The release of intracellular constituents from fresh ryegrass (Lolium perenne L.) during ingestive mastication in dairy cows: effect of intracellular constituent, season and stage of maturity

Boudon, Anne; Peyraud, Jean‐Louis

doi:10.1016/s0377-8401(01)00267-x

Cited by 40 publications

(58 citation statements)

References 36 publications

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“…For example, in fresh-forage-based systems not all of the soluble nutrients are immediately available as a result of mastication (Boudon and Peyraud, 2001;Kim et al, 2006) or as a result of exposure of ingested viable plant cells to the rumen environment (Kingston-Smith et al, 2003b). Although it has been clearly demonstrated that dietary protein can be directly utilised or broken down in the rumen by microbial taxa (Wallace et al, 1997), in situ the plant protein may be protected from degradation by complexing with phenolic compounds (Theodorou et al, 2000;Winters and Minchin, 2001) or can be inaccessible due to being compartmented within plant cells (Kingston-Smith and Theodorou, 2000).…”

Section: Impact Of Diet On Rumen Microbial Biomassmentioning

confidence: 99%

Advances in microbial ecosystem concepts and their consequences for ruminant agriculture

Edwards

Huws

Kim

et al. 2008

Animal

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Microbial transformations in the rumen ecosystem have a major impact on our ability to meet the challenge of reducing the environmental footprint of ruminant livestock agriculture, as well as enhancing product quality. Current understanding of the rumen microbial ecosystem is limited, and affects our ability to manipulate rumen output. The view of ruminal fermentation as the sum of activities of the dominant rumen microbiota is no longer adequate, with a more holistic approach required. This paper reviews rumen functionality in the context of the microbiota of the rumen ecosystem, addressing ruminal fermentation as the product of an ecosystem while highlighting the consequences of this for ruminant agriculture. Microbial diversity in the rumen ecosystem enhances the resistance of the network of metabolic pathways present, as well as increasing the potential number of new pathways available. The resulting stability of rumen function is further promoted by the existence of rumen microbiota within biofilms. These protected, structured communities offer potential advantages, but very little is currently known about how ruminal microorganisms interact on feed-surfaces and how these communities develop. The temporal and spatial development of biofilms is strongly linked to the availability of dietary nutrients, the dynamics of which must also be given consideration, particularly in fresh-forage-based production systems. Nutrient dynamics, however, impact not only on pathway inputs but also the turnover and output of the whole ecosystem. Knowledge of the optimal balance of metabolic processes and the corresponding microbial taxa required to provide a stable, balanced ecosystem will enable a more holistic understanding of the rumen. Future studies should aim to identify key ecosystem processes and components within the rumen, including microbial taxa, metabolites and plant-based traits amenable to breeding-based modification. As well as gaining valuable insights into the biology of the rumen ecosystem, this will deliver realistic and appropriate novel targets for beneficial manipulation of rumen function. Keywords: ecosystem, metabolism, microbiota, nutrient, rumen IntroductionThe purpose of the rumen is to convert dietary material into microbial biomass and end products that can be utilised by the animal. Rumen microorganisms anaerobically ferment complex lignocellulosic plant material, which otherwise would be unable to be utilised by ruminants. Fermentation of dietary material generates microbial biomass and valuable microbial end products, the outflow/diffusion of which provides the ruminant with usable forms of protein and energy. The efficiency and sustainability of ruminant production relies on driving the ecosystem carrying out this conversion to follow an optimal network of metabolic processes. Microbial protein from the rumen accounts for more than half of the total protein entering the intestines (Broudiscou and Jouany, 1995), with three main taxonomic groups accounting for the majority of this microbial ...

