bluuebunny/crossref_metadata_2025 huggingface dataset:
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

Two 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

The 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

A 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

A 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

A 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

Thirty‐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

The 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

Three 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

A 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

The 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

Cu‐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

An 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

The 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

Three 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

The 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

For 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

Two 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

A 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

Twelve 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

A 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

A 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.
PRE‐HARVEST DESICCATION OF HERBAGE SEED CROPS AND ITS EFFECT ON SEED QUALITY
Authors: Roberts H. M. , Griffiths D. J.
Published: April 2006

Seed crops of perennial ryegrass S321 and tetraploid hybrid ryegrass Sabrina were sprayed with 3 pt diquat in 30 gal. water/ac (4.21 diquat in 337 1 water/ha) a few days before the normal date for harvest. Very low germination values were obtained wben the harvested seed was later tested and the production of abnormal seedlings from the treated crops was attributed to the presence of diquat in the seed. On the basis of these results the use of diquat is not recommended as a pre‐harvest desiccant for ryegrass seed crops.
THE EFFECT OF HIGH NITROGEN LEVELS AND STOCKING RATES ON MILK OUTPUT FROM PASTURE
Authors: Gordon F. J.
Published: April 2006

An experiment using 40 lactating dairy cows was conducted for 3 successive years to examine the effects of fertilizer N applied at 400 and 700 kg/ha (358 and 627 lb/ac) at stocking rates of 4.94 and 7.41 cows/ba (2 and 3 cows/ac). The animals were grazed in groups of 10 per treatment, using a fixed rotational grazing system, for 22 weeks in each year.

Milk ontput/cow and/ha was significantly affected by stocking rate, the mean milk outputs being 2499 and 2218 kg/cow (5498 and 4880 lb/ cow) and 12313 and 16396 kg/ha (11032 and 14691 lb/ac) at the lower and higher stocking rates, respectively.

Milk yield/cow at the lower stocking rate was not affected by N level. At tbe higher stocking rate, increasing the amount of N resulted in a 7.4% increase in milk output/cow and/ha. This response to N declined from 1.7% in the first year of the trial to 2.4% in the third year. The response in milk yield to N appeared to he greatest during the first part of the grazing season.

Milk composition, liveweight change, and herbage availahilities and intakes were also recorded.
SHEEP GRAZING PREFERENCES ON A SALTINGS PASTURE AND THEIR SIGNIFICANCE FOR WIGEON (ANAS PENELOPE L.) CONSERVATION
Authors: Cadwalladr D. A. , Morley J. V.
Published: April 2006

Arising from the need to improve the palatability of tussocky, rank Festuca rubra swards to provide a greaer area of grazing for overwintering wigeon which avoided these swards, the effect of sheep grazing on these and close‐mown F. rubra swards was studied by a point‐quadrat method. This showed that close mowing improved the palatability of Festuca rubra swards for sheep to a degree comparable with swards made up of Puccinellia maritima and Agrostis stolonifera, for which sheep and wigeon had previonsly been shown to have a significant preference. The results of the study are discussed in relation to methods of managing an area of saltings pastnre made up of these two types of swards to increase the area of grazing available for wigeon; whilst still being compatible with the objectives of the grazier's sheep husbandry.
THE NUTRITIVE VALUE OF WEEPING LOVEGRASS DURING THE SPRING SEASON
Authors: Vera R. R.
Published: April 2006

Faecal samples from a continuous digestibility trial with Eragrostis curvula were analyzed for cell‐wall contents, acid‐detergent fibre, lignin, asb and N. DM digestibility was regressed on all these fractions and organic‐matter digestibility was also regressed on faecal organic‐matter N. The best predictions of digestibility were obtained by the use of faecal lignin as a percentage of acid‐detergent fibre, and by cell‐wall contents. N was a comparatively poor predictor and it is shown that its relationship with organic‐matter digestibility varies with the level of N in the diet. It is concluded that both lignin and cell‐wall contents could serve as useful internal indicators since their use is unlikely to be biassed by metabolic and microbial contamination.
THE EFFECT OF LEAF NUMBER ON THE SENSITIVITY OF RED CLOVER SEEDLINGS TO PHOTOPERIODIC INDUCTION
Authors: Jones T. W.A.
Published: April 2006

