bluuebunny/crossref_metadata_2025_split huggingface dataset:
Grazing cycle length and silage supplementation: effects on the performance of lactating ewes with twin lambs
Authors: ORR R. J. , NEWTON J. E. 
Published: April 2006

AbstractMasham ewes, stocked at 20 ewes ha−1, reared twins at pasture in 1979 and 1980 and were rotationally grazed around six paddocks. There were three lengths of grazing cycle (18, 30 or 42 d) and the ewes at pasture were either offered silage ad libitum (S) for 8 weeks of lactation or they were not supplemented with silage (N). By feeding silage, S ewes and lambs moved into greater herbage masses (3735 u. 3390 kg organic matter (OM) ha−1), but there was little effect on net herbage accumulation (10.5 v. 10.0 t OM ha−1) and herbage intakes per ewe were similar (2.31 v. 2.27 kg OM d−1) over the 7‐month grazing season. During the period of silage supplementation, total intake was 19% higher for S than N ewes, lamb growth rates were slightly higher (280 v. 273 g d−1) and the ewes lost less weight (−78 v−96 g d−1).For 18‐, 30‐ and 42‐d grazing cycles respectively the herbage masses before grazing were 2825, 3620 and 4240 kg OM ha−1; net herbage accumulations were 9.8, 10.4 and 10.6 t OM ha−1; mean daily herbage intakes by each unit (ewe+lambs) were 2.22, 2.35 and 2.30 kg OM and lamb growth rates from birth to weaning at 20 weeks were 205, 204 and 204 g d−1.Frequent grazing of relatively light herbage masses or infrequent defoliation of heavier herbage masses made little difference to sward or animal performance. It is concluded that, at this stocking rate, different grazing cycles of 18, 30 or 42 d do not affect the performance of lactating ewes.
Some changes associated with the field drying of lucerne and timothy
Authors: ALLI I. , ROBIDAS E. , NOROOZI E. , BAKER B. E. 
Published: April 2006

AbstractLucerne (approximately 10% flowering, 270 g dry matter kg−1) and timothy (boot stage, 310 g dry matter kg−1) were harvested and allowed to wilt for a period of 52·5 h. During the early stages of wilting of lucerne there were increases in the proportion of leaf material (dry weight basis), as well as increases in total available carbohydrate and water soluble carbohydrate concentrations. Approximately 50% of the leaf material in lucerne and in timothy was lost after a drying period of 52·5 h and after tedding and raking operations prior to baling of the hay. This resulted in considerable reduction in the protein content of both lucerne and timothy.
Growth responses to lime and fertilizers and critical concentrations in herbage of white clover in Scottish hill soils
Authors: RANGELEY ANNE , NEWBOULD P. 
Published: April 2006

AbstractThe responses in dry matter (DM) production and changes in nutrient concentration in the shoots of white clover (cv. New Zealand Grasslands Huia) to additions of lime, N, P, K and Mg were investigated in pot and field experiments in a deep peat soil and to additions of N, P, K in two other hill soils in pot experiments. DM production and nutrient concentrations were assessed also for perennial ryegrass in the field experiment. There was no response by white clover to N, but in all soils, and in particular a deep peat, production of shoot DM was increased greatly by lime, P and K, and slightly by Mg. Interactions between lime and P and between P and K were observed. Critical concentrations of nutrients (g kg−1) for white clover appeared to be about 2.0 for P, 10·15 for K and 20 for Ca. Herbage production and nutrient contents of ryegrass and white clover grown on a deep peat in the field suggests that critical concentrations may possibly help to diagnose the need fur maintenance fertilizer dressings.
Effect of silage additives and wilting on silage fermentation, digestibility and intake, and on liveweight change of young cattle
Authors: HAIGH P. M. , PARKER J. W. G. 
Published: April 2006

