bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estimation of the ruminal degradation of forage rape after incubation in nylon bags in the rumen of sheep
Authors: DOVE H. , McCORMACK HEATHER A. 
Published: April 2006

AbstractThe nylon bag technique was used to measure the disappearance of dry matter, nitrogen and non–nitrogenous dry matter from samples of forage rape leaf and stem incubated in the rumen of sheep. Samples were either hand–harvested and chopped or obtained using Iambs with oesophageal fistulae.Differences were observed in the dry matter and nitrogen contents of oesopha1 fistulae extrusa and cut samples; calculations are presented to suggest that these differences were not due to salivary contamination. Compared with cut samples, oesophageal fistulae extrusa had significantly higher initial disappearance, fractional rate of disappearance and predicted disappearance of both dry matter and nitrogen. Observed disappearances from leaf and stem extrusa after 24 h incubation were: dry matter from leaf 0·898 and from stem 0·832; nitrogen from leaf 0·942 and from stem 0·910. Corresponding values for cut leaf and stem were 0·817, 0·726, 0·883 and 0·849, respectively.The rumen degradation of protein (nitrogen × 6·25) was computed for all combinations of leaf, stem, cut and extrusa samples for rumen fractional outflow rates ranging from 0·02 to 0·09. Degradation levels computed from cut samples were much less than those based on oesophageal fistulae extrusa and are suggested to be underestimates. Rumen degradation levels for forage rape leaf and stem were very similar and ranged from 0·83 to 0·75 over the above range of fractional outflow rates.
The effects of frequency of defoliation, date of first cut and heading date of a perennial ryegrass companion on the yield, quality and persistence of diploid and tetraploid broad red clover
Authors: SHELDRICK R. D. , LAVENDER R. H. , TEWSON V. J. 
Published: April 2006

AbstractThe effects of cutting frequency on dry matter yield, crop persistence and herbage quality of representative diploid and tetraploid varieties of broad red clover (Trifolium pratense) were investigated in two trials at Hurley in the period 1975–79.Pure‐sown swards of broad red clover varieties were used in the first trial (A), while both pure‐sown swards and those sown with a perennial ryegrass companion grass were included in the second trial (B).Tria1was cut three or six times per annum, trial B three, four or five times per annum. In both trials, the change from normal management of three cuts per annum to six (trial A) or five (trial B) cuts per annum reduced output, whether in terms of dry matter yield (trial A by 31%; trial B by 33%), N yield (trials A and B by 15%) or metabolizable energy (trial A by 24%; trial B by 28%), and in trial A also led to more rapid reduction in clover plant density. More frequent cutting also raised mean D–value (trial A by 5–3 units; trial B by 3–4 units) and N concentration (trial A by 64 g kg dry matter‐1; trial B by 70 g kg dry matter‐1). Tetraploid (4x) red clover varieties generally out–yielded diploid (2x) varieties, except in trial A in 1976 when, under drought conditions, Granta and Kuhn (both 2x) equalled the yield of Wensum (4x) and out–yielded Norseman and Maris Leda (both 4x).The companion grasses included in trial B formed a sequence from early to late flowering (Aberystwyth S24, Barlenna, Endura), and their inclusion raised dry matter yields and D‐value, though it lowered N concentration in the mixed herbage. Highest annual dry matter yields in this trial, which received supplementary irrigation, were 1641 ha‐1 from a pure–sown crop (Hungaropoly) and 205 t ha‐1 from a mixture (Wensum/ Aberystwyth S24), from three cuts in the first harvest year. Aberystwyth S24 had the greatest effect in raising yields; though least effect on improving digestibility. Endura was the converse, and it was concluded that an intermediate‐maturity variety such as Barlenna was the most satisfactory companion.Both trials A and B suggested that in south–east England, broad red clover can be considered only as a 2–year crop and that ways must be found to prolong its productive life. Strategies to increase the digestibility and hence the economic value of the crop by cutting more frequently than three times per year are unattractive because of the large fall in yield and relatively small improvement in digestibility and hence metabolizable energy concentration.
Further studies on the effect of phosphate fertilizer and propyzamide on the growth of white clover slot‐seeded into permanent pasture
Authors: WILLIAMS E. D. 
Published: April 2006

