bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of fertilizer nitrogen rate and timing on herbage production and nitrogen use efficiency for first‐cut silage
Authors: LONG F. N. J. , KENNEDY S. J. , GRACEY H. I. 
Published: April 2006

AbstractEight field‐plot experiments were carried out on established grassland swards between 1984 and 1988 to examine the effects of date and rate of application of calcium ammonium nitrate (CAN) on herbage dry matter (DM) yield and apparent efficiency of nitrogen (N) use at first‐cut silage.CAN application significantly increased (P <0 ·001) the mean yields of herbage and N uptakes by herbage in all experiments. Herbage yields were similar (P > 0·05) with N rates of 100 kg ha−1, 125 kg ha−1 or 150 kg ha−1 in five experiments but in the other three there were increases above 100 kg ha−1. Date of N application had a significant effect on DM yield in three experiments; this effect was inconsistent for both single and split dressings. Lower production was associated with reduced uptake of N, a trend that primarily reflected lower DM yields and not wide herbage N content variation.It is concluded that selection of the date on which to apply fertilizer N in early spring to obtain optimum herbage yields at first‐cut silage often required little precision. The use of fertilizer N rates >100 kg ha−1 should be questioned where there are likely to be appreciable quantities of available N derived from non‐fertilizer sources.
The efficacy of a high magnesium grass cultivar in controlling hypomagnesaemia in grazing animals
Authors: MOSELEY G. , BAKER D. H. 
Published: April 2006

AbstractA cultivar of Italian ryegrass (Bb 2067), specifically bred for high magnesium content, was assessed for its efficacy in alleviating the incidence of hypomagnesaemia in lactating ewes. Pasture and animal management was regulated to maximize the potential for the development of hypomagnesaemia. The incidence of clinical hypomagnesaemia in ewes grazing the control pasture (cv. RvP) was 21% within the first 10 days and this was accompanied by a significant fall of 35% in serum magnesium concentration. The incidence in ewes grazing the high magnesium cultivar was only 2·5% and there was no significant change in the serum magnesium concentration.The mean magnesium content of Bb 2067 herbage (1·45 gkg DM‐1) was 48% higher than cv. RvP (0·93 g kg DM‐1) while calcium and phosphorus were 15% and 30% higher. The mean dry matter intake of ewes grazing Bb 2067 was higher than that of ewes grazing RvP, and although the difference was not statistically significant there were significantly increased intakes of magnesium, calcium and phosphorus for ewes grazing Bb 2067 compared with RvP. Ewes grazing Bb 2067 ingested more than the recommended allowance of magnesium and were close to sufficiency for calcium and phosphorus, while those grazing RvP were in serious deficit for all three minerals.There was no significant difference in the ewe body weight loss between the treatments but lamb liveweight gain was significantly greater on the Bb 2067 pastures compared with those on cv. RvP.It was concluded that the high magnesium grass provided an effective means of controlling hypomagnesaemia under grazing despite the extreme predisposing conditions imposed in this trial.
Detection of lolines in endophyte‐containing meadow fescue in The Netherlands and the effect of elevated temperature on induction of lolines in endophyte‐infected perennial ryegrass
Authors: HUIZING H. J. , VAN DER MOLEN W. , KLOEK W. , DEN NIJS A. P. M. 
Published: April 2006

AbstractPlants from a Festuca pratensis variety which had caused‘eczema solare’among lambs in The Netherlands revealed the presence of endophytic Acremonium after microscopic evaluation. Combined gas chromatographic‐mass spectrometric analysis of extracts from seeds of these plants showed the occurrence of N‐formyl‐ as well as N‐acetyl‐loline which are formed as a result of the plant‐fungus association.Endophyte‐infected Lolium perenne plants produced lolines only at elevated temperatures while non‐infected plants failed to synthesize these alkaloids under identical environmental conditions. Results indicate that presence of endophytic fungi together with growth at temperatures above 23°C is a prerequisite for induction of alkaloids detected in perennial ryegrass
Protein supplementation of formic acid‐ and enzyme‐treated silages. 1. Digestibilities, organic matter and fibre digestion
Authors: JACOBS J. L. , McALLAN A. B. 
Published: April 2006

