bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE EFFECT OF THE TIME AND LEVEL OF INJECTION OF ANHYDROUS AMMONIA ON THE PRODUCTIVITY OF GRASSLAND
Authors: Walpole P. R. , Hutton K. 
Published: April 2006

ABSTRACTFour levels of nitrogen, 188, 285, 358 and 392 kgJ.ha (150, 225, 285 and 350 units/ac) supplied as anhydrous ammonia were injected on each of four occasions, 18 Dec, 5 Feb., 12 Mar. and 16 Apr. DM and CP yields were estimated at each of three harvests taken on 4 June, 19 July and 28 SeptTotal DM yields showed only a 10% difference between the highest yielding injection date, 12 Mar., which yielded 12270 kg/ha (10946 Ib/ac) and the lowest, 16 Apr., which yielded 11169 kgJ.ha (9963 Ib/ac). Early injection of ammonia promoted growth during the late spring and later injections resulted in increased yields at the two later harvests. The responses per kg fertilizer N were 11.9 kg DM (10.8 lb/unit) and 3.6 kg CP (3–3 Ib/unit). It was concluded that ammonia should be applied to grassland before April and, preferably, during March, for maximum yields of DM and CP.
SILAGE AND MILK PRODUCTION. A COMPARISON BETWEEN BARLEY AND DRIED GRASS AS SUPPLEMENTS TO SILAGE OF HIGH DIGESTIBILITY
Authors: Castle M. E. , Watson J. N. 
Published: April 2006

ABSTRACTGrass silage made in late May from S23 perennial ryegrass was offered to 14 Ayrshire cows in a 16–week winter‐feeding experiment. The silage had a DM content of 23.2% and contained 16–8% CP and 70.4% digestible organic matter in the DM. The silage was fed ad lib. as the sole feed in the control treatment, and supplemented with either barley or higuality dried grass cubes at the rate of 2, 3 and 4 kg/10 kg milk (2, 3 and 4 Ib/gal) in the other 6 treatments. The daily intake of silage DM was 11.6 kg/cow (25.6 lb) in the control, and significantly less in the supplement treatments. Silage intakes were higher in the dried grass than in the barley treatments. The mean daily yields of milk were 14.5 kg.cow (32.0 lb) in the control, 15.7, 16.6 and 17.0 kg (34.6.36.6 and 37.5 lb) in the barley treatments, and 17.8, 20.2 and 19.8 kg (39.2, 44.5 and 43.6 lb) in the drierass treatments, at the 2, 3 and 4 kg rates of feeding, respectively. The solidoat (SNF) content of the milk was lowest in the control treatment and highest in the drierass treatments. It is concluded that grass silage of high digestibility could be made successfully on a farm scale and that, with such a silage, a supplement of higuality dried grass was superior to a supplement of barley for milk production.
THE EFFECT OF INTRAVENOUS INFUSIONS OF METHIONINE ON THE VOLUNTARY INTAKE OF GRASS SILAGE BY SHEEP
Authors: Kelly N. C. , Thomas P. C. 
Published: April 2006

ABSTRACTThe effect of intravenous supplements of L‐methionine on the voluntary intake of a ryegrass silage, prepared using formic acid as an additive, was determined in a 4×4 Latin Square experiment with 4 sheep. Animals receiving no methionine consumed 1061 g DM/day; those receiving 0.8, 1.2 and 2.0 g methionine/day consumed 1015, 1012 and 1078 g DM/day. The concentration of methionine in blood plasma (Y; (imoles/I) increased with the dose rate of methionine infused (X; g/day) such that Y=36.7 + 38.3X (r=0.80; P<0.001). It is concluded that with a diet of this type methionine may be limiting for protein synthesis in the tissues but is not involved in the control of food intake.
NITROGEN AND ITALIAN RYEGRASS
Authors: Wilman D. 
Published: April 2006

ABSTRACTIn an experiment, described earlier (19) to study the regrowth of Italian ryegrass following a cut in late April, the N and nitrate‐N content of herbage at 3 levels of applied N followed a similar pattern to that noted in earlier years in Cambridge. N content, however, did not fall to such a low level as in Cambridge. N yield fell later and less quickly than in Cambridge. The application of a very high level of N, 175 lb/ac (196 kg/ha), raised N and nitrate‐N content and yield from the second or third week onwards. Changes with time in P and K content and yield were broadly similar to those for N. Level of N had only a small effect on content of P and K. Following the period of increase in yield of N, P and K, there was a period of about 6 weeks of relatively constant yield, followed by a fall. The content of N, P and K in fresh, rather than dry, herbage changed little with time from the fourth to the fourteenth week, despite major changes in crop maturity. The ratio P: K was little affected by level of N or time of harvest.
SWARD PRODUCTIVITY WITHIN MICRO‐PATTERNS OF HEIGHT AND FREQUENCY OF DEFOLIATION
Authors: Smith A. , Macauley J. R. 
Published: April 2006

