bluuebunny/crossref_metadata_2025 huggingface dataset:
THE INFLUENCE OF THE QUANTITY OF HERBAGE OFFERED AND ITS DIGESTIBILITY ON THE AMOUNT EATEN BY GRAZING CATTLE
Authors: Hodgson J. , Wilkinson J. M.
Published: April 2006

Six calves, six heifers and six dry cows grazed a mature sward (treatments A and B) and a leafy aftermath (treatment C) in succession. The yields of herbage on the two swards were 7100 lb and 1950 lb DM per acre (7950 kg and 2180 kg per ha), respectively. The amounts of herbage offered daily were 47 lb (21–5 kg) DM per head (treatment A), 70 lb (32 kg) (treatment B), and 60 lb (27 kg) (treatment C), Two estimates of herbage organic–matter intake (O,M,I,) were made on each treatment; records of grazing behaviour were made on treatments B and C, The digestibility of the diet selected on treatment C was higher than that selected on treatments A and B, and the animals ate significantly more O,M, on treatment C, The total grazing times on treatments B and C were similar, but the animals found it more difficult to graze on treatment B

Herbage O.M.I. increased significantly from treatment A to treatment B, even though the quantity of herbage offered per day on treatment A greatly exceeded the amount eaten. The increase in O,M,I, was found to be associated with an increase in faecal 0,M, output, but the digestibility of the diet did not change.
THE EFFECTS OF LEVEL OF NITROGEN FERTILIZER ON BEEF PRODUCTION FROM GRAZED PERENNIAL–RYEGRASS/WHITE–CLOVER PASTURES
Authors: Alder F. E. , Cowlishaw S. J. , Newton J. E. , Chambers D. T.
Published: April 2006

The treatments in this summer–grazing experiment were designed as a 2 × 3 factorial, there being two levels of nitrogenous fertilizer (nitro–chalk), supplying 0 and 336kg of N/ha per annum (NO and N3, respectively) and three stocking rates. The fertilizer was applied in 7 dressings at approximately three–weekly intervals. The animals used were Hereford x Friesian steers; these were slaughtered at the end of the grazing season. The stocking rates were calculated on the basis of expected herbage production. The experiment was laid out in 6 randomized blocks which were grazed in rotation. Two blocks were cut for conservation before grazing each year; up to the end of June only 4 blocks were used for grazing.

There was little contamination of the swards with unsown species. With the NO swards the clover contents declined each year, but remained fairly high at over 20% in 1965. Clover contents also declined each year in the N3 swards and by 1965 were only 2 to 4%.

The quantities of herbage cut for conservation were higher from the swards receiving N. The live–weight gains of the cattle (per head) were higher at the lower stocking rates, the effect of stocking rate being more noticeable in the July to Oct. period. Live–weight gains per ha increased at the higher stocking rates. In 1963 and 1965, as stocking rates increased carcass weights per animal decreased and carcass quality, as indicated by the commercial grades, was poorer. In 1964, a dry spell from July to Oct. necessitated the removal of cattle from the experiment and the effects of treatment on carcass weight and quality were not apparent.
PEDOMETER MEASUREMENTS OF THE DISTANCE WALKED BY GRAZING SHEEP IN RELATION TO WEATHER
Authors: Powell T. L.
Published: April 2006

During the winter months of 1963 and 1964, mature non–pregnant Clun Forest ewes at pasture were equipped with pedometers to study the value of these instruments for measuring distances walked, and to investigate the importance of weather on the distances travelled. Approximately 80 periods were recorded, each of about 24 hours. The accuracy of the measurements was checked by using a rangemeter and it was found that the reliabihty of pedometer records must be assessed on the animal from which they are obtained. The individual characteristics of the pedometers and/or the sheep gave rise to inaccurate records from about 50% of the instruments studied.

Multiple regression analysis of data for each of the three sheep which provided suitable records revealed that, in dry weather, the average distance walked per hour of recording period increased signiJBcantly with mean air temperature in one case and with hours of bright sunshine in another. Wind–speed effects were unimportant. The distance walked by all three sheep increased significantly with hours of daylight per recording period, and this was the only variable found to affect distance walked in wet weather. Differences between average distances walked per hour under dry–and wet–conditions were non–significant.