AbstractTwo silages were made from perennial ryegrass ensiled without wilting in 2‐t capacity silos with the application of either formic acid or an enzyme mixture of cellulases and hemicellulases. Effluent losses were monitored over the ensiling period. Subsequent silage analysis showed that the enzyme‐treated silage had higher concentrations of residual water soluble carbohydrate, lactic acid and acetic acid, and lower concentrations of cellulose, ADF and NDF. Effluent production was higher with the enzyme silage (formic acid, 211 1 t−1; enzyme, 2671 t−1). The silages were either offered as the sole diet or supplemented with rapeseed meal at two levels (60 or 120 g fresh weight kg−1 silage DM offered) to growing steers equipped with rumen cannulae and T‐piece duodenal cannulae. Apparent whole tract digestibilities for DM, OM, N, ADF and NDF were similar for all diets although nitrogen retention (g d−1) was increased with supplementation of both silages (formic acid, 21·1; formic acid + 60 g, 23·5; formic acid+ 120 g, 28·5; enzyme, 22·6; enzyme + 60 g, 25·8; enzyme+ 120 g, 31·6). Rumen pH, ammonia and total volatile fatty acids patterns were similar. Supplementation increased the amount of organic matter apparently digested in the rumen (ADOMR) with formic acid‐treated silage but not with enzyme‐treated silage. Liveweight gains were similar for both unsupplemented silages (0·49 kg d−1). These increased to 0·55 and 0·65 kg d−1 for formic + 60 and formic + 120 respectively. Liveweight gains for the corresponding enzyme‐treated supplemented diets were 0·81 and 0·91 kg d−1 respectively. Liveweight gains on supplemented enzyme‐treated diets were significantly (P < 0·05) greater than those on formic acid‐treated diets.
The effect of cutting on the proportions of perennial ryegrass and white clover in mixtures
Authors: WOLEDGE JANE , REYNERI A. , TEWSON VERONICA , PARSONS A. J. 
Published: April 2006

AbstractIn two experiments with ryegrass/white clover mixtures, the proportion of clover was measured before and after cuts which removed 8‐75% of above‐ground biomass. Cutting was found to reduce the proportion of clover leaf area in the crop in both experiments, sometimes by as much as two‐thirds, and the proportion of clover dry weight, by up to half, in one of them. That is, the harvested material contained a greater proportion of clover than did the sward before the cut. This disproportionate removal of clover was due to clover having a greater proportion of its leaf near the top of the canopy than grass. It showed that preferential removal of clover occurs as a result of the purely passive selection by a mower, not only as a result of grazing by animals which may be capable of active as well as passive selection.Despite the disadvantage to clover of losing more of its leaf area than grass, and in some cases more of its dry weight also, when the mixture was cut, the clover content of the sward did not decrease during the growing season as a whole. This was because, where no nitrogen fertilizer was applied, clover had a greater relative growth rate (RGR) than its companion grass during the growth periods between cuts and this increased its percentage of the mixture. Even where nitrogen was applied, clover equalled the RGR of grass and maintained its proportion of the crop, except in one instance.
Some effects of herbage composition, as influenced by previous grazing management, on milk production by cows grazing on ryegrass/white clover pastures. 1. Milk production in early spring: effects of different regrowth intervals during the preceding winter period
Authors: HOLMES C. W. , HOOGENDOORN C. J. , RYAN M. P. , CHU A. C. P. 
Published: April 2006

AbstractTwo experiments (1a and 1b) were carried out to examine the effects of differences in pre‐grazing herbage mass and composition on milk production by cows grazing in early spring. Swards with high (5 · 1t DM ha−1) or low (2 · 9 t DM ha‐1) pre‐grazing masses in early spring were created by either long or short periods of regrowth during the preceding winter.The low‐mass swards contained lower concentrations of grass stem and senescent material, but higher concentrations of clover, than the high‐mass swards. Herbage from the low‐mass swards was also more digestible.Cows were offered common daily herbage allowances from both swards (26 and 22 kg DM cow−1 in Experiments la and lb respectively). The cows grazing on the low‐mass swards produced significantly greater yields of milk, milk fat and milk protein.The results show that herbage from the lowmass swards was of higher feeding value for lactating cows in early lactation. The practical implications for milk production per cow and per hectare are discussed.
The effects of forage preservation method and proportion of concentrate on digestion of cell wall carbohydrates and rumen digesta pool size in cattle
Authors: HUHTANEN P. , JAAKKOLA S. 
Published: April 2006