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Section: Impact Of Diet On Rumen Microbial Biomassmentioning

confidence: 99%

Advances in microbial ecosystem concepts and their consequences for ruminant agriculture

Edwards

Huws

Kim

et al. 2008

Animal

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“…The release of ICs during ingestive mastication was measured by the method described by Boudon and Peyraud [4]. Ingested boli were collected directly at the cardia, rinsed and their IC contents were compared with the IC contents of the grass.…”

Section: Sampling and Measurements On The Animalsmentioning

confidence: 99%

“…The quantity of IC ingested for the bolus was calculated assuming that the quantity of NDF in the bolus was the same as the quantity of NDF in the eaten grass, before mastication. The final formula is [4]:…”

Section: Calculationsmentioning

confidence: 99%

“…With perennial ryegrass, the stage of maturity has little effect on the proportion of ICs released during ingestive mastication although the eating time per unit of dry matter intake (DMI) is appreciably higher with the most mature grass [4]. The lower efficiency of ingestive mastication with mature grass may be related to a greater mechanical resistance of the plant cell walls.…”

Section: Introductionmentioning

confidence: 99%

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Effects of stage of maturity and chop length on the release of cell contents of fresh ryegrass (Lolium perenne L.) during ingestive mastication in steers fed indoors

Boudon

Mayne²,

Peyraud

et al. 2002

Anim. Res.

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-The objective of the trial was to analyse the effects of the mechanical resistance of cell walls and chewing behaviour on the proportion of intracellular constituents (ICs) released during the ingestive mastication of fresh perennial ryegrass (Lolium perenne L.) by steers. The mechanical resistance of cell walls was varied by the stage of maturity (15 vs. 30 days of regrowth). Herbage was offered at two chop lengths (long and short) for each stage of maturity, to influence chewing behaviour. Four steers, each fitted with a large ruminal cannula, were fed indoors with the ryegrass in a 4 × 4 Latin square design. Ingested boli were collected at the cardia and their IC contents were compared with the IC contents of the grass. The average shear energy was lower with the young grass because of a lower proportion of stems and pseudostems. The eating time per unit of dry matter intake was unaffected by the stage of maturity, but was slightly lower with the short herbages. The nature of the ICs had a strong effect on their release with the larger molecules, or the molecules contained in the chloroplasts, being less rapidly released. The ICs released (as a proportion of intake) ranged from 0.166 for the chlorophyll to 0.612 for the nitrates. The treatments had no effect on the rate of release of the small vacuolar or cytoplasmic ICs. The intracellular nitrogenous fractions, partly in the chloroplast, were released faster in the mature grass, because the animals had to masticate more intensively to obtain a 'swallowable'bolus due to it having a higher shear energy. The release of ICs did not seem to be dependent on the duration of chewing but rather on other parameters of mastication like the force exerted by the jaws, the surface-area of the molars, or the quantity of grass eaten per bolus. Résumé -Effet du stade de maturité et de la longueur des brins sur la libération des contenus cellulaires du ray-grass anglais frais (Lolium perenne L.) au cours de la mastication d'ingestion sur des bouvillons nourris à l'auge. L'objectif de cet essai était d'analyser les effets spécifiques de la résistance mécanique des parois et du comportement masticatoire des animaux sur les proportions de constituants intracellulaires (ICs) libérées lors de la mastication d'ingestion chez des bouvillons nourris avec du ray-grass anglais frais (Lolium perenne L.). La résistance mécanique des parois a été modulée par le stade de maturité (15 vs. 30 jours de repousse). Pour chaque stade, le comportement masticatoire a été modulé en offrant l'herbe à deux longueurs de brins (long vs. court). Quatre bouvillons, munis d'une large canule ruminale ont été nourris à l'auge en carré latin 4 × 4. Des bols d'ingestion ont été collectés directement au cardia et leurs teneurs en ICs ont été comparées avec celles de l'herbe offerte. La résistance mécanique de l'offert a été mesurée comme la moyenne des quantités d'énergie nécessaires pour couper chaque type d'organe végétal, pondérée par les proportions pondé-rales de chacun des organes dans l'offert...