The duration of the juvenile phase in early‐flowering (Dorset Marl) and late‐flowering (S123) red clover is described. Neither cultivar responded to inductive conditions at the first leaf stage but Dorset Marl attained maximum sensitivity by the 3‐leaf stage. A comparable response was obtained with S123 only after the production of 12–13 leaves. The growth characteristics of the two types under continuous long or short days are described and possible explanations are advanced for the characteristic differences in tillering and stem internode number.
THE EFFECT OF FERTILIZER AND GRAZING ON THE BOTANICAL COMPOSITION AND OUTPUT OF AN AGROSTIS/FESTUCA SWARD
Authors: Elliott J. G. , Oswald A. K. , Allen G. P. , Haggar R. J.
Published: April 2006

The results are reported of the effects of fertilizer and grazing or cutting for hay over a period of 6 years on the composition of an Agrostis/Festuca permanent pasture on low‐lying land at Beghroke Hill. Applications of N up to 264 units/ac each year associated with frequent defoliation every 21 days produced only small changes in sward composition; Agrostis spp. declined and Poa trivialis increased. Lolium perenne did not increase from a small initial presence. Records of animal performance and hay yield showed that the mean output from the experiment as a whole was 530 Ib liveweight gain/ac and 0·5 ton hay/ac.
INVESTIGATIONS ON THE DRYING OF HERBAGE AT TEMPERATURES UP TO 50°C*
Authors: Rees D. V. H.
Published: April 2006

Experiments to determine the exposed layer drying rate of cut leaves and stems of a tetraploid (Sabel) and diploid (S23) ryegrass are described. Drying was achieved by passing air through the crop; the changes in weight were monitored continuously. Airflow was fixed throughout the experiments at 37·5 ft/min (0·190 m/s) and the temperatures were controlled in the range 25°C to 50°C. Comparisons were also made of the drying rates at different stages of maturity. Drying curves were determined and moisture content was shown to decay exponentially with time, the relationship approximating closely to a two term exponential.
THE EFFECT OF NITROGEN, STOCKING RATE AND GRAZING METHOD ON THE OUTPUT OF PASTURE GRAZED BY BEEF CATTLE
Authors: Horton G. M. J. , Holmes W.
Published: April 2006

An experiment was conducted in 1971 and 1972 to study the effects of two levels of fertilizer N (50 and 504 kg/ha) on the productivity of pastures grazed by young beef cattle. Two stocking rates were imposed at the lower N level and three at the higher. In addition to rotational grazing, set‐stocking and an integrated grazing‐conservation system were included. The responses/kg N were approximately 1 kg live‐weight gain, 19–24 Meal ME and 8–9 kg DM. Maximum yields of 1200–1300 kg live‐weight gain/ha and 25,000–27,000 Meal ME/ha were recorded. Productivity of set‐stocked pasture was similar to rotational grazing at the high N level, but lower at low N. The integrated system yielded comparable results to high‐N rotational grazing. Performances and herbage intakes per animal reflected the stocking rates imposed.
THE EFFECT OF NITROGEN APPLICATION TO PASTURE ON BEEF PRODUCTION
Authors: Holmes J. C. , Lang R. W.
Published: April 2006

Five grazing experiments each lasting 2 or 3 years were made between 1955 and 1967, all starting in the first year of ryegrass/cocksfoot/clover or ryegrass/clover leys. A high and a low rate of N, 235 and 45 Ib/ac on average (263 and 51 kg/ha) were compared for beef production. High‐ and low‐N treatments gave mean clover contents for the grazing season of 8 and 24 % on a dry‐weight basis, respectively. High N consistently gave a smaller liveweight gain/animal than low N, on average 1±92 and 2±08 Ib/day (0±87 and 0±94 kg/day), respectively. Liveweight gain/ac was 20% greater for high N than for low N, and in terms of net energy the production from high‐ and low‐N, respectively, was 18,500 and 15,000 MJ/ac (45,700 and 37,100 MJ/ha). Data from these experiments, together with published results, were used to calculate a regression of liveweight gain response on N rate and an equation was derived from this to express the output in terms of profit. At 1971 prices profit was maximal at λ0±9/ac (λ2/ha) with 112 Ib N/ac (125 kg N/ha); it was considerably greater at 1973 prices when higher rates of N were justified.
EVALUATION OF A CAPACITANCE METER FOR ESTIMATING HERBAGE PRODUCTION OF OAT CULTIVARS
Authors: Smith I. S.
Published: April 2006

