bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE MEASUREMENT OF PRIMARY PRODUCTION AND UTILIZATION ON HEATHER MOORS
Authors: Grant SheilaA. 
Published: April 2006

ABSTRACTThe measurement of primary production and utilization of heather moors is a necessary part of studies aimed at understanding and ultimately improving secondary (animal) production.Heather is a woody perennial and presente many problems peculiar to itself. With management in mind a more precise method of classification and description of heather moors is suggested.The measurement of quantity of production in terms of standing crop, total edihie DM and annual DM production are described in detail. Chlorophyll extraction techniques are descrihed, these heing more rapid than hand separation and enabling many more samples to be handled.Digestibility and voluntary intake of heather as indices of quality are briefly discussed.A method for the calculation of grazing pressure or utilization is described. The method measures the percentage of available edible (photosynthetic) material which is consumed.
THE EFFECT OF NITROGEN, STOCKING RATE AND FREQUENCY OF GRAZING BY BEEF CATTLE ON THE OUTPUT OF PASTURE
Authors: Escuder J. C. , Andrews R. P. , Holmes W. 
Published: April 2006

ABSTRACTTwo successive grazing experiments were conducted over 12 weeks on perennial ryegrass pastures with 50 and 44 young cattle to study the effect of N fertilizer when applied at a daily rate of 1 or 3 kg N/ha. At each level of N two stocking rates differing hy 20% were imposed. At the liigher N level and stocking rate, three frequencies of grazing were imposed.At the stocking rates imposed N tended to reduce the daily liveweight gain per head, but increased the total liveweight gain per ha by from 0.79 to 1.58 kg/kg N. A 20% increase in stocking rate depressed gain per head in both years. In the first year it did not improve gain/ha, hut in the second year gain/ha was increased by 12–17%.There was a tendency for performance per animal and per ha to increase as the grazing cycle was lengthened. In 1969 the highest yield in the whole season was 1880 grazing days and 1260 kg gain/ha.The overall response to N fertilizer was similar to that recorded in other reports, but it is possible that a lack of K had limited pasture growth.
STUDIES OF RESPONSE TO FERTILIZER NITROGEN
Authors: Hunt I. V. 
Published: April 2006

ABSTRACTThe effect of applying 62.8 or 125.6 kg/ha fertilizer N, 4 or 18 days before, 4 days after or immediately after harvesting primary growth at the hay stage on yield of DM, yield of digestible OM (DOM), uptake of N, % CP and % digestibility of OM (OMD) of the primary growth and regrowth from S24 perennial ryegrass were compared with harvesting the primary growth 4 or 18 days earlier.Pre–harvest application of N had no effect on yield of DM or DOM or on % OMD, but significantly increased uptake of N and % CP on a DM basis in the primary growth. The regrowth response was less than from equivalent amounts of N applied after harvest in proportion to the amount of N removed with primary growth. 20–40% N was taken up in the primary growth, even when applied 4 days before harvest. The proportion taken up was not influenced by the interval between application and harvest, but tbere was a marked increase in uptake wben rate of application rose to 125.6 kg N/ha. Harvesting 4 days earlier resulted in slight loss of bulk in the hay which was fully compensated by its extra quality, by improved regrowth and its more effective response to fertilizer N. The low yield of the primary growth harvested 18 days earlier was not compensated by the mass of the regrowth but it produced tbe highest quality primary growdi and top yield of regrowth.
MECHANICAL MEASUREMENT OF GRAZING TIMES OF SHEEP AND A BIAS IN VISUAL ASSESSMENT
Authors: May P. F. , Kennedy A. P. 
Published: April 2006

ABSTRACTA mechanical device to record time spent in grazing by sheep is described and the results of tests of its performance under field conditions are given. There was good agreement between mecbanicai and visual records under field conditions, and observations made during tbe tests indicate a possible source of bias where visual records are made by an observer watching a group of animals.
A COMPARISON OF THE GROWTH OF A CUT SWARD WITH THAT OF GRAZED SWARDS, USING A TECHNIQUE TO ELIMINATE FOULING AND TREADING
Authors: Smith A. , Arnott R. A. , Peacock J. M. 
Published: April 2006

ABSTRACTA technique is described whereby sward defoliation by sheep can occur in the absence of treading and the deposition of excreta. By using this technique, swards were grazed to a moderate severitj, leaving behind an amount of herbage similar to that left after cutting; the DM yields from both methods are compared. The technique was also used to study other swards which were grazed either very leniently or very severely. Within the limits tested, efficient rotational grazing (i.e. the removal of a large proportion of the herbage on each occasion) did not give the greatest DM yields, except at the first harvest. Cutting‐ and grazing‐treatments produced differences in sward structure.
THE ABSORPTION OF PHOSPHATE AND CALCIUM FROM DIFFERENT DEPTHS IN SOIL BY SWARDS OF PERENNIAL RYEGRASS
Authors: Newbould P. , Taylor R. , Howse K. R. 
Published: April 2006

