bluuebunny/crossref_metadata_2025_split huggingface dataset:
Herbage growth and utilized output from grassland on dairy farms in southwest England: case studies of five farms, 1982 and 1983. II. Herbage utilization
Authors: PEEL S. , MATKIN ELIZABETH A. , HUCKLE C. A. 
Published: April 2006

AbstractUtilized Metabolizable Energy output was calculated and herbage utilization evaluated in two contrasting years on five profitable farms representing a range of soil types.Annual UME output was 72 GJ ha‐1 on average, with a range from 47 to 91 GJ ha‐1. Grazed grass provided 66% of the utilized metabolizable energy, and conserved grass 34%. Higher utilized metabolizable energy output was not always obtained at higher fertilizer N inputs, even when soil moisture conditions favoured herbage growth.The efficiency of utilization of herbage conserved (almost always as silage rather than hay) was calculated by expressing utilized metabolizable energy output as a proportion of the quantity of herbage cut, measured by swath weighings; the mean value was 64%, with a range from 55 to 73%. Cellulose analyses indicated that mean dry matter losses via CO2 and effluent were 10%; the remaining 26% loss appeared to be due to physical losses in the field, surface waste and wastage at feedout.For grazed herbage the utilized metabolizable energy output was expressed as a proportion of herbage accumulation measured over 28‐day periods. The resultant apparent efficiency of utilization averaged 67%, with a wide range from 51 to 83%. The lowest values were on badly drained farms.It is suggested that:(i) there is considerable potential for increasing output from grazing on dairy farms; higher grazing pressure and more flexible management would be needed. Targets should probably be set lower on badly drained soils;(ii) there is great potential for increasing the efficiency of utilization of conserved forage, by careful application of existing technology;(iii) on the farms studied the utilized metabolizable energy output from grazed and conserved fields appeared to be similar.
Effect of anhydrous ammonia treatment on the chemical composition and nutritive value of grass hay and on intake and performance in beef steers
Authors: WYLIE A. R. G. , STEEN R. W. J. 
Published: April 2006

AbstractTwo compositionally similar, mature grass hays, of dry matter contents 699 and 836 g kg‐1, were treated with anhydrous ammonia at levels of 10, 20 and 30 kg NH3 t DM‐1 and 20, 30 and 40 kg NH31 DM‐1, respectively. Treatment at 10 kg t‐1 did not inhibit moulding of the damp hay. The remaining treatments increased the nitrogen contents of damp and dry hay, respectively, from 12.5 and 13.8 g kg DM‐1 to maxima of 250 and 270 g kg DM‐1 and the water‐soluble ammonia‐nitrogen contents of oven‐dried samples from 24 and 23 g kg‐1 to maxima of 118 and 88 g kg‐1 of total nitrogen. While all treated hays had reduced levels of insoluble hemicellulose, ammoniation increased the insoluble cellulose content of damp hay only.In trials of 37 and 80 days duration, respectively, the untreated and 20 and 30 kg t‐1‘damp'‐ammoniated hays and the untreated and 20, 30 and 40 kg t‐1‘dry'‐ammoniated hays were offered ad libitum, unsupplemented or supplemented with 2 kg d‐1 of a barley‐soya compound, to steers of 328 kg and 383 kg mean initial liveweight. Steers offered untreated and 20 and 30 kg t‐1 ammoniated damp hays and untreated and 20, 30 and 40 kg t‐1 ammoniated dry hays, all ad libitum and alone, consumed 5.50, 6.48 and 6.59 and 6.78, 782, 790 and 8.26 kg d‐1 and gained 471,560 and 521 g d‐1 and 490,699,794 and 572 g d‐1, respectively. When supplemented, the same hays, again offered ad libitum, produced live‐weight gains of 529, 515 and 736 g d‐1 and 725, 705,726 and 895 g d‐1, respectively. The apparent in vivo digestibilities of hay dry matter, organic matter, gross energy, hemiceliulose, cellulose and nitrogen were significantly increased by ammoniation.
The effect of different cultivars of clover on numbers of and leaf damage by, some invertebrate species
Authors: MOWAT D. J. , SHAKEEL M. A. 
Published: April 2006

