary N output and ruminal NH 3 -N concentration was altered in neither +BTS nor +PEG. Fecal N output was significantly higher in +BTS than in control, but it tended to be lower in +PEG. The amount of retained N was the highest in +PEG, followed by +BTS and control. This study confirmed indirectly that chemical compound in black tea byproduct silage that lowered protein digestibility was tannins. It was suggested that offering black tea by-products silage at a 5% rate in a diet was such a high level that fecal N output was increased by tannin-protein bindings fractionated as ADIN.