Plant and animal constraints to voluntary feed intake associated with fibre characteristics and particle breakdown and passage in ruminants

1996 ◽  
Vol 47 (2) ◽  
pp. 199 ◽  
Author(s):  
JR Wilson ◽  
PM Kennedy
Keyword(s):  
Organic Matter ◽  
Dry Matter ◽  
Shoot Growth ◽  
Surface Soil ◽  
Clay Soil ◽  
Grass Species ◽  
Soil Nitrate ◽  
The Sun ◽  
N Yield ◽  
Organic Matter Breakdown

Effects of artificial shading to 50% sunlight of nitrogen (N) limited tropical pastures of different grass species on a high (clay loam) and low (granitic loam) fertility soil type were evaluated in a semi-arid. subtropical environment over 3 years. The hypothesis was tested that shade can stimulate shoot growth by providing a modified environment more conducive to organic matter breakdown leading to increased mineralisation and availability of soil N, and the ability of tropical grasses to take advantage of this effect was examined. Unfertilised pastures of green panic (Panicum maximum var. trichoglume), buffel (Cenchrus ciliaris). rhodes (Chloris gayana), and speargrass (Heteropogon contortus) in full sun or shaded by sarlon cloth were sampled on 9 occasions. Additional green panic plots on both soils were irrigated for the first 2 years, and all other plots were dependent on natural rainfall. Shoot and root dry matter and N yield, and soil nitrate and ammonia N, were measured. In one set of green panic plots on each soil, canopy. litter, and surface soil temperatures were monitored continuously, and soil moisture at different depths was measured fortnightly. Shade stimulated shoot dry matter yield over the 3 years by up to 37% in green panic. 22% in rhodes, and 9% in speargrass. Shade decreased buffel yield on the clay soil but had no effect on the granitic soil. Relative increases in yield of shoot N were similar to those for shoot dry matter, except for buffel on the granitic soil where N yield was increased by 39% with no increase in shoot growth. Positive shade responses occurred in all 3 years but were reduced by extreme drought in year 3, particularly on the clay soil. Irrigation gave a greater shade response on the clay but not on the granitic soil. Root mass was lower under shade than in full sun. but there was no long-term trend of progressive decrease. and the change in N yield of roots did not appear to explain the gain in shoot N of the shaded pastures. Nitrogen percentage in the youngest expanded leaf was higher in the shade than the sun leaves only after about 2 to 2 5 months of shading. Surface soil nitrate and ammonia concentrations tended to be higher under shade for most harvests. Shade lowered temperature extremes of surface soil and litter by up to 10-12�C, and improved soil water status. compared with the sun plots. Soil water data were analysed to separate effects on plant water stress and soil microbial activity. The consistent positive response of shoot N yield to shade across grass species. weeds, and soil type. the delay in it becoming evident, and its longevity all support the hypothesis that shade enhances organic matter breakdown and N cycling. Harsh surface temperatures and low soil moisture in open sun pastures appear inimical to high microbial activity. Implications for pasture management are discussed. with the caveat that the outlined benefits of artificial shade may not necessarily arise with tree canopies.

The digestibility and voluntary intake by sheep of six tropical grasses

1972 ◽  
Vol 12 (54) ◽  
pp. 21 ◽  
Author(s):  
DJ Minson
Keyword(s):  
Organic Matter ◽  
Dry Matter ◽  
Grass Species ◽  
Stages Of Growth ◽  
Dry Matter Digestibility ◽  
Digitaria Decumbens ◽  
Chloris Gayana ◽  
The Mean ◽  
Voluntary Intake ◽  
The Difference

