bluuebunny/crossref_metadata_2025_split huggingface dataset:
PERFORMANCE AND VITAMIN A STATUS OF SHEEP GRAZING HIGH‐NITRATE PASTURES
Authors: O'Donovan P. B. , Conway A. 
Published: April 2006

Nitrogen levels of 0,184 and 368 Ib (0,83.47 and 166.94 kg) were applied, as calcium ammonium nitrate, in six dressings throughout the grazing season to a perennial ryegrass/white clover sward. Herbage samples taken, periodically from each treatment and analysed nitrate for, indicated that the latter increased with increasing levels of applied nitrogen. Herbage nitrate levels were higher towards the end of the grazing season than at any other time. There was no consistent relationship between applied nitrogen and total plant nitrogen, although the latter tended to run parallel with applied nitrogen levels during the early part of the year.Sheep performance was significantly increased with the first increment of 184lb (83.47 kg) of nitrogen; a second increment of 1841b resulted in a further, but non‐significant, increase. High‐nitrate pastures did not significantly reduce liver vitamin A storage in sheep. It is suggested that approximately 350 Ib (158.79 kg) of nitrogen, applied uniformly throughout the grazing season, results in pasture nitrate levels which have no adverse affect on sheep performance.
A HISTORY OF THE INTRODUCTION OF TIMOTHY AND COCKSFOOT INTO ALTERNATE HUSBANDRY IN BRITAIN. 1. THE YEAR 1763 AND ITS SIGNIFICANCE
Authors: Beddows A. R. 
Published: April 2006

Timothy (Phleum pratense) and cocksfoot (Dactylis glomerata), although indigenous and commonly distributed, found no place in alternate husbandry in Britain until the end of the eighteenth century. Their value was then discovered as an indirect consequence of the search by the London Society of Arts for plants able to grow during the ‘dead season’ of the year. Letters on the subject were addressed by the society to Europe, Asia, North America and to people at home, but with no positive results. There was, however, in the New England provinces of America a developing enthusiasm at that time for timothy and, although not a winter grower, its merits became a matter for correspondence and discussion within the Society. A consequence was the arrival from America early in 1763 of various lots of seeds, but without any information as to sender(s) or the species. Both timothy and cocksfoot must have been received, for each were sown later that year at Walham Green, London, and the optimism and controversy regarding them led ultimately to a recognition of their worth and place in ley farming. The earliest sowing of American timothy in England occurred in 1743, but was without influence on agricultural thinking.Reference is made to the introduction of European species into North America, and also to the Georgical Committee set up in 1664 by the Royal Society.
THE EFFECT OF SEED WEIGHT AND DEPTH OF SOWING ON THE EMERGENCE AND EARLY SEEDLING GROWTH OF PERENNIAL RYEGRASS (LOLIUM PERENNE)
Authors: Arnott R. A. 
Published: April 2006

Seed of S24 perennial ryegrass of two weight ranges, 0.9–2.1 and 2.5–3.6 mg, were sown in soil at depths of 1.25, 2.5, 5.0 and 7.5 cm. Seedling growth was studied during the 3 weeks following germination.Seeds of both weight ranges germinated equally well at soil depths down to 7.5 cm. However, the number of shoots that emerged was reduced as the sowing depth increased. At similar depths of sowing, seedlings from the heavy seed were heavier and developed more leaves and tillers than those from light seed. Deeper sowing reduced seedling weight and the rate of leaf‐ and tiller‐production. After emergence, the relative growth rates of the seedlings which grew from seed of both weight ranges were similar at those depths of sowing which permitted the highest proportion of emerged shoots to seeds sown. This indicates that the weight advantage gained by the seedlings that developed from heavy seed during their non‐photosynthetic stage of growth was maintained, and was not increased by a greater relative growth rate after photosynthesis began.The implications of the findings are discussed in relation to plant breeding, commercial seed production and sward establishment.
THE USE OF MIXTURES OF GRANULAR DALAPON, BIRDSFOOT TREFOIL SEED AND FERTILIZER FOR ROUGHLAND PASTURE RENOVATION
Authors: Winch J. E. , Watkin E. M. , Anderson G. W. , Collins T. L. 
Published: April 2006

