In vitro effects of and interactions between tannins and saponins and fate of tannins in the rumen

The rate of fermentation of hay was not affected by purified tannins from Ouercus incana and Dichostachys cinerea at 0.13 mg ml^?1 of the in vitro medium whereas a decrease of 4% in the rate was observed for Acioa barteri tannins at this level. At 0.23 mg and 0.47 mg of tannins per ml, the decrease in rate varied from 4 to 13% and 13 to 20%, respectively. The decrease in in vitro true digestibility of dry matter was 3, 6 and 7% for Q incana, D cinerea and A barteri, respectively, at a tannin concentration of 0.47 mg ml^?1, and 17, 21 and 27%, respectively, at 0.93 mg ml^?1. There was no change in the potential extent of digestion up to 0.47 mg ml^?1 for any of the tannins studied. These results suggested that the rate of digestion is affected to a greater extent than the potential extent of digestion or the in vitro true digestibility and that different tannins even at the same level have different degrees of effect. Tannin-saponin interactions were studied using tannic acid (TA), quebracho tannin (QT) and quillaja saponin (S) at different concentrations (0.2, 0.4 and 0.6 mg ml^?1) alone and in combination with each other. The decrease in the rate of digestion and true digestibility was additive when both the TA and the S were present. Similar results were obtained when TA was replaced by QT except that the effects with QT were more marked as compared to TA at the same concentration. Saponins had little effect on the potential extent of digestion and true digestibility. These tannins also decreased the production of short-chain fatty acid (SCFA) and their molar proportions (acetate decreased whereas propionate increased). Efficiency of microbial protein synthesis, expressed as the ratio of ¹⁵N incorporation per unit of SCFA production, was higher with both S and the tannins studied. A substantial amount (71–93%) of tannins soluble in aqueous acetone was released from leaves of some trees and shrubs on incubation in the in vitro medium for 48 h. The rumen liquor was not capable of degrading oligomeric condensed tannins.     

气相色谱内外标法分析啤酒中高级醇含量的比较

该文采用气相气谱定量分析比较了内外标法测啤酒中高级醇含量的准确性,实验结果表明,内标法分离效果好,平行性好,不受进样量浮动和样品含气泡(其他气体)的影响。实验测得回收率为98.4%～99.9%,变异系数<1.5%。     

气相色谱内标法及外标法测定酒中甲醇方法的比较

目的比较气相色谱内标法和外标法测定酒中甲醇的方法。方法通过气相色谱法分离酒中的甲醇,分别用内标法和外标法进行定量,对2种方法进行方法学验证比较。结果 2种方法的线性范围均为22.81～912.48 mg/L,线性相关系数均在0.999以上,检出限均为7.5 mg/L,定量限均为25 mg/L。内标法加标回收范围为85%～105%,相对标准偏差小于2%。外标法加标回收范围为80%～100%,相对标准偏差小于2%。气相色谱直接进样内标法、外标法同时测定10种酒中甲醇含量,经t检验结果无显著性差异。结论 2种方法的测定结果没有显著性差异,可灵活运用于酒中甲醇含量的测定。     

Effects of variety on chemical composition,in situ nutrient disappearance and in vitro gas production of spineless cacti

This study determined the chemical composition, in situ ruminal nutrient disappearance and in vitro gas production kinetics of three cactus varieties grown in northeastern Brazil. The varieties were Gigante, IPA‐20 and Miúda. Results of the chemical analysis showed no significant differences in ash, ether extract, crude protein (CP) and neutral detergent fibre (NDF) between the cactus varieties. However, acid detergent fibre was highest (P < 0.05) for IPA‐20, intermediate (P < 0.05) for Gigante, and lowest (P < 0.05) for Miúda. Fractionation of carbohydrate and true protein based on rates of ruminal degradation indicated that the main carbohydrate component was the rapidly degradable fraction, whereas the main true protein component was the intermediately degradable fraction. No differences in carbohydrate or protein fractions were observed between the cactus varieties. Results of the in situ experiment showed no differences in ruminal dry matter (DM, average 803 g kg^?1 of DM), CP (900 g kg^?1 of CP) and NDF (611 g kg^?1 of NDF) disappearance between the three cactus varieties after 48 h of ruminal incubation. Potential gas production at the end of 48 h of incubation was higher (P < 0.05) for Gigante than for the Miúda or IPA‐20 variety. However, rate of gas production and lag time in gas production were similar for the three cactus varieties at 6.8% h^?1 and 0.6 h respectively. Our results showed little or no differences in chemical composition or ruminal nutrient degradabilities between the three cactus varieties. Copyright © 2003 Society of Chemical Industry     

Evaluating the nutritive values and in vitro degradability characteristics of leaves,seeds and seedpods from Moringa stenopetala

