Effect of method of conservation on the n-alkane C31 concentration of two legumes and three temperate grasses

2006 ◽  
Vol 34 ◽  
pp. 79-85
Author(s):  
M.R. Reyes-Reyes ◽  
S. E. Buntinx ◽  
F. S. Barajas-Torres ◽  
I. C. Gavilán-García ◽  
F.A. Castrejón-Pineda

SummaryThe objective of this study was to compare five methods of forage preservation (ice, dry ice, liquid-N, drying in newspaper, and sundried) on the concentration of the n-alkane C31 in Medicago sativa cv Puebla 76 (lucerne/alfalfa), Trifolium repens latum (white clover), Lolium perenne (perennial ryegrass), Pennisetum clandestinum (kikuyu grass) and Dactylis glomerata (orchardgrass/cocksfoot). The sampled forages in ice and dry ice were kept in hermetically sealed plastic bags in a plastic cooler. The deep frozen samples were put into small plastic bags and submerged in liquid-N. The samples dried in newspaper were placed between sheets of newspaper, and put into hermetically sealed plastic bags. All these samples were taken to the laboratory and freeze-dried approximately 24 h later. The sun-dried samples were taken to the laboratory in newspaper and sun-dried for 48 h. The forage samples were ground and worked on in triplicate, extracted by the Soxhlet method (C34 n-alkane was used as standard and n-heptane as solvent), saponified, separated, purified and injected into a gas chromatograph. The data were analysed for variance as a randomised factorial (n=74). The comparison between means was by the Boneferroni test (P<0.05). The interaction between forage and method of conservation was significant P<0.0001). There were no differences between methods of conservation for white clover (mean 26mg C31/kg DM) or orchardgrass/cocksfoot (mean 31 mgC31/ kgDM). In comparison with liquid-N, (261 mgC31/kgDM), the other methods reduced the concentration of n-alkane in kikuyu grass by 27-35%. Sun and newspaper dried samples increased the concentration of C31 in alfalfa/lucerne by 6 and 15% respectively in comparison with freezing with liquid-N (291 mgC31/kgDM), while that frozen on ice reduced C31 by about 8%. This method, however, increased the ryegrass n-alkane by 12% in relation to liquid-N (169 mgC31/kgDM), but sun drying reduced it by about 40%. It is concluded that drying in liquid-N is the most reliable method for the conservation of samples for n-alkane analysis.

Author(s):  
B. D. Athey ◽  
A. L. Stout ◽  
M. F. Smith ◽  
J. P. Langmore

Although there is general agreement that Inactive chromosome fibers consist of helically packed nucleosomes, the pattern of packing is still undetermined. Only one of the proposed models, the crossed-linker model, predicts a variable diameter dependent on the length of DNA between nucleosomes. Measurements of the fiber diameter of negatively-stained and frozen- hydrated- chromatin from Thyone sperm (87bp linker) and Necturus erythrocytes (48bp linker) have been previously reported from this laboratory. We now introduce a more reliable method of measuring the diameters of electron images of fibrous objects. The procedure uses a modified version of the computer program TOTAL, which takes a two-dimensional projection of the fiber density (represented by the micrograph itself) and projects it down the fiber axis onto one dimension. We illustrate this method using high contrast, in-focus STEM images of TMV and chromatin from Thyone and Necturus. The measured diameters are in quantitative agreement with the expected values for the crossed-linker model for chromatin structure


Author(s):  
Lucia Maria Jaeger de Carvalho ◽  
Bruno Paranhos ◽  
Edgar Francisco Oliveira de Jesus ◽  
José Luiz Viana de Carvalho