The digestibility and voluntary intake of Chloris gayana, Digitaria decumbens, Panicimum maximum var tricboglume, Paspalm dilatatum, Pennisetm Clanhtinum, and Setaria splendih were measured with sheep in metabolism pens. All grasses were grown under the same conditions and cut at the same time. Each grass was cut after growing for 28, 70, and 98 days in the summer and then again (except for P. dilatatum) after 42, 70, and 105 days in the following autumn. Four successive 28-day regrowths of each grass (two cuts only for P. dilatatum) were also harvested during the summer. All 55 cuts were artificially dried and fed at the same time, each cut being fed to eight sheep. Differences in dry matter and organic matter digestibility between grass species were relatively small with a maximum mean difference of six digestibility units between S. splendida and P. clandestinzrm. For the 28-day regrowths S. splendida was 5.1 digestibility units higher but with the more mature regrowths the difference was 6.8 digestibility units. The mean voluntary intake of dry matter of S. splendida and P. clandestinum was 9 and 11 per cent lower than that of D. decmbens (P<0.01) with the largest differences in voluntary intake between grasses occurring at the mature stages of growth. Large differences were found between grass species in both the slope and intercept of regressions relating voluntary intake to dry matter digestibility.

JAMES AND ARTHUR, TWO CULTIVARS OF DAHURIAN WILD RYEGRASS

1990 ◽  
Vol 70 (4) ◽  
pp. 1187-1190 ◽  
Author(s):  
T. LAWRENCE ◽  
P. G. JEFFERSON ◽  
C. D. RATZLAFF
Keyword(s):  
Organic Matter ◽  
Seed Yield ◽  
Crude Protein ◽  
Dry Matter ◽  
Grass Species ◽  
Seedling Vigor ◽  
Dry Matter Yield ◽  
Crude Protein Content ◽  
Cultivar Description ◽  
High Seed Yield

James and Arthur are the first two cultivars of Dahurian wild ryegrass registered for sale in Canada. The main attributes of James and Arthur are excellent establishment vigor, high establishment-year dry matter yield and high seed yield in subsequent years. Organic matter digestibility of both cultivars is similar to that of other wild ryegrass species but the crude protein content of first-harvest forage declines more rapidly than for Altai wild ryegrass. Stands persist two to three years in southwestern Saskatchewan. This short-lived perennial with high seedling vigor is well adapted for seeding in mixtures with long-lived, low seedling vigor grass species for improving the early productivity of pastures.Key words: Elymus dahuricus, cultivar description, dry matter yield, seed yield, forage quality, seedling vigor

scholarly journals Effect of a spring application of nitrogen on the performance of perennial ryegrass-white clover swards at two sites in the Netherlands

1997 ◽  
Vol 45 (2) ◽  
pp. 263-275
Author(s):  
R.L.M. Schils
Keyword(s):  
Lolium Perenne ◽  
Sandy Soil ◽  
Perennial Ryegrass ◽  
White Clover ◽  
Significant Interaction ◽  
Dry Matter ◽  
Clay Soil ◽  
N Application ◽  
N Yield ◽  
Cutting Frequency

In a field trial in 1989-93 on clay soil at Lelystad, Netherlands, a mixed sward of Lolium perenne cv. Profit and Magella and Trifolium repens cv. Retor was given annual applications of 0, 25, 50, 75 or 100 kg N ha-1 and was cut 4-5 or 6-7 times a year. In a trial in 1992-94 on sandy soil in Overijssel, a sward of L. perenne cv. Meltra, Citadel and Condesa oversown with T. repens cv. Retor in 1991 was given annual applications of 0, 50 or 100 kg N ha-1. Average annual dry matter (DM) yields were 14.66 and 13.76 t ha-1 year-1 for the clay and sandy soil, respectively. Yields increased with increasing N rate at both sites. Cutting frequency had no consistent effect on DM yield, and there was no significant interaction between N rate and cutting frequency. T. repens contents decreased with increasing N rate, reducing the DM yield in the cuts after the first in the fertilized treatments. Annual N yields were not affected by N application. The higher cutting frequency increased the T. repens content from 36 to 47% and the N yield from 458 to 524 kg ha-1, but did not affect the DM yield.

