bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of dry matter content and silage additives on the fermentation of grass silage on commercial farms
Authors: HAIGH P. M. 
Published: April 2006

AbstractA total of 1713 samples of silage from commercial farm silos were analysed to investigate the effect of dry matter (DM) content and chemical additives on fermentation as measured by ammonia‐N concentration and pH, Increasing DM content without additive use had a major beneficial influence upon fermentation. When silage DM contents were greater than 260 g kg‐1 83% of silages were well fermented, with average ammonia‐N concentrations of 94 g (kg total N)‐1 and pH 4.36. With diminishing DM concentration the proportion of well fermented silages declined. In the DM range 220‐260 g kg‐1 67% of silages were well fermented with ammonia‐N concentrations of 125 g (kg total N)‐1 and pH 4.30, in the DM range 180‐220 g kg‐1 48% were well fermented with ammonia‐N at 151 g (kg total N)‐1 and pH 4.38 and with DM below 180 g kg‐1 no silages were well fermented with ammonia‐N concentration of 252 g (kg total N)‐1 and pH 4.84.The benefit of chemical additives, albeit at poorly defined and often inadequate rates, was small in comparison to that of increased DM concentration. Below DM concentrations of 180 and 220 g kg‐1, the only benefit was that formic acid decreased ammonia‐N to 151 g (kg total N)‐1 and pH to 4.32 compared with 163 g (kg total N)‐1 and pH 4.43 for untreated silages. Within the DM range 220‐260 g kg‐1 formic acid decreased ammonia‐N level to 104 g (kg total N)‐1 and pH to 4.07, and there was a slight benefit from using sulphuric acid/formalin which decreased ammonia‐N to 117 g (kg total N)‐1 and pH to 4.23 compared with 125 g (kg total N)‐1 and pH 4.27 for untreated silages. Above 260 g DM kg‐1 both formic acid and sulphuric acid/formalin provided a small but consistent decrease in ammonia‐N and pH compared with untreated silages. Chemical additive use conferred no other benefit when compared with untreated silage. Calcium formate/sodium nitrite mixtures and acid mixture use provided no benefit in fermentation compared with untreated herbage.
Preservation of plant material by large scale sorption freeze‐drying
Authors: COLEBROOK W. F. , MELLOR J. D. 
Published: April 2006

AbstractA large‐scale sealed system for freeze‐drying herbage is described. It utilizes the principle of sorption drying and is dependent upon the vapour pressure differential (VPD) between the herbage and the silica gel drying agent. Ice sublimes to vapour from the sample in a system operating at approximately – 10°C and the vapour is adsorbed by silica gel in an air stream recycled by a blower; equal masses (up to 50 kg each) of wet herbage and silica gel are used. The system is simple to construct and is relatively inexpensive.Approximately eight days drying time are needed to reduce moisture content from 90 to 10%. Twenty‐four different species or cultivars of both temperate and tropical grasses and legumes sampled at several stages of maturity have been dried in the system. When snap‐frozen herbage is freeze‐dried by this process the physical and chemical changes that otherwise occur when herbage is harvested and prepared for evaluation can be reduced and sufficient material can be obtained to permit animal feeding studies as well as chemical analyses.
The nature of the relationship of electronic capacitance meter readings to pastures on offer in short swards
Authors: GREATHEAD K. D. , WALLACE J. , BOULTWOOD J. N. 
Published: April 2006

AbstractThe residual standard deviations and distribution of residuals around five models were used to investigate the relationship between recordings from an electronic pasture probe and dry matter harvested from annual pastures (predominantly subterranean clover) at low levels of green feed on offer. Pasture material harvested was that considered to have the greatest influence on the probe i.e., within 5 cm of it.The following conclusions were drawn. When measuring short dense green pastures yielding up to 3000 kg dry matter ha‐1 the model best describing the relationship is a split line. Curvilinear models are better than a linear model; however, both single linear and curvilinear models give biased estimates particularly near the middle and at the lower end of the range.The best fitted model is discussed in terms of the structure of the sward and the probe.
The effect of height and frequency of mowing on the yield and composition of perennial ryegrass—white clover swards in the autumn to spring period
Authors: FULKERSON W. J. , MICHELL P. J. 
Published: April 2006