Aims: The aim of this work was to evaluate the optimal radiation dose to maintain the antioxidant capacity of conventional and organic acaí freeze-dried pulps. Study Design: All analyses were conducted in sextuplicate for each experiment. Place and Duration of Study: Were conducted at the LATAIA and the irradiation processes at the Laboratory of Nuclear Instrumentation, UFRJ, Rio de Janeiro, Brazil. The study was carried out from July, 2018 to March, 2020. Methodology: Frozen acaí pulps from two commercial brands, one of them organic and other conventional were used and purchased in the city of Rio de Janeiro, packed in plastic bags containing 1 kg. For each brand, frozen pulps (5 kg) were thawed at 4ºC, opened and homogenized. Samples were subdivided into aliquots ranging from 20 to 300 g for the assays and frozen inside the plastic bags until analyses. A Cobalt 60, Gammacell irradiator was used and doses of 1.25. 2.5. 3.75 and 5 kGy were applied in the in natura pulps. Antioxidant capacity was performed by the ORAC and DPPH methods and, phenolic compounds by Folin Ciocalteau method and, total anthocyanins and majority anthocyanidins by HPLC. Results: Anthocyanins increases at irradiaton dose up to 3.75 kGy in organic açaí but it was not significant in conventional acaí irradiated at low doses (1.25 to 3.75 kGy). Our results suggested that irradiation doses up to 5 kGy do not decrease total phenolic or anthocyanin contents nor the pulp antioxidant activity compared with non-irradiated pulps. The results showed irradiation did not reduce these analytes, and even increased in the organic acaí. Conclusion: The study evidenced that gamma irradiation can be an alternative safe process for fruit pulps preservation. We conclude that irradiation doses up to 5 kGy can be used in acaí without harming its antioxidant properties.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 77-77
Author(s):  
Kathy J Soder ◽  
Eric D Billman ◽  
Jeff Horst ◽  
Kristi Balk ◽  
Aimee Hafla

Abstract This study correlated Brix values (measure of total dissolved solids via refractometer) with wet-lab analyses (WLA) of sugar concentrations in fresh herbage of two forage species, alfalfa (ALF; Medicago sativa) and orchardgrass (ORG; Dactylis glomerata) to estimate energy value of pastures. Four monthly samplings occurred from May-August, 2019. At each sampling, eight ALF and ORG samples were collected from established monocultures of each species. Solubles were extracted from fresh herbage using a hand-held garlic press. Triplicate Brix readings were recorded per sample using a digital refractometer. Fresh herbage samples were flash-frozen in liquid N, freeze-dried, and analyzed via WLA for total and individual (glucose and fructose) sugar concentrations, as well as nutritive value (CP, NDF, and ADF; Agri-King, Inc., Fulton, IL). The TDN, RFV, and RFQ were calculated. Brix values were correlated with WLA using the PROC CORR procedure in SAS, with significance established at P &lt; 0.05 and trends at 0.05 &lt; P &lt; 0.10. Brix values were negatively correlated (P &lt; 0.001) with WLA of total sugars (-0.65), glucose (-0.6), and fructose (-0.68) in ORG while no significant correlations (P &gt; 0.10) were detected in ALF. Conversely, Brix values of ORG and ALF were positively correlated (P &lt; 0.01) with NDF (0.57 – 0.58) and hemicellulose (0.42 – 0.55), as well as with ADF in ALF (0.54). Brix was negatively correlated (P &lt; 0.05) with CP in ALF (-0.41), but there was no correlation (P &gt; 0.10) with ORG. No correlations (P &gt; 0.10) were detected between Brix and TDN, RFV, and RFQ. These results indicate that the Brix index does not directly translate to forage quality, particularly sugar concentrations, of ALF and ORG, and may inadvertently select herbage with increased fiber concentrations. Producers should consider more accurate methods, such as WLA, for assessing energy value of pastures.