Responses to nitrogen, phosphorus and irrigation by grain sorghum on cracking clay soils in central Queensland

1991 ◽  
Vol 31 (4) ◽  
pp. 525 ◽  
Author(s):  
DE Hibberd ◽  
J Standley ◽  
PS Want ◽  
DG Mayer
Keyword(s):  
Dry Matter ◽  
Clay Soil ◽  
Soil Nitrate ◽  
Floral Initiation ◽  
Large Area ◽  
Factors Affecting ◽  
Grain Yields ◽  
P Rate ◽  
Residual Values ◽  
Nitrogen Phosphorus

The yield and dry matter (DM) responses to nitrogen (N), phosphorus (P) and irrigation in sorghum hybrids E57 and Goldfinger were measured near Emerald, Queensland, on a cracking clay soil (Ug 5.12) deficient in N and P. A raingrown experiment received factorial combinations of 0, 25, 50 and 75 kg N/ha as urea, and 0, 10, 20 and 40 kg P/ha as superphosphate. An irrigated experiment received the same rates of superphosphate in conjunction with 0, 50, 100 and 150 kg N/ha and irrigation applied at 80 mm deficit. Plants were sampled on days 20 (floral initiation), 41 (early booting), 55-57 (anthesis) and 142 (grain harvest). Factors affecting yields on a soil type fairly representative of a large area of the cultivated soils of the Central Highlands were, in decreasing order of importance, N, water and P. Goldfinger initially produced higher DM yields than E57, but E57 produced higher grain yields. Mean grain yields for the 2 hybrids from control plots were 1150 kg/ha (raingrown) and 1190 kg/ha (irrigated). Under raingrown conditions, a grain yield asymptote (1600 kg/ha) was reached with 50 kg N/ha, but rates higher than 150 kg N/ha (2700 kg/ha) would be required to achieve maximum yields under irrigation. Responses to P were smaller, with rates of 10-20 kg P/ha (raingrown) producing maximum yields for both hybrids. Phosphorus rates greater than 40 kg/ha would be required to achieve maximum yields under irrigation. Apparent recovery of fertiliser P was significantly (P<0.05) lower at the highest P rate of 40 kg/ha at anthesis in the raingrown experiment. All other P recoveries either at anthesis or in the grain were not significantly (P>0.05) different. Phosphorus recoveries between the raingrown and irrigated experiments showed little difference. Nitrogen, however, showed much higher apparent recoveries in the irrigated experiment, with no significant (P>0.05) differences between N treatments. A month after harvest the only plots on the raingrown site with an increase in soil nitrate were the 75 kg N/ha treatments; residual values from all other treatments were low.

RELATIONSHIP BETWEEN IN VITRO DIGESTIBILITY AND FINENESS OF SUBSTRATE GRIND AS AN INDICATOR OF VOLUNTARY INTAKE OF HAY BY SHEEP

1969 ◽  
Vol 49 (1) ◽  
pp. 119-124
Author(s):  
J. E. Troelsen ◽  
J. M. Bell
Keyword(s):  
Organic Matter ◽  
Dry Matter ◽  
Grass Species ◽  
In Vitro Digestibility ◽  
Fine Grinding ◽  
Voluntary Intake ◽  
The Difference ◽  
Alfalfa Varieties ◽  
Relationship Of

Hay of two alfalfa varieties and four grass species harvested at six maturity stages each was fed to sheep. Voluntary intakes were measured in grams of dry matter daily per kg of metabolic size. Samples were ground coarsely and finely and digested in vitro. Fine grinding did not increase the digestibility of immature hay, but with advancing maturity the fine substrate was progressively more digestible than the coarse. This difference was inversely related (P < 0.05) to voluntary feed intake. The regression of voluntary intake of dry matter (g/day/kg0.75 body weight) on the difference of in vitro digestibility of organic matter in finely and coarsely ground substrate was −2.32 g in the alfalfa hay and −4.18 g in the grass hay. The coefficient of variation from regression was 14% in the alfalfa and 17% in the grass hays. Fine grinding had a greater effect on the in vitro digestibility of organic matter than of dry matter. This resulted in a higher significance of the relationship of intake with the effect of grinding on the digestibility of organic matter than on that of dry matter.