ABSTRACTA method for measuring the depth in soil from which plants absorb nutrients is descrihed. Radioactive tracers are injected at different depths and when allowance is made for any variations in the extent to which the added tracer is diluted hy labile ions in the soil at each depth the relative quantities of nutrient taken up from different depths can be calculated.Results obtained with perennial ryegrass swards of contrasting age indicated that the nptake of P and Ca always occurred predominantly from within the top 12.5 cm of soil. Apart from the initial few months of a sward's life, the proportion of both elements absorbed from different depths for a whole growing season varied little with age of sward up to 31/2 years. Considerable changes in the relative contrihution of different depths of soil to uptake occurred within a season; the extent of uptake from the surface layers was primarily influenced by variations in soil‐water content and the application of fertilizer to this region.
THE EFFECT OF THE GRAZING ANIMAL ON THE N STATUS OF GRASS SWARDS
Authors: Brockman J. S. , Rope C. M. , Stevens M. T. 
Published: April 2006

ABSTRACTThirty‐one sets of N yield data were considered, taken from seven experiments grazed by sheep. N yield could be explained in terms of fertilizer N rate, an estimate of soil N and an interaction between the two. Fertilizer N increased grass N yield more on grazed swards than on cut swards, and this effect was greatest on soils with high available soil‐N. It is concluded that N recircula‐tion can be substantial on heavily‐stocked swards receiving high rates of fertilizer N, so increasing the efficiency of fertilizer as a source of N in these conditions.
COMPETITION BETWEEN ESTABLISHED AND NEWLY SOWN GRASS SPECIES
Authors: King J. 
Published: April 2006

ABSTRACTThe nature of competition between a grass species either invading or introduced hy sowing into an established grass sward and the estahlished sward was examined by using a divided‐pot tecbnique. The species studied were Lolium perenrte S23 and Festuca rubra SS9, grown at two levels of N and P. Data are given for DM yield, tiller number, species ratio and uptake of N and P.The results show that competition for nutrients was a dominant factor and anything which affected this, such as prior establishment of one species, had an important effect on the success of the introduced species which amounted, under some conditions, to complete inhibition of growth of the latter. The data throw some light on the means whereby dominance is maintained in a pasture community.
A STUDY OF THE UTILIZATION OF SILAGES OF DIFFERENT DRY–MATTER CONTENT BY YOUNG BEEF CATTLE WITH OR WITHOUT SUPPLEMENTARY BARLEY
Authors: Forbes T. J. , Jackson N. 
Published: April 2006

ABSTRACTThree Uages containing 18.7, 35.2 and 51.0% DM were given to young beef cattle without supplementary barley or with a daily allowance of 1.8 or 3.6 kg air‐dry fortified barley. Each diet was given to 9 individually fed animals, the mean fasted liveweight of which at the start of the experiment was 304 kg. The dafly voluntary DM intake was recorded for a 10‐day period for the 9 animals on each silage without supplementary barley. The mean DM intakes per kg W0.73 were 58.4, 94.6 and 104.1 g for Silages 1, 2 and 3 and the intakes increased curvilinearly with the DM content of the silage. The mean daily liveweight gains on Silages 1, 2 and 3 were 0.63,0.73 and 0.75 kg, respectively; the relationship was significantly linear (P <0.01). The barley supplement also had a significantly linear CP <0.01) effect on daily gains. The mean daily gains for 0, 18 and 3 6 kg fortified barley per day were 0.54, 0.74 and 0.84 kg, respectively. The DM and digestible organic matter required per kg liveweight gain were not significantly affected by the DM of the silage, but were significantly (P < 0.01) affected by supplementation.The metabolizable energy (ME) values of Silages 1,2 and 3 were 2.46, 2.52 and 2.50 Meal/ kg DM, respectively. The supplementary concentrate increased the ME concentration significantly (P < 0.05), although the overall increase was small. The mean values were 2.49, 2.54 and 2.61 Meal/ kg DM, respectively, for 0, 1.8 and 3.6 kg fortified barley per day. The digestibilities of DM and organic matter were not significantly affected by the type of silage, but there was a significant increase with increasing intake of supplementary barley.
THE VISUAL ESTIMATION OF PASTURE AVAILABILITY USING STANDARD PASTURE CORES
Authors: Hutchinson K. J. , McLean R. W. , Hamilton B. A. 
Published: April 2006