AbstractSix bulls with ruminal and duodenal cannulae were used in a 6 × 6 Latin square design with a 2 × 3 factorial arrangement of treatments. Barn‐dried grass (G) and direct‐cut silage (S) from the same sward were fed together with 250 (L), 500 (M) and 750 (H) g kg‐1 total dry matter (DM) of a barley‐based concentrate (barley 875 and rape‐seed meal 125 g kg‐1) at the level of 80 g DM kg‐1 live weight0·75. Rumen and total digestibility of cell wall constituents were measured by a double marker and total collection method. Rumen pool sizes of dietary constituents were estimated by emptying the rumen. Particle‐associated enzyme activities were measured from rumen particulate material and feed particles incubated in nylon bags in the rumen.Neutral detergent fibre (NDF) and hemicellulose digestibility were higher (P<0·05) for G diets than for S diets while no differences were observed between the forages in acid detergent fibre (ADF) and cellulose digestibility. Both rumen and total digestibility of cell wall constituents decreased with increasing level of concentrate. The proportion of total cell wall digestion in the rumen was unaffected by the forage preservation method and the proportion of concentrate. NDF, and especially cellulose digestibility, declined quadratically with increasing level of concentrate. Dietary effects on particle‐associated carboxymethylcellulase and xylanase activity were consistent with those observed in cell wall digestion. There were no differences between the forages in rumen pool size of total ingesta or any dietary constituent. Rumen pool size of total ingesta decreased with increasing level of concentrate. On the other hand, DM content of ingesta increased with the level of concentrate, while the pool size of DM, NDF and ADF declined quadratically reaching a minimum on M level of concentrate. The differences in rumen NDF pool size were mainly in the digestible fraction. Calculation of digestion kinetic parameters showed that both the rate of passage and especially the rate of digestion were markedly depressed in animals fed on the highest level of concentrate. The results suggest that a reduced fate of digestion of NDF with high concentrate diets can be partially compensated for by an increased NDF retention time in the rumen of animals fed at a restricted level of feeding.
Influence of growth stage and season on the energy value of fresh herbage. 2. Relationships between digestibility and metabolizable energy content and various laboratory measurements
Authors: GIVENS D. I. , MOSS ANGELA R. , ADAMSON A. H. 
Published: April 2006

AbstractThis paper gives details of a study which has examined the effect of herbage growth type and season on the relationships of digestible organic matter in the dry matter (DOMD) and metabolizable energy (ME) contents measured in vivo to various laboratory measurements including three in vitro estimates of DOMD based on rumen fluid pepsin (RFP), pepsin cellulase (PC) or neutral detergent cellulase (NCD). Seventy herbages harvested over two years and comprising 32 spring primary growths, 14 summer regrowths and 24 autumn growths were used.For DOMD in vivo, significantly different regression relationships were required for spring and autumn‐harvested herbage. Equations based on PC were:Spring herbage: DOMD (g kg‐1 DM) = 436 + 0·501 PC (g kg‐1 DM) 2= 76·7%; r.s.d. = 25·4Autumn herbage: DOMD (g kg‐1 DM) = 594 + 0·195 PC (g kg‐1 DM) 2= 15·5%; r.s.d. = 23·1For autumn herbages there were no significant relationships with ME. As with DOMD in vivo the PC method was shown to provide the most accurate relationship with ME concentration of spring herbage. The relationship was:ME (MJ kg‐1 DM) = 6·16 + 0·0094 PC (g kg‐1 DM) 2= 69·8%; r.s.d. = 0·57For both DOMD and ME the relationships for spring herbage based on PC were the only ones which did not differ significantly from those of an earlier study.It is concluded that even where significant relationships for summer and autumn herbages were developed, the predictors accounted for substantially less of the variability than in spring herbages. This appeared to be largely due to reduced range in the DOMD and ME content in summer and autumn herbages.
Seed development and seed yield potential of Italian ryegrass (Lolium multiflorum Lam.) populations
Authors: HIDES D. H. , KUTE C. A. , MARSHALL A. H. 
Published: April 2006

