Meadow Grass Research Articles

Feed Intake of Young Double-Muscled Bulls Fed on Grass and Supplemented with Sugar-Beet Pulp

Daily dry matter intake in young growing double-muscled bulls, fed indoors on grass, was estimated based on forty-four intake data from 28 animals, ageing at least five months and weighing up to 400kg live weight. Intake was measured during five consecutive days using one of eighteen cuts of grass. Fresh meadow grass (mainly Lolium perenne ) was fed ad libitum and twokg dried sugar-beet pulp was offered per animal and per day. Animal live weight averaged 278 ± 82kg and mean total daily dry matter intake amounted to 5.05 ± 1.59kg or 73.6 ± 13.7g perkg metabolic weight, while pulp dry matter intake amounted to 1.49 ± 0.50kg per day. Regression analysis showed that animal as well as feed characteristics could explain up to approximately 90% of the variation in daily dry matter intake. The supplementation resulted in an extra daily dry matter intake of 0.68g perg pulp dry matter. Intake of double-muscled animals was considerably lower than previously reported for non-double-muscled cattle. An extra supplementation of young grazing double-muscled animals could be advised from these findings, while extra protein should also be considered.

RELATIONSHIP BETWEEN HABITAT AREA AND THE DISTRIBUTION OF TIDAL MARSH BIRDS

To assess the relationship between marsh area and relative abundance of tidal marsh bird species, we surveyed birds on 86 circular plots in 40 salt and brackish tidal marshes in Connecticut. We measured marsh area in two ways: the amount of contiguous marsh vegetation not interrupted by broad barriers (>500 m of open water or >50 m of upland habitat) and by narrow barriers (>30 m of open water or >10 m upland). We determined the relationship between marsh area and the relative abundance of particular species (mean number of individuals per survey plot) with linear or logistic regression. When the broad barrier definition was used, we found that all three species of short grass meadow specialists, Willets (Catoptrophorus semipalmatus), Seaside Sparrows (Ammodramus maritimus), and Saltmarsh Sharp-tailed Sparrows (A. caudacutus), were less abundant or absent in survey plots in smaller marshes. The Seaside Sparrow and Willet also showed a significant tendency to be less frequent in smaller marshes when the narrow barrier definition was used. In contrast, species that used a wider range of wetland types, as in the Virginia Rail (Rallus limicola), Marsh Wren (Cistothorus palustris), and Swamp Sparrow (Melospiza georgiana), were equally frequent on plots in marshes of different areas. Our results are consistent with the hypothesis that fragmentation of marsh systems with artificial habitat causes a decline in the density of short grass meadow specialists in the remaining patches of appropriate habitat.

Evaluation of the terrestrial impact of carbone 14 and tritium released by PWR

Within the scope of a joint IPSN/EDF research program, it is possible to present a statement of the environment out of industrial influence for two areas, one in the Nogent-sur-Seine region, the other around Dampierre, where seasonal sampling was monitored over two years. In Dampierre, the same sampling was implemented within areas exposed to atmospheric releases of the nuclear plant in order to assess the facility impact. The matrices selected for this specific survey include perennial self-sown vegetation (ivy leaves, meadow grass, blackberries), caducous tree leaves (durmast-oak), honey, game, cultivated fruits (apple), pasture grass, milk and cattle meat. The available quantity of results evidences a discrete marking effect by the facilities both in radiocarbon and tritium, but does not allow proposing a modeling.

Phytocenotypes and Ecocenotic Potentials of Meadow Grasses

The systems of Ramenskii's cenobiotic types and Grime's life strategies applied to meadow grasses are compared, and differences between these systems are demonstrated. The parameters of violence of meadow grasses in the aboveground and underground spheres are discussed. The methods for evaluating the degrees of shade tolerance in grasses and their tolerance to sodding are proposed. Two types of explerence are distinguished in meadow grasses (cenophobic and cenofluctuation explerence).