ABSTRACTAn experiment is described in which 10 cutting treatments were applied to plots of perennial ryegrass. In 4 treatments the swards were cut uniformly using one of the following regimes: cut to 15 cm every 2 weeks (regime hf); cut to 15 cm every 6 weeks (hi); cut to 5 cm every 2 weeks (If); cut to 5 cm every 6 weeks (li). In the remaining 6 treatments, each plot was cut in alternate 9 cm strips using combinations of two of the above regimes; hf/hi, hf/lf, hf/li, hi/If, hi/li, and If/li. The non‐uniform cutting in the latter 6 treatments resulted in a micro‐pattern of height and/or frequency of defoliation.DM yield from the best non‐uniform cutting method (If/li) was as great as that from the best uniform method (li). This was due to an increased yield from areas under regime If when adjacent to areas under li, compared with uniform defoliation under regime If. Results for other treatments also showed that the yield from an area can be influenced by the defoliation regime applied to adjacent areas. The trend was for yield to be greatest if adjacent areas were cut high (as opposed to low) or frequently (as opposed to infrequently). There was less bare ground and more perennial ryegrass and weeds at the end of the experiment in areas previously adjacent to frequent (0 as opposed to infrequent (i) cutting regimes.To assist in the interpretation of field results, an experiment was carried out in which uniform and non‐uniform cutting treatments were applied to individual plants of perennial ryegrass growing in pots of soil in a glasshouse. There was some evidence of an interaction between the growth of high and low parts of plants cut non‐uniformly. There is a discussion of the possibility of devising new ways of harvesting grass by cutting. It is suggested that the non‐uniform grazing pattern of livestock may not be wasteful.
The use of a fluorescent pigment to record the distribution by cattle of traces of faeces from dung pats
Authors: BOSWELL C. C. , SMITH A. 
Published: April 2006

AbstractThe extent of post‐defaecation redistribution of faeces by cattle in a grazed pasture was determined by adding to dung pats a pigment which is fluorescent in ultra‐violet light. Traces of faeces which would normally not be detected were located under ultra‐violet irradiation at night. More traces were redistributed from dung pats situated in areas where stock congregated than from dung pats in other areas of paddocks. Most traces occurred at distances of up to 2 m from each indicator dung pat treated with the pigment. The area of sward affected by faeces was over 100 times the area of individual dung pats. It is suggested that the distribution of infective parasitic larvae will follow the distribution of the traces rather than simply that of the dung pats. Grazing behaviour may also be affected by contamination of herbage by traces of faeces.
Harvest ripeness in grass seed crops
Authors: PEGLER R. A. D. 
Published: April 2006

AbstractTen varieties of forage grasses, including perennial and Italian ryegrasses, tall and meadow fescues, cocksfoot and timothy, grown in seed‐production drills were sequentially harvested from 14 days after peaks of flowering. Seed germination capacities were generally good in seed samples harvested early in the mattiration period, with the exception of timothy. PeaJc yields of germinable seed were usually obtained some time after shedding had begun; delay in harvesting resulted in further seed losses, some of which were substantial. The maxima of individual seed weights mostly did not coincide with, and were frequently later than the peaks of germinable seed yields. Endospenns did not generally harden until after the maxima of germinable seed yields. Endosperm development stages were found to be reliable guides to assessment of correct harvest date, and it is suggested that examination of endosperm consistencies be used to corroborate assessment of harvesting times tising moisture meters.
The effect of physical form of a silage on its voluntary consumption and digestibility by sheep
Authors: THOMAS P. C. , KELLY N. C. , WAIT M. K. 
Published: April 2006