Studies On Browse Plants in Ghana II. Digestibility, (d) Digestibility Of Grewia Carpinifolia From The Accra Plains, Using Local Cattle As Experimental Animals

1966 ◽  
Vol 2 (2) ◽  
pp. 113-117
Author(s):  
G. L. Mabey ◽  
R. Rose Innes
Keyword(s):  
Organic Matter ◽  
Crude Protein ◽  
Dry Matter ◽  
Ether Extract ◽  
Crude Fibre ◽  
Experimental Animals ◽  
Nutritive Values ◽  
Digestible Crude Protein ◽  
Accra Plains

SummaryDigestibility of the palatable indigenous shrub Grewia carpinifolia was investigated. Digestion coefficients (%) were—organic matter 70, dry matter 70, crude protein 78, crude fibre 54, nitrogenfree extract 81, ether extract 13 and ash 52. Calculated nutritive values were—starch equivalent 27.3 and digestible crude protein 5.0, giving a nutritive ratio of about 1 : 5. The material used was moderately young.

scholarly journals Assessment of the Content of Dry Matter and Dry Organic Matter in Compost with Neural Modelling Methods

Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 307
Author(s):  
Dawid Wojcieszak ◽  
Maciej Zaborowicz ◽  
Jacek Przybył ◽  
Piotr Boniecki ◽  
Aleksander Jędruś
Keyword(s):  
Image Analysis ◽  
Organic Matter ◽  
Dry Matter ◽  
Neural Model ◽  
Original Method ◽  
Neural Models ◽  
Test Error ◽  
Effective Assessment ◽  
Modelling Methods

Neural image analysis is commonly used to solve scientific problems of biosystems and mechanical engineering. The method has been applied, for example, to assess the quality of foodstuffs such as fruit and vegetables, cereal grains, and meat. The method can also be used to analyse composting processes. The scientific problem lets us formulate the research hypothesis: it is possible to identify representative traits of the image of composted material that are necessary to create a neural model supporting the process of assessment of the content of dry matter and dry organic matter in composted material. The effect of the research is the identification of selected features of the composted material and the methods of neural image analysis resulted in a new original method enabling effective assessment of the content of dry matter and dry organic matter. The content of dry matter and dry organic matter can be analysed by means of parameters specifying the colour of compost. The best developed neural models for the assessment of the content of dry matter and dry organic matter in compost are: in visible light RBF 19:19-2-1:1 (test error 0.0922) and MLP 14:14-14-11-1:1 (test error 0.1722), in mixed light RBF 30:30-8-1:1 (test error 0.0764) and MLP 7:7-9-7-1:1 (test error 0.1795). The neural models generated for the compost images taken in mixed light had better qualitative characteristics.

scholarly journals Population improvement and synthetic cultivar production in forage kale (Brassica oleracea L.)

Euphytica ◽  
2021 ◽  
Vol 217 (7) ◽  
Author(s):  
John E. Bradshaw
Keyword(s):  
Organic Matter ◽  
Annual Cycle ◽  
Dry Matter ◽  
No Reduction ◽  
Optimum Number ◽  
Breeding Method ◽  
Thiocyanate Ion ◽  
Digestible Organic Matter ◽  
Population Improvement ◽  
Field Transplant

AbstractExperimental results are brought together to demonstrate that forage kale population improvement involving full-sib and selfed families can be done on an annual cycle, followed by production of a synthetic cultivar. Furthermore, this new breeding method compares favourably with the two successful methods used to date, namely triple-cross hybrid cultivars from inbreeding and crossbreeding programmes and open-pollinated cultivars from population improvement programmes. The key findings were that natural vernalization of kale in south east Scotland occurred by mid-December so that plants could be pollinated in a glasshouse with heating and lighting by the end of February and seed harvested by the end of May. The resulting full-sib or selfed families could be assessed in a field transplant trial in the same year, from June to November, thus completing an annual cycle. Self-pollination resulted in shorter plants with lower fresh-weight, dry-matter and digestible organic-matter yields, and undesirably higher contents of S-methylcysteine sulphoxide, the haemolytic anaemia factor, and the goitrogenic thiocyanate ion. As a consequence of digestible organic-matter yield being reduced by as much as 22%, the estimated optimum number of selfed parents in a synthetic cultivar was four to eight. Synthetic cultivars are expected to yield as well as triple-cross hybrids as there was no reduction in yield when the latter were open-pollinated.

