bluuebunny/crossref_metadata_2025_split huggingface dataset:
The influence of date of sowing and seed rate on the production of pure‐sown red clover
Authors: FRAME J. , HARKESS R. D. , HUNT I. V. 
Published: April 2006

AbstractHungaropoly tetraploid broad red clover was sown at seed rates of 6, 12 or 18 kg ha‐1 on six dates from April to September 1971. Three crops were harvested in 1972 and one in June 1973.In 1972, total herbage dry matter yields ranged from 5.22 to 12.22 t ha‐1 and red clover dry matter yields from 3.61 to 11.92 t ha‐1 when meaned over all seed rates. April to July sowing dates gave significantly higher yields than later sowings. In general, August and September sowings gave the lowest red clover contents in a range from 63.2 to 96.5%, the highest digestibilities within a range 61.9 to 65.0% and the lowest crude protein contents in a range 15.5 to 17.3%.The influence of seed rate was less marked than sowing date. Mean annual yields of total herbage dry matter increased from 9.88 to 10.85 t ha−1 as seed rate was increased from 6 to 18 kg ha−1. Red clover dry matter yields and contents of red clover and crude protein in the total herbage also followed this trend.The sowing date effects on total herbage yield and content of red clover did not persist into the second harvest year but the seed rate effects were still noticeable.Plant numbers in spring the first harvest year and hence percentage survival from sowing were depressed by late sowing; plant numbers rose but percentage survival declined as seed rate was increased. The seed rate effects on plant population persisted until spring of the second harvest year but sowing date effects did not.Better stands of red clover were obtained from sowings made between April and June, when a seed rate of 12 kg ha−1 was adequate. The adverse effects of late sowing cannot be fully compensated by raising seed rates of clover. There was a significant interaction between seed rate and date of sowing. For April‐May sowings, seed rate was not critical. Thereafter, a linear effect of seed rate on yield was discernible.
The assessment of persistence and its application to the evaluation of early perennial ryegrass cultivars
Authors: CAMLIN M. S. , STEWART R. H. 
Published: April 2006

AbstractBotanical analyses were carried out on the herbage from plots of twelve early cultivars of perennial ryegrass (Lolium perenne) cut in their fourth year and the results related to visual persistence assessments carried out on the cultivars at the end of the second and third harvest years. Persistence assessments were found to be highly and positively correlated with the yields of sown cultivars (r=+0.96***,r=+0.99***) and to be highly and negatively correlated with the yields of unsown herbage species (r =+0.98***, r =−094***). The plots of the less persistent cultivars were invaded by unsown grass species and docks which contributed in varying degrees to total DM yield, reducing the correlation of total yield with persistence. Assessments of botanical composition of swards made at the end of the second year provided reliable predictions of the relative persistence of the cultivars. The results of the investigations indicated that assessment of persistence, as well as yield potential, is fundamentally important in cultivar evaluation.
The spatial distribution of excreta under intensive cattle grazing
Authors: RICHARDS I. R. , WOLTON KAREN M. 
Published: April 2006

AbstractThe spatial distribution of excreta from intensive cattle grazing was recorded and was described by a negative binomial function. This enabled the proportion of a pasture surface affected by excreta to be calculated for various grazing periods. Where the effect of excreta on the sward was short‐lived, as for urine N, or where the total area covered by excreta remained small, as for dung, then little overlapping of effective excreta patches could be expected. Appreciable overlapping of effective patches could, however, occur for the long‐lived urine K effect and this should be taken into account when estimating the proportion of a pasture surface affected.
Nitrogen fixation by white clover in hill pasture
Authors: HAYSTEAD A. , LOWE A. G. 
Published: April 2006

AbstractAn experiment is described in which the amount of nitrogen fixed by the white clover component of a surface‐sown hill sward was determined using small quantities of 15N‐labelled ammonium sulphate. Between 11 July and 22 August 1974 25 kg ha−1 N was fixed. No evidence of a transfer of N from clover to the associated perennial ryegrass was detectable over this period although the N content of the grass growing with the clover was higher. The relative advantages of the isotope technique and the acetylene reduction assay are discussed.
The drying pattern of grass swaths in the field
Authors: CLARK BRENDA J. , McDonald P. 
Published: April 2006