AbstractSix castrated male sheep were used in a two‐period crossover experiment to investigate the effect of mincing on the voluntary intake and digestibility of a silage. The silage was a high‐quality material, containing 68 % digestihle organic matter in the dry matter, prepared from S24 perennial ryegrass cut with a precision chop forage harvester and ensiled with the addition of 2.3 1 t−1 formic acid as preser vative. The median size of particles in the unprocessed silage was 10–20 mm and in the minced silage 2–3 mm.The intakes of dry matter, organic matter and nitrogen for the minced silage were greater than for the unminced material, and for dry matter and organic matter intakes the differences were signi ficant (P<0.01). Mincing was associated, however, with a depression in the digestibility of all three constituents which offset the increase in intake. The intakes of digestible organic matter were 817 g d‐1 for the minced silage and 729 g d−1 for the unminced material (P>0.05). Corresponding figures for digestible nitrogen intakes were 208 gd−1and23.0 gd−1 (P>005).It is concluded that with high‐quality silage diets there is a physical component in the mechanism for the control of voluntary food intake. It is suggested that for sheep, depressions in the digestibility of dietary constituents are unlikely to occur until silages are chopped to a median particle size of 5–10 mm.
The acetylene reduction assay as a means of studying nitrogen fixation in white clover under sward and laboratory conditions
Authors: HALLIDAY J. , PATE J. S. 
Published: April 2006

AbstractThe acetylene reduction assay was used to follow seasonal changes in nitrogen fixation activity in a white clover‐perennial ryegrass ley in Northern Ireland. The annual estimate for fixation by the ley was 268 kg ha−1 (239 lb/acre) nitrogen virtually all of which was fixed during March to October. Nitrogen fixation was curtailed drastically after the ley was cut but recovered as new foliage expanded on the clover. Glasshouse experiments described the effects of temperature, shading and defoliation on nitrogen fixation by white clover, and indicated that these factors might be important in modifying symbiosis under field conditions.
Effect of rotary‐drum‐drier exit temperature and length of pre‐drying storage time on digestibility of dried grass cobs
Authors: MARSH R. 
Published: April 2006

AbstractThe effect of exit temperature of a rotary‐drum‐drier and of the length of pre‐drying storage time on chemical composition and digestibility of dried grass cobs was investigated in two experiments. Increasing exit temperature from 77 to 166°C reduced WSC, NFE and available lysine content and increased CF content of dried grass. In vitro and in vivo DM digestibility was reduced by 16.4 and 24.5 percentage units respectively. Increasing length of pre‐drying storage time also reduced WSC and available lysine content and reduced in vitro and in vivo DM digestibility by 2.4 and 5.1 percentage units respectively. The greatest reduction in in vivo digestibility in both experiments occurred in the CP fraction.
Seedling growth of four grasses
Authors: HAYES P. 
Published: April 2006

AbstractInvestigations were conducted into the seed reserves, shoot and seminal root growth of Lolium perenne, Festuca arundinacea, Holcus lanatus and Poa trivialis. Data are presented for the caryopsis, palea and lemma weights of these species. Shoot lengths of Lolium and Festuca were very similar but seminal root lengths of Lolium were longer and emerged earlier than those of Festuca. The caryopsis in Lolium lost weight much more rapidly in germination than Festuca. Seedlings of Lolium and Festuca showed similar increases in shoot length but Lolium had more rapid rates of seminal root growth and weight loss from the caryopsis. It is suggested that poor field establishment of Festuca may be due to poor mobilization of seed reserves and consequential poor seminal root growth. The possibility of selecting for good seminal root development in Festuca to improve establishment is suggested.
Pathogens occurring on ten varieties of ryegrass at Rothamsted in 1973–74
Authors: PLUMB R. T. , JENKYN J. F. , BOWEN ROBERTA 
Published: April 2006

AbstractSix varieties oi Loliumperenne, three of L. multiflorum and one hybrid (L. multiflorum × L. perenne) were assessed for diseases over two harvest years. Crown rust (Puccinia coronata) and mildew (Erysiphe graminis) occurred on some varieties in 1973. Leaf spotting (Drechslera spp.) was common, but slight on most varieties, in both years. Ryegrass mosaic virus (RMV) and its mite vector, Abacarus hystrix were present on all varieties in the second year. The relative susceptibility of varieties to RMV was similar in the field and in glasshouse tests.
Leaf protein production and use on the farm: an economic study
Authors: DUMONT A. G. , BOYCE D. S. 
Published: April 2006