AbstractNinety‐six plots (3 × 2 m) of well‐established perennial rye grass/white clover pasture were mown to heights of 2·7 (Low) or 3·96 (High) cm (rising plate meter) at 14‐, 28‐, 84‐ or 112‐d intervals in autumn‐winter. A 7‐, 14‐ and 28‐d mowing interval was superimposed in spring on each autumn–winter mowing interval treatment with the low and high mowing heights altered to 2·92 and 4·80 cm, respectively.With the low cutting height, accumulated herbage DM was more than doubled (1806 ± 79 kg DM ha‐1) compared to a ‘high’ (754 ± 49 kg DM ha‐1) cutting height in autumn–winter and this was due to increased harvesting efficiency rather than growth as estimated by leaf extension. Although defoliation interval had no effect on DM yield, the grass component increased and clover decreased. The composition effect carried over into spring. On average, 3·5 tillers were produced over winter for each ryegrass tiller present in autumn and tiller densities were higher in spring. Tillers produced over autumn–winter contributed more than 60% of ryegrass growth by early spring.In early spring (16–30 September), the low cutting height increased herbage DM yield, in mid‐spring (1–14 October) it reduced DM yields particularly in combination with short defoliation intervals, while in late spring (14 October to 11 November) cutting height had no effect on DM yields.Over the entire spring period there was a very marked effect of defoliation interval on DM yields.
The productivity of four forage legumes sown alone and with each of five companion grasses
Authors: FRAME J. , HARKESS R. D. 
Published: April 2006

AbstractFour legumes—white clover cv. Blanca, red clover cvs Violetta (diploid) and Hungaropoly (tetraploid) and lucerne cv. Europe—were established as pure‐sown swards and with each of five companion grasses: timothy cv. Timo, meadow fescue cv. Bundy, sweet brome cv. Deborah and perennial ryegrass cvs Talbot (diploid) and Barlatra (tetraploid), both ryegrasses being of ‘intermediate’ heading date. Two ‘silage’ crops and an ‘aftermath grazing’ crop were harvested in each of three successive years.In the first harvest year, total herbage DM production of red clover ranged from 15·03 to 17·01 t ha‐1. White clover and lucerne swards produced considerably less at 7·12 to 11·01 t ha‐1. In the second harvest year, lucerne swards were the highest producing at 15·54 to 17·14 t ha‐1, while DM production from red clover and white clover swards ranged from 6·75 to 11·87 t ha‐1. Lucerne swards maintained their production superiority in the third year at 16·48 to 17·87 t ha‐1, while production from white clover swards ranged from 6·41 to 10·23 t ha‐1. However, red clover swards declined to 3·30 to 5·81 t ha ‐1; this above‐average decline was mainly caused by the onset of red clover necrotic mosaic virus which affected all red clover plots uniformly in the second harvest year, and by winter conditions before the third harvest year. Total herbage DOM and CP yields of the swards were influenced in a similar manner to DM production.
A model of clostridial dominance in ensilage
Authors: LEIBENSPERGER R. Y. , PITT R. E. 
Published: April 2006

AbstractA simulation model of the growth and fermentation of lactic acid bacteria and clostridia in silage is described. The model is used to predict the occurrence of a well‐preserved lactate silage or a poorly‐preserved clostridial silage. Results of the model are compared with published experimental studies not used in the model's development. The results are summarized with maps showing the combinations of initial water‐soluble‐carbohydrate content, crop buffering capacity, dry matter content, temperature, initial pH, and initial population of lactic acid bacteria which result in a clostridial silage. The specific processes modelled include the growth and death of lactic acid bacteria and clostridia; the use of substrate and accumulation of fermentation end products; release of ammonia; and change in silage pH.
The effect of strategic use of fertilizer nitrogen in spring and/or autumn on the productivity of a perennial ryegrass/white clover sward
Authors: FRAME J. , BOYD A. G. 
Published: April 2006