An electronic pasture‐meter was found to be of limited use for the routine estimation of DM production of oat cultivars for the reason that the relationship between the meter reading and DM varied with different cultivars.
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.
Published: April 2006

Plots of S24 perennial ryegrass were grazed fire times by sheep to stubble heights of 10–15 cm (treatment L), 5 cm (M) and 2 cm (S), other plots were cut (C) at approximately the same height as in M. the quantity of digestible organic matter (DOM) harvested by cutting at 5 cm was not significantly different from that harvested by grazing at the same average height there were only minor differences between grazing treatments in the amounts of DOM harvested, but the number of hours for which the sheep had to be maintained on the plots in order to graze the swards to the required heights increased 4‐fold between treatments L and S. the results are discussed in relation to the total DOM harvested in each treatment.
POTENTIAL PASTURE PRODUCTION IN THE UPLANDS OF WALES
Authors: Davies D. A. , Munro J. M. M.
Published: April 2006

Resown S23 perennial ryegrass pastures showed considerably greater response to the application of fertilizer N (0·1075 kg N/ha per year = 0–960 Ib N/ac) at 305 m O.D. than the native Festuca ovina/Agrostis tenuis and Molinia caerulea dominant communities on identical brown earth and peaty gley soils. Ryegrass DM production during 1967–70 increased with N application rates up to 538 kg N/ha per year (480 Ib N/ac) on the acid‐brown earth, while on the extremely N‐deficient gley soil yield responses were recorded up to 1075 kg N/ha (960 Ib N/ac). Percentage N recovery by ryegrass, bowever, although improved by grazing and re circulation, was less than under lowland conditions and the response to N during the growing season was also lower, exceeding 20 kg DM/kg N from applications in May, June and July only. The recovery of N by Festuca/Agrostis and Molinia in 1968–70 ranged from 3% and 2% at 938 kg N/ha to 14% and 9% at 117 kg N/ba per year, respectively. The respective maximum average DM yields recorded were 29 t/ha and 2.2 t/ha from the native communities and 70 t/ha and 62 t/ha from the corresponding resown pastures (2610, 1950, 6250 and 5520 Ib/ac). The results are discussed in relation to the strategy of land improvement in upland areas.
STUDIES IN MILK PRODUCTION SYSTEMS
Authors: Street P. R.
Published: April 2006

A model is described which can be used to synthesize dairy systems under various price environments and sets of decision rules.

The potential use of the model is illustrated with reference to the seasonal calving pattern as an economic decision.
A FURTHER INVESTIGATION OF THE EFFECT OF NITROGEN AND STOCKING RATE ON THE PRODUCTIVITY OF PASTURE FOR BEEF CATTLE
Authors: Umoh J. E. , Holmes W.
Published: April 2006

The liveweight gain was measured of beef cattle on pastures stocked at 5.9 to 11.8 cattle/ha and receiving 50, 182 or 329 kg N/ha in a 12‐week season. N levels and stocking rates were so adjusted that similar yields of herbage per animal were expected. Results showed that similar liveweight gains per animal, averaging 1.03 kg/day, occurred at all N levels. Liveweight gain/ha ranged from 547 to 1037 kg in 12 weeks and the corresponding quantities of metabolizable energy utilized were 9890 and 17590 Meal. The results confinn earlier work (4, 7).
POTENTIAL PASTURE PRODUCTION IN THE UPLANDS OF WALES
Authors: Munro J. M. M. , Davies D. A.
Published: April 2006

