bluuebunny/crossref_metadata_2025_split huggingface dataset:
Accelerated drying of cut lucerne (Medicago sativa L.) by chemical treatments based on inorganic potassium salts or alkali metal carbonates
Authors: MEREDITH R. H. , WARBOYS I. B. 
Published: April 2006

AbstractLiquid treatments to accelerate drying were applied to lucerne under laboratory conditions by brief immersion (∼3s) of cut shoots. Aqueous solutions of the alkali metal carbonates Li2CO3, Na2CO3 and K2CO3 were found to reduce drying times to 33% moisture content (MC) on a dry weight basis (dwb) by 45%, 55% and 65% respectively. Effectiveness was related to the ionic radius of the cation.From a range of potassium salts (KCl, K2CO3, KHSO4, KOH, K2SO4) in aqueous solution, the only useful reductions in drying time to 33% MC (dwb) came from the alkaline KOH (68%) and K2CO3 (65–76%).It is considered that K+ has a specific function in increasing water loss through the plant cuticle and that association with CO32‐ provides the high pH necessary for this activity.An aqueous solution of K2CO3 (0·16 M) gave greater acceleration of drying than the organic solvent petroleum ether and no benefit was gained by combining these treatments. Addition of a surfactant did not improve the effectiveness of K2CO3 as a desiccant but mixing with a rape‐seed oil emulsion reduced the drying time to 33% MC (dwb) by 11% relative to K2CO3 alone.Under field conditions K2CO3 as an aqueous solution gave only small reductions in the drying time to 33% MC and effectiveness was reduced by the addition of the rapeseed oil emulsion.Better results with K2CO3 (aq) might have been achieved with a more ventilated swath structure but the results strongly suggest that the oilseed rape emulsion is unlikely to improve the effectiveness of K2CO3 under field conditions.
Assessment of contrasting perennial ryegrasses, with and without white clover, under continuous sheep stocking in the uplands. 5. Herbage production, quality and intake in years 4–6
Authors: DAVIES D. A. , FOTHERGILL M. , MORGAN C. T. 
Published: April 2006

AbstractHerbage characteristics were studied over years 4–6 (1988–90) in three perennial ryegrass (Lolium perenne L.) varieties as grass‐only (200 kg N ha‐1) and grass/clover (Trifolium repens L.) swards which received 75kg N ha‐1 in 1988 and 0kg N ha‐1 in 1989 and 1990 when continuously stocked with sheep. Mean total annual herbage production of Aurora, a very early flowering variety, was 11% more than that of late‐flowering Aberystwyth S23 due to 21% higher growth as grass/clover pasture. The grass/clover sward of Meltra, a tetraploid late‐flowering variety, out‐yielded S23/clover by 17%. Herbage production of grass/clover was 86% of that of grass only in 1988 but only 54% of the grass‐only swards averaged for 1989 and 1990. In vitro organic matter digestibility (OMD) of Meltra was 38g kg‐1 OM and 27g kg‐1 OM higher than that of S23 and Aurora respectively. OMD of grass/clover was 15g kg‐1 OM higher than that of grass only during the post‐weaning period. Herbage intake was positively correlated with OMD of herbage.The herbage attributes were related to lamb performance reported previously. Lamb output was positively correlated with intake of digestible organic matter.Differences between the three varieties in herbage characteristics were greater as grass/clover than as grass‐only swards, reflecting their compatibility with white clover. In this respect Meltra was the best and S23 the poorest variety.
A practical equation for pasture growth under grazing
Authors: CACHO O. J. 
Published: April 2006

AbstractA sigmoid equation that accurately describes pasture growth is presented. The equation has three parameters that can be estimated either statistically from experimental results or algebraically from physiological simulation models. The equation produces satisfactory statistical results and it can account for different environmental conditions, through adjustment of parameter values, making it ideal for incorporation into grazing models when a simple but flexible equation is needed.
The digestion of grass silages produced using inoculants of lactic acid bacteria
Authors: SHARP R. , HOOPER P. G. , ARMSTRONG D. G. 
Published: April 2006

