bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of addition of lactic acid and post‐ruminal supplementation with casein on the nutritional value of grass silage for milk production in dairy cows
Authors: CHOUNG J.‐J. , CHAMBERLAIN D.G. 
Published: April 2006

AbstractTwo levels of lactic acid were added to a well‐preserved silage to give silages with three concentrations of lactic acid: 53 (control), 96 (LA‐50) and 134 (LA‐100)g (kg DM)‐1. These silages were given ad libitum with 5 kg d‐1 of a mixture of barley and soya‐bean meal (75:25) to six lactating dairy cows in a 6 × 6 Latin square design experiment to examine the effects on silage intake and milk production of the addition of lactic acid, both with and without a post‐ruminal supplement of 230 gd‐1 sodium caseinate. The six treatments were (1) control silage without casein, (2) control silage plus casein, (3) LA‐50 silage without casein, (4) LA‐50 silage plus casein, (5) LA‐100 silage without casein and (6) LA‐100 silage plus casein. Sodium caseinate was administered as a continuous infusion into the abomasum. Periods were 14d long.Both levels of addition of lactic acid reduced (P < 0·001) the intake of silage, values being 102, 94 and 86 kg DM d‐1 for the control, LA‐50 and LA‐100 treatments respectively, but the casein supplement did not affect the intake of silage. Milk yield was reduced (P < 0·01) only for treatment LA‐100 and, for this treatment, was restored (P < 0·01) by casein given post‐ruminally. With all three silage treatments, casein infusion increased (P<0·001) the yield of protein in milk by 30–35 gd‐1. The concentration of protein in milk increased linearly (P < 0·001) with the addition of lactic acid to the silage.The addition of lactic acid produced a linear reduction (P < 0·001) in the molar proportion of acetate in rumen contents and compensatory linear increases (P < 0·001) in the molar proportions of propionate and butyrate. Changes during the day in the concentration of insulin in blood plasma followed a similar pattern to changes in the molar proportions of propionate. The mean daily concentration of insulin in plasma tended (0·10 < P > 0·05) to be higher for the LA‐100 treatment, and in the immediate period after feeding this difference was significant (P < 0·05).The results confirm the effect of lactic acid in depressing the intake of silage, but they offer no support for the hypothesis that the depression of intake can be offset by an increase in the supply of protein post‐ruminally.
The potential for control of the soft rush (Juncus effusus) in grass pasture by grazing goats
Authors: MERCHANT M. 
Published: April 2006

AbstractTwo experiments were conducted to examine the effect of inter‐tussock grass height and stocking rate on the utilization of the rush (Juncus effusus) by grazing goats. In the first experiment, on rush‐infested Festuca rubralTrifolium repens pasture, the utilization of rushes by goats grazing at a sward height of 3–4cm or 5–6cm was compared with that occurring on plots grazed by sheep at a sward height of 3–4 cm. Sheep grazed minimal amounts of rush. In contrast, it was estimated that 90% and 75% of current seasons growth of rush was grazed by goats at sward heights of 3–4 and 5–6 cm respectively during the first year. With continued goat grazing at 5–6cm there was a dramatic reduction in the cover and vigour of the rushes, and at a sward height of 3–4cm established tussocks were eliminated from the pasture.The second experiment compared the utilization of rushes invading predominantly Agrostis swards stocked with goals at 10, 20 or 30 ha‐1 and in which inter‐tussock sward height was maintained at 4–5cm on all treatments, by adding or subtracting sheep. On one site rush utilization increased with the increase in stocking rate of goats and rush tussocks were eliminated within 3 years at 30 goats ha‐1. On another, there was no difference between plots stocked at 20 or 30 goats ha‐1 and viable tussocks remained. The influence of the composition and productivity of the inter‐tussock herbage and the proportion of rush in the biomass are discussed.Goats can be used lo control rushes in grassland but high stocking levels and low inter‐tussock pasture heights are required to promote adequate levels of utilization.
Intake and digestibility of components of forage rape (Brassica napus) by sheep
Authors: ARMSTRONG R. H. , BEATTIE M. M. , ROBERTSON E. 
Published: April 2006