Trials were conducted to determine the feasibility of combining granular dalapon, P fertilizer and birdsfoot trefoil seed in mixtures for renovating natural grass pastures in Ontario. The aim was to develop a ‘once‐over’ method to facilitate the renovation of pastures characterized by rough topography, rock outcrops or surface boulders.Dalapon at 4 lb. a.i./ac (4.4 kg/ha) controlled the growth of Canada bluegrass (Poa compressa L.) and did not affect the germination and seedling growth of trefoil when applied simultaneously with the seed. Up to 100 lb/ac (112 kg/ha) P2O5 could be added to the mixture without detriment to trefoil establishment. The application of dalapon, P and seed in mixture by fixed‐wing aircraft, helicopter or ground equipment gave five‐to ten‐fold increases in pasture productivity and proved to be a practical method of pasture renovation.
THE GENERAL PATTERN IN SILAGE FERMENTATION IN TWO SUBTROPICAL GRASSES
Authors: Catchpoole V. R. , Williams W. T. 
Published: April 2006

Three sets of previously‐published experiments have been re‐analysed by numerical methods intended for the elucidation of pattern in sequential data. The results suggest that for Setaria sphacelata cv. Nandi and Chloris gayana cv. Samford Rhodes the stable terminal silage to be expected under subtropical conditions is not the high lactic‐acid silage of temperate regions, but a silage with a relatively high proportion of acetic acid. Lactic‐acid silage is formed, but usually behaves as though in a transitional phase. However, silage made from mature Setaria can be maintained in the lactic‐acid phase by the addition of high percentages of sugar. The silage fermentation can sometimes be retarded, or deflected into an undesirable path for reasons that are not understood.The above patterns suggest three hypotheses for more fundamental investigation. First, since acetic‐acid silage can be expected under most subtropical conditions, its properties require careful investigation. Secondly, relatively young Setaria may be regarded as a source of acetic‐acid silage, but the optimum amount of sugar to be added for ensiling more mature grass needs investigation. Thirdly there is an urgent need to investigate the causes of retardation of fermentation, and of its deflection into an undesirable path, because until these causes are understood, the outcome of ensilage will remain uncertain.
THE EFFECT OF FERTILIZER NITROGEN AND WHITE CLOVER ON HERBAGE PRODUCTION
Authors: Wolton K. Margaret , Brockman J. S. 
Published: April 2006

ABSTRACTThe effect of a range of N rates on herbage production from grass/white‐clover and grass swards was investigated in two long‐term grazed experiments. The mixed sward yielded more than the grass swards over the range of fertilizer rates tested which were 0–120 lb N/ac (134.5 kg/ha), but the response of the mixed sward to fertilizer N was less than that of tbe grass sward. Tbis was due to the direct and indirect effect of clover, which was considerable with no fertilizer N but decreased witb increasing rates of application. However, clover was not completely suppressed by N at eitber site and contributed to berhage yields at all N rates.Rate and time of N application and the amount of clover in tbe sward affected tbe seasonal distribution of DM yields. The mid‐season decline was less marked at bigb‐ tban at intermediate‐levels of N supply.
THE EFFECT OF NITROGENOUS FERTILIZER ON THE RATE OF GROWTH OF ITALIAN RYEGRASS
Authors: Wilman D. 
Published: April 2006

ABSTRACTIn an experiment described earlier (13), the N content of Italian ryegrass in spring reached a high value one or two weeks after applying N and then fell quickly at first and then more slowly. After 10 weeks average N content (in DM) was 0.6% from an application of 25 lh N/ac (28 kg/ha), 0.9% from 75 lb N (84 kg/ha), and 12% from 125 lb N (140 kgJha). Nitrate‐N content fell more abruptly and tben remained fairly constant. Percentage nitrate–N (in DM) fell below 0.10% during the second week after an application of 25 lb NJac, during the third week after 75 lb N, and during the fifth week after recciriag 125 lb N. The yield of N increased during the first 5 or 6 weeks, remained fairly constant for 3–5 weeks, and then hegan to fall. During the ninth and tenth weeks, the crop lost an average of 9 lb N/ac per week (10 kg/ha) after an application of 75 Ib N/ac and 12 lb N/ac per week (13 kg/ha) after 125 Ib N.
THE USE OF CATTLE AND SHEEP FOR EVALUATING GRASS AND LEGUME SWARDS, A COMPARISON OF METHODS
Authors: Calder F. W. 
Published: April 2006

ABSTRACTA comparison was made of the effects of grazing with cattie and sheep separateiy hy two methods, continuous and rotationai on two forage mixtures. The two mixtures were timothy (Phleum pratense L.) with iadino white ciover (Trifolium repens L.); and brome grass (Bromus inermis Leyss) witii aifalfa (Medicago sativa L.). The rotationai system of grazing created different effects on sward composition from those caused hy the continuous grazing system. The legumes survived hetter under rotational than continuous grazing. Sheep, under both grazing systems, grazed more severeiy than cattie; they defoliated the ieaf portion of the plants and ieft more stem standing than did the cattle. Protein of the sward increased with the leaf portion, but in vitro digestibility was not altered as leaf to stem ratios changed. Although the gross effects of sheep and cattle were similar, there were differences in detail in the effect on these swards.
COMPARATIVE STUDIES OF PERENNIAL RYEGRASS. TIMOTHY AND MEADOW FESCUE.
Authors: Aider F. E. 
Published: April 2006