AbstractAssessments were made of the clover yield and clover content between early June and late July 1984 of white clover in a permanent pasture which had been slot‐seeded in spring 1982.Past reserves of phosphate or application of propyzamide alone only slightly increased clover dry matter yield but together they increased it from 13 to 785 kg dry matter ha‐1 and gave 31% clover in the total herbage yield. Applications of P2O5 during the experiment, alone or together with past reserves of phosphate, Iased clover yield from 13 to 242 kg dry matter ha‐1 and the proportion of clover from 1 to 10%. However, highest yields (1282 kg) and clover content (37%) were attained when P2O5 and propyzamide were applied to treatments with past reserves of phosphate.These results confirmed the trends evident during the second year and also indicated a potential role for grass‐suppressants in increasing management options during the early years after slot‐seeding.
Influence of structure and composition of ryegrass and prairie grass‐white clover swards on the grazed horizon and diet harvested by sheep
Authors: L'HUILLIER P. J. , POPPI D. P. , FRASER T. J. 
Published: April 2006

AbstractDiet selection from ryegass‐and prairie grass‐white clover swards, vertically stratified into three horizons (A > 6 cm, B 3–6 cm, C > 3 cm), was studied using oesophageally fistulated sheep during summer and autumn. Animals grazed for 3‐day periods. Apparent herbage intake was calculated from total herbage disappearance. The composition of each horizon and of the diet selected was measured daily.Herbage mass (DM ha‐1) and sward height (cm) prior to grazing were not significantly different between swards in each season, and were 2·0 and 20 in summer and 1·6 and 10 in autumn. In summer, 36% and 5% of the green grass leaf (GGL) for prairie grass and ryegrass, respectively, was distributed in horizons A and B. In autumn 39% and 29% of GGL occurred above 3 cm for prairie grass and ryegrass, respectively. GGL distribution determined which sward horizons were grazed. Sheep grazed horizon C (0–3 cm) of summer ryegrass pasture, and the surface canopy (>3 cm) of all other swards.In summer, apparent intake achieved by sheep grazing prairie grass swards was 87% higher than that achieved on ryegrass swards. In autumn a greater GGL distribution above 3 cm with prairie
The indirect estimation of the digestibility in cattle of herbage from Belgian permanent pasture
Authors: BARTIAUX‐Thill NICOLE , OGER ROBERT 
Published: April 2006

AbstractRelationships between herbage organic matter digestibility measured in vivo, and faecal nitrogen concentration were determined. Measurements of in vivo digestibility were made on twenty‐nine herbages, cut from mixed improved permanent pastures with Lolium perenne as the predominant grass and offered ad libitum to cattle. The faecal nitrogen index predicted the herbage digestibility with good accuracy, and the equations obtained should have application for such determinations on Belgian pastures.
Study of the population dynamics of dipterous stem‐borer larvae of ryegrass swards under rotationally grazed or cut conditions
Authors: MOORE D. , CLEMENTS R. O. 
Published: April 2006

AbstractObservations made between 1980 and 1982 showed that dipterous stem‐borers were more common in grazed than cut swards. The two forms of Oscinella frit were particularly prevalent in grazed swards but O. vastator was more evenly distributed and dominated the larval populations of the cut sward in 1981. The population dynamics of all species were probably affected by the number of days on which weather was suitable for high stem‐borer adult activity. It was also found that stem‐borer larval numbers could expand rapidly after periods suitable for high adult activity even when adult numbers had been low for long periods. Despite low numbers of O. vastator being present in winter 1981, their numbers increased markedly and built up to a large population which peaked in September 1981.
Predicting the response of perennial ryegrass to fertilizer nitrogen in relation to cutting interval, climate and soil
Authors: DOYLE C. J. , RIDOUT M. S. , MORRISON J. , EDWARDS C. 
Published: April 2006