AbstractHerbage from forage rape (Brassica napus cv. Lair), harvested in the autumn, was separated into different morphological components and offered ad libitum to weaned lambs and adult sheep in two indoor pen‐feeding experiments. In vivo. digestibility and the voluntary intake of herbage components were measured and related to chemical composition and in vitro digestibility. The organic matter digestibility of all plant components, especially of petiole, was high; lamina, 0·847: petiole, 0·892; upper stem. 0·865; lower stem, 0·771. Lambs and adults digested ‘leaf’ (0·83) vs 0·846) or ‘stem’ (0·782 vs 0·789) equally well. Both lambs and adults ate much less of the components or of whole crop than would be predicted with grass crops of similar digestibility or fibre content. With the exception of lamina, intake was closely related positively to digestibility and negatively lo fibre content. Low intakes of lamina were associated with high concentrations of glucosinolates. In vitro digestibility values obtained on small samples of forage show that the process is adequate for the prediction of in vivo digestibility.
The fine‐scale mapping of grassland protein densities
Authors: CLIFTON K. E. , BRADBURY J. W. , VEHRENCAMP S. L. 
Published: April 2006

AbstractA simple and accurate remote sensing technique for the fine‐scale mapping of grassland protein densities was developed during a study of sward quality and antelope dispersion in Kenya, East Africa. Using measures of spectral reflectance and a vehicular navigation system, estimates of protein densities were recorded at rates exceeding 1000 samples per hour. Nitrogen analyses confirmed that reflectance measures were accurate predictors of protein density for a variety of grass swards but not for two species of sedge. Because the regression coefficients linking reflectance to protein density differed significantly between sward types, good estimates using this method will require a separate calibration for each type of grassland. By monitoring and correcting for variations in ambient light levels, the method can be used under a wide range of lighting conditions and for long periods. This facilitates sampling sufficiently systematically and intensively that contour plots of protein density can be constructed and then correlated with distributions of underlying abiotic factors, foraging activity of sympatric herbivores, or prior maps to characterize successional and historical change.
Growth of prairie grass (Bromus willdenowii) and tall fescue × perennial ryegrass (Festuca arundinacea×Lolium perenne) on the Appalachian Plateau of southern West Virginia, USA
Authors: BELESKY D. P. , STOUT W. L. 
Published: April 2006

AbstractThe productivity and persistence of prairie grass (Bromus willdenowii Kunth) cv. Grasslands Matua were compared with a similarly managed endophyte‐free tall fescue × perennial ryegrass hybrid (Festuca arundinacea Schreb. ×Lolium perenne L.) cv. Johnstone. A field study was conducted on the Appalachian Plateau of southern West Virginia, USA (81°W, longitude; 38°N, latitude; 850m above sea level) for three consecutive years. Nitrogen totalling 0, 168, and 336 kg N ha−1 year−1 was applied to stands managed as hay. Annual herbage yields were similar for both species in year 1 (1989), but by year 3 (1991) Matua sown‐grass yield was about 35% of first‐year yields. Total herbage yield for Matua plots in the third year was similar to first‐year yields owing to encroachment by non‐seeded grasses and white clover (Trifolium repens L.). Matua was susceptible to powdery mildew [Blumeria graminis (DC) E. O. Speer] in this environment, and was similar in productivity (first year only) and nutritive quality to tall fescue × perennial ryegrass hybrid. Matua use may be limited to areas where low‐temperature stress and resultant winter damage is unlikely to occur.
Effects of feeding fodder beet and concentrates with different protein contents on dairy cows offered silage ad libitum
Authors: FISHER G. E. J. , SABRI M. S. , ROBERTS D. J. 
Published: April 2006