ABSTRACTHays made, mainly in May, from pure swards of perennial ryegrass, timothy and meadow fescue were fed to 8‐month old steers in 1963 and to yearling steers in 1964. High‐quality hay was obtained, but no significant differences in growth rate were observed between calves fed on hays from the 3 species. In 1963, barley (1.5 kg DM/ head per day) was fed, in addition to the hays, to half the animals and resulted in a significant increase in live weight gain.The productivity, in terms of liveweight gain/ unit area, of each species when managed for hay and‘zero grazing', or hay and grazing, was calculated. On this calculation perennial ryegrass was the most productive species.
THE EFFECT OF WINTER GRAZING BY SHEEP ON SPRING AND EARLY SUMMER PASTURE PRODUCTION
Authors: Frame J. 
Published: April 2006

ABSTRACTStudies were made in S.W. Scotland of the effect of winter grazing (October to March) by sheep on subsequent spring and early summer pasture production from a sward in its first harvest year and from a permanent pasture. Averaged over the two swards, DM yields in April, May and June were reduced by 38%, 8% and 5%, respectively, as a result of various times and frequencies of grazing, compared with no grazing. Reductions were greatest after grazings in the January to March period, especially grazings involving the month of March. In a trial in which fertilizer N was used to compensate for March grazing, 50 kg NJha raised DM yields in April to the level of those from no grazing, while only 15 kg NJha were needed to raise June yields to parity. Controlled winter grazing of sheep and the use of fertilizer N to restore production losses after early spring grazing are justified.
THE PRODUCTION OF CONTRASTING GENOTYPES OF PERENNIAL RYEGRASS (LOLIUM PERENNE L.) IN MONOCULTURES AND MIXED CULTURES OF VARYING COMPLEXITY
Authors: Rhodes I. 
Published: April 2006

ABSTRACTAn experiment was set up to measure the production from donally propagated micro‐swards of four contrasting ryegrass genotypes, grown in monocultures and in all possible combinations of mixed cultures consisting of two, three and all four genotypes. Water and nutrients were supplied frequently in non‐limiting quantities and the swards were subjected to two cutting frequencies.The yield ranking of the monocultures and mixed cultures diifered at the two cutting frequencies. Under infrequent cutting, though not under frequent cutting, two mixtures, each containing two genotypes, were more productive than their highest yielding components in monoculture. The physiological basis of this apparent synergy is hriefly discussed and it is suggested that the increased yield may he due to more efficient light utilization hy the mixtures. In general, yields of other mixtures, including those consisting of 3 or 4 genotypes were intermediate between the highest and lowest yielding components in monoculture.The agronomic and plant‐breeding implications of the results are discussed.
HARVESTING TETRAPLOID RYEGRASS FOR SEED
Authors: Roberts H. M. 
Published: April 2006

ABSTRACTSequential harvests of two tetraploid ryegrasses have shown that the commercially critical level of 90% germination was attained early in the ripening process. For the greater part of the maturation period the moisture level was maintained at 60% as in diploid grasses, but the rate of moisture loss during the latter part of ripening proved to be slower than in diploids. The large seeds are more susceptible to mecbanical damage at harvest and therefore require lower drum speed.
THE USE OF MEGACHILE ROTUNDATA F. AS A POLLINATOR OF LUCERNE IN GLASSHOUSES
Authors: Atjbury R. G. , Rogers H. H. 
Published: April 2006

ABSTRACTAlfalfa leaf‐cutter (Megachile rotundata F.) bees were used to pollinate lucerne plants in glasshouse compartments. This method was particularly useful in a plant–breeding programme where rapid multiplication was required.Apparatus is described and some results are presented.
THE INFLUENCE OF SAMPLE SIZE AND NUMBER ON THE PRECISION OF ESTIMATES OF HERBAGE PRODUCTION AND CONSUMPTION IN TWO GRAZING EXPERIMENTS
Authors: Waddington J. , Cooke D. A. 
Published: April 2006