AbstractThe drying pattern of grass swaths was monitored using microclimate techniques during a 48 h summer wilting period of good drying conditions. Swath drying pattem, which is dependent upon the swath energy relations, water relations and resistances to evaporation, was explained in terms of changes in the balance of available energy, ambient vapour pressure deficit and swath internal resistance to water vapour transfer throughout the drying period. A typical drying pattern showed limited swath evaporation between sunrise and 09.00 hours, and rapid evaporation between 09.00 hours and 12.00 hours when available energy and vapour pressure deficit were high and swath resistance to water loss low. Between 12.00 and 18.00 hours, because of a decrease in available energy and increase in swath resistance, swath evaporation was reduced. Between 18.00 hours and sunset swath evaporation was near zero.
The effects of rates of nitrogen application on seven perennial ryegrass varieties
Authors: LEE G. R. , DAVIES L. H. , ARMITAGE E. R. , HOOD A. E. M. 
Published: April 2006

AbstractThe dry matter and crude protein production of the perennial ryegrass varieties S24, S23, Premo, Houba, Barlenna, Melle and Sceempter Pasture at annual nitrogen application rates of 212, 425, 637 and 1062 kg ha−1 were studied for the years 1972–74 inclusive. The DM and CP response curves for the variety Melle were steeper than those for other varieties tested and levelled off at a higher N application rate. The results suggest that Melle is a variety with a genotype capahle of utilizing N more efficiently at higher rates than the other varieties tested.
Grass growth in different parts of England in relation to invertebrate numbers and pesticide treatment
Authors: HENDERSON I. F. , CLEMENTS R. O. 
Published: April 2006

AbstractRyegrass swards at fourteeo widely separated sites in England were assessed for yield, botanical composition and invertebrate populations, with and without insecticide treatment during a 4‐year period. Treatment with insecticide reduced the numbers of almost all invertebrate groups sampled and increased grass growth at some time at all but one site. Annual DM output was increased by 0–32% depending upon the site concerned. Evidence is presented which suggests that the yield increases were due to the suppression of aphids, plant‐sucking bugs, stem‐boring fly larvae, and perhaps nematodes.
Limitations of the electronic capacitance meter in measuring yields of grazed tropical pastures
Authors: JONES R. M. , SANDLAND R. L. , BUNCH G. A. 
Published: April 2006

AbstractRelationships between readings of the electronic (capacitance) pasture meter and descriptions of pasture yield were examined over the yearly growth cycle in grazed pastures of Setaria anceps cv. Nandi, with or without Macroptilium atropurpurem cv. Siratro and Desmodium intortum cv. Greenleaf. There was a poor relationship between meter reading and pasture dry matter yield (r =+0.574 pooled over pastures and seasons) but this relationship was improved to r=+0.750 by inclusion of other regressors describing pasture height and proportion of inert material. Meter reading was more closely related to fresh pasture yield (r =+0.830), water yield (r =+0.885) or dried green yield (r =+0.830), although inclusion of a pasture height term still improved the relationship slightly. Suggestions are made about using the meter to estimate dried green yield rather than total dry matter yield, and taking more consideration of the proportion of inert material when relating the meter reading to total dry matter yield.Visual estimation was also compared with actual pasture yield measured by cutting. Even though prior training for yield estimation was inadequate, the relationships between visually estimated and actual yield were as good as those from the pasture meter. It is concluded that the pasture meter will not find a regular use as a sampling tool in most grazed tropical pastures.
Effect of supplementary concentrates on performance of early‐weaned lambs at pasture
Authors: MARSH R. , CHESTNUTT D.M.B. 
Published: April 2006

AbstractTwo experiments in which early‐weaned lambs (4–7 and 5–9 weeks of age) continuously grazed a perennial ryegrass‐white clover sward are described. In both experiments groups of lambs were offered a proprietary concentrate ad libitum, 2/3 or 1/3 of ad libitum allowance, or no concentrate. Mean daily gains over 56 days in Experiment 1 increased from 88 g without concentrate to 275 g with ad libitum concentrate allowance; the range in daily gains over 71 days in Experiment 2 was 201 g to 253 g respectively. In both experiments mean faecal OM output from herbage decreased as concentrate OM intake increased.
A comparison of methods of predicting the in vivo digestibility of heather by sheep
Authors: MILNE J. A. 
Published: April 2006

