体外产气法评定天祝几种高山植物的抗营养因子及饲用潜力

比较和分析了6种富含单宁的家畜可饲高山植物粗蛋白、酸性洗涤纤维、粗灰分的含量,并对其酚类物质的含量进行了测定。结合体外产气技术(in vitrogas production method),对各种植物和添加聚乙烯二醇(PEG)的体外产气量和干物质降解率进行测定。结果表明,灌木粗蛋白含量较高,藏沙棘高达14.3%,缩合单宁含量随植物品种不同而变化,藏沙棘、金露梅和珠芽蓼含量分别为42.45,35.24,32.98 g/kg(DM)。添加PEG后,珠芽蓼、藏沙棘、金露梅和鬼箭锦鸡儿的产气量分别增加了36.9%,38.9%,16.4%和8.6%。     

胶原纤维固化黑荆树单宁对钪吸附的研究

以胶原纤维为基质,通过醛交联剂将黑荆树单宁固化在胶原纤维上,制备了胶原纤维固化黑荆树单宁(IBWT)吸附材料并研究了IBWT对钪离子(Sc3 )的吸附特性.结果表明:在HOAc-NaOAc介质中,IBWT对Sc3 具有较强的吸附能力.50℃下,当溶液中Sc3 的质量浓度为100mg/L、pH值为6.40时,吸附容量达到83.3mg/g.IBWT对Sc3 的平衡吸附量随pH值和温度的升高而升高.吸附过程为吸热过程,吸附平衡符合Langmuir方程.IBWT对Sc3 的吸附主要为化学吸附.进一步实验表明,IBWT经3次重复使用后对Sc3 的吸附容量基本不变.     

葡萄渣对羔羊生产性能、屠宰性能和养分消化代谢的影响

本试验采用单因子完全随机试验设计,选择60只3月龄左右杜寒F₁代公羔进行试验,测定不同水平葡萄渣对羔羊生产性能、屠宰性能和养分消化代谢的影响。本试验设4个饲粮处理组,每个处理15个重复,每个重复一只羊,Ⅰ为基础饲粮,Ⅱ、Ⅲ和Ⅳ处理组为饲粮中分别含有8%,16%和24%的葡萄渣,缩合单宁(condensed tannins,CT)含量分别为0,1.5,3.0和4.5 g/kg。结果表明,Ⅱ、Ⅲ、Ⅳ组羔羊日采食量、日增重、胴体重、屠宰率和胴体脂肪含量都显著高于Ⅰ组(P＜0.05),N表观存留率极显著高于Ⅰ组(P＜0.01),但Ⅰ组羔羊的酸性洗涤纤维和N表观消化率显著高于Ⅳ组(P＜0.05);Ⅱ组羔羊的饲料转化率显著高于Ⅰ组(P＜0.05),净肉率极显著高于Ⅰ组(P＜0.01)。随着CT含量的增加,羔羊的N、中性洗涤纤维和酸性洗涤纤维表观消化率逐渐降低,N的表观存留率逐渐升高,综合考虑羔羊日增重、饲料转化率、屠宰性能和养分利用率等指标,饲粮中葡萄渣以8%~16%为宜。     

饲料中添加缩合单宁对凡纳滨对虾生长性能、体成分、血清生化及抗氧化指标的影响

本试验旨在研究饲料中添加缩合单宁对凡纳滨对虾生长性能、体成分、血清生化及抗氧化指标的影响。选择初体重约为1.38 g的凡纳滨对虾600尾,随机分为5组,每组3个重复,每个重复40尾。5组对虾投喂缩合单宁添加量分别为0 (CT0组,作为对照组)、0.5 (CT0.5组)、1.0(CT1组)、2.0(CT2组)、4.0 g/kg DM(CT4组)的5种等氮等脂试验饲料,试验期56 d。结果表明：随着饲料中缩合单宁添加量的增加,凡纳滨对虾的终末体重、增重率和特定生长率呈线性增加的趋势(0.050.05)。饲料中添加缩合单宁对凡纳滨对虾体成分、肌肉氨基酸含量和血清生化指标均未产生显著影响(P>0.05)。与CT0组相比,饲料中添加1.0～2.0 g/kg DM缩合单宁显著增加了血清过氧化氢酶和超氧化物歧化酶活性(P<0.05),显著降低了血清丙二醛含量(P<0.05)。CT4组凡纳滨对虾血清过氧化氢酶和超氧化物歧化...     

利用体外产气法测定高山牧草和灌木的干物质降解率

用体外产气法测定了几种牧草和灌木的产气量,以及利用PEG测定了缩合单宁对产气量的影响作用。试验发现12h的产气量与48h的干物质降解率之间呈正相关关系,牧草与灌木的相关系数分别为0．814(P＜0．01)和0．378(P＞0．05)。产气量与缩合单宁含量呈不显著的负相关关系。当添加PEG后,样品12h和24h的产气量显著增加(P＜0．05)。添加PEG后,牧草24h(r＝0．993,P＜0．01)和36h(r＝0．956,P＜0．05)的产气量提高率与缩合单宁含量之间呈正相关关系。灌木产气量的提高率与缩合单宁含量也呈正相关关系,但不显著。说明植物中的缩合单宁对牦牛瘤胃微生物有一定的影响作用。     