BACKGROUND: Moringa stenopetala is a multipurpose tree which has several agricultural, industrial and medicinal uses. The nutritive value of East African M. stenopetala has not been fully investigated and pertinent data for ruminants are lacking. The present study was therefore conducted to fill this gap by providing the latest information on chemical composition and in vitro fermentation of M. stenopetala tree parts. RESULTS: The respective metabolizable energy values for leaves, seeds and seedpods were 10.0, 7.0 and 5.1 g kg^?1 dry matter (DM). The crude protein (CP) contents for leaves, seeds and seedpods were 395, 282 and 110 g kg^?1 DM, respectively. For leaves and seeds, 88% and 83%, respectively, of the CP was true protein. Fat contents (g kg^?1 DM) were relatively high in seeds (334) but not in leaves (84) or seedpods (110). No starch was detected in seeds. Leaves were a potentially useful source of calcium,, sodium and manganese, containing 18.5, 4.1 and 0.086 g kg^?1 DM, respectively. The concentrations of essential amino acids in leaves for leucine, valine, phenylalanine, isoleucine and threonine were 8.5, 5.3, 5.3, 4.5, and 4.4 g 16 g N^?1, respectively, and were comparable to those found in soybean and Moringa olifera leaves. The contents of total phenols in seeds and leaves were 1.2 and 56.7 g kg^?1 DM, respectively. CONCLUSION: The chemical composition of leaves and seeds from M. stenopetala revealed its potential as a protein and energy supplement for ruminant livestock. Copyright © 2008 Society of Chemical Industry     

Comparison of in vitro degradation of temperate forages using the gas production and filter bag techniques

BACKGROUND: Two of the most promising in vitro techniques for dynamic forage evaluation are the gas production (GP) and filter bag (FB) techniques. To improve our understanding of how these techniques describe the dynamic degradation of forages, 20 temperate forage samples were analysed by each method at different time points during a 96 h incubation period. The results of the recordings were fitted to a biphasic Michaelis–Menten model describing the degradation of rapidly and slowly degrading forage fractions. RESULTS: GP and disappearance from the FB measurements were correlated at all time points from 6 to 96 h (R² = 0.27–0.74), except at the 24 h incubation point. When GP was transformed into organic matter degradation (OMD), there was an even stronger correlation (R² = 0.54–0.75) between the techniques at all intervals. Comparison of the parameters from the Michaelis–Menten model resulted in correlations (R² = 0.83) between the sizes of the estimated forage fractions, but not between parameter determining the rates of their degradation. CONCLUSIONS: Both the GP and FB techniques have the potential to estimate the degradation of individual feed fractions in forages. Further studies in which the in vitro parameters are evaluated against livestock data, are needed to confirm the findings of this study, however. Copyright © 2007 Society of Chemical Industry     

桔梗的化学成分、药理作用及资源开发的研究进展

桔梗是一种具有较高的食用和药用价值的植物资源,含有多种对人体有益的活性成分,具有抗菌、抗肿瘤、抗氧化等保健作用,有较好的临床应用价值和研发潜力.文章介绍了桔梗的功效成分,保健作用及开发利用状况,旨在促进桔梗的开发利用.     

Comparison of sheep and red deer rumen fluids for assessing nutritive value of ruminant feedstuffs

Four forages (alfalfa hay, barley straw, maize silage and beet pulp), four cereal grains (barley, maize, sorghum and wheat) and four shrubs (Calluna vulgaris, Erica australis, Cytisus cantabricus and Genista occidentalis) were incubated using rumen fluids from sheep and red deer, to examine differences in in vitro fermentation rates and ruminal parameters. For the forages and cereal grains, results suggest few differences between species in parameters related to gas production, rates of fermentation, organic matter disappearance and extent of degradation. Deer showed slightly better results for shrubs than sheep did. Disappearance of neutral detergent fibre was generally greater when the rumen fluid was derived from red deer (P < 0.05). On the other hand, ammonia‐N concentration and total volatile fatty acids (VFAs) were higher in sheep (P < 0.05). Molar proportions of the major VFAs showed significant differences (P < 0.05) associated with the species of the inoculum donor and suggest that fermentation pathways might have been more efficient in red deer. The estimated amount of methane was higher in sheep, regardless of the substrate incubated (P < 0.001). The results indicate that although the sheep could be valid as a model to assess the nutritive value of good quality feedstuffs for red deer, it would fail to offer reliable information on non‐conventional, low‐quality feeds such as shrubs. Copyright © 2005 Society of Chemical Industry     

花椒的化学成分、药理作用及其资源开发的研究进展

花椒是一种具有较高的食用和药用价值的植物资源,含有多种对人体有益的活性成分,具有抗菌、抗肿瘤、抗氧化等保健作用,有较好的临床应用价值和研发潜力。文章介绍了花椒的化学成分,药理作用及开发利用状况,旨在促进花椒的开发利用。     