AbstractInvertebrate numbers were studied in two white clover cultivars trials, grown with perennial ryegrass Weevils (Sitona spp.), slugs, lucerne flea, leatherjackets and as were more common (at least at some life stage) in cultivars of lower cyanogenic potential. Damage to clover foliage by the first three species was also negatively related to cyanogenesis. The production of HCN ranged from 0.025 mg to about 1.8 mg g−1 fresh leaf. There was no evidence of any other factor influencing cultivar preference.Cyanogenesis had most effect on numbers of weevil larvae and leatherjackets. The effect on weevil larvae was attributed partly to intercultivar differences in oviposition, but it was also suspected that larvae had fed on cyanogenic parts of the plant before reaching the root. Leatherjacket numbers developed inter‐cultivar differences during larval growth. In one case these differences were detectable by December. By March in the second experiment there were approximately three times as many leatherjackets at the low as at the high end of the cyanogenic range. Approximately four times as many Sitona larvae were found at the lower as at the higher end of the scale. There was some evidence that a higher clover content in the sward was attractive to ovipositing Tipula paludosa but not in recently harvested cultivars of high cyanogenic potential
A comparison of the herbage productivity of Bromus wildenowii cv. Grasslands Matua with four cultivars of Lolium perenne when grown in association with Trifolium repens
Authors: HOPKINS A. , MURRAY P. J. , PATEFIELD W. M. 
Published: April 2006

AbstractIn a small‐plot trial five grass varieties bromegrass cv. Grasslands Matua, perennial ryegrass CVS. Melle (diploid) and Bastion, Condesa and Meltra (tetraploid) were established as grass/white clover swards with white clover cv. Menna. Productivity was measured under 6‐weekIy cutting both without N fertilizer (No) and with 100 kg N ha−1 applied in spring (N100) Evaluation was made over 2 harvest years, 1986–87.Total mean annual production of herbage dry matter (DM) in the first harvest year at No and No was 5·07 t ha−1 and 6·93 t ha−1 respectively. In year 2, corresponding values were 11·81 and 12·67 t ha−1. In year 1, Matua swards at No and N100 yielded 5·08 and 6·65 t DM ha−1 compared with 507 and 70 t DM ha−1 for the mean of the four ryegrass varieties. In year 2, corresponding values were 12·90 and 12·29 for Matua and 11·54 and 12·78 for the four ryegrasses. In year 1, the digestable organic matter in the dry matter (DOMD) of the Matua swards was lower than that of Melle, Bastion and Condesa at NO, particularly at the first cut. In year 2, differences in DOMD between treatments and varieties were not significant.The proportion of white clover was found to be higher in the No than the N100 treatment, and also higher in year 2 in most treatments. For the No treatment Matua swards had the highest proportion of white clover in year 1 (32% compared with 24% for the mean of the ryegrass varieties) but the lowest proportion in year 2 (27% compared with 60% for the ryegrasses). For the No treatment in year 1 clover production was also 43% higher, on average, from the tetraploid treatments than with Melle as the companion grass; for this comparison in year 2 the differences were not significant.It is concluded that Matua bromegrass/white clover swards receiving no N fertilizer may have a good potential under cutting management. However, the evidence from this trial is that in the second year the proportion of white clover is lower with Matua swards than with perennial ryegrass as the companion grass.
Problems of estimating tissue turnover in grass swards in the presence of grazing animals
Authors: GRANT SHEILA A. , ELSTON D. A. , BARTHRAM G. T. 
Published: April 2006