兴安落叶松单宁含量的器官差异与季节变化

兴安落叶松是生产落叶松单宁的重要原材料,随着天保工程的实施,使得主要原料树皮供应紧张。通过2003～2004年的测定结果表明,除现用的树皮(8.8%～15.4%)生产原料外,根系(约7.8%)、树枝(1.0%～7.0%)甚至叶片(4.0%～8.0%)都可以成为生产原料,而树干木质部含量过低(0.6%～1.4%)不宜成为生产原材料。不同季节单宁含量差异结果表明,秋季(9～10月)的落叶松单宁含量都显著高于其它季节,因此,原材料的收集应该在秋季。此外,叶片单宁含量与光照强度呈现显著正相关。     

In vitro rumen fermentation of the tropical grass Pennisetum purpureum and mixtures with browse legumes: effects of tannin contents

The fermentation of Pennisetum purpureum, alone (PP) or substituted with 0.30 of the tanniferous legumes Acacia cornigera (AC), Albizia lebbekoides (AL), Leucaena leucocephala (LL) and the saponin‐rich Enterolobium cyclocarpum (EC) was studied in vitro, in presence or absence of polyethylene glycol (PEG) as tannin binder. Inactivation of tannins with PEG increased (p < 0.05) gas production with AL and LL from 8 and 12 h to the end of the incubation period respectively. When PEG was added, LL and AC promoted a higher (p < 0.05) gas volume than PP in the first 12 h incubation, and there were not differences between PP and AL. Substrate mixtures reduced (p < 0.05) methane volume produced compared with PP, but this was not related to PEG inclusion (p > 0.10). There was a trend (p = 0.06) for a higher 48 h bacterial attachment to the substrate when incubated without PEG. The decrease in fermentation of EC from 12 h incubation onwards could be associated with a negative mid‐term effect of saponins over cellulolytic bacterial activity. It is concluded that the effects of tannins on microbial fermentation of mixed forage substrates are variable, depending on their nature, but do not have a marked impact on bacterial adhesion or methane production.     

山蚂蝗饲料资源研究进展

山蚂蝗属(Desmodium)植物适应性强,生长快,草产量高,粗蛋白含量高,氨基酸含量丰富,钙磷比适宜,且富含多种微量元素;单宁是其主要抗营养因子,单宁可与蛋白质生成络合物,降低蛋白质利用率,影响干物质、纤维等养分消化率,降低动物采食量,但适量的单宁可降低蛋白质在瘤胃内的降解率,缓解动物臌胀病,提高动物生产性能和抗病能力。将山蚂蝗属植物作为蛋白补充料与粗饲料配合饲喂动物,可提高粗饲料利用价值,降低生产成本。因此,山蚂蝗属植物是我国热带亚热带地区极具潜力的植物性蛋白饲料资源。     

Proteolysis and in situ ruminal degradation of lucerne ensiled with Cistus ladanifer tannins

The effects of ensiling lucerne with graded inclusion of Cistus ladanifer condensed tannins (CT) on in silo fermentative parameters, in vitro organic matter digestibility (IVOMD) and on in situ rumen degradability of dry matter (DM) and crude protein (CP) were studied. Lucerne forage ( Medicago sativa subsp. sativa ) was sprayed with different solutions of C. ladanifer CT extract in 60 ml of water in order for dose 0 (control), 40 (L40), 80 (L80) and 120 (L120) g of CT per kg of lucerne DM and was ensiled in lab‐scale silos. After 35 days, the silages were analysed for chemical composition, and the in situ ruminal degradability was determined in rams. The inclusion of CT in the silages caused an important dose‐dependent reduction in soluble‐N, NH₃‐N and a large increase in true protein content and N bound with neutral detergent fibre (NDF‐N), which indicates an effective proteolysis reduction during ensiling. Also, the rumen undegradable protein (RUP) increased linearly (P < 0.01) with CT inclusion. However, a linear decrease (P < 0.02) of 5%, 13% and 22% of IVOMD was observed for the silages L40, L80 and L120 respectively. The results obtained suggest that C. ladanifer CT can be used as silage additives to reduce proteolysis of high‐protein forages during ensiling. A level of CT of 40 g/kg DM seems to be the best compromise between the gains achieved by the protection of CP degradation in silo and in the rumen and the losses associated with the depression of the digestion and absorption.     

In vitro fermentation patterns and methane production of sainfoin (Onobrychis viciifolia Scop.) hay with different condensed tannin contents

Sainfoin (Onobrychis viciifolia Scop.) is a perennial legume recently reappraised for some positive characteristics leading to highly satisfactory animal performance. Sainfoin’s characteristics may be partly explained by the presence of moderate levels of condensed tannins (CTs) able to protect dietary protein from microbial degradation in the rumen. Decreased CH₄ emissions have been reported for ruminants consuming CT‐containing forage. The aim of this study was to evaluate the effects of CT content on the in vitro fermentation characteristics and kinetics and methane production of four samples of O. viciifolia cut at different phenological stages. Sainfoin hays and one sample of alfalfa hay were incubated at 39°C in anaerobiosis using the in vitro gas production technique. The chemical composition, tannin content and fermentation characteristics and kinetics of sainfoin samples were significantly affected by phenological stage. After 48 h, the CH₄ production in sainfoin hays showed a tendency to increase with the advancement of phenological stage [from 38·6 to 49·8 mL g⁻¹ of degraded organic matter (OM)]. The best period to cut sainfoin for hay making is between early and late flowering, when the forage combines high OM digestibility, low CH₄ production and more efficient microbial fermentation.