气相色谱法多重检验海豹油中二十碳五烯酸、 二十二碳五烯酸和二十二碳六烯酸方法研究

目的建立多重检验海豹油中二十碳五烯酸(eicosapentaenoic acid,EPA)、二十二碳五烯酸(docosapentenoic acid,DPA)和二十二碳六烯酸(docosahexaenoic acid,DHA)的气相色谱法。方法用氢氧化钾甲醇溶液将样品中EPA、DPA和DHA甲酯化,气相色谱程序升温同时分析3个ω-3多不饱和脂肪酸,分别用外标法和内标法进行定量。结果 3个ω-3多不饱和脂肪酸的外标法定量线性范围为50~5000μg/m L,相关系数均0.999,精密度相对标准偏差均10%,回收率均90%;内标法定量的精密度相对标准偏差均10%,回收率均85%;外标法和内标法对3个ω-3多不饱和脂肪酸的结果比较,CV%均小于10%。结论该方法操作简单快捷,适用于进口海豹油中EPA、DPA和DHA的含量简便和准确的测定。     

Unique interrelationships between fiber composition,water-soluble carbohydrates,and in vitro gas production for fall-grown oat forages

Sixty samples of ‘ForagePlus’ oat were selected from a previous plot study for analysis of in vitro gas production (IVGP) on the basis of 2 factors: (1) high (n = 29) or low (n = 31) neutral detergent fiber (NDF; 62.7 ± 2.61 and 45.1 ± 3.91%, respectively); and (2) the range of water-soluble carbohydrates (WSC) within the high- and low-NDF groups. For the WSC selection factor, concentrations ranged from 4.7 to 13.4% (mean = 7.9 ± 2.06%) and from 3.5 to 19.4% (mean = 9.7 ± 4.57%) within high- and low-NDF forages, respectively. Our objectives were to assess the relationships between IVGP and various agronomic or nutritional characteristics for high- and low-NDF fall-oat forages. Cumulative IVGP was fitted to a single-pool nonlinear regression model: Y = MAX × (1 – e ^{[–K× (t – lag)]}), where Y = cumulative gas produced (mL), MAX = maximum cumulative gas produced with infinite incubation time (mL), K = rate constant, t = incubation time (h), and lag = discrete lag time (h). Generally, cumulative IVGP after 12, 24, 36, or 48 h within high-NDF fall-oat forages was negatively correlated with NDF, hemicellulose, lignin, and ash, but positively correlated with WSC, nonfiber carbohydrate (NFC), and total digestible nutrients (TDN). For low-NDF fall-grown oat forages, IVGP was positively correlated with growth stage, canopy height, WSC, NFC, and TDN; negative correlations were observed with ash and crude protein (CP) but not generally with fiber components. These responses were also reflected in multiple regression analysis for high- and low-NDF forages. After 12, 24, or 36 h of incubation, cumulative IVGP within high-NDF fall-oat forages was explained by complex regression equations utilizing (lignin:NDF)², lignin:NDF, hemicellulose, lignin, and TDN² as independent variables (R² ≥ 0.43). Within low-NDF fall-grown oat forages, cumulative IVGP at these incubation intervals was explained by positive linear relationships with NFC that also exhibited high coefficients of determination (R² ≥ 0.75). Gas production was accelerated at early incubation times within low-NDF forages, specifically in response to large pools of WSC that were most likely to be present as forages approached boot stage by late-fall.     

Feeding value,in vitro digestibility and in vitro gas production of different by‐products for ruminant nutrition

Nine by‐products used in animal nutrition were examined for their nutritive value by determining the chemical composition (crude protein, crude fat (ether extract), neutral detergent fibre, acid detergent fibre, lignin), in vitro organic matter digestibility and rumen fermentation kinetics (from gas production curves measured in vitro). The by‐products studied were giant pumpkin, red pepper, stem broccoli, brewer's grain, fresh artichoke, scalded artichoke, lemon peel, orange peel and melon. The nutritive value was very variable, depending on the by‐product and on the process applied to the material during industrial processing. In vitro gas production was measured for 500 mg dry matter in quadruplicate at 39 °C after 6, 12, 24, 36, 48 and 72 h of incubation and fitted to single‐pool exponential equations. The fermentation kinetics indicated that brewer's grain was the only by‐product which fitted well with the p = a + b(1 ? e^?ct) equation model; all other by‐products had a very fast degradation rate and their gas production fitted the equation p = b(1 ? e^?c(t?L)), because in the other exponential model a was negative. © 2002 Society of Chemical Industry     

Effects of tea leaf waste of green tea,oolong tea,and black tea addition on sudangrass silage quality and in vitro gas production