AbstractMethods of predicting the in vivo dry matter digestibility (DMD) of heather were examined in studies on ten samples of heather which had been fed to sheep in standard digestibility trials. DMD was predicted with similar accuracy from estimates of in vitro dry matter digestibility (in vitro DMD) and from the concentration of cell‐wall constituents. In vitro DMD was found to be between 10 and 18 percentage units lower than DMD. Freeze drying the samples was the only modification to the technique which both increased in vitro DMD and the accuracy of the prediction of DMD. Other modifications attempted were the use of different liquor sources, changes in first‐stage incubation time and dilution rate, and nitrogen supplementation of the inocula.The concentration of nitrogen or undigested dietary nitrogen in the faeces could not be used to predict the digestibility of heather with precision. It was concluded that the DMD of a heather diet could be satisfactorily predicted from the in vitro DMD of samples collected from sheep fistulated at the oesophagus.
Silage and milk production: a comparison between additives for silage of high digestibility
Authors: CASTLE M. E. , RETTER W. C. , WATSON J. N. 
Published: April 2006

AbstractThree grass silages made in early June from S23 perennial ryegrass were compared in a 16‐week feeding experiment with twelve Ayrshire cows. The silages were made from uniform herbage which received either formic acid (‘Add‐F’) at the rate of 201 t−1, or a formalin‐sulphuric acid mixture (‘Syiade’) at rates of 2.0 and 4.4 1 t−1. The silages were offered ad libitum either alone or supplemented with a cube containing 38% CP in the DM at the rate of 1.4 kg per 10 kg milk. The daily intakes of silage DM were not significantly different on the three silage treatments, and averaged 10.7, 11.0 and 11.0 kg per cow on the formic acid and the 2.0 and 44 1 t−1 formalin‐acid treatments respectively. The mean daily yields of milk were 15.1, 13.3 and 13.7 kg per cow in the unsupplemented treatments, and 18.2, 18.1 and 18.0 kg per cow in the supplemented treatments on the formic acid and the 2.0 and 44 1 t−1 formalin‐acid treatments respectively.On the basis of total animal production expressed in terms of metabolizable energy requirements, it was concluded that the differences between the three silages were small.
The influence of autxunn cutting regime on the response to temperature of leof growth in perennial ryegrass
Authors: THOMAS HENRY 
Published: April 2006

AbstractPlots of perennial ryegrass were cut in September, October, November and December 1975, and soil surface temperature, leof extension rates, appearance rates and lengths were measured between September 1975 and April 1976.Cutting on progressively later dates in the autumn reduced leof extension rates and leof lengths throughout the following winter and spring, whereas leof appearance rates were reduced for only about 1 month ofter cutting.
An evaluation of a high‐quality grass silage for milk production
Authors: GORDON F. J. , MURDOCH J. C. 
Published: April 2006

AbstractForty British Friesian cows with a mean calving date of 28 January were used in a randomized block design experiment to evaluate a high‐quality grass silage for milk production. The high‐quality silage was made from two consecutive cuts of a perennial ryegrass sward after regrowth intervals of 37 days, wilted to 51% dry matter, finely chopped and ensiled using 2.2 1 t‐1 (0.5 gallons per ton) of formic acid. The resulting silage had a dry matter digestibility of 72.9% and was fed ad libitum with 3.8 kg (8.4 lb) concentrates as a supplement. A medium‐quality grass silage, of lower digestibility and dry matter content (70.0 and 25.4% respectively), was also fed ad libitum in addition to either 3.8, 5.7 or 7.6 kg (8.4, 12.5 or 16.7 lb) concentrates. The feeding treatments were commenced immediately after calving and were terminated on 9 April giving a mean period of 72 d on the treatments. Over the experimental period the animals on the high‐quality silage consumed 15% more silage dry matter and produced 8% more milk that those on the medium‐quality silage with the same level of concentrate supplementation. From the results it was estimated that 1.9 kg (4.3 lb) of additional concentrates would be required with the medium‐quality silage to give an equivalent milk output to that achieved with the high‐quality silage. Milk composition, liveweight change, ration digestibility and nitrogen balance data are also presented.
Maize silage with a non‐protein nitrogen additive as feed for autumn‐calving cows
Authors: PHIPPS R.H. , CRAMP D.G. 
Published: April 2006