1974 ◽  
Vol 14 (67) ◽  
pp. 161 ◽  
Author(s):  
PJ Michell

The total concentration and the relative proportions of the volatile fatty acids (VFA) were measured in rumens of sheep fed 78 single species pasture samples. The pastures consisted of regrowths of white clover (Trifolium repens cv. Grasslands Huia), Manawa regrass (Lolium perenne x multiflorum cv. Grasslands Manawa), Ariki ryegrass (Lolium (multiflorum x perenne) x L. perenne cv. Grasslands Ariki), perennial ryegrass (Lolium perenne cv. Tasmania No. 1) , Currie cocksfoot (Dactylis glomerata cv. Currie) and Apanui cocksfoot (Dactylis glomerata cv. Grasslands Apanui), cut eight times between May, 1969 and August, 1970. Sheep fed cocksfoot had lower VFA concentrations, higher proportions of acetate (HAc) and lower proportions of butyrate (HBu) than sheep fed white clover and ryegrass (P < 0.05). They also had lower proportions of propionate (HPr) than sheep fed ryegrass (P < 0.05). Sheep fed white clover had higher proportions of valerate (HVa) than those fed the grasses (P < 0.05). There were no significant (P < 0.05) seasonal differences in total VFA concentration but HAc was lowest with spring pasture (P < 0.05) and HBu was lowest with autumn pasture (P < 0.05). Total VFA concentration was positively related to digestibility (DMD) (r = +0.52, P < 0.01) but species differences occurred and at similar DMD, white clover produced higher concentrations than ryegrass (P < 0.05) which produced higher concentrations than cocksfoot (P < 0.01). The overall relation between total VFA and intake (DMI) was weak but seasonal differences occurred and at similar levels of DMI, winter pasture produced higher VFA concentrations than spring-summer pasture (P < 0.01). The proportion of HPr was positively related to VFA concentration (r = +0.53, P < 0.01) and to water soluble carbohydrate (WSC) content (r = +0.51, P < 0.01) and relations with DMD and DM1 were weak and non-significant (P > 0.05).


1980 ◽  
Vol 7 (1) ◽  
pp. 101 ◽  
Author(s):  
DO Huett ◽  
RC Menary

The aluminium distribution in transverse sections of fractured and freeze-dried roots of cabbage, lettuce and kikuyu grass was studied by energy-dispersive X-ray analysis. The mean ratios of the integrated counts corresponding to Kα emission spectra for aluminium, phosphorus and silicon were recorded between aluminium and control treatments over three experiments. Peak-to-back- ground ratios (PA/B) were calculated and the aluminium ratios corrected for variations in the corresponding total silicon ratios. Aluminium was found to be uniformly distributed along roots of the three species. The highest peaks (PA) and peak-to-background ratios, suggesting higher concentrations, were recorded in the epidermis followed by the cortex. Aluminium was recorded in the stele of all species and in the protoplasm of cortical cells, with smaller amounts in the protoplasm of xylem parenchyma cells for lettuce and kikuyu grass. The distribution of aluminium supports the hypothesis that its entry to the stele can be achieved by transport both into meristematic cells and the symplasm via the cortex and hence bypassing the barrier at the endodermis. The latter evidence was supported by the presence of aluminium in the radial wall (and cytoplasm) of the endodermis for each species. There was a poor correlation between the distribution of aluminium and phosphorus.


1993 ◽  
Vol 121 (3) ◽  
pp. 315-321 ◽  
Author(s):  
J. Fraser ◽  
K. Sutherland ◽  
R. C. Martin

SUMMARYWhite clover (Trifolium repens L.) is well adapted to the cool moist climate of Atlantic Canada, where it improves digestibility and protein content in pastures, but little is known about its role in pasture stockpiled for autumn grazing in this region. The objectives of this study were to determine the effect of autumn harvest dates on dry matter yield and clover content in herbage mixtures. Two experiments conducted in Nova Scotia between 1985 and 1991 on two different soil types showed that the effects of autumn harvest dates were inconsistent from year to year. Herbage growth rates ranged from 11 to 41 kg/ha per day between early September and mid-October. Clover content was generally lower in August–early September than in November harvests and declined in subsequent years irrespective of harvest date or forage species. Kersey White and Sonja white clovers were the highest yielding cultivars. Crude protein declined in late autumn harvests whereas acid detergent fibre tended to increase, and there were differences between years. Forage quality was significantly better in tall fescue (Festuca arundinacea Schreb.) than orchardgrass (Dactylis glomerata L.)/white clover mixtures.