Shifts in dominance of native and invasive plants in experimental patches of vegetation

Abstract While it is widely accepted that disturbance often promotes the process of plant invasion, few data are available on specific relationships between different types of disturbance and success of plant invaders. Nor is much known about variation in invader behaviour in response to changing composition of the dominant native species in the recipient habitats. In the middle Main valley near Wurzburg (Germany), two invasive Brassicaceae forbs, Bunias orientalis and Rorippa austriaca , are frequently associated with a small number of dominant native species in the herbaceous vegetation of productive, disturbed sites. Variation in the relative dominance of these species suggests high variability between sites in the factors influencing the local invasion process. In our study, we examined variation in regeneration mode, type and frequency of disturbance, and native species composition, and considered life history differences between the two invasive species as factors contributing to the distinct dominance patterns. These factors were tested in a controlled field experiment in which individuals of the two invasive species and four native species were grown in mixed stands for almost 3 years. The development of the plants was monitored by cover values and all plants were harvested at the end of the study. All factors investigated contributed considerably to the development of distinct dominance patterns in the species mixtures. Relative to the natives, both invasive species were promoted by regeneration from vegetative fragments as compared to development from sexual offspring. While both invasive species were generally promoted by disturbance relative to the natives, they differed in their response to distinct types of disturbance, and these differences were strongly affected by species composition. Our results indicate that invasion success of R. austriaca may depend more on soil disturbance, soil transport and deposition, while B. orientalis is expected to particularly expand at mown sites that do not have dense cover by meadow grasses. Whether the native resident vegetation is mainly composed of successional competitors that suffer from disturbance or of ruderal competitors that compete early and strongly with the invasive species may be of critical importance for invasion by the two species.

Comparison of the German and the Dutch protein evaluation system in dairy nutrition when applied to different rations with graded protein levels

The Dutch (DVE) and the German (nXP) protein evaluation system were compared using data from four specially designed dairy feeding trials. The criterion for comparison was the divergence between predicted and observed milk protein yield with the respective protein evaluation system. Different forages were fed in each series of experiments, namely red clover/meadow grass, meadow grass, grass silage and maize silage, respectively. To achieve a diversified database, protein was supplied at 2 or 3 different levels in each experiment. Across all measured data, the two protein evaluation systems resulted sometimes in considerable differences between predicted and observed protein yield. The observed yield was overestimated by 223 g per cow and day with the DVE system and by 144 g per cow and day with the nXP system. The magnitude of the bias varied depending on the type of ration fed. In experiments with fresh forage the difference between predicted and observed milk protein yield was far greater with the DVE system than that calculated with the nXP system (difference 322 g vs. 162 g), whereas after feeding grass silage the differences between the two protein evaluation systems were small (194 g vs. 182 g). In experiments with maize silage the predicted value was close to the observed value both with the DVE and the nXP system (difference 48 g vs. 80 g).

Radiocaesium contamination of meadow vegetation—time-dependent variability and influence of soil characteristics at grassland sites in Austria

Long-term trends of 137Cs and 40K concentrations in meadow grass and soil–plant transfer data at eight different sites in Upper Austria are presented. Geometric means of 137Cs TF-data and T agg values vary between 0.03–1.06 and 0.0005–0.0184 depending on site, respectively. 40K results are less variable with TF values covering a range of 0.31–2.01. Only at one site was a significant decrease of 137Cs concentration (decay-corrected) in meadow vegetation observed during the observation period 1992–1999. Seasonal trends of 40K and 137Cs were investigated at one site in 1996. Both elements show decreasing concentrations in plants from beginning of May–July, followed by a peak in September. Although this pattern was not very pronounced, there are some hints that it may explain deviations of long-term trends in 137Cs levels in grass caused by unusual weather conditions as indicated by phenological climate data (beginning of sweet cherry and black elder blossoming). Finally, TF values were correlated with soil characteristics, revealing a negative correlation of radiocaesium soil–plant transfer with soil pH, exchangeable and extractable fractions of Mg, Ca and Na as well as a positive correlation with exchangeable Al.