The DM and N contribution of S184 white clover in mixed ryegrass/clover swards was recorded at Pant‐y‐dwr Hill Centre (305 m) for 4 years, 1967–70. By direct comparison with fertilized grass swards it was estimated that the clover N contribution on peaty gley soil averaged 100 kg N/ha per year (89 Ib N/ac) under cutting and 98 kg N/ha (87 ib/ac) under grazing with faecal return. On more fertile acid brown earth the corresponding contributions were 81 and 90 kg N/ha (72 and 80 Ib/ac). Full replacement of clover by N fertilizer would require average annual applications of 268, 229, 156 and 128 kg fertilizer N/ha, respectively (239, 204, 139 and 114 Ib N/ac).
THE EFFECT OF HEAVY DRESSINGS OF SLURRY ON FORAGE MAIZE PRODUCTION
Authors: Pain B. F. , Phipps R. H.
Published: April 2006

ABSTACT

Cow slony was incorporated into land at levels equivalent to 0, 125, 250 or 500 t/ha (0, 50, 100 or 200 tons/ac) shortly before sowing maize (INRA 200). Quantity and quality determinations were made on the crop at 73, 93, 115 and 137 days after plant emergence.

The slurry dressings delayed the emergence of maize plants. The 250 t/ha (100 tons/ac) treatment gave a significant increase in DM yield at the final harvest, but 500 t/ha (200 tons/ac) tended to depress yields of the whole crop and of the ear. There was no significant effect on the percentage DM of the crop.

Slurry applications increased the level of E and nitrate‐N in the plants, but depressed Mg. Crude protein and in vitro digestibility were not affected.
EFFECT OF HIGH FERTILIZER NITROGEN AND STOCKING RATES ON LIVEWEIGHT GAIN PER ANIMAL AND PER HECTARE
Authors: Marsh R. , Murdoch J. C.
Published: April 2006

The effect of increasing annual fertilizer N application rate from 400 to 800 kg/ha (357 to 714 lb N/ac) and stocking rate from 5.0 to 7.5 animals per forage ha (2.02 to 3.04 animals per forage ac) on herbage availability, digestible OM intake and live weight gain was investigated in a grazing experiment repeated in 3 consecutive years. A 21×1 day rotational paddock grazing system was used in which the grazing area was increased in the ratio of 1:1.5:3 on two predetermined occasions.

Increasing the fertilizer N application rate increased herbage availability by 12% but failed to increase live weight gain. Increasing stocking rate decreased herbage availability per ha and per animal, and also live weight gain per animal, but increased live weight gain per forage ha by 17.6%.
THE USE OF PROPIONIC ACID AS AN ADDITIVE FOR MAIZE SILAGE
Authors: Leaver J. D.
Published: April 2006

Two clamps of maize silage were prepared in mid‐October, one with 0·33% propionic acid applied during harvesting and one without additive. The treated silage had a peak temperature 3°C below that of the untreated silage. The estimated loss of DM during ensiling was 8% greater in the untreated silage. The stability and acceptability of the silages were tested after exposure to air. The treated silage was slightly more stable than the untreated milage and the intakes by heifers were sligbtly greater. The digestibilities of the two silages estimated in wether sheep were similar, averaging 68·6% digestible OM in the DM at maintenance level and 63·5% at a high level of feeding. The intakes and growth rates of calves and beifers oifered the two silages were also similar.
FORAGE COMPOSITION AND THE CONDUCT OF DIGESTION TRIALS FOR THE COMPARATIVE EVALUATION OF LABORATORY PROCEDURES
Authors: Osbourn D. F. , Cammell S. B. , Terry R. A. , Outen G. E.
Published: April 2006

Fifty‐four grass, legume and whole‐crop maize forages were frozen and fed to sheep in amounts calculated to meet their daily DOM requirements for maintenance. The mean level of feeding achieved was 1·01±0·014 ± maintenance, and the mean and median values of the standard error of means of the coefficients of apparent DM digestibility determined were 0·66 and 0·50 percentage units. The range in composition of the forages was: cell walls 25·0– 64·2, digested cell walls 15·1–50·0, and apparently digested organic matter 56·4 to 76·1 g/100 g DM. The proportion of the DOM arising from cell walls had an even greater range (22–72%) and differed markedly between the forage species in mean value and in respect of the trend with advancing maturity. It was concluded that the conduct of the digestion trials and the range in composition of the forage samples examined were adequate to provide samples of herhage suitable for the comparison of laboratory procedures of forage evaluation.
A COMPARISON BETWEEN SPRING AND AUTUMN PASTURE FOR BEEF CATTLE AT EQUAL GRAZING PRESSURES
Authors: Marsh R.
Published: April 2006