AbstractA linear programming model to provide information on the economic feasibility of on‐farm production and use of leaf protein from grass is described. The unwilted grass is mechanically separated into a protein‐rich ctird, which is fed to pigs or other non‐ruminants, and a high‐dry matter, fibrous residue which is ensiled and fed to ruminants.In the model, the gross margin from a livestock farm which uses a conventional silage system for a dairy herd is compared with that from the same farm using forage fractionation. The difference in gross margins is available to pay for the additional cost of the fractionation equipment and to provide additional profit.The model considers the machinery performance, costs and labour constraints within which the new system would have to operate if it were to be economic. Results indicate that under a wide range of farm sizes and situations, forage fractionation shows an economic advantage over present forage conservation methods if machinery of the required throughput and cost were to be developed for on‐farm use.
Factors influencing the proportion of natural hybrids between Lolium perenne L. and Festuca pratensis Huds. in permanent pastures
Authors: GYMER P. T. , WHITTINGTON W. J. 
Published: April 2006

AbstractHybrids between ryegrass and meadow fescue form rarely but occur widely in old pastures. In one experiment six different hybrid genotypes were able to compete, on equal terms, with members of their parental species. In two others the proportion of the total yield due to one hybrid genotype was increased by added fertilizer or by reduced water supply.
The physiological response to cutting in Italian ryegrass
Authors: CLARK BRENDA J. , PRIOUL J.‐L. , COUDERC H. 
Published: April 2006

AbstractThe kinetics of decline in net photosynthesis and transpiration after cutting was followed in a batch of Lolium multiflorum leaves at light saturation in an assimilation chamber where air temperature, leaf temperature, carbon dioxide concentration and water vapour concentration were controlled. After leaf excision the rates of photosynthesis and transpiration increased or remained the same for 1–2 min and then decreased sharply following a curve with two breaks of slope at 15 min and 30 min. To investigate stomatal behaviour, fragments of leaf tissue were removed, fixed by freezing in liquid nitrogen, then examined by scanning electron microscopy. The stomata were optically closed by 15 min after excision. The practical implications for field drying of Italian ryegrass are discussed.
Comparisons of some factors affecting digestibility in sheep and cows
Authors: THOMAS S. , CAMPLING R. C. 
Published: April 2006

AbstractA comparison was made of some factors affecting digestibility in sheep and cattle. In one experiment four castrated male sheep and four non‐lactating cows were given diets of hay and of hay and concentrates, and in another experiment similar groups of animals were offered diets consisting mainly of hay or hay and lucerne cobs. In both experiments there was good agreement in digestibility between the sheep and cows. With diets which did not stimulate maximum rumination, sheep tended to ruminate for a longer time per day than cows. At high feed intakes rumination times were similar in sheep and cows. Times spent eating, ruminating or chewing per unit of feed DM were 6 to 19 times longer in the sheep than in the cows. Retention times of stained hay in the gut tended to be slightly shorter in sheep than cows and those of stained barley husk and of processed lucerne were similar in the sheep and cows. The median size of faecal particles was 1.4 to 1.9 times greater in cattle than sheep. The similarities and differences between sheep and cattle in the factors affecting digestibility are discussed.
Silage and milk production: a comparison between four rates of groundnut cake supplementation of silage of high digestibility
Authors: CASTLE M. E. , RETTER W. C. , WATSON J. N. , ZEWDIE E. 
Published: April 2006

AbstractGrass silage made in late May from S24 perennial ryegrass was offered to twelve Ayrshire cows in a 16‐week feeding experiment. The silage had a DM content of 25.3%, a pH of 3.91, and contained 16.8% CP and 68.4% digestible organic matter in the DM. The silage was fed ad libitum and was the sole feed in the control treatment. In the other three treatments the silage was supplemented with a cube offered at rates of 0.8, 1.4 and 2.0 kg per 10 kg milk. The cube contained 82.2% groundnut, plus molasses and minerals, and had 37.9% CP in the DM. The daily intake of silage DM was 11.4 kg per cow on average over the four treatments which did not differ significantly. The mean daily milk yields were 14.8 kg per cow in the control treatment, and 16.5, 18.2 and 18.4 kg in the 0.8, 1.4 and 2.0 kg supplement treatments respectively. The SNF, CP and lactose contents of the milk were Wghest on the 1.4 kg supplement treatment. It is concluded that with a high digestibility silage, there is little evidence to support the feeding of more than 1.4 kg of high‐protein cubes per 10 kg milk in the declining phase of lactation.
Overgrazing and soil erosion on hill pastures with particular reference to the Peak District
Authors: EVANS R. 
Published: April 2006