AbstractThe productivity of a mixed sward, comprising perennial ryegrass cvs Barlano and Bastion and white clover cvs Donna and Aran, was measured under sixteen fertilizer N treatments. These involved 0.25, 50 and 75 kg N ha‐1 in spring only, in autumn only and in all combinations of spring N and autumn N. A simulated grazing regime of six cuts annually at 3‐ to 6‐week intervals was imposed.Increasing rates of total N application increased total herbage DM regardless of application pattern. Yield response was greater with N applied in the spring, and total herbage DM was higher with high spring N‐low autumn N than the reverse. Mean yield responses at the first harvest to 25, 50 and 75 kg ha‐1 N in spring were 13.6, 10.8 and 11.6 kg DM per kg N. Corresponding responses at the final harvest to N rates in the autumn were 7.2, 5.8 and 6.8 kg DM per kg N. Responses were similar at these times for treatments receiving combined spring and autumn N.Over all treatments, mean annual production of total herbage was between 7.08 t ha‐1 DM with no N and 8.19 t ha‐1 with 75 kg ha‐1 N in both spring and autumn. Owing to drought, mean production in year 2 fell by 32% compared with year 1.White clover production fell progressively with increasing N application. Treatments with spring‐applied N gave the most marked decrease. White clover was more markedly depressed than the associated grass by the drought in the second year. The mean reductions in white clover content were 0.17, 0.07 and 0.12 percentage units per kg applied N for spring N, autumn N and combinations. Autumn N use depressed white clover less than spring N but the yield response of grass was less.It is concluded that any applied N adversely affects white clover performance to some degree. Where management factors are unfavourable to white clover even strategic N use may not be wise. Instead, it is suggested that a ‘dual‐sward’ approach be adopted in practice, namely, grass/white clover swards with no N. and complementary grass swards receiving optimum applied N to give better production at times when grass/white clover swards are relatively less productive.
The effect of cereal incorporation on the fermentation of spring‐and autumn‐cut silages in laboratory silos
Authors: JONES D. I. H. 
Published: April 2006

AbstractThe effect of adding ground oats and barley on the ensiling characteristics of autumn‐and spring‐harvested ryegrass was studied in laboratory scale silos.The addition of oats or barley at rates of 13 or 53 kg t−1 of grass significantly improved the fermentation of late autumn ryegrass silage in the first year. Ammonia N levels were reduced from over 20% of total N to 11% or less. Similar addition to autumn‐cut ryegrass higher in soluble carbohydrate content in the second year also significantly reduced pH and ammonia levels but all silages were well fermented. Addition of cereals to spring‐cut ryegrass containing over 20% soluble carbohydrate had no effect on fermentation. Cereal addition increased silage DM and decreased silage fibre content in all experiments.The results are discussed in relation to the potential advantage of cereal addition in the ensiling of grass crops.
Changes in mass and chemical composition of grass roots during decomposition
Authors: LARSSON K. , STEEN E. 
Published: April 2006

AbstractThe decomposition of dead roots of perennial grasses was examined in nylon litter bags not containing soil at two soil depths, 10 and 20 cm, and also in larger nylon bags containing soil at 020 cm depth. Bags were sampled three times during the growing season to determine weights of organic matter, crude protein, Klason lignin and non‐structural and structural carbohydrates.From 3 July to 5 October (94 days) the litter bags at 10 and 20 cm and the nylon bags lost, respectively, 35,38 and 65% of their organic mass of particle size < 1 mm.Non‐structural carbohydrates constituted 6% of the organic matter in the original sample but only 1% or less during the sampling period. Klason lignin increased from 22 to 29% and crude protein from 8 to 10% of the remaining organic matter, whereas structural carbohydrates changed very little.The constituents were degraded at different rates. The non‐structural carbohydrates had decomposed almost completely by the first sampling and of the other constituents the structural carbohydrates were degraded most rapidly. Before the first sampling unexpected amounts of structural carbohydrates, particularly glucans, had disappeared.The results help to explain rapid declines in root mass (up to 50%) during summer in perennial grass leys observed in earlier experiments.
Effects of supplementation on the ingestive behaviour of grazing steers*
Authors: DOUGHERTY C. T. , FORBES T. D. A. , CORNELIUS P. L. , LAURIAULT L. M. , BRADLEY N. W. , SMITH E. M. 
Published: April 2006