AbstractThe purpose of this study was to evaluate the efficiency of two inoculants of lactic acid bacteria (LAB) on grass silages. The evaluation was made in terms of silage composition, rumen fermentation, digestion and animal production. Over a 2‐year period two lots of silage were prepared in two 100‐tonne capacity clamps. In each case an untreated silage and an inoculant‐treated silage were prepared simultaneously from an identical herbage source using independent sets of silage‐making equipment. The inoculant used in the first year was Pioneer Brand 1188 (Pioneer Hi‐Bred UK), and in the second year a slightly different inoculant from the same source (Pioneer Hi‐Bred) was used. The two inoculants were essentially similar in composition, comprising a mixture of Lactobacillus plantarum and Streptococcus faecalis; the strains included in the second inoculant were selected for their capacity to tolerate higher temperatures. The fermentation of the inoculant‐treated silages appeared to be dominated by homofermentative LAB compared with the untreated silages. The use of either inoculant was associated with a change in the rumen volatile fatty acid (VFA) pattern, with a significantly greater molar proportion of propionate and a corresponding reduction in both acetate and butyrate. There was a trend indicating an enhanced efficiency of microbial protein synthesis within the rumen of the heifers for the inoculant‐treated silages, although this was only significant when concentrate was offered with the silage in one experiment. The inoculant‐treated silages had significantly greater intake characteristics than did the untreated silages, though this was not reflected in a statistically significant improvement in average daily liveweight gain in either year.
Reseeding in the Falkland Islands: seed rate and fertilizers for establishment
Authors: DAVIES T. H. , RILEY JANET 
Published: April 2006

AbstractFive experiments were carried out to measure the effects of seed rate and fertilizers on the establishment and early growth of reseeded grass mixtures in the Falkland Islands.Experiments 1 and 2 compared seed rates within the range 7·5‐35kg ha−1. Experiment 3 assessed the effects of three levels of each of nitrogen (N), P2O5, K2O and CaCO3 applied as seedbed fertilizers. Experiments 4 and 5 were similar in intent to Experiment 3, but treatments consisted of either nil or a very heavy application of the same fertilizer elements. In all experiments, the grass seed mixtures were sown in late summer after rotavation and burning of Cortaderia pilosa dominant indigenous vegetation on peaty soils. Percentage ground cover was estimated in the following spring and dry matter production through the first year was determined by sample harvests.Initially, heavier seed rates resulted in higher percentage ground cover of sown species, but dry matter production over the season following sowing showed a significant increase only between the 25 and 35 kg ha−1 rates in Experiment 2. The modest levels of seedbed fertilizers applied in Experiment 3 had no significant effect on either percentage ground cover of sown species or dry matter production. Even at the higher levels used in Experiments 4 and 5, only N consistently increased dry matter yields, although a significant positive response was also obtained from CaCO3 in the final harvests.The implications of the results to farmers in the Falkland Islands who may be contemplating reseeding are discussed.
The implications of controlling grazed sward height for the operation and productivity of upland sheep systems in the UK. 2. Effects of two annual stocking rates in combination with two levels of fertilizer nitrogen
Authors: SIBBALD A. R. , MAXWELL T. J. , MORGAN T. E. H. , JONES J. R. , REES M.E. 
Published: April 2006

AbstractWhen grazed sward surface height was controlled within the range 3·75‐5·25 cm during spring and summer, the effects of two annual stocking rates of twenty (SR20) and twelve (SR12) Cheviot ewes per hectare with their lambs and two rates of nitrogen fertilizer, 100(N100) and 200(N200)kg Nha−1 per year on animal performance and yield of silage from areas of pasture surplus to grazing requirements were measured. Decision rules for management of sward height resulted in good control of swards and consistent and satisfactory individual animal performance across treatments. Total output of lamb was greater for SR20 than for SR12 (699 vs 424kg live weight ha−1; P < 0·001). Yield of silage was less for SR20 than for SR12 [27 vs 184 kg dry matter (DM) per ewe; P < 0·001] and less for N100 than for N200 (65 VS 146 kg DM per ewe; P < 0·01). Around the mating period, when sward height fell below 3·5cm, supplementary feed was offered. More concentrates were offered to the SR20 than to the SR12 ewes (12·3 vs 1·2kg DM per ewe; P < 0·001) and to the N100 than to the N200 ewes (8·3 vs 5·2kg DM per ewe; P < 0·01); trends in the amounts of hay offered during that period were similar.
The effects of phosphorus and form of nitrogen supply on leaf cell size and nutrient content in Trifolium repens and Lotus uliginosus
Authors: HART A. L. , COLLIER W. A. 
Published: April 2006