AbstractRates of leaf extension and senescence were measured over three‐day intervals on neighbouring sets of caged and uncaged tillers on several occasions during summer 1983, both when grazing animals were present and also when they were absent. The weather was dry and drought conditions developed as the season advanced.Comparison of data from caged and uncaged tillers indicated that some consistent differences occurred. Loss of information through grazing (affecting 30% of uncaged, larger than average, tillers), contributed to the significantly reduced estimates of leaf extension of ungrazed, uncaged tillers compared with caged tillers. Senescence rates were higher in the open plot than under the cages; old leaves were grazed on only 8% of uncaged tillers so that data loss was less important as a cause of bias. In the drought conditions prevailing, it was thought that caging in the presence of grazing animals resulted in reduced moisture stress and contributed to the above results.Comparisons of caged and uncaged tillers when grazing animals were absent were made to examine the environmental effects of caging and the slight difference in tiller marking procedure. No differences were found in leaf extension rates, though a trend towards higher senescence rates for the uncaged populations was evident. It was concluded that the criteria limiting the use of cages (a period of protection less than the average interval between both leaf appearance and repeated defoliation) should be extended to include a time limit set by the need to avoid bias associated with the environmental effects of caging and cessation of grazing. To define this time limit better in particular circumstances, the extent and direction of bias in the estimation of leaf extension and senescence rates as affected by period of caging, tiller handling procedures, sward and climatic conditions requires further investigation.In the case of vegetative tillers, estimates of leaf extension rates can be made considerably more precise by using tiller size variables (pseudostem length, total green leaf length, leaf width) as covariates. A suggestion for the number of tillers to be measured per transect is given. However, no such increase in precision can be made for estimates of senescence rates.
Modifying growth patterns in nine grasses with mefluidide
Authors: HAGGAR R. J. , ISAAC S. P. , STANDELL C. J. 
Published: April 2006

AbstractMefluidide was applied at 150ga.i.ha−1 on one of three dates (7, 28 March or 18 April, 1984) to irrigated field plots of nine grasses. Spraying suppressed flowering in the primary growth of most species, especially when carried out in mid‐ April. However, spraying at this time proved too damaging to amounts of herbage harvested. Spraying in March reduced mean yields by about one‐third at the first harvest and increased mean yields at the second harvest. In addition, spraying at this time increased herbage quality, as indicated by higher N and lower fibre contents, at least at the first harvest. In general, the grasses most responsive to mefluidide were tall‐growing and/or early‐flowering species, e.g. Arrhenatherum elatius, Festuca rubra, Dactylis glomerata and Holcus lanatus; by comparison, Lolium perenne was relatively less affected by spraying. The findings indicate the potential of mefluidide for overcoming the normal decline in herbage quality associated with flowering, and for transferring growth from spring to midsummer, albeit at some cost to total annual production.
Effect of seed crop management on the potential seed yield of contrasting white clover varieties.
Authors: MARSHALL A. H. , HOLLINGTON P. A. , HIDES D. H. 
Published: April 2006

AbstractThree contrasting white clover varieties, Olwen (large‐leaved), Menna (medium‐leaved) and S184 (small‐leaved) were sown with and without a grass companion in 30 cm drills. Two grazing and one mechanical spring defoliation managements were imposed. Counts of the total number of inflorescences and of the percentage in various ripeness categories were made throughout the period of seed crop development to determine the pattern of inflorescence development and optimum harvest date. Inflorescence numbers were greatest in cv. S184 and least in cv. Olwen and, in general, varieties produced both more inflorescences and a greater proportion of ripe inflorescences when grown under spring defoliation managements similar to those for which they were bred. Thus, cv. Olwen produced more ripe inflorescences, and a lower proportion of brown inflorescences (semi‐ripe), after mechanical defoliation while cv. Menna produced more ripe inflorescences following mechanical defoliation and rotational grazing. However, cv. S184 produced more ripe inflorescences under both grazing managements than under mechanical defoliation. Optimum harvest date was not affected by management or variety, total inflorescence number and maximum ripe inflorescences having reached a peak on 11 September. However, varieties differed in the proportion of ripe and brown (semi‐ripe) inflorescences on this date, with cv. Menna and cv. S184 containing a significantly higher proportion of brown inflorescences than cv. Olwen, The implications of these differences in inflorescence development, the proportions of inflorescences in the various ripeness categories and their contribution to seed yield are discussed in relation to the management of white clover seed crops and harvesting method under UK climatic conditions.
Water‐soluble carbohydrates in perennial ryegrass breeding
Authors: HUMPHREYS M. O. 
Published: April 2006