AbstractGreenhouse and field experiments were carried out to study the seed development and seed yield potential of three populations of Italian ryegrass (Lolium multiflorum Lam.). These included an ecotype (Bb 1276) collected in the Lombardy Plain region of northern Italy, cv. Tribune, which was derived from this ecotype, and cv. Lemtal, a widely used cultivar from Belgium. Artificial seed shedding techniques in the green‐house study showed that Bb 1276 began shedding seed at a higher moisture content than cv. Tribune which in turn was higher than cv. Lemtal. The pattern and rate of shedding was similar for all three populations and generally Bb 1276 and cv. Tribune gave a greater proportion of shed seed than cv. Lemtal. Although the pattern of decline in seed moisture content was similar for all three populations, generally cv. Lemtal had a higher moisture content than cv. Tribune with Bb 1276 the lowest. Cultivar Lemtal had the highest mean 1000 seed weight, and Bb 1276 the lowest, with cv. Tribune intermediate. The field study involving cv. Tribune and cv. Lemtal showed that with the exception of 1000 seed weight, which for cv. Tribune was some 6% lower than that of cv. Lemtal, all the seed yield components were similar. Seed yields taken every 3 days after the standing crop had reached 50% moisture content showed that both cultivars increased in yield until harvest 3. After this date the seed yield of cv. Lemtal remained stable up to harvest 5 while that of cv. Tribune declined. The maximum seed yield of cv. Tribune was achieved at a seed moisture content of 42·9% while that of cv. Lemtal remained stable from 42·3% to 37·5%. The seed moisture content of the two cultivars again showed a similar pattern of decline but it was not possible to show consistent differences between cv. Lemtal and cv. Tribune. The 1000 seed weight of cv. Tribune was lower than that of cv. Lemtal, and the maximum seed weight of cv. Tribune appeared to be achieved earlier. Germination counts taken after harvest showed both populations exhibiting a high level of post harvest dormancy. Later counts taken 3 months after harvest were significantly higher than those taken earlier and there were no differences between cultivars or harvests.The results are discussed in relation to the potential for selecting for improved seed yield potential in Lolium multiflorum Lam. Populations from northern Italy and suggestions are made for maximizing the harvested seed yield of cv. Tribune.
Sodium fertilizer application to pasture. 1. Direct and residual effects on pasture production and composition
Authors: CHIY P. C. , PHILLIPS C. J. C. 
Published: April 2006

AbstractResults are given on the effect of sodium (Na) fertilizer applied as NaNO3 in five application sat 0 (Nil), 32 (Low) or 64 (High) kg Na ha ‐1yr‐1 and the residual effect of sodium chloride(NaCl) fertilizer applied in the previous year on the growth rate and the chemical composition of herbage cut at fortnightly intervals over the grazing season.Na fertilizer at Low and High rates increased herbage Na contents by 20 and 40% respectively. Magnesium (Mg) content in herbage was increased at Low Na fertilizer application rate but there was no difference between the Nil and the High Na treatments. Calcium (Ca) content was increased in proportion to Na fertilizer level. Potassium (K) content of Nil Na herbage exceeded that of Low and High, but there was no effect of treatment on total harvested K yields. The contents of phosphorus (P), sulphur (S), true protein (TP) and modified acid detergent fibre (MADF) in herbage were not affected, but the dry matter digestibility (DMD) was increased with increasing Na fertilizer level. Applying Na fertilizer at the Low and High levels gave similar increases in water‐soluble carbohydrates (WSC) and ash contents and decreased crude protein (CP) and non‐protein nitrogen (NPN) contents. Net herbage accumulation(fresh and dry weight) was increased by 15 and 26% at the Low and High Na fertilizer application rates respectively.NaCl fertilizer residues from the previous year increased herbage Na, DM, DMD and WSC contents, reduced K contents and did not affect Ca, P, S, CP, TP and NPN contents. Residues from Na fertilizer decreased MADF and ash contents at the Low and High Na application rates.The main and residual effects of Na fertilizer were generally maximal in early season and diminished as the season progressed, with many of the effects eliminated by late season. Proportionally 0·70 of Na applied was recovered in the first two grazing seasons after application. The effects of Na fertilizer on mineral ratios are also described, together with the implications for animal health.
A comparison of diploid and tetraploid perennial ryegrass and tetraploid ryegrass/white clover swards under continuous sheep stocking at controlled sward heights. 1. Sward characteristics
Authors: SWIFT G. , VIPOND J. E. , McCLELLAND T. H. , CLELAND A. T. , MILNE J. A. , HUNTER E. A. 
Published: April 2006

