scholarly journals In vitro determination of ruminal dry matter and cell wall degradation, and production of fermentation end-products of various by-products

2002 ◽  
Vol 51 (3) ◽  
pp. 189-199 ◽  
Author(s):  
Josefa Madrid ◽  
M. Dolores Megías ◽  
Fuensanta Hernández
Keyword(s):  
Cell Wall ◽  
Dry Matter ◽  
Cell Wall Degradation ◽  
End Products ◽  
By Products

EFFECT OF STRUCTURAL AND CHEMICAL FACTORS OF FORAGES ON POTENTIALLY DIGESTIBLE FIBER, INTAKE, AND TRUE DIGESTIBILITY BY RUMINANTS

1988 ◽  
Vol 68 (3) ◽  
pp. 787-799 ◽  
Author(s):  
V. GIRARD ◽  
G. DUPUIS
Keyword(s):  
Cell Wall ◽  
Dry Matter ◽  
Plant Cell Wall ◽  
Neutral Detergent Fiber ◽  
Optimum Number ◽  
Apparent Digestibility ◽  
Cool Season ◽  
Dry Matter Digestibility ◽  
True Digestibility

In view of the large variation found in plant cell wall digestibilities with ruminants, an attempt was made to group 124 feeds into different lignification classes (clusters) on the basis of chemical characteristics. Each feed cluster was described using a structural coefficient [Formula: see text] that related the potentially digestible fiber (PDF, %) to the ratio between lignin and cell wall volume. The optimum number of clusters was determined iteratively by performing a regression of the apparent digestibility of dry matter at maintenance level (DDM1, %) against the PDF and cell soluble (SOL, %) contents of feeds. The [Formula: see text] coefficients varied from 0.05 (grains, N = 13) to 1.85 (corn silage, N = 3) and increased with the maturity of the grasses from 0.88 (legumes, vegetative cool season grasses, N = 26) to 1.33 (mature, cool season grasses, N = 19). Predicted PDF were closely correlated (r > 0.9, P < 0.01) to in vitro cell wall disappearances (IVCWD). Apparently digestible cell wall in four grasses and four legumes increased linearly with 96-h IVCWD and standard error (SE) was similar to the SE of predicted apparent digestible SOL from SOL concentrations. Assuming that similarity between SE could be also observed in larger samples, PDF and SOL were used in summative equations to predict apparent dry matter digestibility. DDM1 discounted for intake (DDM1 – 4, %) was regressed against SOL and PDF concentrations of 87 feeds:[Formula: see text]with ds and df, the true digestibilities of SOL and PDF. Estimates of ds and df were 0.98 and 0.95 for a zero-production (maintenance) level of intake, and 0.91 and 0.79 for an intake level four times maintenance. Since the true digestibility of the PDF component was only 4% – 13% lower than that of the cell soluble component, the concentration of PDF in cell wall was the major determinant in the variation in apparent digestibility of forages. Key words: lignin, neutral detergent fiber, true digestibility, cluster analysis, feeds

Digestibility and chemical composition of fractions of lucerne during spring and summer

1970 ◽  
Vol 75 (2) ◽  
pp. 213-222 ◽  
Author(s):  
K. R. Christian ◽  
D. B. Jones ◽  
M. Freer
Keyword(s):  
Chemical Composition ◽  
Dry Matter ◽  
Dry Weight ◽  
Chemical Components ◽  
Shoot Height ◽  
Time Of Year ◽  
Highly Correlated ◽  
Leaf Composition

SUMMARYBulk harvests of primary growth were made at intervals during the spring and summer of 2 consecutive years from an ungrazed area of lucerne (Medicago sativa) and the digestibility by sheep was measured. At the same times, shoots of known length representative of the sward were collected, divided into 7·5 cm lengths, and separated into leaf and stem for the determination of ash, nitrogen, cellulose, and in vitro organic matter digestibility.Digestibility and leaf: stem ratio of the bulk harvests decreased and dry matter increased as the season advanced. Leaf composition changed little, but stem increased in lignin and decreased in ash and in vitro digestibility. In vitro digestibility and leaf: stem ratio were highly correlated with sheep digestibility.Chemical composition of shoots of known heights was similar to that of the bulk harvests. Leaf weights/shoot tended to increase linearly with height of shoot, whereas stem increased nearly as the square of the height. Dry matter of leaf and stem were inversely related to leaf:stem ratio. Stem digestibility decreased with leaf:stem ratio and with increase in shoot height.Chemical components of shoot fractions were associated with each other and were largely dependent on the distance from the top of the shoot at which they had been taken, irrespective of shoot height or time of year. Bottom stems had lower ash, nitrogen and digestibility but higher cellulose, dry weight and dry matter than top stems, whose composition approached that of leaves. Leaf fractions showed little consistent trend with position on the shoot.Some of the difficulties in studying changes in plant composition under field conditions are discussed.