Two comparisons between spring and autumn pasture for beef cattle were made. Animals used in all comparisons were of similar breed and weight and were subjected to the same feeding regime for 6–8 weeks before turn‐out. The pastures were grazed on an equal grazing pressure basis between season comparisons. The pastures received similar rates of fertilizer N between seasons and had similar lengths of rest period for regrowth.

Intakes of digestible OM were greater per unit of metabolic liveweight in spring than in autumn. Daily liveweight gains in spring were high, being 1·09 and 1·37 kg (2·4 lb and 3·0 lb), but were lower from autumn pasture at 0·98 and 0·71 kg (2·2 lb and 1·6 lb). Weather was implicated as a factor affecting daily gain from autumn pasture. Greater herbage yields in spring supported 42 and 204 more grazing days per ha which together with the greater gains per animal supported 80–120% more liveweight gain/ha.
VARIATIONS IN SEED QUALITY BETWEEN CERTIFIED SEED LOTS OF PERENNIAL RYEGRASS, AND THEIR RELATIONSHIP TO NITROGEN SUPPLY AND MOISTURE STATUS DURING SEED DEVELOPMENT
Authors: Ene B. N. , Bean E. W.
Published: April 2006

Ten Certified Seed lots of S23 perennial ryegrass produced in different counties in England during 1966, and ten lots produced in 1972, were examined for differences in characters affecting seed quality. The 1966 seed lots differed significantly in 1000–seed weight, germination rate, N content of the seed and seedling dry weight, and there was a significant correlation between seed N content and the seedling weight of the progeny.

In both S23 and S24 perennial ryegrass N applied at inflorescence emergence or at anthesis increased N content of the seed and seedling dry weight. In S24 application of N at anthesis increased 1000–seed weight also. When plants of S23 perennial ryegrass were subjected to reduced moisture supplies their seed N content was increased. It is concluded that late N applications to grass seed crops may affect seed quality.
SWARD PRODUCTIVITY UNDER ALTERNATE OR REPEATED CUTTING OF ADJACENT SMALL AREAS
Authors: Smith A. , Arnott R. A. , Macauley J. R.
Published: April 2006

Cutting patterns producing high and low areas were imposed on swards of Dactylis glomerata and Lolium perenne to test whether output could be increased when compared with traditional uniform cutting methods. In two experiments, swards of both grasses were divided into parallel 9 cm strips which were cut alternately on different occasions to a height of 5 cm. These swards yielded a similar quantity of herbage DM to that from other swards cut uniformly at the same height and frequency. In a third experiment, swards of Lolium perenne were divided into alternate strips of unequal width (9 and 4.5 cm). The narrow strips were allowed to grow to a height of 15 cm and were occasionally trimmed at this height. The wide strips were cut to 5 cm at 2–or 4–weekly intervals. Areas cut to 5 cm every 2 weeks yielded significantly more DM when adjacent to high areas than when adjacent to areas cut to 5 cm every 2 weeks (i.e. under uniform cutting). The interaction between adjacent areas having different defoliation regimes is discussed in relation to the possibility of obtaining some additional output from a suitable no niform cutting system compared with uniform cutting. Sward productivity under no niform grazing patterns of livestock is also discussed.
POTENTIAL PRODUCTIVITY OF RED CLOVER VARIETIES IN S.W. SCOTLAND
Authors: Hunt I. V. , Frame J. , Harkess R. D.
Published: April 2006