AbstractData from thirty‐three experiments conducted at three ADAS Experimental Husbandry Farms were used to compare unwilted non‐additive‐treated silage with silage treated with formic acid, a formalin and formic‐acid mixture, a calcium‐formate and sodium‐nitrite mixture, a formalin and sulphuric‐acid mixture and wilted silage made without or with formic acid or a formalin and formic‐acid mixture.Formic acid significantly reduced pH and wilting significantly increased silage pH compared with other treatments. Formalin‐acid mixtures significantly reduced pH compared with untreated silage. Formic acid in conjunction with formalin or wilting significantly increased water‐soluble carbohydrate in silage compared with other treatments except wilting. Formic acid either alone or combined with either formalin or wilting significantly reduced silage butyric acid content compared with other treatments. Formic acid treatment either alone or combined with formalin significantly increased lactic acid as a proportion of total silage acids compared with other treatments except sulphuric acid‐formalin.All treatments significantly increased silage dry matter (DM) intake compared with untreated silage and intakes of wilted silage were significantly greater than of unwilted silage. Daily liveweight gains on all treatments were significantly higher than on untreated silage.Herbage water‐soluble carbohydrate necessary for successful preservation as silage without additive use was approximately 30 g (kg DM)−1 and with additives containing formic acid it was approximately 25 g (kg DM)−1.It is suggested that formic acid application to unwilted silage either alone or in conjuction with formalin was the best treatment for improving subsequent preservation as silage, and that animal performance was enhanced by addition of acid‐formalin additives to unwilted herbage or formic‐acid application to unwilted or wilted herbage.
Alfalfa establishment without tillage as influenced by insecticide and vegetation suppression
Authors: ROTH G. W. , WOLF D. D. , HAGOOD E. S. 
Published: April 2006

AbstractConventional alfalfa (Medicago sativa L.) establishment methods may create considerable potential for erosion. Conservation tillage practices that result in stand establishment without disturbing the soil greatly would be beneficial in reducing soil losses. Thus, field experiments were conducted to evaluate the success of alfalfa establishment without tillage in a perennial grass sod. Variables included rate of carbofuran (2, 3‐dihydro‐2, 2‐dimethyl‐7 benzofuranyi methylcarbamate) insecticide and control of existing vegetation with chemicals. Establishment without tillage was compared with a conventional method of establishment. Carbofuran at 1.1 kg ha−1 applied in the row with the seed, when compared with a control, increased yields during the year of planting but no response was observed in the year after seeding. Yields of alfalfa established without tillage using either glyphosate (N‐(phosphonomethyl)glycine) or paraquat (1,1‐dimethyl‐4, 4‐bipyridinium chloride) for sod suppression were equivalent to or better than yields obtained from conventional sowings except for the 2 April sowing. Paraquat was more effective for tall fescue (Festuca arundinacea Schreb.) suppression when applications were made on 26 April after spring tiller emergence was complete than on 2 April when some of the tillers may have been protected from the spray by basal sheath tissue.Broadcast application of paraquat resulted in higher alfalfa yields and decreased non‐alfalfa components due to more complete sod suppression than application in bands over the row.
The effect of temperature on the spring growth of perennial ryegrass at three contrasting sites
Authors: BAKER ANNE‐MARIE , YOUNGER A. 
Published: April 2006

AbstractThe effect of temperature on the spring growth of perennial ryegrass swards was studied at three contrasting sites. Two of these were situated on land restored after opencast coal mining, one of which had been drained. The third was on undisturbed land of the same soil type. Rates of leaf extension were measured in an attempt to give an early indication of differences in plant growth in the spring of 1982.Spring growth started earliest on undisturbed land. On the restored land drainage proved beneficial, for although the onset of growth was delayed compared to the undisturbed site the subsequent rates of growth were similar. Both the onset and the rate of growth were slower on the undrained site. Highly significant relationships existed between leaf extension rate and soil temperature at each site. However, when sites were compared, differences in soil temperature could only partly explain observed differences in growth rate between sites.It was concluded that some factor other than soil temperature was responsible for the difference in spring growth between the undisturbed site and the undrained opencast site in this experiment.
Concentrate supplementation of grazing dairy cows. 2. Effect of concentrate composition on herbage intake and milk production
Authors: MEIJS J. A. C. 
Published: April 2006