AbstractIn two changeover design experiments, fifteen early‐ and sixteen late‐lactation cows were used to investigate the effects of offering food beet with ad libitum grass silage and concentrates with different CP content on milk yield and quality. In Experiment 1 (early lactation) cows were offered no fodder beet (0) or 4 kg DM d−1 (4) in conjunction with one of three concentrates containing 159, 191 or 244g CP kg−1 DM (L.M.H.). Treatments were therefore 1L/0, 1L/4, 1M/0, 1M/4, 1H/0 and 1H/4. In Experiment 2 (late lactation) cows were offered the same level of fodder beet in conjunction with two concentrates containing 129 and 229 (L,H) g CP kg−1 DM. Treatments were therefore 2L/0, 2L/4, 2H/0 and 2H/4.In both experiments feeding fodder beet reduced silage DM intakes (P < 0·001) and increased total DM intake (P < 0·05 to P < 0·001). The substitution rate (r) ranged from 0·46 to 0·59kg of silage DM (kg−1 fodder beet DM).In Experiment 1, fodder beet tended to increase milk yield, composition and yield of constituents, but the effect was statistically significant for milk protein content only (P < 0·01). In Experiment 2, milk yields for 2L/0, 2L/4, 2H/0 and 2H/4 were 11·3, 12·1, 11·7 and 12·5 kg d−1 respectively (s.e.d. 0·43, non‐significant), fat contents were 44·4, 47·3, 44·3 and 46·8g fat kg−1 respectively (s.e.d. 0·73, P < 0·001), protein contents were 34·3, 35·6, 35·3 and 36·2 g protein kg−1 respectively (s.e.d. 0·28, P < 0·001), fat yields were 494, 574, 512 and 579 g fat d−1 respectively (s.e.d. 20, P < 0·001) and protein yields were 385, 426, 407 and 442 g protein d−1 (s.e.d. 13, P < 0·01) respectively.Increasing CP in the concentrate significantly increased milk yield in Experiment 1 (23·9, 22·5, 23·5, 23·8, 26·2, 26·5kg d−1 for 1L/0, 1L/4, 1M/0, 1M/4, 1H/0 and 1H/4 respectively, P < 0·05). Higher CP in concentrate also resulted in significantly increased milk protein yield in early‐lactation (P < 0·001) and milk protein content in late‐lactation (P < 0·01) cows. There was a significant interaction between fodder beet and concentrate CP content for milk protein yield (P < 0·001) in Experiment 1.
Yield and composition of red clover treated with growth regulators in early spring
Authors: NARASIMHALU P. , KUNELIUS H. T. 
Published: April 2006

AbstractThe effect of growth regulators on the yield and quality of red clover (Trifolium pratense L.) was assessed in two growing seasons. An early‐flowering cultivar (Florex) and a late‐flowering one (Altaswede) were treated with the growth regulator, daminozide butanedioic acid [mono (2,2‐dimethylhydnizide)] or mefluidide [N‐(2,4‐dimethyl‐5{[(trifluoromethyl)sulphonyl]amino}phenyl) acetamide], either in early (mid‐May) or late (late May) season and at low rate [daminozide, 4kg active ingredient (a.i.) ha−1; or mefluidide, 0·13 kg a.i. ha−1] or twice the low rate (high rate), and compared with no treatment. Red clover yielded two‐ to three‐fold more dry mater (DM) in the first than in the second harvest, and growth regulator treatments did not redistribute yields more evenly between the two harvests. Growth regulator effects on the yield and composition of red clover were mainly confined to the first cut herbage. Daminozide increased first‐cut and annual yields of DM and in vitro digestible DM (TVD); the latter was increased particularly for Altaswede, as compared with the untreated red clover. Mefluidide decreased first‐cut yields of DM and IVD for Florex only, but the annual yields for both cultivars were unchanged by this treatment. Changing the rate or time of growth regulator application did not affect DM or IVD yield in red clover. The treated red clover contained less water‐soluble carbohydrate in the first cut than did the untreated crop. The high rate of daminozide, when applied early, decreased neutral detergent fibre and increased IVD contents in the first‐cut red clover compared with the other combinations of rate and time. Altaswede produced as much DM annually and had a higher IVD content than Florex when these cultivars were cut on common dates, twice during the short growing season in Atlantic Canada.
The productivity and response to inorganic fertilizers of species‐rich wetland hay meadows on the Somerset Moors: nitrogen response under hay cutting and aftermath grazing
Authors: KIRKHAM F. W. , WILKINS R. J. 
Published: April 2006

AbstractThe productivity and response to fertilizer nitrogen (N) was measured in herb‐rich wetland hay meadows within a Site of Special Scientific Interest (SSSI) in Somerset, UK. Output from hay cut after 1 July each year and from beef production at aftermath grazing was measured over a total of 4 years.Total utilized metabolizable energy (UME) output averaged from 40·6 GJ ha−1 year−1 without fertilizers to 61·7GJha−1 at 200kgNha−1 (N‐200), the highest rate used, with about two‐thirds of this output from hay. N response was markedly curvilinear above about 50kgN ha−1, but data from a concurrent experiment suggested that the comparatively low replacement rates of P and K applied were limiting at higher N rates. When hay cutting was delayed until early August in a wet year, yield response to N was lost because fertilized swards had passed a peak in yield several weeks before harvest.Compared with other published data, the results suggest that output and response to N is not constrained by the diversity of the flora or the damp conditions. The data will help to estimate the financial implications for farmers of restricted or zero fertilizer use within SSSIs and the wider Environmentally Sensitive Areas.
Patterns of nodal rooting in Trifolium repens (L.) and correlations with stages in the development of axillary buds
Authors: NEWTON P. C. D. , HAY M. J. M. 
Published: April 2006