Habitat associations of breeding Meadow Pipits Anthus pratensis in the British uplands

Habitat associations of Meadow Pipits breeding in British upland 1 km and 10 km squares were investigated using data from the British Trust for Ornithology's (BTO) Breeding Bird Survey (BBS, 1994–97), The New Atlas of Breeding Birds in Britain and Ireland 1988–1991 and habitat data from the Institute of Terrestrial Ecology's (ITE) Land Cover Survey (1994). Meadow Pipit density was highest in 200 m sections of BBS 1 km transects containing unenclosed grass moor, heather and bog, but there was no difference in Meadow Pipit density between these habitat types. Meadow Pipit density (number of individuals per 1 km square) increased with heather cover up to about 7.5 200 m sections (of ten per 1 km square) of heather, but fell thereafter. There was a positive association between Meadow Pipit density and the extent of grass moor cover. The ITE Land Cover data gave results that were consistent with the BBS habitat data at both the 1 km and 10 km square scale. There was a non-linear relationship between hill grass cover and Meadow Pipit abundance, which reached a maximum when hill grass covered between 40%and 60% of a square. Our results suggest that a mosaic of heather, bog and grassland may be the optimum habitat for Meadow Pipits. Recent changes in land management practices may have led to the disappearance or degradation of these mosaics in some areas. Meadow Pipits are widespread and easily counted. We suggest that this species might be a useful bioindicator of changes in heather and grassland ratios that result from land management practices such as grazing and rotational burning, though further research is required.

Use of high pressure liquid chromatography (HPLC) for the determination of cda-tocopherol levels in forage (silage/grass) samples collected from different regions in Ireland

First, second and third cut grass silage samples were collected from eight regions around Ireland (184 samples in total) and analysed for vitamin E content. Fresh grass samples were also collected at one site in Co. Cork and analysed for α-tocopherol content. The concentration of α-tocopherol [μg/g dry matter (DM)] was determined using high performance liquid chromatography analysis. A wide variation in α-tocopherol levels in silage samples was found. α-Tocopherol levels in first, second and third cut silage samples ranged from 4.9 to 20.8, 4.4 to 13.0 and 1.3 to 3.9 μg/g DM, respectively. The mean values of α-tocopherol in first, second and third cut silage samples were 11.3±0.9, 9.7±0.7 and 2.3±0.5 μg/g DM, respectively. There was no significant difference in α-tocopherol levels between first and second cut silage samples. However, third cut silage samples had significantly (P meadow grass>hedgerow>white clover>red clover.

Effects of distance and pollen competition on gene flow in the wind-pollinated grass Festuca pratensis Huds.

Pollen dispersal and gene flow in the grass meadow fescue (Festuca pratensis Huds.) were studied using two populations which were homozygous for different allozymes at the Gpi-2 locus. The populations were established in a concentric donor-acceptor field experiment. Gene flow was found mainly to be affected by the distance between the donor and acceptor plants. Analysing 21 132 acceptor plant progenies, gene flow was shown to decrease rapidly with distance to the donor field up to 75 m, and beyond this distance much more slowly. The ability of donor pollen to fertilize acceptor plants depended very much on the density of the acceptor plants. Pairs of acceptor plants produced more compatible pollen locally, and captured significantly less donor pollen than single-plants. Despite the higher seed production of acceptor plants planted in pairs, the absolute number of heterozygous seeds carrying the donor allele was always lower than for single-plants. Wind direction had only a slight effect upon the type of pollen captured. Because of pollen production within the two plant populations being continuous and overlapping, the time when anthesis occurred had little effect on gene flow between the populations. Vigorous and tall acceptor plants with many panicles, high seed yield and high 1000-seed weight were able to capture more donor pollen than shorter plants. The results may be used to assess the risk of gene flow and to develop strategies for monitoring the spread of transgenes from genetically modified grasses.

