Losses of the digestible components of annual ryegrass (Lolium rigidum Gaudin) during senescence

Changes in the digestibility and chemical composition of a L. rigidum cv. Wimmera sward sown in May, 1985 were measured from 21 d pre-anthesis (9 Oct.) until 69 d after anthesis (7 Jan.) when the plants were dead. Max. yield of 11.7 t DM/ha was reached 8 d pre-anthesis. The in vitro DM digestibility (IVDMD) of whole plants decreased from 58% at anthesis to 36% 69 d after anthesis. This was associated with a decrease in the IVDMD of stem, leaf blades and sheaths. In the 3rd stem internode, which was considered representative of the stem, the loss of digestible yield was due to loss of DM soluble in neutral detergent (NDS). The NDS consisted mainly of non-structural carbohydrates. Similar losses of NDS contributed to loss of digestibility in the uppermost leaf blade and leaf sheath. The digestibility of NDS was generally 80-95% but in the leaf blade this declined to 45% as NDS was mobilized during leaf senescence. NDF digestibility of the stem declined from 35% at anthesis to 19% when dead; corresponding values for the uppermost leaf blade were 83 and 54%, resp., and for the leaf sheath 46 and 37%, resp. These characteristics of a senescing grass sward are discussed in relation to options for improving digestibility of dead grass pastures.

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Varietal differences in the chemical composition and in vitro digestibility of rice straw

The Journal of Agricultural Science ◽

10.1017/s0021859600071513 ◽

1992 ◽

Vol 119 (1) ◽

pp. 27-33 ◽

Cited By ~ 18

Author(s):

J. Vadiveloo

Keyword(s):

Cluster Analysis ◽

Chemical Composition ◽

Rice Straw ◽

Leaf Blade ◽

Relative Proportion ◽

Leaf Sheath ◽

The Other ◽

In Vitro Digestibility ◽

Stem Leaf

SummaryFour varieties of rice straw, MRl, MR71, MR84 and MR27, were separated into the following botanical fractions; inflorescence, stem, leaf blade and leaf sheath. The relative proportion of each fraction in whole straw was estimated and analysed for its chemical composition and in vitro digestibility (IVD). The composition and IVD of whole straw was then calculated. Cluster analysis showed that MRl was distinct from the other varieties. This could be attributed to a high proportion of stem (32·3%), high IVD (36·9%), low insoluble ash (4·0%) and a low silica content (2·7%) in the whole straw. The genetic distance between any two varieties ranged from 5·4 × 10-3 to 47·8 × 10-3 and was largest between MRl and the other varieties. Cluster analysis also showed that within a variety, the chemical composition and IVD of the stem, leaf blade and leaf sheath were similar, suggesting that sampling errors may be reduced if the inflorescence, which comprises 7–13% of the whole straw, is excluded when the material is analysed. Stepwise and canonical discriminant analyses indicated that the important variables to be measured when comparing straw varieties were IVD, crude protein and insoluble ash.

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Using near infrared reflectance spectroscopy to estimate the nutritive value of senescing annual ryegrass (Lolium rigidum): a comparison of calibration methods

Australian Journal of Experimental Agriculture ◽

10.1071/ea97067 ◽

1998 ◽

Vol 38 (1) ◽

pp. 45 ◽

Cited By ~ 10

Author(s):

K. F. Smith ◽

R. J. Simpson ◽

R. D. Armstrong

Keyword(s):