AbstractHerbage intake is usually depressed when beef cattle grazing abundant pastures are supplemented with energy‐rich feedstuffs but relatively little is known about the effects of supplementation on the components of ingestive behaviour. An experiment was conducted to establish the effect of ground corn (Zea mays L.) on the ingestive behaviour of yearling Angus and Angus × Hereford steers (Bos taurus) (mean live weight (LW) of 323 kg) grazing autumn stockpiled Boone cocksfoot (Dactylis glomerata L.) using a tethered grazing system in which the experimental unit was the tethered steer and its grazing area (45 m2) for one grazing session. Herbage dry matter (DM) mass was 1662 kg ha−1 and herbage DM allowance was 7–5 kg steer−1 for each grazing session. Herbage DM intake was measured as the difference between herbage DM mass offered and refused. Grazing took place during two daily sessions each of about 2 h duration commencing at 08.00 and 14.00 h for 9 days. Ground corn (0, 1·5, 3·0 and 4·5 kg steer−1) was fed each day at 12.00 h and had no significant (P < 0·05) effect on rate of DM intake, rate of biting or DM intake per bite. Mean DM intake was 6 2 kg steer−1 d−1 (87 mg (kg LW)−1 min−1). Steers averaged 4832 bites per grazing session, with a mean DM intake per bite of 644 mg (2·0 mg (kg LW)−1) and a mean rate of 44 bites min−1. Data obtained at the beginning and end of each grazing period on ingestive behaviour of one group of four steers (mean LW of 306 kg) fitted with oesophageal fistulae supported data for the two groups of normal steers and showed no response to supplementation. Mean values for rate of DM intake, DM intake per bite and rate of biting established for the fistulated cattle were 73 mg (kg LW)−1 min−1, 521 mg bite−1 (1·7 mg (kg LW)−1) and 39 bites min−1, respectively.
The effect of fasting on short‐term cattle grazing behaviour
Authors: GREENWOOD G. B. , DEMMENT M. W. 
Published: April 2006

AbstractThe effects of fasting on feeding behaviour, intake rates, and diet quality were studied with steers grazing vegetative Lolium multiflorum swards. Fasting interrupted the normal alternation of grazing and rumination and led to longer grazing times (0·65 vs. 0·45 of observed time), shorter rumination times (0·15 vs. 0·30 of observed time), and higher total dry matter (DM) intakes (6200 g DM vs. 3750 g DM d−1)‐Fasting did not affect prehended bite size which averaged 047 g DM bite−1. Declining bite size within a day was explicable by changes in herbage mass. Biting rate (38.9 bites min−1) and instantaneous intake rate (2675 g DM min−1) of fasted animals were considerably higher than non‐fasting animals in the mornings, but neutral detergent fibre (NDF) concentration of the diet (0 742 of organic matter) was generally not depressed by fasting. Consequently, non‐fasted animals appeared to be feeding suboptimally since their nutrient intake rates were considerably lower than that which they are capable of exhibiting. Mastication rates per unit NDF intake were considerably lower in the morning for fasted animals (0·78 chews g−1 NDF intake) which suggested that their intake rates may have led to larger ingested particle size. Therefore, on Lolium multifiorum swards, the steers attained a higher intake rate by masticating the forage less while maintaining diet quality.
Herbage growth and utilized output from grassland on dairy farms in southwest England: case studies of five farms, 1982 and 1983. I. Herhage growth
Authors: PEEL S. , MATKIN ELIZABETH A. , HUCKLE C. A. 
Published: April 2006

AbstractHerbage growth was measured in two contrasting years on five farms representing a range of soil types. On fields cut for conservation in 1982 DM production varied between farms from 12.3 tha‐1 to 14.1 tha‐1 in line with fertilizer N levels, which ranged from 220 to 333 kg ha‐1. In 1983 production was from 10.3 tha‐1 to 12.3 tha‐1; this again corresponded with fertilizer N, except on farm B which had the shallowest soils. On fields used for grazing all farmers used rotational management. Herbage accumulation was measured by trimming to 25 mm and harvesting after 4 weeks. As on conservation fields, herbage accumulation was generally greater on farms using more N, at least up to 300 kg ha‐1.In 1982 growth consistently exceeded predictions based on plot experiments. In 1983 growth was on average less than predicted on grazing fields but slightly more than predicted on cutting fields‐We conclude that such predictions of annual production are a valuable aid to farm planning, and need not be reduced to allow for on‐farm conditions, although they are least good at low levels of N. Predictions of individual cuts were not satisfactory, with a strong tendency to overestimate first cut and underestimate second cut.There was no indication that annual herbage production was less on badly drained than on well drained soils. Indeed, in the dry summer of 1983 badly drained land appeared to have an advantage, despite considerable poaching damage in the spring. Furthermore, there was no evidence that production was deficient on swards dominated by Holcus and Agrostis spp.
The influence of tall fescue on the germination, seedling growth and yield of birdsfoot trefoil
Authors: STEPHENSON R.J. , POSLER G.L. 
Published: April 2006