It is concluded that for measuring the distances walked by sheep, the disadvantages of the pedometer outweigh its advantages.
THE GROWTH AND DEVELOPMENT OF SOME GRASS SPECIES UNDER COMPETITIVE STRESS
Authors: Rhodes I.
Published: April 2006

Three experiments were carried out in a semi‐controlled glasshouse environment to determine the response of individual plants to competition; (i) between seedlings of different species, (ii) between seedlings derived from seeds of differing sizes within a species, and (iii) between seedlings and established plants.

Differences were detected in seedling competitive ability between species and between plants derived from differing seed sizes. In associations of species of very high and very low competitive ability the differences in competitive ability were accentuated by an increase in plant density.

Established plants of Phalaris coerulescens were less aggressive to seedlings growing in close proximity than were plants of Lolium rigidum and H1 ryegrass. Despite the early death of established swards of L. rigidum, and the consequent removal of competitive stress, there was no rapid increase in the growth and development of seedlings in these swards. Possible mechanisms causing this effect are discussed.

There was evidence of a specific relationship between the species of the established sward and the seedling species, in particular seedlings of HI ryegrass were particularly susceptible to competition from established plants of their own species.

Dry weight per plant, tiller production, rate of leaf appearance and leaf size were ail affected by competition between seedlings; however, tiller production was generally more severely affected than rate of leaf appearance and leaf size.

Dry weight per plant, tiller production, seedling height, number of leaves per tiller and number of seeds per seedling were all affected by competition from established plants.
THE EFFECT OF STOCKING RATE AND SUPPLEMENTARY CONCENTRATE FEEDING ON MILK PRODUCTION
Authors: Castle M. E. , Drysdale A. D. , Watson J. N.
Published: April 2006

The effect of stocking rate and of feeding a supplement of barley on milk yield and quality was studied in an experiment with 18 spring‐calved Ayrshire cows grazing from early May until early September in 1964 and 1965. Three treatments were compared: (A) grazing at a normal stocking rate with no supplements fed (the control); (B) grazing at a high stocking rate with no supplements fed; (C) grazing at a high stocking rate, as on treatment B, with a supplement of 8 Ib rolled barley per cow daily. On treatment A, 0.92 ac/cow was used for grazing, plus some conservation, and on treatments B and C, 0.70 and 0.58 ac in 1964 and 1965, respectively. The average daily milk yields were 35.4, 32.9 and 37.0 Ib (16.1, 14.9 and 16.8 kg), respectively, on treatments A, B and C in 1964, and 39.1, 32.3 and 38.8 Ib (17.8, 14.7 and 17.6 kg) in 1965. Milk production/ac was 24 and 32% higher on treatment B than on treatment A in 1964 and 1965, respectively.

The response to the barley feeding on treatment C was equivalent to an extra 1 gallon milk from 20 Ib barley in 1964 and from 12 Ib barley in 1965 (10 litres of milk from 20 and 12 kg barley). The total‐solids content of the milk from the three treatments was not significantly different. It is concluded that, at the present price of barley and the price received for milk, an increase in stocking rate, with a consequent increase in the milk yield per acre, was more profitable than feeding barley.
THE CONTROL OF STOMACH‐WORM INFECTION IN YOUNG CATTLE*
Authors: Michel J. F.
Published: April 2006

Study of the epidemiology of parasitic gastro‐enteritis in calves suggested that control measures should consist of moving calves in mid‐July to pastures not grazed by cattle since the winter and at the same time giving them adequate anthelmintic treatment in order that they should not contaminate the new pasture. Controlled trials are described in which calves managed according to these proposals made far better weight gains than comparable calves remaining on the same pasture throughout the season. Observations made in different parts of the country suggest that the same measures may be widely applicable. Possible causes of failure are discussed.
DRY MATTER PRODUCTION AND LIGHT INTERCEPTION OF CROP SURFACES
Authors: Alberda T. , Sibma L.
Published: April 2006

The growth curves of closed grassland swards obtained during the growing seasons of six successive years were compared with each other and with theoretical growth rates calculated by de Wit's method and based on the mean light energy input data for the same years. The form of the growth curve consisted of a period with a constant rate, lasting for 6–7 weeks in May‐June, then rapidly shortening to 3 weeks in August‐September, after which there was a rather abrupt change to zero values. A comparison with theoretical values showed that a period of constant growth rate was possible, because the promoting influence of increasing LAI counteracted the effect of increasing respiration. Before the longest day this period was lengthened by an increasing daylength; thereafter the reverse was found. There is no ready explanation for the sudden decline to zero values. This is thought to be associated with changes in the rate of photosynthesis.
FERTILE TILLER PRODUCTION AND SEED YIELD IN MEADOW FESCUE (FESTUCA PRATENSIS L.)
Authors: Lewis J.
Published: April 2006

