Chemical changes and respiratory drift during the air drying of ryegrass

Melvin, Jean F.; Simpson, Beulah

doi:10.1002/jsfa.2740140404

Cited by 27 publications

(12 citation statements)

References 13 publications

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“…The extent of loss of water-soluble carbohydrates due to respiration was similar to that found by other workers (Wylam, 1953;Melvin and Simpson, 1963;Carpintero et al, 1969). The loss was mainly as sucrose and fructan.…”

Section: Discussionsupporting

confidence: 90%

The influence of the carbohydrate fraction and additives on silage quality

Pettersson

Lindgren

1990

Grass and Forage Science

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Respiration losses, effect of sugar content, formic acid addition and inociilation were evaluated in relation to initial fermencation and silage quality in three experiments. Changes in the content of fermentable substrate during post-harvest respiration and initial fermentation were studied in the laboratory. Soluble carbohydrates were estimated as glucose, fructose, sucrose, fructans and starch by an enzymatic method.About 70*70 of the sugars remained after 30 h of conventional wilting, as opposed to less than 50% in a chopped sample kept in the dark. During the first days of fermentation the metabolic activity was very intensive. Sugars, which accounted for lOi^^o of the dry matter, were fermented within 4 d. There were indications, mainly in clover silages, that substances other than water-soluble carbohydrates were used as energy sources.Low-sugar crops were obtained by shading the fields. After 3 d the sugar in the grass had decreased to half of the original content. This effect was less pronounced in clover. The amount of available substrate and dry matter (DM) content had a major influence on silage quality. In an unwilted crop at least 25 g of water-soluble carbohydrate was needed per kg of fresh material to obtain an acceptable silage Correspondence; Mr K, Lurden Petiersson, Swedish University of Agricultural Sciences, Departmeni of Animal Nuiriiion and Management, Kungsangens gSrd. S-75323, Uppsala, Sweden;quality in the controls, while 20 g was sufficient in inoculated silage. Formic acid addition makes the fermentation less sensitive to water-soluble carbohydrate content. Inoculation of willed silage increased lactic acid production and decreased the pH. There was also less variation in silage quality.

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Section: Discussionsupporting

confidence: 90%

The influence of the carbohydrate fraction and additives on silage quality

Pettersson

Lindgren

1990

Grass and Forage Science

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“…However, although the respiratory losses in terms of DM are relatively small, they nevertheless assume importance when expressed in terms of w.s.c. Wylam (94) 64) have reported that fructan and fructose contents decrease almost continuously throughout the drying period and that sucrose levels decrease initially but then increase.…”

Section: The Field Stagementioning

confidence: 98%

A Review of the Effects of Oxygen on Ensilage

Ruxton¹,

Clark²,

McDonald³

1975

Grass and Forage Science

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“…Previous investigations (1,5,6,11) into the drying of herbage have attempted to evaluate the various factors that influence the rate of drying. The more important variables include: species or variety; maturity stage; respiration rate and therefore DM loss; method of harvesting, i.e.…”

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confidence: 99%

Investigations on the Drying of Herbage at Temperatures Up to 50°c*

Rees

1974

Grass and Forage Science

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Experiments to detemiine the exposed layer drying rate of cut leaves and stems of a tetraploid (Sabel) and diploid (S23) ryegrass are described. Drying was achieved by passing air through the crop; the changes in weight were monitored continuously. Airflow was fixed throughout the experiments at 37-5 ft/min (0-190 m/s) and the temperatures were controlled in the range ZS^C to 50°C. Comparisons were also made of the drying rates at different stages of maturity. Drying curves were determined and moisture content was shown to decay exponentially with time, the relationship approximating closely to a two term exponential. INTRODUCnONPrevious investigations (1, 5, 6, 11) into the drying of herbage have attempted to evaluate the various factors that influence the rate of drying. The more important variables include: species or variety; maturity stage; respiration rate and therefore DM loss; method of harvesting, i.e. whether the crop is to be dried whole, chopped or lacerated; the degree of wilting; the moisture content at the start of drying. In general, workers (3, 4, 12) have tended to use relatively large amounts of material which have either been allowed to dry under controlled conditions in a chamber or by being subjected to various airflows of known temperature and speed. Apart from requiring large quantities of homogeneous material these techniques cause differential drying within the mass and consequently the formation of a moisture gradient from the outer to the inner layers.*For a list of the symbols used in this paper, see page 55.To avoid these restricting factors and to ensure that the water holding capacity of the air was never a limiting factor the technique of drying in thin-layers was adopted (1,7, 13); a thin layer being one in which the moisture content gradient in depth and over the cross-sectional area during drying is negligible. Data produced by this technique could be used to predict drying rates under different conditions experienced in barn dr>'ing of hay, to compare the effect of various crop treatments on the drying rate, and to simulate, with a computer, deep-layer drying. Various aspects of herbage drying using the thin-layer techniques have been investigated. Tuncer (13) investigated the drying behaviour of certain grasses (including ryegrass and timothy) and the effect on the drying rate of chop length and the humidity and temperature of the drying air. No attempt was made to evaluate a relationship between the rate of drying and drying conditions, and discussion on the rate of drying did not include the possible effects of maturity and initial moisture content. EXPERIMENTAL Crops. Two strains of ryegrass, S23 which is a diploid perennial and Sabel which is a tetraploid hybrid between perennial and Italian, were dried. An estimate of stage of growth was obtained from plant size as recorded in Table 1; enabling the efFect of maturity to be investigated and also to compare the drying rates of each cultivar. Apparatus. The apparatus has been described previously (9) and consists of eight d...

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Chemical changes and respiratory drift during the air drying of ryegrass

Cited by 27 publications

References 13 publications

The influence of the carbohydrate fraction and additives on silage quality

The influence of the carbohydrate fraction and additives on silage quality

A Review of the Effects of Oxygen on Ensilage

Investigations on the Drying of Herbage at Temperatures Up to 50°c*

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