AbstractForty per cent of while clover nodes had roots when a pasture was rotationally grazed by sheep compared with 29% when grazed continuously by set stocking. Nodal roots were most frequent during spring and least frequent during summer. About 5% of nodes had a root primordium which had not developed but was still viable. A high proportion of nodal roots (66%) occurred within 10 nodes of the apex. Root presence was highly correlated with the establishment and survival of branches but was less closely related to branch initiation or the viability of axillary buds. It is suggested that the association between nodal roots and branches is strongest when resources are limited, and that root survival at a node is enhanced by the presence of a branch originating at the same node.
Establishment of lucerne after maize in conservation tillage systems†
Authors: BYERS R. A. , BAHLER C. C. , STOUT W. L. , LEATH K. T. , HOFFMANN L. D. 
Published: April 2006

AbstractExtensive slug damage reported for lucerne (Medicago sativa L.) establishment in grass sod and small grain fields when using conservation tillage prompted this 3‐year study on establishing lucerne in maize (Zea mays L.). Different crop residues were created by harvesting maize for grain and silage and including a silage+rye (Secale cereale L.) winter cover crop treatment. Conventional tillage (ploughed in spring) following grain harvest was included as a control. In addition, a combination treatment of methiocarb bait broadcast on the surface and carbofuran granules applied in the furrow with the seed was compared with an untreated control. Finally, three planting dates, early and late April and late May, simulated the spring planting season. Planting lucerne in the different maize residues had a significant effect on lucerne yields, especially the silage+rye residue treatment, which caused the lowest lucerne yields. Highest yields of lucerne occurred when it was planted after silage, a treatment in which residue was minimal.The earliest planting date gave the highest lucerne yields in the establishment year. Slugs did not reduce the establishment of lucerne in any maize residue, nor were lucerne yields affected by slug feeding. This was attributed to the low slug populations observed early in the growing season. Establishing and producing lucerne in maize residues was more successful in this study because of the lower slug populations than those usually encountered in grass sod or small grain residues.
The effect upon fermentation and nutritive value of silages produced after treatment by three different inoculants of lactic acid bacteria applied alone or in combination
Authors: ROOKE J. A. , KAFILZADEH F. 
Published: April 2006

AbstractSilages were made from the first cut of a predominantly perennial ryegrass sward. The silages were either untreated (W) or treated with formic acid (31 t−1, F) or with 106 lactic acid bacteria (LAB) g−1 grass of each of three strains alone (A. Lactobacillus plantarum MTD1; B, Pediococcus species 6A2; C, L. plantarum 6A6) or in combination (AB. AC) to give seven treatments. The silage fermentation in 10‐kg silos was followed chemically and microbiologically and the nutritive value of selected treatments evaluated using 2‐t silos.The control silage (W) fermented well. Addition of formic acid restricted fermentation and produced a silage with a high ethanol concentration. After day 4, all inoculated silages had lower pH values and higher lactic acid concentrations and a higher ratio of lactic acid to acetic acid than the control silage. Chemically there was little difference between the inoculated silages in terms of final composition. Microbiologically the LAB applied in treatments B and C dominated the LAB populations in those silages when applied alone; however, they were suppressed when applied in combination with inoculant A.When fed to sheep, the intake of the formic acid‐treated silage was significantly (P < 0·01) lower than that of the other silages and the intake of silage treated with inoculant A significantly (P < 0·001) higher than that of silages treated with inoculants B and C. The apparent organic matter (P < 0·001) and nitrogen (P < 0·01) digestibilities of the formic acid‐treated silage were also significantly lower than those of the other silages.
Effect of plant age and severity of defoliation on regrowth of sheep's burnet during substrate moisture depletion
Authors: DOUGLAS G. B. , ROBERTSON A. G. , CHU A. C. P. , GORDON I. L. 
Published: April 2006