AbstractThis paper describes the derivation of a series of equations for estimating mean grass production on cut swards under different fertilizer nitrogen, soil and climatic regimes. Using data from the National Grassland Manuring Trial GM20 for a late flowering perennial ryegrass, equations have been estimated for the individual cuts. On the basis of data from cutting trials at Hurley, equations for extrapolating yields under cutting strategies with different first cut dates and regrowth intervals have been derived. The resultant model for predicting yields has then been tested against data obtained from two separate cutting trials. Although in individual cases significant differences between predicted and observed mean yields were noticed, in general the predicted yields were a reasonable approximation to observed yields. Comparison of the predicted yields with those derived from an earlier study by the authors indicated an improvement in the accuracy of prediction.
The influence of the system of silage harvesting and feeding and the use of protected protein on milk production
Authors: GORDON F. J. 
Published: April 2006

AbstractThe study compared two systems of silage harvesting, direct‐cutting flail harvesting (flail‐direct) or pre‐cutting, followed by wilting and collection by a meter‐chop harvester (precision‐wilted). Each silage was self or easy fed to dairy cows. In addition, the response to protected soya bean meal included in the supplementary concentrate was also examined.Approximately 400 t of each of the two silages were produced from the same swards under good weather conditions with formic acid applied as an additive. The resulting silages were well preserved and had mean particle lengths of 43 and 29‐mm, and D‐values of 0‐74 and 0‐71 for the flail‐direct and precision‐wilted silages, respectively.During a 159‐d feeding period commencing on 5 November, the silages were offered to 88 British Friesian cows in a 23 factorial design, continuous feeding experiment. The cows calved during the experiment and had a mean calving date of 18 January. The feeding treatments involved both silage types, two systems of silage feeding (self and easy) and two sources of protein in the supplementary concentrate given after calving (soya bean or 100 g kg‐1 protected soya bean). No concentrates were offered pre‐calving and all animals were given 7.6 kg d‐1 concentrates post‐calving.There were no significant interactions between the system of silage harvesting and feeding.Animals on the precision‐wilted silage consumed 14% more silage dry matter (10.9 vs. 9.6 kg DM d‐1) over the total period and by the end of the experiment were producing 7% less milk per day (25.4 vs. 27.2 kg). However, the responses in the output of total milk constituents (fat and protein) were lower than those obtained in milk yield. Animals offered silage by self feeding had similar dry matter intakes, but produced marginally less milk than those easy‐fed.Ration digestibility and nitrogen utilization data, obtained from a concurrent change‐over design experiment, suggested that the energy from the precision‐wilted silage was less efficiently utilized for milk production.There was no significant response in either milk yield or composition to the inclusion of protected soya bean in the supplement.
Comparative studies of ingestive behaviour and diet composition in oesophageal‐fistulated and non‐fistulated cows and sheep
Authors: FORBES T. D. A. , BEATTIE M. M. 
Published: April 2006

AbstractA series of comparisons was made of the bite rates of fistulated and non‐fistulated cattle and sheep, grazing four grassy hill plant communities over four years. Both bite rates and grazing times were recorded on two occasions. Comparative observations were also made on faecal cuticle concentrations on one grassy and one dwarf shrub community and on faecal ash, nitrogen (N) and acid detergent fibre (ADF) concentrations throughout one year.Faecal N concentrations were slightly but consistently higher in fistulates than in non‐fistulates, but faecal ADF and ash concentrations and the relative proportions of faecal cuticle fragments were similar and did not indicate differences in either diet composition or digestive efficiency. Bite rates did not differ significantly between fistulates and non‐fistulates, except on the two occasions when fistulates carried Vibracorders to measure grazing time without preliminary training, and grazing times did not differ significantly. There were significant differences between cattle and sheep in most variables.On the basis of this evidence, there is no reason to expect that fistulated and non‐fistulated animals of similar history and nutritional background will differ in grazing behaviour or diet composition.
A study of the potential of lucerne as a silage crop in a high‐rainfall area
Authors: REID D. 
Published: April 2006