AbstractIn a small drainage basin in the Peak District rates of soil erosion were measured between October 1966 and September 1968. The vegetated margins of ground denuded of vegetation (scars) were retreating by 9.3 mm per annum and rills and sheet wash removed annually from these scars up to 34 t ha−1 soil. Erosion was taking place primarily within Agrostis‐Festuca swards and also in heather moor, but not on peat‐covered slopes under cotton grass (Eriophorum vaginatum) moor. The Agrostis‐Festuca sward supported a higher sheep population than did the other vegetation types. In May 1974 most scars had been colonized by vegetation; this was related to a marked decrease in sheep numbers in 1969 and not to climatic factors.
The white clover contribution during the first 24 months after sowing
Authors: WILMAN D. 
Published: April 2006

AbstractPerennial ryegrass was sown in a field trial with or without a small‐leaved white clover, S184, in September 1969 and cut five times per year in 2 successive years. Yield of clover was low and very unevenly distributed in time. Clover performance is described in four distinct periods, April‐June 1970, July‐September 1970, April‐June 1971 and July‐September 1971, in which yield of clover was respectively low, moderate, low and fairly high and the indirect contribution, the enhanced yield of other sward components, was respectively nil, moderate, moderate and moderate. The ratio of indirect to direct contributions on an annual basis concealed very large differences both within and between years. The presence of clover increased the N content but did not affect the P or K content of other sward components.
The effect of short‐term grazing of red clover on ewes at mating
Authors: DICKSON I. A. , FRAME J. , MACLEOD N. S. M. , KELLY MORAG 
Published: April 2006

AbstractFour groups of ewes grazed swards of red clover (Trifolium pratense cv. Hungaropoly) for 28‐day periods ending 28, 14 or 0 (two groups) days before mating. One of the groups on red clover for the period immediately before mating continued on red clover during mating. At all other times before mating and for 7–8 weeks after mating commenced these ewes were grazed on a predominantly perennial ryegrass‐white clover sward. A fifth (control) group was on the ryegrass sward throughout. There was no apparent adverse effect of red clover on ovulation rate, conception rate or embryo mortality.
The incidence of vims‐like symptoms and ryegrass mosaic virus in perennial ryegrass pastures in the West of Scotland
Authors: HOLMES S. J. I. , CHANNON A. G. 
Published: April 2006

AbstractIn 1972 and 1973 fields of perennial ryegrass in the West of Scotland were surveyed for ryegrass mosaic virus (RMV). Visual determinations of foliar symptoms were made in the field and leaf samples were collected for diagnosis of the virus by electron microscopy and by sap transmission to S22 Italian ryegrass.In 1972, ninety‐eight fields were surveyed and virus‐like symptoms were observed in 59%, but tests showed that only 21% were infected with RMV. In the more extensive 1973 survey, 201 fields selected on a stratified random basis were examined and whilst 45% had virus‐like symptoms only 5% proved to be infected with RMV.Symptoms were most readily seen in fields which had a high percentage of long, lush perennial ryegrass. Analysis of data collected in 1973 on management practices did not reveal any obvious association between the incidence of virus‐like symptoms and the cutting and grazing regimes, the grazing animal used or the level of nitrogen applied.
The value of timothy (Phleum pratense L.) in ryegrass — timothy mixtures managed to simulate intensive grazing
Authors: SWIFT G. 
Published: April 2006

AbstractThe performance of timothy in mixtures with perennial ryegrass was assessed under a simulated intensive grazing management over two harvest years in 1974–75. Three seed rates of S23 perennial ryegrass were factorially combined with three rates of Scots timothy and compared with pure stands of each grass. All were sown with Huia white clover. When cut six times at monthly intervals and with an annual N input of 350 kg ha−1, there were no significant differences in total DM production in either year. The 2‐year mean DM yield for the nine mixtures and six pure swards was 9·77 t ha−1 (range 9·34–10·16). Compared with the pure ryegrass swards, in both years the ryegrass‐timothy mixtures produced earlier spring growth but were significantly lower yielding at the second cut. Over the first five cuts the proptortion of timothy in the three mixtures with 22·4 kg ha−1 ryegrass seed averaged 26% in the first year and 37% in the second. Corresponding calculated mean DM yields of timothy were 2·75 and 3·00 t ha−1.It is concluded that an early timothy variety is capable of competing with a late‐heading perennial ryegrass in frequently cut swards managed to simulate intensive grazing. The strong development of timothy in the dry summer of 1975 suggests that in mixtures of late perennial ryegrass varieties, an early variety of timothy should be beneficial for its spring growth in grazed swards.