Influence of sward botanical composition on performance of cool temperate grassland under contrasting nitrogen fertilization regimes

Eight field experiments, which tested the effects of lime, phosphorus (P), and two rates of nitrogen (N) on a range of permanent grassland swards in Northern Ireland (NI), were re‐examined to investigate the influence of sward botanical composition on aerial dry matter (DM) productivity under ‘low’ and ‘high’ levels of ? input. The aim of the investigation was to verify results previously obtained using ‘pure’ single‐species swards, which suggested that secondary grasses are more productive than perennial ryegrass at low levels of ? input (i.e., < 100 kg ? ha‐1 a‐1)#lb The swards used in the investigation varied considerably in botanical composition, but were largely dominated by three main species: perennial ryegrass (Lolium perenne L.), creeping bent (Agrostis stolonifera L.), and rough stalked meadow grass (Poa trivialis L.), all of which were characteristic of fertile habitats. The results confirmed that under reduced ? input management, swards dominated by these secondary grasses are capable of out‐performing those in which perennial ryegrass is a major component. The superior (aerial) productivity of the secondary grasses was attributed to their ability to conserve resources and maintain high shoot‐to‐root ratios under ‘moderate’ ? stress conditions.

The influence of secondary senescence processes within the culm of a pseudoviviparous grass (Poa alpina var. vivipara L.) on the supply of water to propagules.

An anatomical investigation of the culm of pseudoviviparous alpine meadow grass (Poa alpina var. vivipara L.) revealed that transpiration flow, as delimited by Lucifer Yellow tracer dye, was maintained despite advanced senescence (as evidenced by loss of chlorophyll and chloroplasts), with leafy spikelets driving transpiration flow. Transpiration flow was not hindered by cavitation or tylosis in older culms, the low frequencies of these senescence processes being bypassed via nodal plexi. Despite this, water content of plantlets declined over time and water stress became apparent, suggesting that water supply via the determinate culm was not sufficient for the increasing transpirational demand of indeterminate plantlets. The implications of declining water content on the biomechanical properties of the culm, and concomitant limitations on the pseudoviviparous reproductive strategy, are discussed. Nomenclature of grass follows Hubbard.

Feeding of Scheloribates laevigatus (Acari: Oribatida) on different stadia of decomposing grass litter ( Holcus lanatus)

Summary The feeding of the panphytophagous mite Scheloribates laevigatus on litter of the abundant meadow grass Holcus lanatus was studied in laboratory experiments. The micro-anatomy of the digestive tract and the isolation of fungi from the microcosms, the mite surface and the digestive tract were used to compare the feeding on dried-remoistened leaves, representing the initial stadium of decomposition, and partly decomposed litter. Additionally, food preference tests between sterilised litter and driedremoistened leaves and exposition of litter and dried-remoistened leaves on soil surface were used. Scheloribates laevigatus fed on the fungi growing on the dried and remoistened grass leaves in the initial stadium of grass litter decomposition. The crashed and partly destroyed fungal hyphae formed a food bolus in the mesenteron. No leave pieces were observed in the food boli. The Scheloribates laevigatus individuals feeding on grass litter in a later decomposition stadium consumed plant debris, spores and fungal mycelium. Litter was less preferred by Scheloribates laevigatus than the dried-remoistened leaves in the food preference tests. The Scheloribates laevigatus choice between the litter and the dried-remoistened leaves was influenced by fungal communities. The sterilisation of leaves influenced the mite choice. The sterilised leaves were not preferred in comparison to the non-sterilised ones in the preference tests. The exposition of leaves and litter on soil surface before the experiment had no influence on the mite choice.