This study evaluated the fermentation characteristics and in vitro gas production of sudangrass (Sorghum sudanese) silage with tea leaf waste of green tea, oolong tea and black tea added. All types of tea leaf waste contain large amounts of nitrogen (N) and tannins, and a small amount of low‐water‐soluble carbohydrates. Sudangrass was preserved without (control) and with green tea waste (GTW), oolong tea waste (OTW) or black tea waste (BTW) at rates of 50, 100 and 200 g kg^?1 fresh matter in laboratory silos. The pH and butyric acid levels were significantly lower in GTW at all rates and in OTW at the 200 g kg^?1 rate, whereas those levels were high in the control and BTW‐treated silage. Lactic acid level was appreciably higher in GTW‐ and OTW‐treated silage than the control and BTW‐treated silage. The addition of all types of tea waste increased the total N and tannins of the silage, whereas the acid detergent insoluble N was increased in the OTW‐ and BTW‐treated silage. GTW treatment increased gas production within a 96‐h period compared with the control, whereas OTW and BTW additions at 200 g kg^?1 rates caused lower gas production. It is concluded that the fermentation characteristics and feed value of the silage incorporating with tea leaf wastes are different for these types of tea leaf. Among the three kinds of tea waste, GTW is the most valuable material as a silage additive. Copyright © 2004 Society of Chemical Industry     

Assessment of nutritive value of cereal and legume straws based on chemical composition and in vitro digestibility

The nutritive value of 17 straws was determined on the basis of their chemical composition, in vitro dry matter (DM) digestibility and rumen fermentation kinetics (from gas production curves measured in vitro). Five roughages were from the cereal species Avena sativa (oat), Hordeum vulgare (barley), Secale cereale (rye), Triticum aestivum (wheat) and Zea mays (maize stover). The other 12 samples were legume straws, two samples from each of the species Cicer arietinum (chickpea), Lens culinaris (lentil) and Phaseolus vulgaris (bean) and one sample from each of the species Lathyrus sativus (chickling vetch), Lupinus albus (white lupin), Pisum sativum (field pea), Vicia articulata (one‐flowered vetch), Vicia ervilia (bitter vetch) and Vicia sativa (common vetch). All samples were collected after harvesting from different farms located in León (northwestern Spain). Based on their chemical composition, digestibility and gas production characteristics, species could be clustered into two groups with a significant linkage distance, one for cereal straws that merged at a level of similarity of 80% and the other for legume straws with a degree of similarity of 50%. Species varied widely and significant differences (P < 0.05) were observed between the two groups of straws. Legume straws showed higher crude protein (74 ± 6.1 vs 29 ± 2.2 g kg^?1 DM) and lower fibre (584 ± 18.1 vs 793 ± 27.5 g neutral detergent fibre kg^?1 DM) contents than cereal straws and, consequently, DM digestibility coefficients (0.670 vs 0.609; standard error of difference 0.0054) and metabolisable energy values (7.4 ± 0.15 vs 5.7 ± 0.24 MJ kg^?1 DM) were significantly greater in legume than in cereal straws. Although there were noticeable differences among species within each botanical family, legume straws showed better nutritional quality than cereal straws, indicating that they could be considered promising and interesting sources of roughage for incorporation into ruminant diets. Copyright © 2005 Society of Chemical Industry     

Difference in in vitro fermentability of four carbohydrates and two diets,using ileal and faecal inocula from unweaned piglets

An experiment was conducted to examine differences in the in vitro fermentability of four carbohydrate‐rich feed ingredients and two weaning piglet diets with and without these ingredients, using both the ileal contents and the faeces of unweaned piglets as inocula. In the first part of the experiment, cumulative gas production was measured over time, using faecal inocula mixed from nine specially raised crossbred piglets (no creep feed or antibiotics) at 3 weeks of age. Inulin, lactulose, unmolassed sugar beet pulp, wheat starch and the two diets were used as substrates and fermented in vitro for 72 h. Gas production was measured as an indicator of the kinetics of fermentation. Fermentation end‐products, including volatile fatty acids and ammonia, and organic matter loss, were also measured. For the fermentations of feed ingredients, samples were also collected for polymerase chain reaction/denaturing gradient gel electrophoresis analyses initially and after the fermentation process, to study changes in the composition of the bacterial community. This procedure was repeated 1 week later, using ileal contents from the same piglets as inoculum. There were significant differences between the inocula, in terms of both overall fermentation characteristics and composition and between the substrates. There was also a significant interaction between inocula and substrates, which suggests that there were potentially important differences in the microbial activity occurring in these two areas of the gastrointestinal tract (GIT). For the two diets, one with and one without addition of these fermentable ingredients, there were significant differences in terms of the kinetics, but less so in terms of the end‐products of fermentation. It was concluded that inocula from both the small and large intestine should be used to obtain a more accurate assessment of potential feed ingredients which will stimulate fermentation in the piglet GIT. Copyright © 2005 Society of Chemical Industry