ABSTRACTA coring technique (6), that may be used for estimating the mean amount of herbage on closely grazed pastures, has been adapted to include visual scoring. Two methods are described, both of which use sets of pasture cores from the sward as reference standards. The observers score the herbage on view at random sites against the standards. In the first method the scores are converted to herbage yields directly by reference to the yields of the standards. In the second method a double sampling regression technique is used and the set of standards is used as a visual guide only.
THE RATE OF WATER LOSS FROM GRASS SAMPLES DURING HAY‐TYPE CONSERVATION
Authors: Morris R. M. 
Published: April 2006

ABSTRACTThe loss of water from small bulk samples of five grass species was studied under constant conditions of humidity, temperature and lighting. A logarithmic curve was fitted to the data and the different species compared on the basis of a loss coefficient derived from the fitted curve. The species varied significantly in this aspect; those with high surface‐area to dry‐weight ratios generally lost water fastest The presence of stem material appeared to increase the rate of water loss considerably. High humidity during drying caused the grasses to lose water more slowly and to retain much more water at equilibrium with the surrounding air. Chemical treatments to speed water loss, using a solvent and a fungal toxin were tested. Both appear to have some promise. Selection for high water loss in grass breeding may also be possible.
THE DISPOSAL OF COPPER‐ENRICHED PIG‐MANURE SLURRY ON GRASSLAND
Authors: Batey T. , Berryman C. , Line C. 
Published: April 2006

ABSTRACTCu‐enriched pig‐mannre slurry was applied to grassland at two rates, 5000 and 10,000 gal/ac (56,000 and 112,000 I/ha), on three occasions, supplying a total of 5.4 Ib/ac (6.1 kg/ha) and 10.8 Ib/ac (12.2 kg/ha) Cu, respectively. At the higher rate, soil Cu extractable with EDTA increased from 24 ppm to 7.3 ppm Cu in samples taken to a depth of 3 in. (7.5 cm) and Cu in herhage DM increased from 9.1 ppm to 21.2 ppm Cu (mean of 5 cuts). Much of the additional Cu in the herhage was thought to be derived from external contamination. In other tests, leafy herbage sampled a few hours after applying slurry contained 338 ppm Cu in the DM.Samples of soil and herbage were taken in 1969, 1970 and 1971 from farm grassland that had received Cu‐enriched pig‐manure slurry each year; levels of Cu increased in the soil, Cu levels in herbage were variable and appeared to be affected by the rate of grass growth.The evidence suggests that there is at present littie risk of Cu toxicity following applications of Cu‐enriched pig‐manure slurry; the greatest risk to susceptible stock would appear to be by ingesting either grazed or conserved herbage contaminated with slurry. To avoid possible hazards from a build‐up of Cu in the soil, a maximum annual application of ahout 8.5 Ib/ac (9.5 kg/ha) Cu is suggested until more is known on the availability of Cu in slurry to crops and grass.
THE EFFECT OF NITROGEN AND STOCKING RATE ON THE OUTPUT OF PASTURE GRAZED BY BEEF CATTLE
Authors: Yiakoumettis I. M. , Holmes W. 
Published: April 2006

ABSTRACTAn experiment was conducted in two successire years to measure the effect of two levels of fertilizer N, 50 and 300 kg/ha (45 and 270 Ib/ac) on the productivity of pastures grazed by young beef cattle. Two stocking rates were imposed at the lower N level and 4 at the higher level. The responses per kg fertilizer N were approximately 1 kg liveweight gain, 20–24 Meal ME and 8–9 kg DM. Maximal yields of about 1000 kg gain/ha (890 Ib/ac) and 19,000 Meal ME/ha (7700 Mcal ME/acre) were recorded.Animal performance was similar on the low and the high N pastures. There was evidence that the chemical quality of pasture was lower on the low N pasture in the first year, but there was no difference in the second year.The numbers of dung pats per ha and the refusal of herbage due to fouling were reduced by Increasing the stocking rate.
A STUDY OF THE INTAKE OF DRINKING WATER BY DAIRY COWS AT GRASS
Authors: Castle M. E. 
Published: April 2006