AbstractThe effect of feeding either traditional concentrates containing starch or high quality fibrous concentrates on the performance of grazing dairy cows was examined in a trial in which cows were given concentrates with either 350 g starch and sugars (kg dry matter (DM))‐1 (high‐starch) or 100 g starch and sugars (kg DM)‐1 (high‐fibre). The swards used consisted predominantly of perennial ryegrass and were usually aftermaths following cutting. Each area was grazed for 3 or 4 d at each grazing and a two‐machine sward‐cutting technique was used for estimating herbage intake.The effect of concentrate composition on the herbage intake of grazing cows at a high daily herbage allowance of 28 kg OM above 4 cm cutting height was investigated in 1983 and 1984. With 54 kg OM d‐1 of high‐starch concentrates the mean herbage intake was 11·5 kg OM d‐1 per cow while cows fed 5.3 kg d‐1 of high‐fibre concentrates consumed on average 12–6 kg OM d‐1. The mean substitution rate of herbage by concentrates was reduced from 0·45 kg herbage OM (kg concentrate OM)‐1 with the high‐starch concentrate to 0·21 with the high‐fibre concentrates.The effect of the treatments on milk production was studied in 1984. The cows consumed 5·5 kg OM d‐1 as concentrates and grazed at a lower herbage allowance of 19 kg OM above 4 cm cutting height. With high‐fibre concentrates milk production and 4% fat‐corrected milk production were 13 and 1·8 kg d‐1, respectively, higher than with the high‐starch treatment. The daily live weight gain with the high‐starch concentrates was 0·17 kg per cow more than with the high‐fibre concentrates.
Effect of grazing severity on grass utilization and milk production of rotationally grazed dairy cows
Authors: MAYNE C. S. , NEWBERRY R. D. , WOODCOCK S. C. F. , WILKINS R. J. 
Published: April 2006

AbstractTwo experiments were carried out to examine the effects of grazing severity on the performance of January/February calved British Friesian dairy cows. In Experiment 1, three groups of cows were rotationally grazed across twenty‐four one‐day paddocks with high (H), medium (M) or low (L) herbage allowances. Cows on treatment M were offered a daily herbage allowance designed to achieve a residual sward height of 50 mm, assessed by a rising‐plate sward stick. The daily herbage allowance (g organic matter (kg live‐weight)‐1 on treatments L and H were 0.30 below and above that for M, respectively, to give residual sward heights of 42 and 59 mm. In Experiment 2, three groups of cows were grazed across twenty‐four one‐day paddocks to obtain residual sward heights of 50 mm (severe), 60 mm (moderate) and 80 mm (lax).Average milk yields on the L, M and H treatments in Experiment 1 were 11.8, 14.6 and 14.5 kg d,‐1 and in Experiment 2 they were 13.7, 16.0 and 17.0 kg d‐1 on the severe, moderate and lax treatments, respectively. The results indicate that the critical herbage height below which milk production per cow declines may vary with the production potential of the animal. There were no significant treatment effects on milk composition.Milk output ha‐1 and utilized metabolizable energy ha‐1 were greatest with the low herbage allowance in Experiment I and the moderate treatment in Experiment 2. Net herbage accumulation on the severe treatment in Experiment 2 was 30% lower than that on the lax treatment, as a result of treading damage in early season.It is concluded that, in a rotational grazing system, a reasonable compromise between sward utilization and animal performance can be achieved by grazing January/February calved cows to a residual sward height of 60 mm as assessed by a rising‐plate sward stick. This is equivalent to a sward surface height of about 80 mm.
Slot‐seeding investigations. 6. A comparison of the spread and productivity of different white clover varieties introduced into permanent pasture
Authors: WILLIAMS E. D. , HAYES M. J. 
Published: April 2006

AbstractSeeds of six cultivars of white clover were sown in 1983 in slots in tares of permanent pasture in soil‐filled tanks in spring and in small plots in the field during midsummer. The clover cultivars investigated were the large‐leaved Olwin and Milk nova, the medium‐leaved Grasslands Huia and Aberystwyth S100, and the small‐leaved Kent Wild White and Aberystwyth S184. Seeds from an indigenous clover population were also sown in the tanks. All herbage was defoliated at three‐ to six‐week intervals to simulate rotational grazing and assessments were made until autumn 1984.Leaf and stolon production and spread of stolons from the slots were more rapid in Milkanova, S184, Huia and Kent than in Olwen and S100 In the tanks, harvested yields of clover leaf and petiole were largest for Milkanova and Olwen and least for the indigenous population; both Olwen and S100 had a smaller percentage of their total weight outside the slot area than had the other varieties. In the field, Milkanova greatly out yielded all other varieties and S100 yielded the least, contributing 48 and 27%, resf actively, to total herbage yield. The yield of grass differed little between varieties in tanks but in the field it tended to be higher with the smaller than with the larger‐leaved varieties. Total herbage yield was largest for Olwen and Milkanova in tanks and for Milkanova in the field. The greatest weight of stolons in tanks was produced by Olwen and in the field by Olwen and Kent, but the greatest length of stolons and number of nodes in both environments occurred in the smalt‐leaved varieties, especially Kent. Least length of stolons and fewest nodes in the tanks were produced by Olwen and in the field by Milkanova.It was concluded that all the varieties investigated could be successfully slot‐seeded into permanent pastures but that the choice of variety will depend on subsequent use and management of the resulting swards.
The practical and economic consequences of integrating maize with grass production on dairy farms in southern England: a computer simulation
Authors: DOYLE C. J. , PHIPPS R. H. 
Published: April 2006