ABSTRACTEstimates of forage production and consumption were made, using dry‐weight differences between samples from protected and grazed areas. Two sizes of cage for protecting areas from grazing were compared in four forages: brome grass (Bromus inermis Leyss.)/Iucerne (Medicago sativa L.); crested wbeatgrass (Agropyron crista‐tum L.)/lucerne; intermediate wbeatgrass (A. intermedium (Host.) Beauv.)/Iucerne; and Russian wild‐rye (Elymus junceus Fisch.).Production, over a three‐year period, ranged from 1985 to 6286 kg/ha when estimated from 0.84 m2 cages. Consumption ranged from 1584 to 5878 kg/ha. Yield estimates wben using 2.51 m2 cages averaged 8% less than estimates from 0.84 m2 cages.The number of caged sites needed in each plot to estimate a 95% confidence interval for annual production were 14 for four replicates, and over 30 for fewer replicates. Requirements for consumption estimates were similar. To estimate production within a 90% confidence interval 19, 10 and 4 caged sites were required from two, three, and four replicates, respectively. Consumption estimates within tbis confidence interval required 22, 10, and 5 samples from two, tbree, and four replicates, respectively.Caging requirements were tbe same for all combinations of plot size and forage species. Large cages increased precision sligbtly wben used on Russian wild‐rye, probably because the forage was in rows 0.91 m apart.
THE EFFECT OF SUPPLEMENTARY BARLEY UPON GROWTH AND EFFICIENCY OF FOOD CONVERSION IN CALVES KEPT AT HIGH GRAZING INTENSITY
Authors: Hodgson J. , Tayler J. C. 
Published: April 2006

ABSTRACTThree groups of Hereford × Friesian steer calves, bom in early January 1969, were strip‐grazed on eqoal areas of a sward of S321 perennial ryegrass from May to September inclusive, and received kibbled barley at the rate of nil, 3/4% or 1 1/2% of liveweight per day. Adjustments were made to the number of animals per group in order to maintain the same high grazing intensity (defined as 8 cm stubble height in grazed areas) on all treatments. The animals receiving supplementary barley gained weight at a rate 17–19% higher than the controls, but there was no significant difference in growth rate between the high and low levels of supplementation. The effficiency of conversion of barley was only 5–12 kg per animal liveweight gain/100 kg barley OM.The high level of supplementation resulted in an increase in stocking rate of 36 % over that of the control group, and an increase in liveweight gain per unit area of land grazed of 63%. The additional liveweight gain due to supplements, expressed per unit area of land grazed, was relatively constant at 21–24 kg liveweight gain/ 100 kg barley OM consumed.
THE ELECTRONIC MEASUREMENT OF SMALL HERBAGE YIELDS USING A HIGH SENSITIVITY CAPACITANCE METER
Authors: Lovett J. V. , Burchi G. J. 
Published: April 2006

ABSTRACTThe capacitance meters available in the past for estimating herbage yields have lacked sensitivity at the extremes of their range of measurement. The preliminary evaluation of a highly sensitive capacitance meter described here indicates that accurate measurement is possible in the range 0.1100 kg DM/ha. The implications of this development for the measurement of herbage of low availability are discussed.
REPEATABILITY OF A TWO‐STAGE IN VITRO SYSTEM OF DIGESTIBILITY MEASUREMENT
Authors: Brundage A. L. 
Published: April 2006

ABSTRACTFive substrates (high‐quality brome grass, low‐quality brome grass, lucerne pellets, lucerne cubes, and barley straw) were analyzed for DM disappearance in a two‐stage in vitro system in nine consecutive runs. Samples for each run were inoculated in duplicate with four independent collections of rumen fluid from the same mature, non‐lactating Holstein cow. Data repeatability was excellent for the two lucerne substrates, good for high‐quality brome grass, and poor for low‐quality brome grass and barley straw.
THE AGRONOMIC EVALUATION OF SYN 1 TALL FESCUE IN THE WEST OF SCOTLAND
Authors: Frame J. 
Published: April 2006

ABSTRACTThe agronomic value of Syn 1 tall fescue, a synthetic variety derived from North African parent material, was determined in three experiments. Herbage yield, sward purity and digestibility were measured under cutting treatments for incremental sward growth during autumn/winter, and for sward regrowths during autumn/winter, spring and a complete season. Similar data were obtained for sward regrowths during autumn/winter and spring under defoliation by grazing. Syn 1 was compared with several of the north‐temperate region tall fescues, e.g. S170, Rozelle and Manade, also with S143 cocksfootSyn 1 showed yield superiority in autumn/early winter when there were comparable populations of tall fescue. Under cutting management, Syn 1 swards thinned out rapidly because of lack of winter‐hardiness and yields were depressed in the second season; the effects were worst under the winter foggage‐type management. Under grazing, with probably less severe defoliation, Syn 1 swards maintained yields for an additional season, but thereafter failed to persist Syn 1 swards had low spring‐ and annual‐yields.The yield advantage of Syn 1 in autumn/early winter was not sufficient to be of great agricultural value and with its shortcomings in winter‐hardiness and annual yield, it was considered unsuitable for West of Scotiand conditions. The main value of plant material such as Syn 1 may lie in ccmferring autumn/winter growth potential to winter‐hardy north‐temperate tall fescues in a breeding programme.
STUDIES IN RESPONSE TO NITROGEN
Authors: Hunt I. V. 
Published: April 2006