Author(s):  
R.A. Moss ◽  
R.N. Burton ◽  
B.E. Allan

Grasslands Kara cocksfoot, Grasslands Nui ryegrass, Grasslands Roa tall fescue, Grasslands Gala grazing brome and Grasslands Maru phalaris were sown as single grass species with either white or Caucasian clover during December 1993, on a Lismore stony silt loam in Canterbury. Plots were irrigated and rotationally grazed by sheep. Total herbage produced during the first measurement period (September 1994 to July 1995) averaged 13.6 t DM/ha. All white clover-based swards produced similar yields, but with Caucasian clover, phalaris-based swards produced the most and ryegrass and grazing brome the least. Production tended to be lower from pastures sown with Caucasian than white clover (12.9 cf. 14.2,kg DM/ha). During the second measurement period (July 1995 to May 1996) total production was similar with both legumes. When evaluated over both measurement periods, phalaris and tall fescue gave the highest and cocksfoot and ryegrass the lowest production when sown with white clover, while cocksfoot and grazing brome were the lowestproducing swards with Caucasian clover. Ten --months-after-sow.ing,-white-cIover-contributed-in excess of40% of the DM in all swards except with ryegrass and grazing brome where it contributed 20%. The proportion of white clover then declined in all pastures over the following 20 months, ryegrass-based swards having the highest (10%) and cocksfoot the lowest (1%). When sown with Caucasian clover the legume content of swards increased during the 12 months from spring 1994 in swards containing phalaris, tall fescue and grazing brome. The proportion of legume in -cocksfoot swardsmdeclined-continuously from 22 to 4% over the 20 months while it increased continuously from 4 to 28% with ryegrass. The legume content in lo-month-old pastures was higher when sown with white than with Caucasian clover but this ratio was reversed by 28 months. This occurred with all pasture types but was most pronounced with ryegrass and cocksfoot pastures. The present experiment shows Caucasian clover can make a major contribution in irrigated pastures in Canterbury. 'Wattie Bush, RD 22, Peel Forest, Geruldine Keywords: Bromus stamineus, Dactylis glomerata, Festuca arundinacea, grazed pastures, herbage production, Lolium perenne, Phalaris aquatica, Trifolium ambiguum, Trifolium repens


1973 ◽  
Vol 13 (61) ◽  
pp. 165 ◽  
Author(s):  
PJ Michell

Neutral detergent fibre (NDF), acid detergent fibre (ADF) and water soluble carbohydrate (WSC) levels were determined on 80 samples of known apparent dry matter digestibility (DMD) and voluntary intake of dry matter (DMI). The pastures consisted of regrowths of six species: Trifolium repens (white clover cv. Grasslands Huia), Lolium perenne x L. multiflorum (short rotation ryegrass c.v Grasslands Manawa), Lolium perenne (long rotation ryegrass cv. Grasslands Ariki), Lolium perenne (perennial ryegrass cv. Tasmania No. I), Dactylis glomerata (cocksfoot cv. Currie) and Dactylis glomerata (cocksfoot cv. Grasslands Apanui), cut eight times between May 1969 and August 1970. Overall, white clover had a lower NDF and a lower WSC content than the ryegrasses but both groups had similar ADF contents. Cocksfoots had higher NDF and ADF, and lower WSC contents than the ryegrasses. NDF and ADF could be used to predict the DMD of all species in all seasons with residual standard deviations (RSD) of 3.0 and 3.2 DMD units (per cent) respectively. No significant relations (P < 0.05) were present between DMD and WSC content. Seasonal differences were present in the relations between DMI and chemical composition. The RSD of the overall regressions of intake with NDF, ADF, and WSC contents were 9.3, 9.4, and 8.9 DMI units (g/day/kg0.75) respectively. Within seasons, DMI was best predicted by regressions with detergent fibre content and here the RSD had a range of 3.4 to 5.2 DMI units. Within species over all seasons, DMI was predicted best by regressions with WSC content and the RSD had a range of 5.7 to 7.9 DMI units. The usefulness of the chemical composition measurements in explaining the reason for the low intakes, previously found with winter pasture, is discussed.


