摘要
旨在研究茶渣单宁含量对绵羊养分消化利用与氮代谢参数的影响。本研究分析了茶渣(RTL)的营养成分和单宁含量;用体外法测定6种配比茶渣/大豆粕混合料(0∶10、1∶9、2∶8、3∶7、4∶6、10∶0,其中茶渣缩合单宁(RTL-CT)含量依次为0.00、0.16、0.31、0.47、0.63和1.57g.kg-1 DM)的瘤胃液与瘤胃液+HCl-胃蛋白酶干物质(DM)与粗蛋白质(CP)降解率(rdDM、tdDM、rdCP、tdCP);用4只安装永久性瘤胃瘘管的甘肃高山细毛羊羯羊(1岁半,体质量(29±2.55)kg),按4×4拉丁方方案进行试验,研究了饲粮RTL-CT水平(A、B、C、D分别为0.00、0.77、1.53、2.30g.kg-1 DM)对绵羊养分消化利用与氮代谢参数的影响,共4个15d的饲粮循环(预试期9d,收集期6d)。试验结果:(1)3个茶渣样的粗蛋白质(CP)、粗纤维(CF)、单宁(单宁酸等价,TAE)与CT含量范围分别为23.23%～28.11%、16.68%～17.84%、1.98%～2.10%和1.47%～1.57%。(2)茶渣/大豆粕混合料的rdDM、tdDM、rdCP、tdCP均随茶渣比例提高而线性下降,变化范围相应为61.39%～25.67%、79.61%～26.47%、60.76%～16.68%和84.85%～17.69%。(3)体内试验中,高比例茶渣影响采食量,饲粮D(P<0.01)、C(P>0.05)的DM与有机物质(OM)采食量低于A、B;RTL-CT对DM、OM、中性洗涤纤维、酸性洗涤纤维、氮、钙和磷的消化率无显著影响(P>0.05);但随RTL-CT水平提高尿氮排出量线性下降,导致氮存留率上升,C的氮存留率较A提高23.61%(P<0.05),B、D分别提高12.57%和15.88%(P>0.05);随RTL-CT提高,瘤胃液pH、总氮浓度无显著变化(P>0.05),而NH3-N与血浆尿素氮(BUN)含量线性下降,C、D的NH3-N分别是A的50.36%(P>0.05)和46.55%(P<0.05),BUN相应为A的68.04%与59.99%(P<0.05)。可见,茶渣是高蛋白质、低纤维物质,单宁含量为中等的物质;本试验中,RTL-CT降低了饲粮的体外瘤胃CP降解率,但未影响体内全消化道消化率,且通过减少尿N排出而提高了氮存留率;但高比例RTL-CT降低了绵羊采食量。显然,RTL-CT 1.53g.kg-1 DM对饲粮蛋白质的保护效果较好,且对采食量无显著影响。
The present experiment was conducted to determine the effects of tannin content in residue of tea-leaves（RTL） on digestion and utilization of nutrients and metabolic parameters of nitrogen in sheep. The contents of nutrients and tannin in RTL were analysed; The in vitro degradability（rdDM, tdDM. rdCP. tdCP） of dry matter（DM） and crude protein（CP） of mixtures with six ratio of RTL to soybean meal（0：10, 1：9, 2：8, 3：7, 4：6, 10：0 ）, which levels of RTL condensed tannin（RTL-CT） of the mixtures were 0. 00, 0.16, 0. 31, 0.47, 0.63, 1.57 g · kg^- 1 DM, respectively, was measured by incubating in rumen fluid and rumen fluid ＋ HCl-pepsin. To study the effects of RTL-CT contents on digestion and utilization of nutrients and metabolic profiles of nitrogen in sheep, four High Mountain Fine-wool wethers （one and a half years old and average live weight of （29 ± 2. 55） kg） fitted with permanent rumen fistula and a 4 X 4 Latin square design with four cycles of diet each of 9 d for preliminary followed 6 d for sampling were used in this experiment. The contents of RTL-CT in diets were 0.00（A）, 0.77（B）, 1.53（C）, 2.30（D）g · kg -1DM . The results showed that; （1） the range of contents of CP, crude fiber （CF）, TAE（tannic acid equivalent） and CT in three samples of TRL were 23. 23%-28. 11%, 16.68%-17.84%, 1.98%-2. 10%, 1.47%-1.57%, respectively. （2） The degradabilities of DM and CP of the mixtures in rumen fluid and rumen fluid ＋ HCl-pepsin（rdDM, tdDM, rdCP, tdCP） decreased linearly as the contents of RTL-CT , the range of change were 61.39%-25.67%, 79.61%-26.47%, 60.76%-16.68%, 84.85%-17.69%, respectively. （3） Invivo, the intake of diet was affected by high-raito of RTL, compared with diet A and B, the intakes of DM and organic matter （OM） of diet C （P〉0.05） and diet D （P〈0.01） were lower; the digestibilities of DM, OM, calcium （Ca）, phosphorus （P）, neutral detergent fiber （NDF） and acid detergent fiber （ADF） of diets were unaffected by the contents of RTL-CT（P〉0.05）. But the excretions of urinary nitrogen were decreased linearly and retention of N increased as the RTL-CT level, the retention of nitrogen of diet B, C, D were raised by 12.57% （P〉0.05）, 23.61%（P%0.05） and 15.88% （P〉0.05）than for diet A, respectively; there were no significant changes of the levels of pH and total nitrogen of rumen fluid （P〉0.05） as the levels increasing of RTL-CT, while the contents of NH3-N and plasma urea nitrogen（BUN） linearly decreased, the levels of NH3-N and BUN of diet C and D were 50.36 %（P〉0.05） , 46.55%（P〈0.05）and 68.04%, 59.99%（P〈0.05）lower than that of diet A, correspondingly. It follows that residue of tea-leaves were a matter with high-protein, low-fiber and middle content of tannin; under the condition of this experiment, the in vitro rdCP were decreased by RTL-CT, but the digestibilities of CP in total gastrointestinal tract were unaffected by levels of RTL-CT, and N retentions were increased owing to reducing of the excretion of N in urine as RTL-CT; yet high ratio of residue of tea-leaves in diet resulted in lowing of intake by sheep. Obviously, the protection effect of RTL-CT with 1.53 g · kg 1DM on protein was better, but no significant effect on the intake of diet.
出处
《畜牧兽医学报》
CAS
CSCD
北大核心
2012年第1期71-81,共11页
ACTA VETERINARIA ET ZOOTECHNICA SINICA
基金
现代农业产业技术体系建设专项资金
国家农业科技成果转化资金项目(2008GB2G100324)
关键词
绵羊
茶渣
单宁
缩合单宁
消化
存留
sheep
residue of tea-leaves
tannin
condensed tannin
digestion
retention
作者简介
潘发明（1983），男，甘肃民勤人，硕士，主要从事反刍动物营养研究，E-mail：pan-faming@163．com
通讯作者：李发弟，教授，E-mail：lifd@gsau．edu．cn