AbstractWater‐soluble carbohydrate (WSC) contents of the early heading perennial ryegrass cultivar Aurora and five late heading cultivars were assessed in samples from spaced plants cut five times in 1982. Aurora had the highest overall WSC content. Majestic and Aberystwyth S23 had the lowest while Perma, Melle and Ba 9795 were intermediate. Samples from F1 and F2 spaced plants derived from crosses between Aurora and the five late heading cultivars were also analysed for WSC contents and heading dates were recorded. As expected, heading date behaved as a polygenic character controlled mainly by additive gene effects. However, WSC contents behaved in a more complex way with evidence of non‐additive gene effects comprising dominance, overdominance (heterosis) and epistasis. It was concluded that by crossing contrasting cultivars, significant improvements in WSC content could be achieved, which may be more stable than those obtained by within‐cultivar selection.
The effect of frequency and height of defoliation on the production and persistence of ‘Grasslands Matua’ prairie grass
Authors: BELL C. C. , RITCHIE I. M. 
Published: April 2006

AbstractThe performance of prairie grass (Bromus willdenowii Kunth) cv. Grasslands Matua was examined under mowing at five defoliation intervals (10, 20, 30, 40 and 50 d) and two defoliation heights (3 cm and 8 cm). Annual and seasonal production of both the total herbage and of Matua, and the proportion of Matua in the sward, increased with less frequent defoliation. To a lesser extent, increasing the height of defoliation increased dry matter yield. Matua tiller numbers were increased by less frequent defoliation and were greater under the 8 cm than the 3 cm defoliation height. To increase prairie grass production and persistence, rest intervals between grazings of 40 to 50 d are recommended, or alternatively, a management involving silage or hay cutting offers scope.
The effect of dry feed additives on the nutritive value of silage
Authors: MOSELEY G. , RAMANATHAN V. 
Published: April 2006

AbstractSilages were prepared in late September from a mixed crop of perennial ryegrass and white clover with low dry matter and high nitrogen content. Six different treatments were used during ensiling; addition of either molassed sugar beet pulp or rolled barley, at 50 kg and 25 kg (t fresh grass)−1, formic acid at 51 t−1 and no additive (control).All silages were well fermented with low levels of ammonia and pH. The addition of rolled barley or sugar beet pulp increased the dry matter content of the silages incrementally and appeared to assist the retention of nitrogen in the silage.Dry matter intakes of silages with 50 kg of barley or sugar beet pulp tonne−1 were similar to the control silage when fed to wether sheep but at 25 kg t−1, dry matter intake increased by 0·15 with barley and 0·04 with sugar beet pulp compared to the control. The digestibility of dry matter (DM) and organic matter (OM) were significantly higher than the control for silages treated with formic acid or high levels of barley and sugar beet pulp whereas neutral‐detergent fibre (NDF) digestibility did not appear to be significantly affected.All treated silages had a significantly higher metabolizable energy (ME) content than the control, and additions of barley or sugar beet increased the ME content. The ME intakes of all treated silages were also significantly greater than those of the control, and the formic acid‐treated and low barley silages were the highest. This appeared to be associated with significantly higher energy digestibility and DM intake.Addition of rolled barley during ensilage resulted in greater nitrogen intake, availability and retention compared to additions of sugar beet pulp. The higher retention with barley silages was associated with a significantly lower proportional loss of absorbed nitrogen in urine, which indicated a more efficient utilization of nitrogen.These differences require further study to determine the mechanisms involved in the interactions between the energy source and herbage protein, both during fermentation and in the rumen.
A comparison of buffer and partial storage feeding of a straw/concentrate mixture to grazing dairy cows
Authors: ROBERTS D. J. 
Published: April 2006