The seed‐producing capacity of two varieties of meadow fescue, S215 and S53, sown at three different spacings, was compared. One level of nitrogen was applied on three different dates in the spring. Tiller counts were made periodically during the growth of the crop. Fertile‐tiller production was found to be related to vegetative growth.

The varieties differed not only in yield, but also in growth dynamics. A larger percentage of overwintering shoots became fertile in the hay variety, than in the pasture variety.

Drill spacings had significant effects on plant establishment and on vegetative‐and fertile‐tiller numbers. In both years N applied in March gave the highest production of fertile tillers. Date of N application did not produce marked trends in yield. The influence of spacing and date of N application on the number and density of spikelets indicated that the plant adjusted itself to environmental factors. Thus spikelet numbers were reduced in early heads with narrower drill spacing and with late applications of N. Head emergence was earlier in narrow drills, but time of N application in the spring did not produce significant differences in this respect.
EFFECT OF DIFFERENT CULTURAL TREATMENTS ON ROOT DEVELOPMENT IN A GRASS SWARD GROWING ON DEEP PEAT
Authors: Boggie R.
Published: April 2006

Previous work has shown that on deep peat the root systems of sown grasses are shallow. In order to study the effect of cultivation on root development, an experiment was laid down in an area of deep peat where sown grass swards were established on plots which had been subjected to different cultivation treatments. Root development is shown to be affected by depth of cultivation and this is discussed in relation to surface sowing of peatland areas.
THE USE OF BARN‐DRIED HAY AND SILAGE IN FATTENING YOUNG BEEF CATTLE
Authors: Forbes T. J. , Irwin J. H. D.
Published: April 2006

A series of trials was carried out in which barn‐dried hay and silage were fed to young fattening cattle with or without supplementary barley. Liveweight‐gains on silage and barn‐dried hay alone were too low to provide an adequate finish during winter feeding. Liveweight‐gains on hay alone were always higher than those obtained on silage alone, the difference being more marked in lighter animals. There was a marked response to supplements of 3 and 4 lb (1.4 and 1.8 kg) of barley, the response being significantly greater in silage‐fed cattle than in those fed on barn‐dried hay. There was some evidence of growth compensation with the introduction of a barley supplement to cattle on silage diets, but there was no such response in those fed on hay. Compensatory growth was not accompanied by improved digestibility or N retention.
A COMPARISON OF DIRECT‐ AND SWATH‐HARVESTING OF S24 RYEGRASS SEED
Authors: Nellist M. E. , Rees D. V. H.
Published: April 2006

An experiment is described in which 32 plots of S24 ryegrass were harvested by two methods, direct‐ and swath‐harvesting at four cutting dates over a period of 14 days. The difference between the two methods was marginal but highest yields and quality were obtained by cutting when seed moisture content was between 53 and 40% and harvesting from the swath when it was about 30%, By the time the seed in the uncut crop had reached 30% moisture, yield from direct harvesting was greater than that from cutting followed by swath‐harvesting, although the yields from both methods were falling. The practical significance of these results is discussed.
THE USE OF CATTLE WITH OESOPHAGEAL FISTULAE IN GRASSLAND EXPERIMENTS
Authors: Alder F. E.
Published: April 2006

Oesophageal‐fistulated calves and cattle were used in various experiments during 1963 to 1966; results for 1966 are reported.

The method of inserting the fistula, the routine care of the animals and the methods of sampling through the fistula, are described.