AbstractTwo 1·0 ha plots of a late‐heading diploid perennial ryegrass (var. Contender) and a late‐heading tetraploid ryegrass (var. Condesa), and two 1·4 ha plots of the tetraploid with Aberystwyth S184 small‐leaved white clover, were direct sown in May 1987. Over the three years 1988–90 they were continuously stocked by Mule ewes with Suffolk‐cross twin lambs, from early April to the end of August, at a target sward surface height (SSH) of 4–6 cm on one set of plots (constant swards) and, on the other set, al 4–6 cm rising after June to a target 6–8 cm (rising swards). The heights were achieved by variable stocking. Fertilizer N was applied only to the grass plots at the rate of 150‐ 180kgN ha‐1 annually.SSH was mainly within the target 4–6 cm, after higher initial heights at turnout in 1988and 1990. Mean heights of the constant swards (April‐ August) averaged 5·53, 4·43 and 5·04cm in the three years. The rising swards (July‐August) increased in height over the constant swards by an average of 0·88, 0·48 and 0·55 cm, in successive years.Clover content of the herbage mass dry matter in the grass/clover swards increased over each grazing season to average 13·0, 26·5 and 21·2% in the three years, with a high mean stolon density of 130 in m‐2 in August 1990. Ryegrass tiller densities in year 3 were 23% higher in the diploid than in the tetraploid swards, which had 43% more than the 10000 tillers m‐2 of the tetraploid ryegrass/clover swards.It is concluded that the combination of a densely stoloniferous small‐leaved clover with the open growth habit of a tetraploid ryegrass can achieve swards of high clover content under continuous sheep stocking.
Performance of morphologically diverse orchardgrass clones in spaced and sward plantings
Authors: BUXTON D. R. , LENTZ E. M. 
Published: April 2006

AbstractThis study was conducted to determine effects and interactions of plant density on digestibility and plant morphology of diverse orchardgrass (Dactylis glomerata L.) clones. Propagules of ten orchardgrass clones with contrasting morphology from two maturity groups (inflorescence emergence differed by 8d) were evaluated in sward (0·15‐m centres) and spaced (0·60‐m centres) plantings. Plants were harvested from spring growth on a common date near anthesis and from summer growth when about 5 weeks of forage growth had accumulated. The plants were separated into morphological parts before measuring their size and in vitro digestible dry matter (IVDDM). There were few plant density × orchardgrass clone interactions, and correlation coefficients of clones grown at the two plant densities generally were high (e.g. 0·87 in spring and 0·67 in summer for IVDDM of total herbage). Plant density had little effect on morphology of leaf blades from reproductive tillers, but leaf blades of vegetative tillers were 12% (spring) and 22% (summer) longer from sward than from spaced plantings. Moreover, reproductive tillers were 26% taller in sward than in spaced plantings. Also, leaf blades of vegetative tillers in spring growth were more than twice as long, of similar width and 65% thicker than leaf blades from reproductive tillers. Because divergent genotypes respond similarly to plant density, it is concluded that observations taken in spaced plantings of orchardgrass can be used to make inferences about relative differences in sward plantings for the traits studied.
Response of permanent and reseeded grassland to fertilizer nitrogen. 2. Effects on concentrations of Ca, Mg, K, Na, S, P, Mn, Zn, Cu, Co and Mo in herbage at a range of sites
Authors: HOPKINS A. , ADAMSON A. H. , BOWLING P. J. 
Published: April 2006

AbstractThe concentration of mineral elements in herbage from permanent swards of mixed species composition (predominantly Agrostis spp., Holcus lanatus, Festuca rubra, Lolium perenne, Poa spp., etc.) was compared with that from sown perennial ryegrass (Lolium perenne) at two fertilizer rates (0 and 300kg N ha−1 year−1, both with P and K) and with L. perennel Trifolium repens (at 0 N with P and K). The investigation was conducted over four years at sixteen contrasting sites in England and Wales. Herbage samples for mineral analysis were taken at first and fourth harvests (May and August) each year from plots under 4‐weekly cutting. There was a wide degree of variation between sites, particularly for concentrations of Ca, Mg, Na and all trace elements analysed. Herbage from L. perenne reseeds had significantly higher concentrations of Ca, Mg, Na, Co and S, but K, Mo, Zn, Cu and P were generally lower than in the permanent swards. L. perennel T. repens swards had the highest concentration of major cations, but trace element levels were generally intermediate between those for 0 N permanent and L. perenne swards. Fertilizer N reduced concentrations of Ca, Mn, Mo and S, and increased Mg, Na and Zn, with no consistent effects on K, Co and Cu. Herbage at harvest 4, compared with harvest 1, had higher Ca, Mg, Na, Mn, Zn and S. Permanent and L. perenne swards responded similarly to fertilizer N and between harvest dates. Results are discussed in relation to previous reports of botanical and fertilizer effects on mineral concentrations, and the mineral requirements of livestock. Changes in mineral concentration resulting from reseeding permanent swards are considered unlikely to increase mineral‐related livestock disorders, and in many cases could be beneficial, though problems might arise on sites where some elements, e.g. Cu and Mg, are low.