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“…Boudon & Peyraud (2001) e Kingston-Smith et al (2003), porém, postulam que existe diferença na liberação do conteúdo intracelular após a quebra da parede de células vegetais e como conseqüência, efeito na digestão dos componentes intracelulares. Boudon & Peyraud (2001) propõem que a mastigação inicial de forragens frescas libera relativamente poucos componentes da célula e que alguns componentes só podem ficar disponíveis para os microorganismos se a parede celular é quebrada. A inclusão da liberação de nutrientes em modelos mecanísticos pode ser feita pela agregação de variáveis de estado que representam os a disponibilidade de nutrientes em dependência de mastigação, ruminação e as frações diferentes de nutrientes (açúcares solúveis, nitrogênio não-protéico, etc.…”

Section: Pgrunclassified

Modelagem da redução do tamanho de partículas na alimentação de ruminantes

Saenz

2005

Ciênc. agrotec.

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RESUMOO tamanho de partícula influencia o valor nutricional do alimento porque pode afetar o consumo de matéria seca, a digestão e utilização de nutrientes pelos microorganismos ruminais e, o desempenho animal. Alguns modelos são apresentados para ilustrar a evolução da representação da redução do tamanho de partícula. Em geral, as diferentes propostas se comportam adequadamente e provêem informação útil para produção ou pesquisa. Porém, todos os modelos demonstram inexatidão em certos pontos. Nesta revisão são discutidas as razões para esses problemas e é proposta a inclusão de novas variáveis relacionadas com a cinética de partículas, ingestão descontínua de alimentos e liberação do conteúdo celular com o objetivo de aumentar a precisão de futuros modelos de consumo e digestão. Termos para indexação: cinética ruminal, consumo, digestibilidade, modelos de simulação. ABSTRACTParticle size seems to be an important factor influencing the nutritional value of the feed because it may affect dry matter intake, microbial digestion and utilization of nutrients and animal performance. Some models are described to present different attempts to represent particle size reduction. In general, the diverse approaches behave adequately and provide useful information for production or research. All models, however, demonstrate inaccuracy in some points. The reasons for these failures are discussed and the inclusion of new variables related to particle kinetics, pulses of feed and cell content release to increase accuracy of predictions in future models of feed intake and digestion of ruminants is proposed. Index terms: digestibility, feed intake, ruminal kinetics, simulation models. As forragens representam uma fração importante do consumo de energia em sistemas de produção de ruminantes. Existem muitos fatores que influenciam o consumo voluntário de alimentos (CVA) pelos ruminantes. A restrição física do CVA devido a atributos físicos das forragens é um dos mais importantes. Entre esses atributos, o tamanho de partícula pode ser um fator importante que influencia o valor nutricional do alimento porque afeta tanto o consumo de matéria seca (CMS) como a taxa na qual os nutrientes ficam disponíveis para digestão e utilização microbiana. Dependendo da qualidade da forragem, a redução de tamanho de partícula pela moagem ou peletização pode incrementar o consumo de forragens e alimentos fibrosos substancialmente (SOEST, 1994).O tamanho de partícula também afeta a taxa de passagem da ingesta através do rúmen. Quando o conteúdo ruminal chega a um ponto onde incremento adicional não é possível, a taxa de passagem da ingesta determina o consumo de alimento (BOSCH, 1991). A taxa na qual o alimento é reduzido a partículas suficientemente pequenas para atravessar o orifício retículo-omasal, e a taxa de degradação pelos microorganismos, são os fatores mais importantes que limitam o desaparecimento de digesta do rúmen.Por outro lado, embora uma fração das partículas ruminais possuam tamanho adequado para atravessar o orifício retículo-omasal...

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The release of intracellular constituents from fresh ryegrass (Lolium perenne L.) during ingestive mastication in dairy cows: effect of intracellular constituent, season and stage of maturity

Cited by 40 publications

References 36 publications

Advances in microbial ecosystem concepts and their consequences for ruminant agriculture

Advances in microbial ecosystem concepts and their consequences for ruminant agriculture

Effects of stage of maturity and chop length on the release of cell contents of fresh ryegrass (Lolium perenne L.) during ingestive mastication in steers fed indoors

Modelagem da redução do tamanho de partículas na alimentação de ruminantes

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