ABSTRACTThe average daily intake of drinking water of two groups of 10 spring‐calved Ayrshire cows, one gronp on a paddock and the other on a Wye College system of grazing, was measured on 4 days/week for 20 weeks. Trends in water intake were similar on both systems, the average daily intake being 23.0 ±8.5 kg (5.1 ± 1.9 gal)/cow. The average DM content of the herbage was 17.8% and the mean air temperature 134°C (56 1°F). The weight of water drunk was positively related to the daily milk yield and the DM percentage of the herbage, and negatively related to daily rainfall and relative humidity. All of these relationships were significant. Possible changes in the provision of water for dairy cows at grass are discussed.
THE UTILIZATION OF DRIED GRASS BY EARLY WEANED LAMBS
Authors: Tait R. M. 
Published: April 2006

ABSTRACTThree groups of 8 Polled Dorset Iambs were weaned at 8 weeks of age and were fed dried grass, a 50–50 mixture of dried grass and protein‐supplemented barley and protein‐supplemented barley. All rations were completed. Digestibility trials were also conducted and the effect of level of feed intake on nutrient digestibility investigated.The dried grass resulted in rates of gain comparable to those produced by the pelleted barley ration. Feed conversion efficiency was lowest for the grass and highest for the barley ration. An interaction between the dried grass and barley was observed in nutrient digestibility. Increasing the level of feeding from approximately maintenance to appetite tended to result in slight depressions in the digestibility of energy and protein of all rations.The results suggest that dried grass can be used successfully for intensive feeding of early weaned lambs and little nutritional advantage appears to be gained from combining dried grass with barley.
THE EFFECT OF WHITE CLOVER ON THE PRODUCTION OF YOUNG AND OLDER GRASSLAND COMPARED TO THAT OF NITROGEN FERTILIZER
Authors: Kleter H. J. , Bakhuis J. A. 
Published: April 2006

ABSTRACTThe result of a study over many years on the effect of white clover (Trifolium repens L.) and nitrogen fertilizer on the production of young and old grassland are discussed. In young and old grassland, clover and N fertilizer increased production and N content. The effect of clover on production was somewhat greater in young grassland than in old. This difference was associated with a difference in the clover percentage in the sward. Statistical treatment of the results of similar studies by other workers showed that, given equal percentages, the clover in an older sward clearly had a greater effect than the clover in the first few years after sowing. Variation in the production of both young and somewhat older grass/clover swards are mainly due to differences in the clover percentage.
HEADING DATES OF S24 PERENNIAL RYEGRASS AND SPRING TEMPERATURES
Authors: Roy Marjory G. 
Published: April 2006

ABSTRACTFor spaced plants of Lolium perenne cv. S24 at the Welsh Plant Breeding Station, Aberystwyth, and at the National Institute of Agricultural Botany, Cambridge, linear relationships were obtained between the recorded heading dates and (a) mean March earth temperatures at 30 cm depth and (b) mean March plus mean April earth temperatures at 30 cm depth. The residual standard deviations were ±2.97 days and ±2.65 days, respectively, A mean March earth temperature of 8°C predicted heading on 5 May, 6° C predicted heading on 12 May, and 4°C predicted heading on 20 May. For sites with an average April temperature significantly below 8.7°C a correction of +2 days per degree mean temperature difference in April had to be applied to these dates. These equations could be used to predict dates for 50% ear emergence in swards with a 50% confidence limit of ±22 days for sites in Central and Southern England and Wales. In certain years, cold, wet weather in May appeared to delay heading considerably at two Scottish sites.
THE GROWTH OF BEEF CATTLE FED ON MAIZE SILAGE SUPPLEMENTED WITH DRIED LUCERNE, FISHMEAL OR UREA
Authors: Wilkinson J. M. , Lonsdale C. R. , Tayler J. C. 
Published: April 2006

ABSTRACTTwo experiments are reported in which 119 steers were fed ad lib. on maize silage, supplemented with different proportions of dried lucerne. In addition, the effect of including white fishmeal with the silage at levels up to 13% of the total diet was studied in one experiment. In another, the effect of adding urea to the silage (at 0.9% of the DM) was investigated.In hoth experiments the response in liveweight gain to increasing amounts of lucerne was curvilinear. The highest mean level of daily gain (1.5 kg/head per day) in the first experiment was achieved when the diet contained 62% lucerne or 13% fishmeal. In the second experiment the highest mean daily gain (1.1 kg/head per day) was achieved when the diet contained 71% lucerne.Daily liveweight gains were simOar for the cattle fed 25% of the diet as lucerne with sQage to which urea had heen added, and for those fed higher proportions of lucerne with untreated silage.
PASTURE YIELD INSTRUMENT USING A RADIO FREQUENCY BRIDGE
Authors: de la m. Nichols G. 
Published: April 2006