Individual stall‐feeding experiments in 1966 gave recovery values of 99.7% for herbage extruded through the fistulae, in relation to herbage eaten. The in vitro organic‐matter digestibility of the grass offered and of the extrusa samples were identical. The digestibility of the grass fed in these experiments was high, but was comparable with that of herbage used in the grazing experiments reported. Grazing studies on grass/white clover pastures are reported. The digestibility was determined on all samples and they were separated into various plant fractions. Results obtained were compared with herbage samples cut at the same time. In most cases the digestibility and % N of the extrusa sample was higher than that of the corresponding herbage sample. The quantity of dead material present increased, and more was eaten, as the season advanced; it was of low digestibility. Results of intake studies with grazing animals are presented and the use of oesophagea‐istulated cattle as an aid in such studies is discussed.
LOSSES IN THE NUTRITIVE VALUE OF HEAVILY‐WILTED HERBAGE ENSILED IN EVACUATED AND NON‐EVACUATED POLYTHENE CONTAINERS
Authors: Jackson Norman
Published: April 2006

A conservation experiment is described in which the losses entailed in ensiling heavily‐wilted herbage of 37–43% dry‐matter content either by complete sealing in polythene alone, or by complete sealing followed by evacuation of air, were investigated.

The metabolizable energy values of the grass and silages were determined, and the silage volatile‐acids fraction investigated by gas chromatography. The results indicate that there are no significant fermentation differences between the two types of silage. The mean dry‐matter loss for the sealed, unevacuated silos was 6.5% and for the evacuated silos 7.8%. These losses, and the individual crude‐ and digestible‐nutrient losses, are discussed in relation to other published work.
THE EFFECT OF FERTILIZER NITROGEN ON SILAGE FERMENTATION
Authors: Fox J. B. , Brown S. M.
Published: April 2006

Direct‐cut grass which has been heavily fertilized often produces silage with a poor fermentation. An investigation was carried out to study the effect of rate and timing of N applications to herbage intended for direct‐cut silage. A small but consistent increase in silage pH was recorded after high levels of N were applied 7–8 weeks before cutting. The application of additional N fertilizer 10–14 days before cutting the sward had an adverse effect on silage fermentation. Changes in herbage composition following different levels of applied N are outlined.
INFLUENCE OF NITROGENOUS AND PHOSPHATIC FERTILIZERS ON SETARIA SPHACELATA IN SOUTH AFRICA
Authors: Malherbe C. E.
Published: April 2006

In an experiment in which three levels of P and five levels of N fertilizer were applied, it was found that at the highest levels of fertilization the hay yields were increased fourfold, the percentage of crude protein was doubled, the crude‐protein yield increased sevenfold, and the P uptake increased five times over those of the control. This increased production was mainly a result of the use of N fertilizer, although significant PxN interactions were obtained at the higher levels of N fertilizer. By itself, P fertilizer had little effect on any of the above increased yields. It would appear that very much higher production, especially of CP and P, might be attained, if even higher levels of fertilizer were applied.

Basing income on hay yields and expenditure on fertilizer costs, the greatest profit was obtained from the higher levels of fertilization. This applied especially to N fertilizer.
THE INTRODUCTION OF PANGOLA GRASS INTO THE CARIBBEAN ISLANDS*
Authors: Osbourn D. F.
Published: April 2006

The origin and introduction of Pangola grass Digitaria decumbens (Stent) into the Caribbean islands is described. The rapid spread of this species in cultivation throughout the regions is ascribed to four characteristics which coincided so closely with the economic and technical needs of the region as to override the inherent disadvantages of this grass. Its outstanding characteristics are ease of establishment, vigour, adaptability, palatability and resistance to grazing. The agronomic and nutritional characteristics and the productive potential of Pangola grass are com‐pared with other forage species cultivated in the region and with a temperate grass species. These characteristics are discussed in the context of the introduction and evaluation of forage species and the intensification of output from forage crops.
BEEF PRODUCTION FROM PASTURE LEYS IN UGANDA*
Authors: Stobbs T. H.
Published: April 2006

The potential for producing beef in savanna grassland areas is discussed in relation to the results obtained from grazing trials on sown pastures at Serere Research Station, Uganda. Liveweight gains from small East African Zebu stock are used to illustrate the progress that has been made in the selection of improved pasture species and mixtures grown at various levels of fertilizer application. The utilization of herbage from selected pastures is shown to vary under different grazing management systems, grazing pressure having the greatest effect upon animal production. The need for further investigations and the integration of existing research findings into farming practice is stressed.
A COMPARISON OF SILAGE MADE IN POLYETHYLENE CONTAINERS WITH AND WITHOUT THE REMOVAL OF AIR BY EVACUATION
Authors: Wilson R. F. , Terry R. A. , Osbourn D. F.
Published: April 2006