AbstractMaize silages made in October were fed to forty‐three autumn‐calving cows during a 20‐week winter feeding trial. The control silage received no additive whereas a non‐protein nitrogen (NPN) additive was applied to the other silage at harvest time. The four experimental feeding treatments were: A, maize silage + 6 kg d−1 barley; B, maize silage with NPN + 6 kg d−1 barley; C, maize silage + 5 kg d−1’barley + 1 kg d−1 extracted decorticated groundnut cake; D, maize silage with NPN. The mean daily milk yields of cows on the treatments were 14.7, 15.1, 15.3 and 15.0 kg respectively. All cows received maize silage ad libitum. There were no significant differences in milk yield but the milk produced by the cows on treatment D had significantly lower concentrations of milk fat, protein and solids‐not‐fat when compared to the other three treatments. The cows on treatment D had a negative liveweight change which was significantly different (P < 0.05) from those of the cows on treatments B and C.
Dalapon resistance at an early seedling stage in Lolium perenne
Authors: THORNTON M. S. , CHARLES A. H. 
Published: April 2006

AbstractThe inhibitory effect of the herbicide dalapon on germination and shoot elongation was evaluated in two perennial ryegrass cultivars, Melino RvP and Cropper. These cultivars had been shown to be dalapon resistant and susceptible, respectively, in a previous comparison of 14‐week‐old plants.Dalapon (10‐2 and 10‐3 m) significantly reduced rates of germination and shoot elongation to the same extent in both cultivars.It is suggested that the effects of dalapon on germination and shoot elongation during the first 9 days of development are not indicative of levels of resistance in more mature plants.
The effect of partial neutralization of formic acid silages with sodium bicarbonate on their volimtary intake by cattle and sheep
Authors: FARHAN S. M. A. , THOMAS P. C. 
Published: April 2006

AbstractIn two 4 × 4 Latin Square experiments, one with dry cows and one with sheep, animals were given ad libitum early‐cut ryegrass silages prepared using formic acid (2.31 t−1) as an additive. The silages were offered either untreated or partially neutralized with either a low (8 g kg−1 fresh weight) or high (16 g kg−1) level of sodium bicarbonate or with sodium bicarbonate solution (50 g kg−1) given as an intraruminal infusion at a rate sufficient to provide bicarbonate at a rate similar to that provided by the high level of dietary addition.In cows the bicarbonate treatments were associated with a depression in the intake of organic matter which at the high level of addition of bicarbonate was statistically significant (P < 0.05). In sheep the bicarbonate treatments were associated with a slight increase in the intake of organic matter but the efFects were non‐significant (P > 0.05). In both species water intake increased directly with the quantity of bicarbonate ingested.In both experiments the bicarbonate treatments increased rumen pH but there were no significant treatment effects on the concentration of ammonia or of total or individual short‐chain fatty acids in the rumen fluid. In sheep, bicarbonate addition or infusion had no effect on the digestibility of organic matter but at the high levels of bicarbonate supplementation there was a tendency for the digestibility of nitrogen to be depressed.In two further experiments each with two dry cows determinations were made of the effects on food intake of (a) the insertion of water‐filled bags into the rumen and (b) the removal of digesta from the rumen. Treatment (a) produced consistent and significant (P < 0.05) depressions in dry matter intake and treatment (b) increased (P < 0.05) dry matter intake in one cow but not in the other.The lack of significant improvement in silage intake through the addition of sodium bicarbonate to the diet indicated that the acidity of the silage was not a major factor limiting appetite. On the other hand, the effects of the insertion of water‐filled bags into the rumen and of the removal of digesta from the rumen on feed intake were consistent with appetite being controlled through a rumen‐fill mechanism.
A mathematical model to study forage conservation methods
Authors: PARKE D. , DUMONT A. G. , BOYCE D. S. 
Published: April 2006