AbstractWhite clover (Grasslands Huia) and lotus (Grasslands Maku) were grown in pots of soil at a range of phosphorus supply, and reliant on symbiotic nitrogen fixation (SN plants) or entirely on mineral nitrogen (MN plants). Shoots increased in weight with phosphorus supply. White clover MN shoots were bigger than those of SN plants except at the lowest level of phosphorus supply; lotus MN shoots were only bigger than SN shoots at the highest level of phosphorus supply. Leaf growth rate and size increased with phosphorus supply but were not significantly affected by the nitrogen treatments.Estimates of cell size were made by determining DNA concentration, by digestion of tissue followed by counting and by taking vinyl impressions of epidermal cell surfaces. Lotus cells are bigger than those of white clover. ‘Digested’ cell sizes were not significantly affected by changes in phosphorus supply. Epidermal cell size increased with phosphorus supply, but the relationship was weaker in SN than in MN plants. Methods which give values for ‘average’ cell size are capable of detecting large‐scale differences, but methods able to resolve cell heterogeneity are necessary for an accurate picture of the relationship between leaf growth and cellular nutrition.Average concentrations of total and inorganic phosphorus on a DNA basis did not differ between the species, contrary to concentrations on a dry weight basis, indicating that differences in phosphorus efficiency can be partly explained on the basis of average differences in cell size. Differences in inorganic phosphorous on a DNA basis at higher levels of supply suggested an additional intrinsic difference in cellular accumulation of inorganic phosphorus between the two species.
Effect of forage hydration on lag time during in vitro digestion of meadow hay
Authors: MILLER J. R. , HOBBS N. T. 
Published: April 2006

AbstractDigestion of plant cell wall has been observed to be a first‐order process with an initial lag. Lag is defined as the period of time immediately after forage is exposed to the fermentive environment during which digestion does not occur or occurs at a greatly reduced rate. The effects of forage hydration on lag were investigated by focusing on the first 20 h of in vitro digestion of meadow hay. Samples were hydrated for 0, 1, and 16 h before fermentation. Digestion kinetics was estimated by both a first‐order kinetics model (KM) and an increasing relative‐rate model (RRM). Model parameters were obtained using a non‐linear least‐squares procedure. The effect of forage hydration was significant, especially for the 16‐h treatment. The RRM produced a better fit for the data from each treatment, and a better fit was obtained when each data set was analysed separately.
The productivity and response to inorganic fertilizers of species‐rich wetland hay meadows on the Somerset Moors: the effect of nitrogen, phosphorus and potassium on herbage production
Authors: KIRKHAM F. W. , WILKINS R. J. 
Published: April 2006

AbstractThe effects of fertilizer nitrogen (N), phosphorus (P) and potassium (K) on herbage production were investigated in herb‐rich hay meadows in Somerset, UK. Swards were cut after 1 July each year, followed by one or two aftermath cuts. Dry‐matter (DM) yield at cutting, metabolizable energy (ME) production and recovery of N, P and K were measured over 4 years.Total annual DM production increased from 4·7t ha−1 without fertilizers to 10·5t ha−1 with 200 kg N, 75 kg P and 200 kg K ha−1 per year, and ME output from 38·8 GJ ha−1 to 92·5 GJ ha−1. Applying moderate replacement rates of P and K without N increased annual DM and N yields by 43% and 36% respectively, but N response was modest unless high rates of P and K were used. Annual ME output and recovery of N, P and K were all significantly increased by taking an additional, earlier cut for silage, even though DM yield was unaffected.The results suggest that potential output of these meadows is similar to that of a wide range of less diverse permanent pastures. Data from this and a concurrent experiment will help to estimate the financial implications of fertilizer and cutting date restrictions within Sites of Special Scientific Interest and the wider Environmentally Sensitive Areas.
Effect of continuous stocking by sheep at four sward heights on herbage mass, herbage quality and tissue turnover on grass/clover and nitrogen‐fertilized grass swards
Authors: BINNIE R.C. , CHESTNUTT D. M. B. 
Published: April 2006