A note on the in vitro dry-matter digestibility determination of mixed herbage and browse samples collected with oesophageal fistulated steers

1981 ◽  
Vol 96 (2) ◽  
pp. 483-485 ◽  
Author(s):  
C. Shorrock
Keyword(s):  
Dry Matter ◽  
Dry Matter Intake ◽  
Faecal Output ◽  
Pasture Legumes ◽  
Dry Matter Digestibility ◽  
Grazing Cattle ◽  
Tropical Conditions ◽  
Number Of Authors

The determination of in vitro dry-matter digestibility (DMD) of grass and pasture legumes under both temperate and tropical conditions is well established (Tilley & Terry, 1963; Minson & McLeod, 1972). One application of the in vitro DMD estimation of pasture samples is, together with an estimate of faecal output, the measurement of the herbage dry-matter intake of grazing cattle. Pasture samples are usually collected with oesophageal fistulated cattle. This technique is well documented and has been reviewed by a number of authors (Langlands, 1975; Minson et al. 1976).

scholarly journals Characteristics of Tomato Cell Wall Degradation in Vitro

1977 ◽  
Vol 60 (2) ◽  
pp. 207-210 ◽  
Author(s):  
Stephen J. Wallner ◽  
Heidi L. Bloom
Keyword(s):  
Cell Wall ◽  
Cell Wall Degradation

scholarly journals COMPARATIVE CELL WALL CONSTITUENT LEVELS OF TANNIN-FREE AND TANNIN-CONTAINING CULTIVARS OF FABABEANS (VICIA FABA L.)

1978 ◽  
Vol 58 (4) ◽  
pp. 775-781 ◽  
Author(s):  
R. R. MARQUARDT ◽  
J. A. McKIRDY ◽  
A. T. WARD
Keyword(s):  
Cell Wall ◽  
Dry Matter ◽  
Condensed Tannin ◽  
Unit Weight ◽  
In Vitro Digestibility ◽  
Acid Detergent Fiber ◽  
Dry Matter Digestibility ◽  
Series Of Experiments ◽  
Similar Basis

A series of experiments has been carried out with tannin-free and tannin-containing cultivars of fababeans. The in vitro dry matter digestibility of the cotyledon portion of the two groups of fababeans was the same (88.2%) whereas the in vitro digestibility of the testa portion of the tannin-free cultivars was much higher (27.6%) than that of the tannin-containing cultivars (9.2%). The concentrations of certain cell wall constituents in the testae of tannin-free and tannin-containing cultivars were also different (P < 0.01); the respective average values for the two groups were: condensed tannins, 0.2 and 4.9%; lignin, 4.2 and 6.2%; acid detergent fiber, 72 and 66%; and cellulose, 67 and 60%. There was a negative correlation between the in vitro dry matter digestibility and the amount per unit weight of whole beans of either condensed tannin (r = −0.86, P < 0.01) or lignin (r = −0.89, P < 0.01). When expressed on a similar basis there was no correlation between levels of cellulose or acid detergent fiber and in vitro dry matter digestibility.

Influence of water stress on parameters associated with herbage quality of Panicum maximum var. trichoglume

1975 ◽  
Vol 26 (1) ◽  
pp. 127 ◽  
Author(s):  
JR Wilson ◽  
TT Ng
Keyword(s):  
Cell Wall ◽  
Water Stress ◽  
Dry Matter ◽  
Stem Elongation ◽  
Physiological Age ◽  
Wall Material ◽  
Panicum Maximum ◽  
Dry Matter Digestibility ◽  
Influence Of Water

Plants of Panicum maximum var. trichoglume grown in soil in pots under a controlled environment were subjected to water stress and the effect on forage quality was assessed. Stress was applied as a series of drying and re-wetting cycles, and harvests of total laminae, stem, root, and also specific laminae, were taken 5, 10, 17, 27 and 57 days after the commencement of stress treatment. When compared with control plants of similar chronological age, the dry matter digestibility (estimated by an in vitro technique) of the stressed plants was lower in leaves 4, 6 and 8, similar in total green laminae and in leaves 10 and 12, and higher in stem and dead laminae. The cell wall content of various tissues of the stressed plants was lower than that of the controls. Water stress delayed stem elongation and flowering. It is postulated that stress also delayed the normal ontogenetical changes of the leaves. If comparison was made on a physiological age basis then stress markedly lowered the dry matter digestibility but had little effect on the cell wall content. The broader implication of delayed ontogeny is briefly discussed. The decrease in dry matter digestibility in stressed plants was not associated with changes in the proportions of cellulose, hemicellulose or lignin, but reflected a decline in digestibility of cell wall material.

scholarly journals Different Cell Wall-Degradation Ability Leads to Tissue-Specificity between Xanthomonas oryzae pv. oryzae and Xanthomonas oryzae pv. oryzicola

Pathogens ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 187
Author(s):  
Jianbo Cao ◽  
Chuanliang Chu ◽  
Meng Zhang ◽  
Limin He ◽  
Lihong Qin ◽  
...  
Keyword(s):  
Cell Wall ◽  
Tissue Specificity ◽  
Mesophyll Cell ◽  
Xanthomonas Oryzae ◽  
Cell Wall Degradation ◽  
Intercellular Spaces ◽  
Mesophyll Cells ◽  
Degradation Ability