Leaf Blade ◽

Nutritive Value ◽

Near Infrared ◽

Leaf Sheath ◽

Plant Part ◽

Annual Ryegrass ◽

Lolium Rigidum ◽

Near Infrared Reflectance ◽

Calibration Methods ◽

Calibration Equations

Summary. The suitability of near infrared reflectance (NIR) spectroscopy for predicting the concentration of several quality traits in samples of annual ryegrass (Lolium rigidum Gaud.) herbage was assessed in 2 separate experiments. In the first experiment, NIR calibration equations were developed for 6 traits (water-soluble carbohydrates, dry matter digestibility, neutral detergent solubles, neutral detergent solubles digestibility, neutral detergent fibre digestibility and nitrogen) using 4 calibration methods. No significant differences were found in the accuracy of NIR equations developed using either stepwise multiple linear regression (SMLR) or partial least squares regression (PLS) techniques when the equations were used to predict the concentration of constituents in those samples not used during the calibration process. The process of removing samples identified by the computer as spectral outliers was found to improve those statistics that related NIR data to the reference data of the samples used during calibration development (i.e. improved the goodness of fit of the regressions). However, when the resulting equations were used on all of the samples there was no improvement in the accuracy of the prediction of composition, and the estimates were less accurate for 2 of the equations. In the second experiment, plant part-specific equations (leaf blade, stem and leaf sheath) were developed. The specific equations were found to be no more accurate than those developed using a subset of all samples when used to analyse samples of the same plant part. However, using equations developed on either stem or leaf sheath samples to predict the composition of leaf blade samples led to inaccurate estimates of composition, illustrating the potential for error when NIR calibration equations are used on dissimilar samples. The similarity of the NIR estimates of decline in nutritive value and those obtained using reference analyses was illustrated by plotting the actual and predicted decline in nutritive value. The results of the experiments in this paper illustrate the need to monitor the accuracy of any NIR prediction of nutritive value. Striving for very low standard errors of calibration either by eliminating outliers or by limiting the plant tissues used during calibration did not lead to more accurate predictions of the composition of samples other than those used during the calibration process.

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Selecting for nutritive value in Digitaria milanjiana. 3. Relation of chemical composition and morphological and anatomical characteristics to the difference in digestibility of divergently selected full sibs, and comparison with D. eriantha ssp. pentzii

Australian Journal of Experimental Agriculture ◽

10.1071/ea9910631 ◽

1991 ◽

Vol 31 (5) ◽

pp. 631 ◽

Cited By ~ 7

Author(s):

Y Masaoka ◽

JR Wilson ◽

JB Hacker

Keyword(s):

Chemical Composition ◽

Leaf Blade ◽

Dry Matter ◽

Nutritive Value ◽

Morphological Characteristics ◽

Cell Types ◽

Leaf Sheath ◽

Anatomical Characteristics ◽

Dry Matter Digestibility ◽

The Difference

Comparisons were made of the dry matter digestibility (DMD) and yield of plant fractions harvested from long-established swards of 6 genotypes of Digitaria milanjiana selected from 3 F1 families for high and low leaf digestibility, and D. eriantha ssp. pentzii (pangola grass). Defined leaf blade, sheath and stem internode fractions were collected at different sward development stages and analysed for DMD, chemical composition, and tissue morphological and anatomical characteristics. The leaf blade of each high-digestibility genotype was consistently superior (1.9-4.5 percentage units) in DMD to that of its low digestibility counterpart, and to pangola grass, at both vegetative and reproductive -- stages. For leaf sheath and stem, the superiority in DMD of the high digestibility group was not evident or was less pronounced. The high DMD selections had green leaf dry matter yields comparable to those of the low DMD group but higher than those of pangola grass. The gain in DMD for leaf blade of the high over the low digestibility selection was consistently correlated with a decrease in cell wall content, acid detergent fibre or lignin, and poorly correlated with other chemical and leaf morphological characteristics. High and low DMD genotypes did not differ in the proportion of cell types in leaf or stem, or in other measured anatomical characteristics.

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Developing a Petri dish test to detect resistance to key herbicides in Lolium rigidum

10.1101/2021.04.08.438914 ◽

2021 ◽

Author(s):

Martina Badano Perez ◽

Hugh J Beckie ◽

Gregory R Cawthray ◽

Danica E Goggin ◽

Roberto Busi

Keyword(s):

