In Vitro Digestibility of Barley Straw Treated with Sodium Hydroxide at Elevated Temperatures

1974 ◽  
Vol 17 (4) ◽  
pp. 0780-0782 ◽  
Author(s):  
S. L. Phoenix ◽  
W. K. Bilanski ◽  
D. N. Mowat
1970 ◽  
Vol 50 (3) ◽  
pp. 657-662 ◽  
Author(s):  
B. G. OLOLADE ◽  
D. N. MOWAT ◽  
J. E. WINCH

The response of roughages to sodium hydroxide (NaOH) treatment varied with type of roughage. Treatment with NaOH at 23 C for 24 hr increased in vitro dry matter digestibility (IVDMD) by 8,5, 39.6 and 21.5 percentage units for alfalfa stem, barley straw and corn stover, respectively. Increased IVDMD values were brought about, in part, by increased water solubility and decreased cell wall constituents. No significant changes occurred in acid detergent fiber, cellulose or lignin content. The IVDMD values of barley straw ranged from 38% at 0% NaOH to 81% with 12% NaOH at 130 C. At all temperatures and durations, IVDMD increased with increase in concentration of NaOH up to the 8% level. Above 8% NaOH, no further increase in IVDMD occurred. Temperature affected the rate as well as the extent of the response to NaOH. Treatments at 100 C for 90 min resulted in IVDMD values approximately 10 percentage units higher than at 23 C for 24 hr.


1972 ◽  
Vol 15 (6) ◽  
pp. 1091-1093 ◽  
Author(s):  
S. L. Phoenix ◽  
W. K. Bilanski ◽  
D. N. Mowat

Author(s):  
K. A. Khazaal ◽  
E. Owen ◽  
J. M. Palmer ◽  
A. P. Dodson ◽  
P. Harvey

To date, practical methods of improving the digestibility of straw are largely confined to treatment with alkalis (Sundstol and Owen, 1984). Though effective, these chemicals can be hazardous for on-farm use and are potential pollutants. Biological methods of upgrading straw using fungi or enzymes (Zadrazil, 1984) would be less hazardous and more acceptable if practical and economic techniques could be developed. The present experiment examined the potential of ligninase enzyme produced from the fungus Phanerochaete ohrysosporium for upgrading straws. The aim was to define treatment conditions required. Treatment with sodium hydroxide was included as a positive control. Treatment effects were assessed by measuring changes in digestibility in vitro and chemical composition.Seventy two treatments were compared. 10 g samples of milled (1.0 mm) straw were immersed (ambient temperature 15°C) in 100 ml buffered (pH 3.5) solution, with one of four levels of ligninase (zero; 0.1 unit/10 g straw; 1.0 unit; 10 units; one unit of enzyme oxidises 1 μmol veratryl alcohol to veratraldehyde per minute, at pH 2.75), with or without hydrogen peroxide (ligninase depends on H2O2 for its oxidative reaction), veratryl alcohol (used to induce the ligninase production and activity), or both of them.


1998 ◽  
Vol 78 (4) ◽  
pp. 673-679 ◽  
Author(s):  
A. El-Meadaway ◽  
Z. Mir ◽  
P. S. Mir ◽  
M. S. Zaman ◽  
L. J. Yanke

Three experiments were conducted to study the effects of substituting rumen fluid (RF) with faecal suspension (FS) as an inoculum for determination of in vitro dry matter digestibility (IVDMD, experiment 1) and gas production (exp. 2). Barley grain (BG), Persian clover (PC), alfalfa (ALF), bromegrass (BR) and barley straw (BS) were used to evaluate the efficacy of the two inocula. In exp. 1, IVDMD was determined using RF or FS containing 3, 6 and 9% fresh cattle faeces as inocula. Except for BS, IVDMD values obtained with either RF or FS containing 3% faeces were not different (P > 0.05). In contrast, FS containing 6 or 9% faeces resulted in lower (P < 0.05) IVDMD than those obtained with RF. Total VFA, butyric and valeric acids of in vitro supernatant were higher (P < 0.05) in RF than FS incubated buffers. Molar proportions of acetic and propionic acids were variable among feeds. Mean acetic:propionic ratio was similar (except for BG) for RF or FS. In exp. 2, substitution of RF with FS containing 6, 11 or 16% cattle faeces as inoculum generally resulted in an increased lag time for four feeds (PC was not included). The rate of gas production was lower when FS was used instead of RF for ALF and BR. For BG however, use of FS resulted in a higher (P < 0.05) rate of gas production than when RF was used. Total gas production values were similar within all the feeds regardless of the source of inoculum. In experiment 3, the relative size of the total and cellulolytic populations were higher for RF than for FS, with a greater diversity of genera of bacteria isolated from RF. Results from this study indicate that FS has the potential to be used instead of RF to obtain IVDMD and gas production for BG and forage hay but not for poor quality roughages such as BS. However, more research with FS is required to confirm these findings. Key words: IVDMD, gas production, rumen fluid, faecal suspension