Xanthomonas oryzae pv. oryzae (Xoo) and Xanthomonas oryzae pv. oryzicola (Xoc) lead to the devastating rice bacterial diseases and have a very close genetic relationship. There are tissue-specificity differences between Xoo and Xoc, i.e., Xoo only proliferating in xylem vessels and Xoc spreading in intercellular space of mesophyll cell. But there is little known about the determinants of tissue-specificity between Xoo and Xoc. Here we show that Xoc can spread in the intercellular spaces of mesophyll cells to form streak lesions. But Xoo is restricted to growth in the intercellular spaces of mesophyll cells on the inoculation sites. In vivo, Xoc largely breaks the surface and inner structures of cell wall in mesophyll cells in comparison with Xoo. In vitro, Xoc strongly damages the cellulose filter paper in comparison with Xoo. These results suggest that the stronger cell wall-degradation ability of Xoc than that of Xoo may be directly determining the tissue-specificity.

scholarly journals Structural basis of peptidoglycan endopeptidase regulation

2020 ◽  
Vol 117 (21) ◽  
pp. 11692-11702 ◽  
Author(s):  
Jung-Ho Shin ◽  
Alan G. Sulpizio ◽  
Aaron Kelley ◽  
Laura Alvarez ◽  
Shannon G. Murphy ◽  
...  
Keyword(s):  
Cell Wall ◽  
Structural Basis ◽  
Bacterial Cells ◽  
Cell Wall Degradation ◽  
Open Conformation ◽  
Poor Understanding ◽  
A Cell ◽  
Inhibitory Domain

Most bacteria surround themselves with a cell wall, a strong meshwork consisting primarily of the polymerized aminosugar peptidoglycan (PG). PG is essential for structural maintenance of bacterial cells, and thus for viability. PG is also constantly synthesized and turned over; the latter process is mediated by PG cleavage enzymes, for example, the endopeptidases (EPs). EPs themselves are essential for growth but also promote lethal cell wall degradation after exposure to antibiotics that inhibit PG synthases (e.g., β-lactams). Thus, EPs are attractive targets for novel antibiotics and their adjuvants. However, we have a poor understanding of how these enzymes are regulated in vivo, depriving us of novel pathways for the development of such antibiotics. Here, we have solved crystal structures of the LysM/M23 family peptidase ShyA, the primary EP of the cholera pathogenVibrio cholerae. Our data suggest that ShyA assumes two drastically different conformations: a more open form that allows for substrate binding and a closed form, which we predicted to be catalytically inactive. Mutations expected to promote the open conformation caused enhanced activity in vitro and in vivo, and these results were recapitulated in EPs from the divergent pathogensNeisseria gonorrheaeandEscherichia coli. Our results suggest that LysM/M23 EPs are regulated via release of the inhibitory Domain 1 from the M23 active site, likely through conformational rearrangement in vivo.

scholarly journals Nutritional diversity of agricultural and agro-industrial by-products for ruminant feeding

2012 ◽  
Vol 64 (5) ◽  
pp. 1246-1255 ◽  
Author(s):  
J.A.G. Azevêdo ◽  
S.C. Valadares Filho ◽  
D.S. Pina ◽  
E. Detmann ◽  
L.G.R. Pereira ◽  
...  
Keyword(s):  
Crude Protein ◽  
Dry Matter ◽  
Energy Content ◽  
Neutral Detergent Fiber ◽  
Ether Extract ◽  
Nitrogenous Compounds ◽  
Fiber Digestibility ◽  
Nutritional Characteristics ◽  
By Products

Fifty-seven by-products were collected from regions throughout Brazil. Chemical composition, in vitro neutral detergent fiber digestibility (IVNDFD), and total digestible nutrients (TDN) were determined with the objective of grouping by-products with similar nutritional characteristics. The by-products belonging to group one (G1) presented the highest content of neutral detergent fiber exclusive of ash and nitrogenous compounds [aNDFom(n)] and lowest energy content, with 42.5% and 38.8% of IVNDFD and TDN, respectively. A new cluster analysis was carried in order to better characterize G2 by-products, six subgroups (SGs) were established (SG1 to SG6). SG1 by-products had the highest and the lowest values for lignin and TDN, respectively. SG2 by-products had the highest aNDFom(n) value, with TDN and IVNDFD values greater than 600 and 700g/kg, respectively, and crude protein (CP) value below 200g/kg in dry matter (DM). Among all the subgroups, SG3 had the highest TDN (772g/kg) and IVNDFD (934g/kg) values and the lowest lignin (23g/kg in DM) value. The ether extract was what most influenced the hierarchical establishment of residual grouping in SG4. SG5 by-products had the highest concentration of non-fibrous carbohydrate. Different from the other subgroups, SG6 by-products had the highest value of available CP.

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