AbstractThe influence of tall fescue (Festuca arundinacea Schreb.) on germination and seedling growth of birdsfoot trefoil (Lotus corniculatus L.) was evaluated during 1983‐85 at Manhattan, Kansas. Studies were designed to evaluate tall fescue cv. Kentucky‐31 for possible allelopathic compounds, determine the effects of tall fescue on the germination, seedling growth and yield of birdsfoot trefoil, and to characterize the chemical properties of tall fescue. Fescue produced allelopathic compounds, particularly during the spring and autumn months when it was actively growing. The greatest trefoil inhibition occurred with fescue plant extracts prepared during the autumn (September and October). The concentration of fescue extracts influenced trefoil germination, with greater inhibition as fescue concentration increased. In a sand medium under greenhouse conditions, fescue extracts prepared in spring and autumn reduced trefoil growth by 50 and 56%, respectively, with no inhibition during the summer months. Under field conditions, full strength fescue extracts reduced trefoil plant populations by 14 and 57% with spring and autumn prepared extracts, respectively. Fescue competition reduced sod‐seeded trefoil plants per unit area by 17 and 31% for spring and autumn seeding, respectively. Full strength fescue extracts reduced trefoil seedling growth by an average of 37%, and trefoil dry matter yields by 53%.
Particle size reduction of the leaves of a tropical and a temperate grass by cattle
Authors: WILSON J. R. , McLEOD M. N. , MINSON D. J. 
Published: April 2006

AbstractThis study investigates forage particle breakdown, which is a factor of potential importance for the low intake of forages, particularly tropical grasses. A comparison was made between fresh leaf blades of a tropical grass, green panic (Panicum maximum var. trichoglume) and a temperate grass, Italian ryegrass (Lolium multiflorum). Leaf blades were chopped into 50 mm lengths and fed to cattle with oesophageal and rumen fistulae. Particle size was assessed on chewed samples immediately after eating and after digestion for 6, 12, 24, 48, 96 h and 3 weeks in nylon bags in the rumen.Chewing during eating reduced particle size more in length than in width and more in green panic than in ryegrass. Mean length was decreased 9·2‐fold and 4·7‐fold for the two species respectively, and mean width 5·4‐fold and 2·3‐fold. Green panic leaf had a higher cell wall content and higher dry matter content than ryegrass leaf.Digestion caused a substantial reduction in the width of the particles but not in the length. Width reduction occurred more rapidly in the ryegrass which was reduced to narrow fibres within 12–24 h of digestion while in green panic the same extent of degradation took < 48 h. After 96 h digestion, mean width of the chewed material had been reduced 40‐fold in ryegrass compared with only 165‐fold in green panic; all particles of both species were < 1 mm in diameter. The mean length of particles after 96 h digestion was similar to that of the chewed feed. Ryegrass was more digestible than green panic, a difference of 150 g kg DM−1 which was maintained from within the first 6 h of digestion up to 96 h digestion. After three weeks the digestibility of ryegrass was c. 50 g kg DM−1 higher than that of green panic but the proportion of cell wall that was ultimately indigestible was the same (0465) for both species.
The relationship between spoilage and Listeria monocytogenes contamination in bagged and wrapped big bale silage
Authors: FENLON D. R. , WILSON J. , WEDDELL J. R. 
Published: April 2006

AbstractA farm‐scale trial to compare the effectiveness of polythene bags and wrapping of big bale silage was monitored for Listeria monocytogenes contamination. There was no significant difference between the level of L. monocytogenes found in wrapped and bagged big bale silage, but the work confirmed that big bale silage is prone to contamination by Listeria organisms, and that the degree of Listeria contamination could be significantly reduced by the removal of obviously spoiled material prior to feeding.