The effect of partial evacuation of air from polyethylene containers, at the time of sealing, on the chemical composition and nutritive value of silage was determined. Four containers of 500‐kg capacity were filled with herbage harvested from each of four swards, namely, S170 tall fescue, Syn I tall fescue, Tetila Tetrone Italian ryegrass and an S24 perennial ryegrass/S100 white‐clover mixture. All the containers were sealed immediately after filling and half of them were evacuated. The silages resulting from these treatments were offered ad lib. to store sheep and the intake and digestibility of the dry matter determined. The evacuation of the silos had no significant effect upon the chemical composition of the silage produced. The intake and digestibility of the dry matter in the silages were not significantly influenced by evacuation.
THE YIELD, CANOPY STRUCTURE AND LIGHT INTERCEPTION OF TWO RYEGRASS VARIETIES IN MIXED CULTURE AND MONOCULTURE
Authors: Rhodes I.
Published: April 2006

Two experiments were carried out to measure the yield, canopy structure and light interception of S23 and Ba 6280 perennial ryegrass in monoculture and mixed culture. The mixed culture outyielded both monocultures only under frequent cutting and a high fertilizer regime. Measurements of canopy structure and light profiles within the canopies under these latter treatments indicated that the greater residual leaf area after defoliation in S23 and in the mixture may have resulted in their superior production compared with Ba 6280. The fact that a greater percentage of the intercepted light energy was distributed over the most photosynthetically efficient tissue may explain the higher production of the mixture when compared with S23 in monoculture.
A HISTORY OF THE INTRODUCTION OF TIMOTHY AND COCKSFOOT INTO ALTERNATE HUSBANDRY IN BRITAIN
Authors: Beddows A. R.
Published: April 2006

The seed of cocksfoot (Dactylis glomerata) was first sown as such in England by Bartholomew Rocque. It initially received little publicity, and did not induce the same spate of writing as timothy (Phlewn pratense). The first seed appears to have come from America simultaneously with timothy, although cocksfoot was not at the time a species of much significance there. Yet in England it attained a more secure place, probably because its cultural requirements were less demanding than those of timothy. Its agronomic characteristics were however a frequent subject of discussion and controversy. Before the end of the nineteenth century seed was being imported from Denmark, America and New Zealand. During the second quarter of the twentieth century breeders began exploiting the great variation in plant type and performance to be found among indigenous populations. This work and that of breeders abroad made many cultivars, with different agronomic characteristics, available to farmers. As a result, by means of leys and ‘self’ stands, it is possible to produce fresh herbage over a much extended growing season.
THE CARRYING CAPACITY OF PASTURES
Authors: Cowlishaw S. J.
Published: April 2006

The data from all published results of grazing trials in which three or more rates of stocking were compared for one or more years were examined. Where possible regression equations and correlation coefficients were calculated. In many cases, a significant negative correlation was found between stocking rate per acre and live‐weight gain per animal per day. In no case was the relationship positive, and no point of discontinuity was found in the linear relationship. The slope of the line appeared to be related to the length of the grazing season; the longer the season, the steeper the slope. The application of these results in practice is discussed in agronomic and economic terms.
PATTERNS OF SPRING GROWTH IN SWARDS OF DIFFERENT GRASS VARIETIES
Authors: Davies Alison , Calder D. M.
Published: April 2006

Production of dry matter by swards of ryegrass and cocksfoot varieties in winter and spring is dependent on a number of growth processes, each with different environmental requirements. Growth in the strict sense with the production of new leaves has been found to continue throughout the winter in Aberystwyth, although the rate of production fell very low during periods when the mean air temperature approached freezing, especially in cocksfoot varieties.

Because of the ceiling set by the natural balance between leaf death and leaf formation, net increases in weight of above–ground parts in undefoliated plants may not occur for extended periods during winter. When, however, tiller numbers start to increase, or the ceiling is raised by an increase in size of tillers, dry–weight increases can come about. The extension of leaves and intern odes in spring, measured in terms of sward height, seems to be largely governed by flower initiation. A certain degree of extension was found to be present before this in an Algerian type.