AbstractThe results are reported of a 2‐year plot experiment investigating the potential of lucerne as a silage crop in a comparatively high‐rainfall area (annual average of about 900 mm). The performance of the lucerne on the remainder of the field in which the plot experiment was located is also discussed. With below‐average rainfall in the sowing year a good establishment was obtained and a single cut to a stubble height of 75 mm in August gave a dry matter yield of 3 t ha‐1. In the first harvest year, summer rainfall was again below average and a total dry matter yield of 13·8 t ha‐1 resulted from three cuts to 75 mm above ground level. However, the total yield was reduced to 10·11 ha‐1 in the second year when the rainfall was considerably above average. Attempts to increase the feeding value of the lucerne herbage by increasing cutting frequency and by increasing cutting height showed little effect over the standard system of three cuts to a stubble height of 75 mm. The effects of applying potassium fertilizer at rates supplying 100,200 or 300 kg K ha‐1 either as a single spring dressing or in equally divided dressings were not significant in either of the two years
The influence of ethofumesate on the growth and development, chlorophyll and nitrogen content of Lolium perenne L.
Authors: DEAN M. R. , OLLERENSHAW J. H. , STEWART W. S. 
Published: April 2006

AbstractPot experiments and a hand‐weeded field trial were carried out to investigate the direct effect of ethofumesate on the growth and development of Lolium perenne cv. S24.In the field trial, ethofumesate was applied in autumn as Nortron 20% ec formulation in a volume of 2001 ha‐1 at rates of 0, 1 or 2 kg a.i. ha‐1. Treatments had no direct effect on yield in the following summer. In both the field trial and pot experiments there was initial growth suppression in the form of a reduction in shoot dry weight, lamina dry weight, tiller number per plant and plant height. However, ethofumesate increased the chlorophyll and nitrogen contents of L. perenne laminae, but only when available soil nitrogen was not limited.It is concluded that ethofumesate can increase the yield of L. perenne by suppressing weed competition, but there is no evidence of the herbicide directly increasing the growth or yield of cv. S24.
The potential of an all‐grass diet for the late‐winter calving dairy cow
Authors: RAE R. C. , THOMAS C. , REEVE A. , GOLIGHTLY A. J. , HODSON R. G. , BAKER R. D. 
Published: April 2006

AbstractIn a trial lasting 3 years at Jealott's Hill and 2 years at Ravenscroft Hall, a total of 73 January‐ March‐calving Friesian x Holstein cows and heifers were given a diet consisting almost exclusively of ensiled and grazed ryegrass for an entire lactation to establish the level of milk production which grass alone can support. From calving to turnout in April/May (average duration 87 days), the animals were given high digestibility (DOMD = 678g kg‐1 DM) ryegrass silage ad libitum. After turnout, they grazed ryegrass swards until housing in autumn. Thereafter, the cattle were given ryegrass silage of lower digestibility (DOMD = 600–620 g kg‐1 DM) for the remainder of the lactation and during the dry period.Mean silage dry matter intakes from calving to turnout were 13–2 kg day‐1 at Jealott's Hill and 11·5 kg day‐1 at Ravenscroft Hall. Average milk yields were 21‐1 kg day‐1 for cows and 16‐1 kg day‐1 for heifers with 39‐2g fat kg‐1, 29‐6g protein kg‐1 and 47–9 g lactose kg‐1. Over the complete lactation, average milk yields were 4680 kg and 4006 kg for the cows and heifers, respectively, with 39‐4 g fat kg‐1, 31·4 g protein kg‐1 and 46·9 g lactose kg‐1. Animal health and fertility were satisfactory. The results demonstrated the value of high quality grazed and ensiled ryegrass and provided a measure of milk production from grass only.
The effects of feeding fodder beet to dairy cows offered silage ad libitum
Authors: ROBERTS D. J. 
Published: April 2006

AbstractIn a 16‐week winter feeding experiment, 48 autumn calving cows and heifers were used to compare a control diet, with two diets including fodder beet at a low and a high level. The control diet was ad libitum silage and 6 kg d‐1 of concentrates (13.4 MJ (kg DM)‐1 of ME and 197 g (kg DM)‐1 of CP). The cows offered fodder beet were fed the control diet (C) plus fodder beet at either 2 (L) or 4 (H) kg DM d‐1. Soya bean meal was offered with the fodder beet at 0.5 or 1.0 kg d‐1 for diets L and H, respectively.Total dry matter and metabolizable energy intakes were 15.2,16.4 and 17.3 kg DM d‐1; 177, 195 and 211 MJ d‐1 for treatments C, L and H, respectively. The mean milk yields were not significantly affected by the feeding of fodder beet. There was a significant improvement in the fat and protein content of the milk and yield of constituents. The milk composition and yield of solids were: fat content 42.3,44.2 and 45.9 (s.e.d. 1.25) g kg‐1; protein content 33.0, 34.5, 35.3 (s.e.d. 0.76) g kg‐1; fat yield 964,1027,1095(s.e.d. 63.2); protein yield 757, 801, 841 (s.e.d. 48.8) for treatments C, L and H, respectively. The treatments had no significant effect on live weight or condition score change.
Herbage potassium levels in a permanent pasture under grazing
Authors: TALLOWIN J. R. B. , BROOKMAN S. K. E. 
Published: April 2006