1973 ◽  
Vol 13 (61) ◽  
pp. 158 ◽  
Author(s):  
PJ Michell

Pure species swards of Trifolium repens (white clover cv. Grasslands Huia), Lolium perenne (perennial ryegrass cv. Tasmanian No. I ) , Lolium perenne x L. multiflorum (short rotation ryegrass cv. Grasslands Manawa), Lolium perenne (long rotation ryegrass cv. Grasslands Ariki), Dactylis glomerata (cocksfoot cv. Currie) and Dactylis glomerata (cocksfoot cv. Grasslands Apanui) were mechanically cut in May, August, September-October, and November 1969, and January, March, May, and August 1970. The material from these cuts was artificially dried, and digestibilities and voluntary intakes measured using penned sheep. Overall, the digestibility and voluntary intake of white clover was significantly higher (P < 0.05) than that of any of the grasses, the digestibility of Apanui cocksfoot was significantly lower (P < 0.05) than that of the ryegrasses and there were no significant differences (P < 0.05) between the intakes of the various grasses. Under the management system used, the digestibility of the grasses remained relatively stable over the summer, autumn and winter, rose to a peak in early spring and fell in late spring after ear emergence. The digestibility of white clover remained high over the winter and early spring and declined slowly over the summer. The voluntary intakes of all the species were at their lowest levels in the winter, rose to a peak in the spring, fell in the late spring to a stable level over the summer, and fell again in the autumn. At any digestibility level, the intake of spring-summer cut pasture was approximately 20 per cent higher than that of winter cut pasture. The intake of autumn cut pasture was intermediate. The overall relation between intake (I) and digestibility (D) was I = 1.06D + 2.7 � 8.4 (P < 0.01). Within the spring-summer cuts, the relation was I = 1.01 D + 14.6 � 4.0 (P < 0.01) and within the winter cuts it was I = 1.08D - 5.9 � 4.1 (P < 0.01).


1974 ◽  
Vol 14 (66) ◽  
pp. 33 ◽  
Author(s):  
PJ Michell

Gross energy levels and energy digestibilities were determined on 80 single species pasture samples of known dry matter digestibility. Crude protein, ash and ether extract levels were also determined. The pastures consisted of regrowths of six species, Trifolium repens (White clover cv. Grasslands Huia), Lolium perenne x multiflorum (manawa ryegrass cv. Grasslands Manawa), Lolium (multiflorum x perenne) x L. perenne (ariki ryegrass cv. Grasslands Ari ki), Lolium perenne (perennial ryegrass cv. Tasmanian No. 1), Dactylis glomerata (currie cocksfoot cv. Currie) and Dactylis glomerata (apanui cocksfoot cv. Grasslands Apanui), harvested eight times between May 1969 and August 1970. The gross energy levels in pasture dry matter and pasture digestible organic matter were highest with white clover (means 4.64 and 4.98 K cal g-1) and lowest with the ryegrasses (4.50 and 4.80 K cal g-1). They were also higher in the winter (4.60 and 4.91), autumn (4.53 and 4.90) and spring (4.56 and 4.86), and lower in the summer (4.49 and 4.77). Relations between gross energy levels and chemical composition were weak. The strongest relation was with crude protein content (r = +0.41, P < 0.01). Relations of energy digestibility and digestible energy level in pasture dry matter, with dry matter digestibility had high correlations (r = +0.97, P < 0.01, and r = +0.92, P < 0.01) and were similar to previously published relations. However, seasonal differences occurred in both relations and, at low dry matter digestibilities, winter pasture had higher energy digestibilities and higher levels of digestible energy than spring-summer pasture. Species differences occurred in the latter relation and, at high dry matter digestibilities, white clover had higher levels of digestible energy than the grasses.


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