AbstractA mathematical model which simulates a single‐cut forage conservation system is described. It was designed to investigate the effect of machine performance on the nutrient content of conserved forage but its scope is much wider, so that the effects of such aspects as crop growth characteristics, climatic differences and management policy can be assessed. An example of the use of the model to determine the value of chemical additives to high moisture content hay is described in detail. Various uses of the model are discussed and some of its limitations are shown to be caused by a lack of data on factors determining dry matter losses.
Competition between Lolium perenne and Poa trivialis during establishment
Authors: HAGGAR R. J. 
Published: April 2006

AbstractThree experiments were carried out in boxes to determine the response of L. perenne seedlings to competition from P. trivialis seedlings at different densities and ages and when the proportions of the two species were varied according to the replacement principle. Tiller numbers per plant were significantly reduced by P. trivialis at densities commonly found in the field. Prior establishment of P. trivialis caused disproportionate damage to L perenne tillering and the early removal of such plants resulted in yield benefits to L. perenne. When sown together, P. trivialis was shown to be competitive towards L. perenne during the first 4 weeks of establishment but during the next 4 weeks, although competition was still occurring between the two species to the detriment of Poa, relative productivity (but not total productivity) was marginally greater in the mixture. The need for early herbicide treatment to prevent interspecific competition between graminaceous species during establishment is discussed.
Winter hardiness in Lolium multiflorum Lam. III. Selection for improved cold tolerance and its effect on agronomic performance
Authors: HIDES D. H. 
Published: April 2006

AbstractNine varieties of Italian ryegrass were subjected to two generations of selection for cold tolerance using a controlled environment test. Selection led to a significant overall improvement in average tiller survival from 39·8 to 47·7%, even though the selection intensity achieved was not more than 20%. Although individual varieties varied in initial tolerance from 31·1 to 71·4%, the cold room tests were not sufficiently sensitive to attach significance to differences in response to selection which varied from 0·3 to 17·6%. Agronomic assessment of spaced plants indicated that the winter and spring growth potential of all nine varieties was unaffected by selection for cold tolerance. Although some of the selected populations showed a significant decline in their total yields and persistency, others showed no significant change in these characteristics. The plant breeding implications of these results are discussed.
The digestibility of diets containing processed dried lucerne by sheep and cows
Authors: THOMAS S. , CAMPLING R. C. 
Published: April 2006

AbstractA series of trials was conducted to compare the digestibility of organic matter in castrated male sheep and non‐lactating and lactating cows given diets containing lucerne cobs. Similar digestibility coefficients were determined when sheep and non‐lactating cows were given hay and lucerne cobs, but lactating cows digested diets of hay, lucerne cobs and concentrates less well than sheep. It is concluded that if sheep are used in digestibility trials with diets containing processed lucerne and concentrates intended for milking cows, appreciable errors of prediction of digestibility of organic matter may arise.
The effect of controlling bracken [Pteridium aquilinum (L.) Kuhn] on pasture production
Authors: Davies G. E. , NEWBOULD P. , BAILLIE G. J. 
Published: April 2006

AbstractThe outcome of spraying two bracken‐infested hill sites in July with asulam at the commercial rate of 4·5 kg a.i. per ha was a 98% reduction in frond numbers which persisted for the following 3 years. Broad‐leaved grasses, Agrostis tenuis, Agrostis canina and Poa pratensis, were susceptible to asulam and were severely reduced at both sites while fine‐leaved grasses, Festuca ovina and Deschampsia flexuosa, were resistant. Over a period of 3 years after spray application the original bare ground under the bracken canopy and that produced by the effects of asulam was recolonized by the recovery of the broad‐leaved grasses and an increase in the cover of herbs. The latter also increased on the unsprayed control areas.A favourable aspect and an abundance of the productive broad‐leaved grasses appeared to be the main factors which determined the amount of increase in herbage yield observed following spray treatment. One such area gave a herbage DM yield of 3039 kg ha‐1 during the growing season which was 47% greater than the control while an area with a less favourable aspect and dominated by the less productive fine‐leaved grasses gave a herbage yield of 2069 kg ha‐1 which was only 18% greater than the control.