AbstractHerbage potassium levels were measured in 1986 in a permanent pasture under continuous grazing with cattle and receiving 200 kg N ha−1. In April, before grazing started, K concentration in the herbage was relatively uniform across the pasture, with a value of 1·9 ± 0·038% K in the herbage dry matter. In July, a significantly lower concentration of herbage K was found in the grazed areas of the pasture (1·8 ± 0·10%) compared with the level (2·4 ± 0·088%) found in the rejected areas of the sward. The difference between the grazed and rejected areas was similar in September, with 1·6 ± 0·087% and 2·2 ± 0·172% K, respectively, in the herbage dry matter. This result suggests that herbage growth in the grazed areas might have been limited by K supply and highlights the need for more information on the K requirements of grazed grassland.
Harvest frequency effects on forage yield and quality of rapes and rape hybrids*
Authors: JUNG G. A. , SHAFFER J. A. , STOUT W. L. , PANCIERA M. T. 
Published: April 2006

AbstractSpring‐seeded rape requires approximately two‐thirds of the growing season in the north‐cast USA, to reach physiological maturity. Harvest frequency studies were conducted with rapes and rape hybrids in Pennsylvania to determine whether forage yields and/or quality can be improved with multiple harvests, and whether cultivars respond similarly to harvest management. Nitrogen was applied at 75 kg ha−1 at seeding and 75 kg ha−1 70 d after seeding. Additional fertilizer was applied according to soil test results. A split‐split‐block design was used. Harvest frequencies of 180, 90, 60, or 30 d were randomly assigned to blocks. Cultivars were randomized within each harvest frequency, with four replicates. Amount of regrowth of all cultivars after mid‐August was highly variable, depending on weather. Foliar diseases and aphids lowered yields in different years. Cultivars differed in susceptibility to diseases and aphids as well as in morphology. Forage yields and crude protein yields of rape generally were highest with the 90‐d harvest frequency, whereas crude protein concentration was highest with the 30‐d frequency. Mean in vitro dry matter digestibility (IVDMD) values were high regardless of harvest frequency, cuttivar, or sampling date. Yield differences between cultivars generally were greatest with one harvest at 180 d; mean yield was highest for forage rapes, intermediate for winter oil rapes, and lowest for rape x Chinese cabbage hybrids. Under frequent harvesting, BLE rape and the rape x Chinese cabbage hybrid performances were exceptional as regards forage yield and quality.
Use of a model to optimize the interaction between frequency and severity of intermittent defoliation and to provide a fundamental comparison of the continuous and intermittent defoliation of grass
Authors: PARSONS A. J. , JOHNSON I. R. , HARVEY A. 
Published: April 2006

AbstractA previously described model of grass growth was used to analyse the effect of the severity of defoliation and the duration of the subsequent regrowth on the overall balance between photosynthesis, gross tissue production and leaf death and so on the amount that could be harvested/consumed per hectare under intermittent defoliation. Maximum yield per hectare was shown to be achieved whenever the fluctuations in LAI during regrowth and defoliation led lo the same low average LAI that was previously shown to give maximum yield (amount harvested/consumed per hectare) under continuous grazing. Thus, it is suggested that production under both continuous and intermittent defoliation may best be characterized, and diverse managements may be rationalized, on the basis of the average sward state, the average achieved. The analysis leads us to reconsider some widely held concepts of the growth and utilization of grass applied in both agronomic and ecological theory, and the provision of practical guidelines for management.