Goose grazing selectivity along a depletion gradient

The micro-habilat food selectivity along a gradient of increasing grazing intensity of wintering pink-footed geese Anser brachyrhynchus and barnacle geese Branta leucopsis foraging on winter wheat Triticum aestivum and smooth meadow grass Poa pratensis was investigated. Protein content of ungrazed primary and secondary leaves of winter wheat did not differ, whereas the protein content of tertiary leaves was significantly lower. Secondary leaves were significantly longer than both primary and tertiary leaves, whereas tertiary leaves were significantly longer than primary leaves. Protein content of primary and secondary leaves of Poa pratensis did not differ, whereas the protein content of tertiary leaves was significantly lower. Primary leaves were significantly shorter than both secondary and tertiary leaves, which did not differ significantly. For all leaf categories, there was an increase in the removal with increasing goose grazing intensity. The geese showed a sequential selection of winter wheat leaves according to the protein content, initially preferring primary and secondary leaves, but increasingly selecting tertiary leaves of poorer quality as high-quality leaves became depleted. Foraging on Poa pratensis. geese selected secondary leaves according to the protein content, whereas tertiary leaves were preferred to primary leaves, although these had a protein content equal to secondary leaves. This, however, may be explained by the primary leaves being too short to maintain intake rates. It is concluded that feeding preferences cannot be established on the basis of protein contents of food plants alone and that green biomass estimates not necessarily reflect resource availability.

Goose grazing selectivity along a depletion gradient

The micro‐habilat food selectivity along a gradient of increasing grazing intensity of wintering pink‐footed geese Anser brachyrhynchus and barnacle geese Branta leucopsis foraging on winter wheat Triticum aestivum and smooth meadow grass Poa pratensis was investigated. Protein content of ungrazed primary and secondary leaves of winter wheat did not differ, whereas the protein content of tertiary leaves was significantly lower. Secondary leaves were significantly longer than both primary and tertiary leaves, whereas tertiary leaves were significantly longer than primary leaves. Protein content of primary and secondary leaves of Poa pratensis did not differ, whereas the protein content of tertiary leaves was significantly lower. Primary leaves were significantly shorter than both secondary and tertiary leaves, which did not differ significantly.For all leaf categories, there was an increase in the removal with increasing goose grazing intensity. The geese showed a sequential selection of winter wheat leaves according to the protein content, initially preferring primary and secondary leaves, but increasingly selecting tertiary leaves of poorer quality as high‐quality leaves became depleted. Foraging on Poa pratensis. geese selected secondary leaves according to the protein content, whereas tertiary leaves were preferred to primary leaves, although these had a protein content equal to secondary leaves. This, however, may be explained by the primary leaves being too short to maintain intake rates.It is concluded that feeding preferences cannot be established on the basis of protein contents of food plants alone and that green biomass estimates not necessarily reflect resource availability.

Export of carbon from leaf blades of Poa alpina L. at elevated CO2 and two nutrient regimes

The hypothesis was tested that, in plants of the alpine meadow grass (Poa alpina L.) exposed to elevated CO2, net photosynthesis and export from source leaves is reduced as a result of feedback from sinks. Nutrient supply was used as one way of reducing photosynthesis and export. Single plants were grown in sand culture under specified controlled environmental conditions for a period of 50 d at two levels of nitrogen and phosphorus (‘low’: 0.2 mol m−3 N, 0.04 mol m−3 P; ‘high’: 2.5 mol m−3 N, 0.5 mol m−3 P). Compartmentation within, and export of carbon from, individual youngest fully expanded leaves of acclimated plants was determined using 14C feeding and efflux plus mass balance calculations of carbohydrate export. Independent of treatment, the bulk of soluble carbohydrate (65–75%) was present as fructan, with most of the remainder being sucrose. Depending on nutrient supply, CO2 could alter export from source leaves either by a reduction in the amount of sucrose present in a readily available pool for transport, or by altering the rate constant describing phloem loading.