Weed Management ◽

Technology Use ◽

Petri Dish ◽

Resistance Testing ◽

Annual Ryegrass ◽

Lolium Rigidum ◽

Management Interventions ◽

Wide Range ◽

Whole Plants ◽

On Farm

AbstractOverreliance on herbicides for weed control is conducive to the evolution of herbicide resistance. Annual ryegrass (Lolium rigidum Gaud.) is a species that is prone to evolve resistance to a wide range of herbicide modes of action. Rapid detection of herbicide-resistant weed populations in the field can aid farmers to optimize the use of herbicides for their control. The feasibility of a portable agar-based test to rapidly and reliably detect annual ryegrass resistance to key herbicides such as clethodim, glyphosate, pyroxasulfone and trifluralin on-farm was investigated. The three research phases of this study show that: a) easy-to-interpret results are obtained with non-dormant seed from well-characterised susceptible and resistant populations, and resistance is detected as effectively as with traditional dose-response pot-based resistance assays. However, the test may not be suitable for portable use on-farm because of b) the low stability of some herbicides such as trifluralin and clethodim in agar and c) the tendency of seed dormancy in freshly-harvested seeds to confound the results. The agar-based test is best used as a research tool as a complement to confirm results obtained in traditional pot-based resistance screenings. Comprehensive agar test and / or whole-plant resistance tests by herbicide application at the recommended label rate (whole plants grown in pots) are the current benchmark for proactive in- and off-season resistance testing and should be promoted more widely to allow early detection of resistance, optimization of herbicide technology use and deploy appropriate weed management interventions.

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Production of corynetoxins in vitro by Corynebacterium sp. isolated from annual ryegrass seedheads

Australian Journal of Agricultural Research ◽

10.1071/ar9880063 ◽

1988 ◽

Vol 39 (1) ◽

pp. 63 ◽

Cited By ~ 3

Author(s):

AL Payne ◽

PA Cockrum

Keyword(s):

Incubation Temperature ◽

Annual Ryegrass ◽

Lolium Rigidum ◽

In Vitro Production ◽

The Family ◽

Agar Surface ◽

Vitro Production ◽

Corynebacterium Sp ◽

Annual Ryegrass Toxicity

Corynetoxin complex is the family of tunicamycin-like antibiotics isolated from annual ryegrass (Lolium rigidum) seedheads infected with a plant pathogenic Corynebacterium and identified as the causative toxins for annual ryegrass toxicity (ARGT) in Australia. Only trace amounts of corynetoxins have been reported to be produced in vitro. Enhanced in vitro production of corynetoxins by Corynebacterium sp. has now been demonstrated. The important conditions required were growth on an agar surface, absence of light, low incubation temperature and strain of the organism. Strains of the Corynebaterium sp. grown under conditions not supporting corynetoxin production failed to produce corynetoxins when subsequently grown under more favourable conditions. Even when maintained under the most favourable conditions, toxigenicity of strains declined on repeated subculturing. While levels of toxin typically produced in vitro were only about 5% of those found in infected ryegrass seedheads, they were high enough to be a useful source of corynetoxins for experimental purposes.

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EFFECTS OF DATES OF SEEDING AND LEVELS OF N FERTILIZATION ON YIELDS, CHEMICAL COMPOSITION AND IN VITRO DIGESTIBILITY OF FORAGE KALE

Canadian Journal of Plant Science ◽

10.4141/cjps76-011 ◽

1976 ◽

Vol 56 (1) ◽

pp. 63-70 ◽

Cited By ~ 8

Author(s):

G. PELLETIER ◽

J. P. F. DARISSE ◽

E. DONEFER

Keyword(s):

Chemical Composition ◽

Brassica Oleracea ◽

Crude Protein ◽

Dry Matter ◽

N Fertilization ◽

In Vitro Digestibility ◽

Whole Plants ◽

Different Levels ◽

Brassica Oleracea L

Forage kale (Brassica oleracea L.) was seeded on three dates and fertilized at different levels of N as NH4NO3 for 3 yr. The highest dry matter (DM) yield was obtained with the earliest date of seeding and with levels of N fertilization of 120 kg/ha. The yield of crude protein (CP) was relatively constant among years, for the different dates of seeding and for N fertilization above 120 kg/ha. Increasing N fertilization or delaying seeding increased the leaf:stem ratio, and consequently the CP content. The levels of NO3-N in stems, leaves and whole plants were at an acceptable level for safe feeding. The cellulose, crude fiber, Ca and P contents were not affected greatly either by the dates of seeding or by the levels of N fertilization. The in vitro DM digestibility (IVDMD) was not affected markedly by any treatment.