AbstractRegrowth of 3‐ and 4‐month old (‘young’ and ‘old’ respectively) sheep's burnet [Sanguisorba minor ssp. muricata (Spach) Briq.] was studied under limiting and non‐limiting moisture conditions in a glasshouse. Moisture deficits were imposed by using a single cycle of withholding moisture until first wilting. Plants of each age were defoliated severely at three levels which represented approximately 80–100% canopy removal. These levels were based on the proportion retained of the eight most mature leaves on each plant and were referred to as complete [0% residual leaf area (rLA)] and partial [50% rLA (four leaves) and 100% rLA (eight leaves)] defoliation. Vegetative growth and total non‐structural carbohydrate (TNC) levels were studied.Leaf number (0‐8 leaves), area (0‐115 cm2) and dry weight (0‐1·0 g) differed (P < 0·05) between defoliation intensities at the start of regrowth, while stubble (1·2 g) and root (12.·6 g) dry weights were similar. Soluble sugars [< 6% dry matter (DM)] and starch (< 1% DM) occurred in leaf, stubble and root. Old plants were morphologically and physiologically more developed than young plants. For example, stubble (2·0 g) and root (21·5 g) dry weights of old plants were greater (P < 0·05) than those of young plants (04 and 3·7 g respectively).Defoliation intensity had a major effect on regrowth, with completely defoliated plants at the final harvest having leaf numbers (forty‐nine leaves) and areas (235 cm2) almost twice those of partially defoliated plants. Stubble soluble sugar levels (38% DM) were lower than those of partially defoliated plants (5·5% DM), and it was suggested that these contributed to regrowth. Moisture regime had a negligible influence on plant growth. However, plants in the dry regime had soluble sugar levels 1·4 (stubble) ‐1·7 (roots) times higher than those watered adequately, which suggested that plants adjusted to the water depletion. The effects of plant age on regrowth were similar for most characters, but the larger and physiologically more mature old plants would probably be more tolerant of successive defoliations.
Leaf number as a criterion for determining defoliation time for Lolium perenne, 1. Effect of water‐soluble carbohydrates and senescence
Authors: FULKERSON W. J. , SLACK K. 
Published: April 2006

AbstractThis study sought to define the optimum defoliation interval for Lolium perenne, with the maximum interval being determined by the onset of senescence, as reflected by the number of fully expanded leaves, and the minimum interval set by the replenishment of water‐soluble carbohydrates (WSCs).In a glasshouse set at 13°C/23°C night/day temperature and at a plant spacing of 94 m−2 (3290 tillers m−2), the accumulation of dry matter against leaf number and days was exponential to the four‐leaf stage of the regrowth cycle. Senescence commenced at the 3·5‐leaf stage.WSCs in roots, stubble and leaf showed a very significant linear relationship with leaf number. Levels of WSCs in leaves were restored to predefoliation values by the one‐leaf stage, after which WSCs accumulated preferentially in the stubble, rising to 22% at the four‐leaf stage.Regrowth after 6 d was significantly greater for plants defoliated at the three‐leaf stage than at the one‐leaf stage, but this difference disappeared at the end of the regrowth cycle. This questions the importance of WSCs in determining the yield of ryegrass under normal rotational grazing management.Regrowth at 6 d was related positively to stubble WSCs (r2= 0·66) and to stubble DM per tiller(r2=0·71)
Effect of spreading method, application rate and dilution on ammonia volatilization from cattle slurry
Authors: FROST J. P. 
Published: April 2006

AbstractResults from a series of five small‐scale plot experiments which simulated different strategies for lowering ammonia volatilization following slurry application to grassland are reported. Strategies studied were band spreading, shallow‐channel application, spike injection, rate of surface application and dilution. Volatilization was measured over the first 4 h following application with ventilated enclosures. Band spread slurry resulted in 0·4 of the volatilization that occurred from surface application of the same rate of slurry. The benefit of band spreading was shown to arise from higher application rates in the bands when compared with the same quantity of slurry spread over the surface. When surface‐spread slurry was applied to the same depth of slurry as in bands, the volatilization per unit volume of slurry was the same. Shallow‐channel application was more effective than band spreading and lowered volatilization per unit volume of slurry to <0·1 of that from surface‐spread slurry. Spike injection was equally effective as shallow‐channel application but, owing to perceived difficulties in machine design, construction and operation, was deemed impractical. Shallow‐channel application has potential, though further work is required to optimize centre‐to‐centre spacing of the channels. As the application rate of surface‐applied raw slurry increased, ammonia volatilization per unit volume of slurry applied decreased. Application at 50 m3 ha−1 resulted in 0·4 of the specific volatilization per unit volume of slurry that occurred at 6·3 m3 ha−1. Within the dilution treatments, the amount of water added to the slurry was linearly and inversely related to volatilization. At a dilution of 0·9‐1·2:1 water: slurry the specific volatilization per unit volume of slurry was 0·5 of that from undiluted slurry.