Export of carbon from leaf blades of Poa alpina L. at elevated CO2 and two nutrient regimes

The hypothesis was tested that, in plants of the alpine meadow grass (Poa alpina L.) exposed to elevated CO 2 , net photosynthesis and export from source leaves is reduced as a result of feedback from sinks. Nutrient supply was used as one way of reducing photosynthesis and export. Single plants were grown in sand culture under specified controlled environmental conditions for a period of 50 d at two levels of nitrogen and phosphorus (low': 0.2 mol m -3 N, 0.04 mol m -3 P; 'high': 2.5 mol m -3 N, 0.5 mol m -3 P). Compartmentation within, and export of carbon from, individual youngest fully expanded leaves of acclimated plants was determined using 14 C feeding and efflux plus mass balance calculations of carbohydrate export. Independent of treatment, the bulk of soluble carbohydrate (65-75%) was present as fructan, with most of the remainder being sucrose. Depending on nutrient supply, CO 2 could alter export from source leaves either by a reduction in the amount of sucrose present in a readily available pool for transport, or by altering the rate constant describing phloem loading.

Model comparisons of EMC of meadow grass in the temperature range of 20 - 50°C

Moisture equilibrium data for adsorption and desorption of water from meadow giass (Festuca pratensis) were investigated at a temperature range of 20 - 50°C and water activity from 0.3 to 0.99. The experimental procedure used was a gravimetric dynamic method with continuous registration of sample weight changes. A special laboratory drying device has been developed for the purpose. Sorption capacity decreases as temperature increases. Rehydration of the dried material results in hysteresis, hour models available in the literature (Chung-Pfost, Halsey, Henderson, and Oswin) were evaluated to determine the best fit for the experimental data. The Oswin equation was a good model for moisture adsorption and desorption of Festuca pratensis.

Dynamic modeling of the cesium, strontium and ruthenium transfer to grass and vegetables.

From 1988 to 1993, the Nuclear Safety and Protection Institute (Institut de Protection et de Sûreté Nucléaire--IPSN) conducted experimental programs focused on transfers to vegetation following accidental localized deposits of radioactive aerosols. In relation to vegetable crops (fruit, leaves, and root vegetables) and meadow grass these experiments have enabled a determination of the factors involved in the transfer of cesium, strontium, and ruthenium at successive harvests, or cuttings, in respect of various time lags after contamination. The dynamic modeling given by these results allows an evaluation of changes in the mass activity of vegetables and grass during the months following deposit. It constitutes part of the ASTRAL post-accident radioecology model.

Influence of supplemental alfalfa quality on the intake, use, and subsequent performance of beef cattle consuming low-quality roughages.

Three experiments were conducted to evaluate influences of supplemental alfalfa quality on intake and use of low-quality meadow grass roughages (MG) by beef cattle. In Exp. 1, 15 steers (250 kg) were assigned to three treatments: 1) MG (5.2% CP), no supplement; 2) MG plus high-quality alfalfa (18.8% CP); and 3) MG plus low-quality alfalfa (15.2% CP). High- and low-quality alfalfa supplements were fed at .45 and .55% BW, respectively. Total DMI was greater (P < .01) for alfalfa-supplemented steers than for MG. Likewise, intake of digestible DM, DM digestibility (DMD), and ruminal ammonia level were greater (P < .01) for supplemented steers. In Exp. 2, 96 pregnant Hereford x Simmental cows (537 kg; body condition [BC] score 4.86) were assigned to the same treatments as in Exp. 1. For d 0 to 42, cows grazed on 19.1 ha of stockpiled MG (4,539 kg/ha; 6.8% CP), whereas, on d 43 to 84, cows received MG hay (5.2% CP). Supplemented cows gained more BW (P < .01), BC score (P < .01), and had heavier calf birth weight (P < .01) than nonsupplemented cows. However, there were no treatment effects (P > .10) on cow cyclicity, pregnancy rate, or calving interval. In Exp. 3, 90 pregnant Angus x Hereford cows (475 kg; BC score 4.59) were assigned to three treatments: 16.1%, 17.8% or 20.0% CP alfalfa supplement, with levels of .63, .55, and .50% of BW, respectively. Weight gain and BC score for the 84-d study displayed a quadratic response (P < .10), yet represented only 7 kg BW and .2 units of BC score. In conclusion, alfalfa hay supplementation was effective in increasing DMI and digestibility. However, alfalfa hay quality did not dramatically affect BW, BC score, and(or) calf birth weight, when fed on an isonitrogenous basis.