A reassessment of the potential productivity of 37 varieties of red eiover suggests that DM productivity is equivalent to grass given fertilizer N at 252 kg/ha for the 1st year, 209 kg/ha for 2nd year and 144 kg/ha for 3rd year of production. Corresponding equivalents for CP productivity of the red clover swards were 298, 228 and 206 kg N/ha. Varietal differences in productivity were significant Average yields of total herbage DM in the 1st, 2nd and 3rd harvesting years were 10.9, 8.7 and 8.2 t/ha, containing 6.5, 5.9 and 6.0 t/ha red clover, respectively. For two harvesting years, the most productive varieties were Essi, Kuhn, Hungaropoly, Robina, Tilo Daehnfeldt, Redhead and Corona Otofte. Rea 4N and a few other tetraploid varieties were very productive in the 3rd year. Hungaropoly, although showing a decline in the 3rd year, was the most productive over 3 years, with an average yield of 11.5 t/ha per year total herbage DM containing 10.2 t/ha per year red clover DM.

Such high potential DM production warrants further investigation into the persistence of red clover, its conservation and the problems of its utilization by livestock.
BACTERIAL DECOMPOSITION OF GRASRUCTOSAN OF DIFFERENT DEGREES OF POLYMERIZATION
Authors: Kühbauch W. , Kleeberger A.
Published: April 2006

The bacterial decomposition of grass fructosans with different degrees of polymerization was monitored in vitro. The period required for the microbial decomposition of polymeric fructosans was directly related to the extent of polymerization. It was concluded that there might be a relationship between the digestibility of other organic nutrients of fodder plants and polymerization and that polymerization increases with maturity of the plant.
ESTIMATION OF THE BOTANICAL COMPOSITION OF OESOPHAGEAL EXTRUSA SAMPLES. 1. A MODIFIED MICROSCOPE POINT TECHNIQUE
Authors: Hamilton B. A. , Hall D. G.
Published: April 2006

Extras samples were collected from ocsophageally fistulated sheep that had been fed mixtures of known proportions of a legume and a grass. The botanical composition of these samples was estimated by two microscope point techniques. When estimates were made by recording hits on each species the legume content of the ingesta was consistently underestimated by up to 23%. Much of this underestimate was attributed to the weight per unit area of the leaves of the legume being approximately twice that of the grass leaves. When the microscope hits were adjusted for the weight per unit area of each of the plant components (leaves, petioles, flowers and seed pods) the relationship between the estimated and actual legume consumed was improved, the greatest difference between actual and estimated legume being approximately 5%.
THE STATE OF HAYMAKING TECHNOLOGY—A REVIEW
Authors: Klinner W. E. , Shepperson G.
Published: April 2006

The main objectives of research and development In haymaking are to minimize dependence on weather and to reduce loss of nutrients. Treatment of a cut crop, especially by mechanical conditioning, shortens drying time substantially while the use of chemical desiccants before or after cutting may also increase the drying rate.

The advantages of terminating field exposure before drying has been completed are particularly important. Barn drying from about 40% moisture content (m.c.) wet basis has given good results. A useful alternative might be the application of preservatives to hay of high moisture content. The suppression of harmful spores, whether through barn drying or preservative treatment, lessens the risks to human and animal health.
VARIATION IN HEADING DATES OF PERENNIAL RYEGRASS CULTIVARS AS INFLUENCED BY SPRING AND EARLY SUMMER TEMPERATURES
Authors: Camlin M. S.
Published: April 2006

Ear emergence data for 9 cultivars of perennial ryegrass have been recorded in Northern Ireland at the Plant Testing Station, Crossnacreevy, each year since 1967. These data show that while early spring (March‐April) temperatures have a marked effect on the heading of early cultivars such as Gremie and Aberystwyth S24, the behaviour of later cultivars is more directly affected by temperatures at the time of their stem internode elongation. Ear emergence dates of late cultivars bear no fixed relationship to those of early cultivars.

It is concluded that while records of early spring temperatures can be used to predict, with reasonable accuracy, the heading dates of early cultivars, such records do not provide a reliable basis for the prediction of heading dates of later cultivars. In Northern Ireland, reliable prediction of cutting dates for later cultivars to obtain herbage of a required level of digestibility is only possible on a short‐term (one‐two week) basis. Such predictions must take account of growing conditions in each individual year.