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Corynetoxins are not detoxicated by in vitro fermentation in ovine rumen fluid

Australian Journal of Agricultural Research ◽

10.1071/ar9860523 ◽

1986 ◽

Vol 37 (5) ◽

pp. 523 ◽

Cited By ~ 2

Author(s):

P Vogel ◽

MG McGrath

Keyword(s):

Rumen Fluid ◽

Annual Ryegrass ◽

Inhibition Assay ◽

Lolium Rigidum ◽

In Vitro Fermentation ◽

Bacterial Inhibition ◽

Annual Ryegrass Toxicity

Tunicamycin and seed galls of annual ryegrass (Lolium rigidum) containing corynetoxins, the causal agents of annual ryegrass toxicity, were incubated in ovine rumen fluid-buffer mixtures. A bacterial inhibition assay of extracted incubation mixtures revealed that no detoxication occurred under these in vitro conditions.

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In vitro degradation dynamics of neutral detergent fiber and silage quality of waste from production of heart of palm of peach palm

Revista Brasileira de Saúde e Produção Animal ◽

10.1590/s1519-99402122082021 ◽

2021 ◽

Vol 22 ◽

Author(s):

Samuel Galvão de FREITAS ◽

Geraldo Fábio Viana BAYÃO ◽

Augusto César de QUEIROZ ◽

Robérson Machado PIMENTEL ◽

Carlos Magno ROCHA Junior ◽

...

Keyword(s):

Chemical Composition ◽

Crude Protein ◽

Leaf Sheath ◽

Neutral Detergent Fiber ◽

In Vitro Degradation ◽

Fermentation Profile ◽

Fermentation Parameters

ABSTRACT The objective of the present work was to evaluate the chemical composition, fermentation profile, and degradation parameters of the neutral detergent fiber of three silages made with the waste from production of heart of peach of palm, which consisted of leaf, leaf sheath, and their compound (55% leaf and 45% leaf sheath). The waste was packed in experimental silos and open after sixty days of fermentation; silage samples were collected for determination of chemical composition and degradation parameters of neutral detergent fiber at 0, 3, 6, 9, 12, 24, 36, 48, 72, and 96 h of incubation in vitro. A difference was detected in the dry matter, crude protein, neutral detergent fiber, acid detergent fiber, and lignin contents between the three types of silage. The leaf silage showed a higher fractional degradation rate and a higher potentially digestible fraction of neutral detergent fiber over the 96 h of incubation. As for the fermentative parameters, silage made with the leaf showed a higher pH (3,79) and lactic acid (1,18%), acetic acid (0,39%) and propionic acid (0,24%). The butyric acid was higher for compound silage (0,012%) and ammoniacal nitrogen was higher for sheath silage (0,94%). The leaf silage displayed better chemical characteristics, fermentation parameters and in vitro degradability properties, proving to be the silage with best nutritional value for feeding ruminants.

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The production of toxin in annual ryegrass, Lolium rigidum, infected with a nematode, Anguina sp., and Corynebacterium rathayi

Australian Journal of Agricultural Research ◽

10.1071/ar9790201 ◽

1979 ◽

Vol 30 (1) ◽

pp. 201 ◽

Cited By ~ 26

Author(s):

BA Stynes ◽

DS Petterson ◽

J Lloyd ◽

AL Payne ◽

GW Lanigan

Keyword(s):

Plant Tissues ◽

Annual Ryegrass ◽

Lolium Rigidum ◽

General Sense ◽

Plant Component

Experiments confirmed that galls induced by nematodes (Anguina sp.), which develop in the place of seeds on ryegrass plants, become toxic to animals when colonized by Corynebacterium rathayi. The distribution of the toxin within the galls was determined by measuring the levels in extracts from the plant and from the parasite components. Bioassays showed that the toxicity of the plant component was considerably greater than that of the bacterial component. An amount of toxin constituting a dose lethal to nursling rats was extracted from between 0.15 and 0.25 mg of plant component compared with between 5.52 and 5.75 mg of bacterial component. These results suggest that the toxin is produced in the plant tissues in response to the presence of the bacterium. Furthermore, the extracts inhibited the growth of C. rathayi in vitro, which suggests that the toxin behaves in a general sense like a phytoalexin.

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