AbstractA mathematical model of the production, harvesting and utilization of maize and grass silage on a dairy farm with an autumn‐calving herd is described. Using the model the comparative costs and benefits of growing and feeding maize in place of grass silage are examined for three sites in southern England. It is concluded that a winter milk production system based on maize rather than grass should improve profits by at least £30, and possibly by as much as £80 cow‐1. This financial improvement is attributable to higher feed intakes and lower harvesting and fertilizer costs with maize silage. Simulating the results over a 10‐year period also revealed that the switch from grass to maize should lower the risks in terms of the annual variability of silage yields and herd profits. Furthermore, it would appear unnecessary to completely turn over from grass to maize production to realize a significant financial benefit. Setting aside just 25% of the conservation area to maize and feeding a mixture of maize and grass silage is projected to increase profits from winter milk production by £30 to £45 cow‐1.
Ingestive behaviour of beef cattle grazing alfalfa (Medicago sativa L.)†
Authors: DOUGHERTY C. T. , SMITH E. M. , BRADLEY N. W. , FORBES T. D. A. , CORNELIUS P. L. , LAURIAULT L. M. , ARNOLD C. D. 
Published: April 2006

AbstractDevelopment of simulation models of grazing beef cattle requires measurement of the components of the ingestive process and the establishment of relationships between these components and the structure of the sward. The ingestive behaviour of eight half‐sib Angus steers (live weight (LW), x̄= 270 kg) grazing alfalfa (Medicago sativa L.) was studied at three stages of maturity (26, 40 and 47 days of regrowth) and at four allowances of herbage dry matter (DM) (1·0, 1·5, 20 and 2·5 kg per 100 kg LW) at each of two daily grazing sessions. A tethering system of grazing was used in which the experimental unit was a tethered steer and its plot for one grazing session. Grazing sessions commenced at 08.00 and 14.00 h EDT. Intake (DM) increased linearly from 1·98 kg per steer session at a DM allowance of 1 kg (100 kg LW)−1 to 2 89 kg steer session at an allowance of 2·5 kg (100 kg LW) −1 as utilization of herbage declined linearly from 0·69 to 0·43. Herbage DM in take per bite increased from 1 0 g at 1 kg (100 kg LW) −1 allowance to 1·5 g at 2·5 kg (100 kg LW) −1 allowance. Rates of biting were not affected by herbage allowance and averaged 21 bites min−1. Dry matter intake increased from 1·77 to 3 41 kg per steer session as the alfalfa matured and herbage mass changed from 1500 to 4656 kg ha−1. Mean rates of biting were 24 bites min−1 for steers grazing the youngest alfalfa and 16 bites min−1 for steers on the oldest forage. Herbage DM intakes per bite were 1·1 g and 1·7 g at the same stages. Rates of DM intake approached 2 kg h−1 and maximum daily DM intake was estimated at 2 75 kg (100 kg LW) −1. Intake of alfalfa was limited by allowance and mass of herbage above a canopy horizon of 20 cm and, to a lesser extent, by the length of fast.
Forage quality and animal selection of Arachis pintoi in association with tropical grasses in the eastern plains of Colombia
Authors: LASCANO C. E. , THOMAS D. 
Published: April 2006