ABSTRACTA single unit grass‐meter has been developed to replace the twin transmitter‐receiver units which have been in use since 1958.In the new design a radio‐frequency capacitance bridge is mounted on top of a measuring head. Introduction of grass into the measuring head unbalances the bridge and the amount of unhalance, which is a function of the mass of the herbage, is indicated on a micro‐ammeter. Two ranges are incorporated so that sheep pastures with short grass and cow pastures with long grass can be measured.
THE POTENTIAL VALUE OF BIRDSFOOT TREFOILS (LOTUS SPP.) FOR THE IMPROVEMENT OF NATURAL PASTURES IN SCOTLAND
Authors: Charlton J. F. L. 
Published: April 2006

ABSTRACTTwelve introducdons of common birdsfoot trefoil (L. corniculatus L.) obtained from the USA, Canada and the USSR were classified and compared with S100 white and Essex red clovers when grown as spaced single plants and as spaced aggregate clumps on a lowland site at Auchincruive during 1968–69. Semi‐erect and low‐growing forms, early and late‐flowering types were recorded. In terms of DM yield, the Rnssian variety Morshansk and its Canadian descendant Leo were most promising, the former outyielding both clovers over the experimental period.Two sward experiments were conducted at an upland site in south Ayrshire during 1967–8 on the effect of variations of renovation treatment and fertilizer application on the establishment and production of surface‐sown trefoils. The USA variety Empire behaved simflarly to white clover in that it established and yielded satisfactory under all renovation treatments. A marked yield response to K application and a depression caused by fertilizer N were obtained in the second experiment The trefoil varieties Leo and Empire were as productive as S100 white clover. Legume establishment was notably more satisfactory after spring sowing.These results suggest that common birdsfoot trefoil has potential value as an alternative to white clover on dry soils of low fertility in Scotland where grazing pressure is traditionally not very severe.
A NEW GRAZING SYSTEM FOR BEEF CATTLE—THE TWO FIELD SYSTEM
Authors: Hood A. E. M. , Bailie J. H. 
Published: April 2006

ABSTRACTA new simplified grazing management system has been devized for spring‐ or antumn‐born calves scbednled for beef production at 18 months of age on a grass/cereal system. The new system which can be conveniently described as the two‐field system obviates the need for paddock fencing and paddock water installations, is simple to operate and is giving results in terms of liveweight gain performance and stocking rates per acre which are comparable with those from paddock systems.The new system employs the old practice of set‐stocking. Two fields are used, however, and these are alternately set‐stocked and cut for silage, or vice‐versa. It has been found that by using N fertilizer to the same extent as in intensive paddock systems, i.e. around 250–350 units N/ac, it has been possible to achieve similar stocking rates/ac and performance has been unimpaired.No bealth upsets have occurred as a result of applying fertilizers on fields in the presence of grazing cattle over a period of four years at two centres, Jealott's Hill and The Leaths, in trials involving hundreds of beef cattle and dairy cows.This new system of grazing management for beef cattle is now well proven and can now be recommended to farmers as an alternative to paddock grazing.
THE YIELD RESPONSE OF A TALL FESCUE/WHITE CLOVER SWARD TO NITROGEN RATE AND HARVESTING FREQUENCY
Authors: Frame J. 
Published: April 2006

ABSTRACTA series of eight fertilizer N rates, ranging from 0 to 377 kg N/ha per year, at increments of 53.8 kg N, was applied to a S170 tall fescue/SlOO white clover sward. The annual rates were split into 8, 6 or 4 equal dressings for harvests at intervals of 3, 4 and 6 weeks, respectively, over a 24‐week growth period from March to September, in each of two years. Residual harvests were taken 6 weeks later in October.Curves relating annual herbage yields to N rate were fitted to tbe data. Total herbage DM responses to 108 kg N/ha were small because of the typical white clover yield N rate interaction, but were almost linear from 108 to 323 kg N/ha at all harvesting frequencies. Tbe decline in rate of response at tbe bigher N application levels was less marked with frequent than with infrequent defoliation. Tall fescue DM responses were substantially linear from 0 to 323 kg N/ha. For the first and second years, relative DM yields of total herbage for harvesting frequencies of 3, 4 and 6 weeks were 100:108:120 and 100:111:131, respectively.Total herbage CP response curves were similar to those for DM, but continued to rise more steeply to the highest N rate tested, 377 kg N/ha. Tall fescue CP responses were linear from 0 to 377 kg N/ha. Harvesting frequency did not markedly influence CP yields.Total herbage DM yield was 14% less in the second year compared witb the first. The decline was due to a reduction in white clover, attributed mainly to the effect of repeated N applications, also the subsidiary effects of companion grass and weather.