1975 ◽  
Vol 21 (3) ◽  
pp. 313-322 ◽  
Author(s):  
M. C. N. Jayasuriya ◽  
Emyr Owen

SUMMARY1. Four experiments have been carried out to determine the effect of treatment of spring-sown barley straw (var. Deba Abed) with sodium hydroxide (NaOH) solution and subsequent neutralization with hydrochloric acid (HCl) on its digestibility and intake by sheep.2. In Experiment 1, chopped straw was mixed with 4·5 or 9·0 g NaOH in 200 or 800 ml water/100 g, straw, and after 24 hr neutralized with HCl and left for a further 24 hr before being offered to castrated male sheep (wethers) in a maintenance diet containing 35% concentrates. Organic-matter digestibility of straw significantly increased, by 8 and 11 percentage units respectively, after treatment with 200 ml solution containing 4·5 and 9·0 g NaOH. Volume of solution did not affect digestibility.3. In Experiment 2, straw treated as in Experiment 1 was given ad libitum. The highest intake was for straw treated with 200 ml solution containing 4·5 g NaOH/100 g straw, treatment with 9·0 g NaOH giving a significantly lower intake but higher than that of untreated straw.4. In Experiment 3, the in vitro digestibility of milled straw, treated as in Experiments 1 and 4, increased with increasing volumes of solution up to 120 ml/100 g straw, but the response to successive increments of NaOH declined progressively.5. In Experiment 4 chopped straw was mixed with 4·5, 6·75 or 9·0 g NaOH in 30, 60 or 120 ml water/100 g straw and offered as in Experiment 1. Treatments significantly increased straw digestibility, by 8 to 16 percentage units. Increasing the volume of water from 30 to 60 ml significantly improved digestibility, by 5 percentage units at the two lower levels of NaOH. The response to an increase in the level of NaOH was less, and inconsistent. In vitro and in vivo digestibilities were significantly correlated, but it is concluded that the in vitro technique used overestimates the digestibility of treated straw.


1989 ◽  
Vol 69 (4) ◽  
pp. 963-972 ◽  
Author(s):  
E. INNOCENTI ◽  
D. N. MOWAT ◽  
I. B. MANDELL

The effects of temperature, treatment time and levels of SO2 and NH3 on the in vitro digestibility and chemical composition of corn stover and barley straw were evaluated. Sulphur dioxide improved (P > 0.05) in vitro dry matter digestibility (IVDMD) and in vitro cell wall digestibility (IVCWD) of corn stover when treated at 70 °C for 24 h. However, high SO2 levels (4 and 6%) at higher temperature (90 °C) and for a longer time (72 h) reduced (P < 0.05) IVDMD and IVCWD and increased (P < 0.05) lignin content. When barley straw was treated with SO2 at 70 °C, IVDMD and IVCWD were greater (P < 0.05) when the treatment was carried out for 72 h than for 24 h. The improvement in in vitro digestibilities with SO2 was associated with solubilization of large amounts of hemicellulose. Ammonia treatment at 70 °C for 24 h reduced (P < 0.05) hemicellulose content and increased (P < 0.05) IVDMD and IVCWD as well as apparent lignin content. Suphuration enhanced the effect of ammoniation on IVDMD and IVCWD and reduced lignin content, but did not further reduce hemicellulose over NH3 alone in both crop residues. Improvements in in vitro digestibilities obtained with NH3 treatment followed by SO2 were associated with reductions of hemicellulose and lignin. Sulphur dioxide and NH3 treatment at 70 °C for 24 h produced a greater improvement in IVDMD and IVCWD in barley straw than in corn stover. Treatment with SO2 following ammoniation further increased (P < 0.05) NH3-N and sulphur contents of corn stover. Key words: Chemical treatment, sulphur dioxide, ammonia, corn stover, barley straw, chemical composition, in vitro digestibility


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