EFFECT OF ROTATIONS, TILLAGE TREATMENTS AND FERTILIZERS ON THE AGGREGATION OF A CLAY SOIL

1971 ◽  
Vol 51 (2) ◽  
pp. 235-241 ◽  
Author(s):  
G. S. EMMOND
Keyword(s):  
Green Manure ◽  
Crop Residues ◽  
Surface Soil ◽  
Clay Soil ◽  
Soil Aggregation ◽  
Wheat Crop ◽  
Green Manure Crop

Soil aggregation was lowest in a fallow-wheat rotation and increased in other fallow-grain rotations with the second, third, and fourth crops after the fallow year. The best aggregation was under continuous wheat. Rotations containing hay crops, particularly those with grass, increased soil aggregation significantly. The influence of tillage treatments on soil aggregation declined with increased depth. Various tillage treatments affected surface soil aggregation, in the following order: green manure crop plowed under > cultivated with trash cover > crop residues plowed under > cultivated with residues burned off = crop residues disced in. Fertilizer (11–48–0) applied to the wheat crop of the various tillage treatments increased soil aggregation except where the crop residues had been removed. The application of barn manure increased soil aggregation.

Soil stripping and replacement for the rehabilitation of bauxite-mined land at Weipa. I. Initial changes to soil organic matter and related parameters

Soil Research ◽  
2000 ◽  
Vol 38 (2) ◽  
pp. 345 ◽  
Author(s):  
G. D. Schwenke ◽  
D. R. Mulligan ◽  
L. C. Bell
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Field Experiments ◽  
Surface Soil ◽  
Soil Disturbance ◽  
Microbial Biomass C ◽  
Low Grade ◽  
Double Pass ◽  
Organic C ◽  
The Difference

At Weipa, in Queensland, Australia, sown tree and shrub species sometimes fail to establish on bauxite-mined land, possibly because surface-soil organic matter declines during soil stripping and replacement. We devised 2 field experiments to investigate the links between soil rehabilitation operations, organic matter decline, and revegetation failure. Experiment 1 compared two routinely practiced operations, dual-strip (DS) and stockpile soil, with double-pass (DP), an alternative method, and subsoil only, an occasional result of the DS operation. Other treatments included variations in stripping-time, ripping-time, fertiliser rate, and cultivation. Dilution of topsoil with subsoil, low-grade bauxite, and ironstone accounted for the 46% decline of surface-soil (0–10 cm) organic C in DS compared with pre-strip soil. In contrast, organic C in the surface-soil (0–10 cm) of DP plots (25.0 t/ha) closely resembled the pre-strip area (28.6 t/ha). However, profile (0–60 cm) organic C did not differ between DS (91.5 t/ha), DP (107 t/ha), and pre-strip soil (89.9 t/ha). Eighteen months after plots were sown with native vegetation, surface-soil (0–10 cm) organic C had declined by an average of 9% across all plots. In Experiment 2, we measured the potential for post-rehabilitation decline of organic matter in hand-stripped and replaced soil columns that simulated the DS operation. Soils were incubated in situ without organic inputs. After 1 year’s incubation, organic C had declined by up to 26% and microbial biomass C by up to 61%. The difference in organic C decline between vegetated replaced soils (Expt 1) and bare replaced soils (Expt 2) showed that organic inputs affect levels of organic matter more than soil disturbance. Where topsoil was replaced at the top of the profile (DP) and not ploughed, inputs from volunteer native grasses balanced oxidation losses and organic C levels did not decline.

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