AbstractThe effects of continuous stocking by sheep at sward surface heights (SSH) of 3, 5, 7 and 9 cm in grass/clover (GC) and nitrogen‐fertilized grass (GN) swards were examined in relation to herbage mass and quality, clover content, tiller density and rates of herbage production and senescence in two periods in each of three grazing seasons (1987‐89). The GN swards received a total of 300 kg N ha−1 each year in six equal dressings from March; GC swards received a single dressing of 50 kg N ha−1 in March each year.Herbage mass measured from ground level increased linearly with SSH with overall mean herbage masses of 0·89, 1·38, 1·78 and 2·12 t OM ha−1 (s.e.m.0·024, P < 0·001) at SSH of 3, 5, 7 and 9 cm respectively. GN and GC swards had mean herbage masses of 1·58 and 1·51 t OM ha−1 (s.e.m. 0·051, NS) respectively. Mean N content of herbage on GN swards was greater than that on GC swards and declined with increasing SSH. Crude, fibre (CF) content of herbage was similar for both sward types and increased with increasing SSH.Clover content of GC swards remained low throughout the experiment, ranging from 0·002 to 0·074 of herbage mass. However, from tissue turnover rates it was estimated that its contribution to herbage production was in the range of 0·049–0·219 of net herbage growth.Total growth increased with increasing SSH in both sward types, with maximum growth rates in GN swards of 143 and 130 kg DM ha−1 d−1 and in GC swards of 88·2 and 85·4 kg DM ha−1 d−1 in Periods 1 (up to early July) and 2 (after July) respectively. Senescence rates ranged between 13·3 and 50·1 kg DM ha−1 d−1 and tended to be higher in Period 2 than in Period 1. Net production increased with increasing SSH in Period 1, while in Period 2 net production declined at SSH above 6·5 cm.The increased net herbage production in taller swards was not associated with greater utilized metabolizable energy production at sward heights above 5 cm.
The effects of incorporating sugar‐beet pulp with herbage at ensiling on silage fermentation, effluent output and in‐silo losses
Authors: FERRIS C. P. , MAYNE C. S. 
Published: April 2006

AbstractThree studies were undertaken with the aim of examining in‐silo losses associated with ensiling mixtures of beet pulp and herbage. In Experiment 1, first‐regrowth perennial ryegrass was ensiled untreated or mixed with either 40 or 120 kg unmolassed beet pulp t−1 fresh grass prior to ensiling. In each of Experiments 2 and 3, second‐regrowth ryegrass was ensiled untreated or mixed with either 40, 80 or 120 kg unmolassed beet pulp t−1 fresh grass prior to ensiling. Dry‐matter concentrations of herbage ensiled in Experiments 1, 2 and 3 were 141, 157 and 139 g kg−1 respectively.Time‐course studies indicated a more rapid fermentation with the untreated silages. Ensiling beet pulp with herbage resulted in significant improvements in silage fermentation, reflected in reductions in silage pH and ammonia nitrogen concentrations, with these effects being pronounced at beet pulp inclusion in excess of 80kg t−1. Beet pulp inclusion increased the dry‐matter concentrations of the resulting silages while reducing crude protein, modified acid detergent fibre and gross energy concentrations. In Experiment 1 beet pulp retained 1·62 and 1·641 effluent kg−1 at the 40 and 120kg t−1 application rates respectively. In Experiments 2 and 3, effluent retentions were 1·40, 1·29 and 0·93 1 kg−1 and 2·87, 2·19 and 1·781 kg−1 at the 40, 80 and 120kg t−1 beet pulp inclusion rates respectively. In each of Experiments 1 and 3, in‐silo losses were reduced with increasing level of beet pulp inclusion, while in Experiment 2 in‐silo losses were relatively unaffected by treatment. Nutrient losses in effluent were reduced by the inclusion of beet pulp in all three experiments, while nutrient losses in surface waste and invisible nutrient losses tended to increase with higher levels of beet pulp inclusion.It is concluded that the inclusion of beet pulp with herbage at ensiling can result in an improved silage fermentation and a reduction in in‐silo losses, while at the same time retaining considerable quantities of effluent within the silo. However, with herbage dry‐matter concentrations below 160gkg−1, beet pulp inclusion in excess of 120 kg t−1 herbage would be required to eliminate effluent production totally.
Effects on milk production of feeding silage and three levels of sugar‐beet pulp either as a mixed ration or as an ensiled blend
Authors: FERRIS C. P. , MAYNET C. S. 
Published: April 2006