AbstractA small plot grazing trial was conducted in the Eastern Plains of Colombia to assess seasonal forage quality and selection by oesophageal‐fistulated steers of Arachis pintoi associated with four Brachiaria species. Quality of the legume was high in terms of leaf crude protein (CP) (17%) and in vitro dry matter digestibility (IVDMD) (62%) but varied with season of the year. Associated grasses bad high average leaf CP levels in the dry (7.8%) and wet (98%) seasons. The legume content in the forage on offer was high and varied, from 28% in the dry season to 58% in the wet season. Corresponding values m the diet selected were 37%. and 60%, indicating that animals selected legume in a slightly higher proportion than was present in the total forage on offer. This was further confirmed by selection indices greater than 0–5 in three of the four associations and by a selection index of 0–56 when pooling the data for the four pastures. Increased grass quality and high legume selection resulted in a high quality diet in the dry (CP 9 7%; IVDMD 61 %) and wet (CP 156%; IVDMD 62%) seasons. The results indicated that A. pintoi is a high quality legume, well accepted by grazing cattle throughout the year in the savannas.
Leaf age structure and canopy photosynthesis in rotationally and continuously grazed swards
Authors: PARSONS A. J. , JOHNSON I. R. , WILLIAMS J. H. H. 
Published: April 2006

AbstractThe leafage structure of ryegrass canopies and its role in canopy photosynthesis were compared under continuous and rotational grazing by sheep. Under continuous grazing, an increase in the intensity of grazing increased the proportion (by leaf area) of young leaves in the sward. A mechanistic mathematical model was used to demonstrate how this may have arisen, even though it would largely have been the young leaves that were eaten.However, the observations do not confirm the hypothesis that continuously grazed swards have a characteristically greater proportion of young leaves, and so a greater photosynthetic potential, than rotationally grazed ones. The proportion of young leaves increased during regrowth following severe rotational grazing (residual LAI < 05) and the photosynthetic potential of the canopy became greater than under continuous grazing.A model of canopy photosynthesis was used to demonstrate that the observed difference in the proportion of young leaves alone was unlikely to account for all the differences in canopy photosynthesis between managements, and further differences in canopy structure were evaluated. Despite the delay in the restoration of leaf area following severe grazing in a rotation, the total photosynthetic uptake of a system involving some 12–13 days regrowth and 3 days grazing exceeded that of a well‐utilized continuously grazed sward. Re growths of longer duration led to progressively greater total photosynthetic uptake, though this was not considered synonymous with greater yield.
The chemical composition and nutritive value of grass silages prepared with no additive or with the application of additives containing either Lactobacillus plantarum or formic acid
Authors: ROOKE J. A. , MAYA F. M. , ARNOLD J. A. , ARMSTRONG D. G. 
Published: April 2006

AbstractA mixture of perennial and hybrid ryegrasses(234 g DM kg‐1) was forage harvested and ensiled after a 24‐h wilt in good ensiling conditions in 2‐t capacity silos with no additive application (control) or with the application of either Lactobacillus plantarum, 4 × 106 (g fresh weight of grass)‐1, or of 31 formic acid t‐1. Sufficient 2‐kg capacity laboratory silos were also filled with grass to monitor the changes in chemical composition of the ensiled grass with time. In laboratory silos, inoculation with L. plantarum resulted in a more rapid fall in silage pH (p < 0.001) and a more rapid production of lactic acid (P < 0.001) than in the control silage. At the end of the storage period (laboratory silos, 80 d; 2‐t silos, 200‐300 d), the inoculated silos had lower pH (p ammonia‐N (g kg N1) and acetic acid contents (p < 0.01) and higher water soluble carbohydrate (WSC), lactic acid (P<00.1) and ethanol (p < 0.05) contents than the control silage. The formic acid‐treated silage had significantly lower contents of ammonia‐N (g kg N‐1, p < 0.05), acetic and tactic acids (p<0.01) and higher contents of WSC and ethanol (p < 0.01) than the control silage. When fed to wether sheep, the digestibilities of DM, organic matter and gross energy were not altered by additive treatment. The digestibility of modified acid‐detergent fibre was lower for both the inoculated (P < 0.01) and formic acid‐treated silages (p < 0.05). However, N retention was improved (p < 0.05) by both additive treatments. Silage intake was improved (p < 0.01) by additive treatment from 53.4 (control) to 58.0 (inoculated) and 60.4 (formic acid) g DM (kg live weight0.75)‐1d‐1.