ABSTRACTRegression equations have been calculated for the primary growth of a ryegrass sward as FM (fresh matter), DM, DOM and for uptake of N, K, P, Ca, Na and Mg after application of 59,118 or 177 kg fertilizer N/ha on 16 Apr. These have been used to predict changes in response with time, the responses in terms of time, the dates when specific yields of DM are attained, the different characteristics of herbages at specified yields of DM and the effects of changing harvesting interval on annual DM yield and uptake of minerals.DM and DOM show significant responses to 118 kg N/ha but no response to the next increment throughout the 57‐day growth period. All other attrihutes, including FM, showed responses to 177 kg N/ha.Calculated response as days gained suggest that for short‐interval grazing systems the use of even 118 kg N/ha is questionable.The reduction in annual DM production and the increase in N uptake when growth intervals are shortened are related to the form of their growth curves.
INFLUENCE OF DRYING AND STORAGE CONDITIONS ON NONSTRUCTURAL CARBOHYDRATE ANALYSIS OF HERBAGE TISSUE—A REVIEW
Authors: Smith Dale 
Published: April 2006

ABSTRACTNo one method of drying can be relied upon for all plant species, plant parts, or form (e.g., fresh v. ensiled herbage). Least changes in nonstructural carbohydrates appear to occur when fresh tissue is immersed in boiling alcohol. Freeze‐drying provides results more similar to fresh tissue than heat‐drying. Heat‐drying at high temperatures (above 80°C) can cause thermo‐cbemical degradation, while slow drying at low temperatures (below 50°C) allows time for DM losses by respiration and enzymatic conversions. The most acceptable heat‐drying results have been obtained by drying for a short time at a high temperature (i.e. 100°C) and thereafter at a moderate temperature (i.e. 70°C).Changes in nonstructural carbohydrate concentrations occur during the storage of either freeze‐ or heat‐dried tissues. Thus, analyses should be conducted as soon as possible after tissue sampling. The least changes occur during storage in alcohol, following killing of the tissue in boiling alcohol.
THE EFFECTS OF DEFOLIATION ON EMERGENT ANNUAL GRASS SWARDS UNDER SIMULATED GRAZING
Authors: Greenwood E. A. N. , Titmanis Z. V. , Campbell N. A. 
Published: April 2006

ABSTRACTFor three weeks after emergence, micro‐swards of Lolium rigidum were defoliated to a height and at a frequency which represented a range of set stocking rates of less than, similar to, and more than 7–8 sheep/ha as based on the results of Greenwood and Arnold (6) and referred to as D1, D2 and D3 respectively. The effects of these defoliation regimes on the growth and development of emergent swards were evaluated according to their effect on increments of DM from plant parts, rate of appearance of leaves and tillers, concentration of soluble carbohydrates, and on the uptake and concentration of inorganic nutrients.Defoliation began five days after emergence, when the dry weight of the shoot was 3g/m2. After 20 days of treatment, 6±7 g/m2 of DM had been removed from D1, 5±5 g/m2 from D2 and 51 g/m2 from D3; and the dry weight of shoot remaining was 13, 7 and 4±5 g/m2 on D1, D2 and D3 respectively. The effect of defoliation on dry weight of plant parts increased in severity in the order leaf 1, stem+sheaths, leaf 2, roots, leaf 3, tiller 1, tiller 2, leaf 4. Average relative growth rate of the sward was reduced from 17% per day on D1 to 13% per day on D3. There was no necrosis of root tissue. Emergence of the later leaves and of the tillers was retarded by up to three days by more frequent defoliation. Alcohol‐soluble carbohydrates in the root fell from over 6% to about 1±5% on all treatments. Uptake of N. P and K was limited by increasing intensity of defoliation and because concentrations of those elements were not greatly affected, the limitation could be ascribed mainly to the effects of defoliation on plant size.The plausibility of the technique for the experimental simulation of grazing of emergent annual grass swards in Western Australia is discussed. It is concluded that for set‐stocking rates of less than about 12 sheep/ha, grazing, while reducing DM production just after emergence, is unlikely to produce severe physiological stresses in the sward.