AbstractTwenty‐one British Friesian dairy cows, in mid‐lactation, were used in a seven‐treatment, partially balanced change‐over design experiment consisting of three periods each of 4 weeks' duration. Treatments involved offering grass silage either without a sugar‐beet pulp (beet pulp) supplement (US) or supplemented with beet pulp at silage/beet pulp dry matter ratios of 80:20 (C40), 65:35 (C80) and 55:45 (C120), and offered in the form of a mixed ration. A further three treatments consisted of offering ensiled blends of silage and beet pulp, produced by mixing 40 (E40), 80 (E80) and 120 (E120)kg beet pulp t−1 of grass at ensiling. Silage was offered ad libitum on all treatments, with cows receiving 1kg d−1 of a concentrate supplement containing 470 g crude protein kg−1 fresh weight.Dry matter intakes increased with increasing level of beet pulp inclusion in the diet, irrespective of method of beet pulp inclusion in the diet. Similarly, milk fat + protein yields increased with increasing level of beet pulp offered. However, when comparisons were made between the two methods of beet pulp inclusion in the diet with beet pulp requirements equivalent to those obtained in treatments C40, C80 and C120, namely 2·28, 4·53 and 6·21 kg d−1, offering beet pulp as a supplement to an untreated silage resulted in fat + protein yields of 32 (s.e.d. 9·8), 53 (s.e.d. 19·5) and 81 (s.e.d. 21·3)gd−1 greater than would have been achieved had equivalent quantities of beet pulp been included at ensiling as part of an ensiled blend. This effect can be attributed to the higher metabolizable energy intakes with the control silage supplemented with beet pulp at feeding, a consequence of the loss of nutrients from the beet pulp fraction during ensiling, in the case of treatments E40, E80 and E120. However, when account is taken of differences in the efficiency of recovery of edible silage dry matter between ensilage systems and differences in forage dry‐matter intake between treatments, overall efficiency of feed use was not significantly different between the two systems of beet pulp inclusion in the diet.
Enzymes as silage additives for grass–clover mixtures
Authors: SELMER‐OLSEN I. 
Published: April 2006

AbstractSeven laboratory‐scale experiments were carried out to study the effects of cellulases/hemicellulases on silage fermentation of herbage from mixed swards of timothy (Phleum pratense), meadow fescue (Festuca pratensis) and red clover (Trifolium pretense). Enzyme‐treated silage (approximately 3500 HEC units kg−1 grass) reached a low pH sooner, had lower end pH, contained less NH3‐N and more lactic acid than did the untreated silage (P < 0·05). Applied with an inoculant, these effects were even stronger. With easily ensiled crops (experiments 1, 2, 5 and 6) preservation was first of all improved by inoculation of lactic acid bacteria; however, for the low‐sugar crops (experiments 3, 4 and 7) enzyme treatment was more significant. The enzymes derived from Aspergillus spp. gave more acetic acid than the enzymes from Trichoderma reesei. The Trichoderma enzymes liberated 4·8 g WSC kg−1 FM gamma‐irradiated grass during 60 d at pH 4·3 (P < 0·05). On average, for all silages enzyme treatment increased the sum of residual sugar and fermentation products by 3·7 g kg−1 FM (21 g kg−1 DM) compared with the silages not treated with enzymes (P < 0·001). Enzyme treatment increased the instantly degradable part of the feed, but total in sacco and in vitro digestibilities were not affected.
Effects of delay in reapplication of nitrogen fertilizer following cutting silage from a ryegrass sward
Authors: SHELDRICK R. D. , LAVENDER R. H. , MARTYN T. M. 
Published: April 2006

AbstractPlots of a 2‐year‐old sward of Merlinda perennial ryegrass received a routine dressing of 100 kg N ha−1 as compound fertilizer in March 1991, followed by further dressings of 100 kg N ha−1 after cuts 1, 2 and 3 in a simulated four‐cut silage system, either the same day as cutting or with a delay of 3, 7, 10 or 14 d. Partial irrigation ensured that fertilizer could be taken up immediately. Annual total dry matter yield, the dry matter yield for the experimental cuts 2–4 and their apparent response to N showed no effect of delays of 0–10 d in reapplication of fertilizer, but a significant (P < 0·01) reduction for 14 d delay. Significantly (P= 0·001) higher apparent recovery of N in the cut herbage was recorded where reapplication of fertilizer had been delayed by 7 or 10 d (93% and 91% respectively) in comparison with either smaller (0 delay, 78%; 3 d delay, 87%) or greater delay (14 d, 86%). It is suggested that lower recoveries at 0 and 3 d result from the sward's reduced NO3 uptake following defoliation and that, while in practical situations the conditions may not be as rigorous as those imposed in this experiment, further experiments to determine the fate of N not recovered in the herbage are warranted, so defining management circumstances in which immediate reapplication of N might not be advisable.