AbstractA straw/concentrate mixture was offered to set‐stocked dairy cows over a 24‐week period. The cows were offered grazed herbage only (G), or grazed herbage with a straw/concentrate supplement offered either for 45 min after each milking (B), or overnight (P). The overnight treatment involved housing the cows between afternoon and morning milking. The straw/concentrate mixture contained 0·33 long barley straw, 0·28 barley, 0·12 soya bean meal, 0·25 molaferm and 0·02 minerals. During the first 8 weeks of the experiment an average of 2·25 kg of concentrate were fed, and from weeks 9–24, 2·0 kg of concentrate were fed.The feeding of the straw/concentrate mixture led to a decrease in estimated herbage dry matter (DM) intake, particularly for treatment P. Estimated total DM intakes were increased throughout the experiment by offering the straw/concentrate mixture. However, total metabolizable energy (ME) intakes were only increased in mid‐and late season.Milk yield was higher in early season for treatment G; 28·1 kg d−1 compared to 26·8 kg d−1 and 25·5 kg d−1 for treatments B and P respectively. In late season the cows in treatment G had lower milk yields; 13·3 kg d−1 compared to 15·5 kg d−1 and 16·8 kg d−1 for treatments B and P respectively. Milk fat content was increased in early season in treatment P, and milk protein content tended to be reduced throughout the experiment for cows offered the straw/concentrate mixture overnight. Over the whole experiment there were no differences in yield of milk solids.
The effect of fertilizer sulphur on grass production for silage
Authors: KLESSA D. A. , FRAME J. , GOLIGHTLY R. D. , HARKESS R. D. 
Published: April 2006

AbstractThe effects of rate and pattern of fertilizer S application on herbage production from Perennial ryegrass‐dominant swards at six potentially S‐deficient sites in south‐west Scotland were measured under a silage cutting regime (3 cuts year‐1) with high fertilizer N application (300 kg ha−1 year‐1). Fertilizer S (as gypsum) was applied at annual rates from 0 to 48 kg ha−1 as single spring applications before the first cut or split before each of the three cuts. The residual effect of S in the year following its application was assessed at one site.Applied S increased total DM production at four of the six sites. These increases were restricted to the second and/or third cuts and were generally in the range 10‐30% greater than where no S was applied. Timing of S application was not important in influencing annual DM yield. The residual effect of gypsum in the year following application was small.The supply of available soil S is limiting herbage production in certain areas and soil types of south‐west Scotland. Areas of S deficiency are likely to increase in the future and need to be identified more precisely than they are at present.
Effect of changing grazing severity on the composition of perennial ryegrass/white clover swards stocked with beef cattle
Authors: GIBB M. J. , BAKER R. D. 
Published: April 2006

AbstractDuring an experiment in which the height of mixed perennial ryegrass/while clover swards was maintained throughout the season at 3 or 7 cm (S and T, respectively), or were maintained al those heights until 30 June then changed (ST and TS), a limited study was made of the effects on the population densities and masses of the two species. During the earlier part of the season the short swards (S and ST) developed higher tiller and stolon growing point (sgp) densities, but with a reduced mass of ryegrass, principally of the pseudostem fraction, than the tail swards (T and TS). Thiere was little effect of sward height on the mass of clover. Whilst there was a general tendency for tiller and sgp densities to increase during the latter part of the season, tiller density increased greatly where sward height was reduced (TS) and both tiller and sgp densities were reduced where sward height was allowed to increase (ST). Changing sward height, whilst limiting the accumulation of dead grass material (TS), allowed grass leaf and dead masses to increase (ST), and adversely affected the increase in the clover component, principally of stolon material, in both ST and TS.
Application of a sequential sampling technique to DIY assessment of leatherjacket (Diptera: Tipulidae) populations in grassland
Authors: BLACKSHAW R. P. 
Published: April 2006

AbstractThe use of brine in plastic pipes inserted into the ground is now an established technique for sampling leatherjackets in grassland. Three sequential sampling plans were compared with a standard twelve‐pipe sample for the probability of a recommendation to spray and the number of sample units necessary before a decision over a range of population densities. Data derived from field studies showed a good fit with the expected outcomes. All four plan models were applied to leatherjacket distribution data from Northern Ireland, This shows the number of samples required before a decision was reduced with sequential sampling and that the use of single sequential samples would increase the risk of error. The results are discussed in the context of the physical limitations of the brine sampling procedure and it is concluded that a sequential scheme based upon groups of four pipes would reduce average sampling time by 36% without increasing error.