Practical distinctions between early and late types, which are based on flowering dates or sward height, or on parameters influenced by these characters, are not associated with similar differences in production of above–ground parts. These distinctions do not, therefore, permit a completely full and accurate picture to be obtained of winter– and spring–growth potentials in different varieties.
SOURCES OF VARIATION IN THE IN VITRO DIGESTIBILITY OF TROPICAL GRASSES
Authors: McLeod M. N. , Minson D. J.
Published: April 2006

The in vitro DM digestibility of four tropical pasture species, Cenchrus ciliaris, Chloris gayana, Digitaria spp., Setaria spp. and one temperate grass, Lolium perenne, were studied, using the method described by Tilley and Terry (13).

In vitro digestibility was affected by fineness of grinding, sample size, pH of original rumen fluid and size of rumen fluid inoculum. Different relations were found between the in vivo and in vitro results for the five species, with a maximum predicted difference of 3–5 digestibility units.

It was considered that the in vivo digestibility of tropical grasses could be accurately predicted by this method, provided that the procedure was standardized and samples of known in vivo digestibility similar to those being tested are included in each run.
THE USE OF LIVEWEIGHT–GAIN TRIALS FOR PASTURE EVALUATION IN THE TROPICS
Authors: Stobbs T. H.
Published: April 2006

A grazing experiment is described in which the liveweight gains of small East African Zebu heifers were measured from Hyparrhenia rufa/Stylosanthes gracilis and H. rufa/Centrosema pubescens swards. The design of this trial enabled animal production to be assessed from variations in liveweight gain since stocking rate was maintained at the same level on both pastures, but the overall stocking rate was varied according to seasonal changes in herbage availability.

Production was measured both by using individual animals within a group as independent units, and by true animal replication. Gains from individual animal blocks were shown to be of value for comparing pasture species, provided that the composition of the grazing group was varied. Problems of conducting and interpreting small–scale grazing trials as means for evaluating pastures are discussed.
THE DIGESTIBILITY AND PRODUCTIVITY OF SELECTED HERBAGE VARIETIES
Authors: Harkess R. D. , Alexander R. H.
Published: April 2006

Much of the published digestibility data refer to swards grown in the south of Britain. In order to study digestibility curves in a more northerly latitude, several pure swards were established in the west of Scotland in 1962 and 1963. Varieties included S22 and Tetila Italian ryegrass, S37 cocksfoot, S170 tall fescue, S215 meadow fescue, Scots timothy, English broad red clover, and SI00 white clover. In addition to primary growth in vitro digestibility, the effect of various cutting managements on digestibility and productivity was measured. Flowerhead emergence was delayed, with the result that the digestibility curve was later than is reported from southern Britain. Highest yields of digestible organic matter were obtained from the less frequent cutting regimes, but the mean digestibility of the herbage was lower. Pre‐dictibility of herbage digestibility is desirable as the basis of a reliable and planned herbage utilization programme, particularly for conservation.
INTAKE AND LIVEWEIGHT GAIN OF BEEF CATTLE FED ON MAIZE SILAGE AND DRIED PELLETED WHOLE‐CROP BEANS (VICIA FABA L.)
Authors: Lonsdale C. R. , Tayler J. C.
Published: April 2006

Three groups of eight 9‐month‐old steers were fed ad lib. on maize silage alone and with 29 or 57% of the total DM intake as dried and pelleted whole‐crop field beans (Vicia faba L.). The total daily DM intakes were 3.7,5.0 and 5.8 kg/head, respectively. The corresponding daily liveweight gains were 0.44, 0.74 and 0.97 kg/ head and the respective values for efficiency of food conversion were 12, 15 and 17 kg liveweight gain per 100 kg DM intake. It is suggested that high‐protein artificially‐dried forages make a very suitable supplement to a low‐protein whole‐crop cereal silage.
THE USE OF SHEEP FITTED WITH OBSOPHAGEAL FISTULAE IN GRAZING STUDIES
Authors: Hodgson J.
Published: April 2006

Studies were carried out on the effects of diurnal variation, fasting before sampling, and acclimatization to a sward on the chemical composition and in vitro OM digestibility of samples of extrusa collected from sheep fitted with oesophageal fistulae. The N content of extrusa samples increased markedly during the morning, and tended to decline again in the evening. The diurnal changes in digestibility were similar, but the variation was much smaller. There was no significant correlation between either N content or OM digestibility and grazing speed measured in bites per minute. There were no significant changes in either the N content or OM digestibility of successive samples of extrusa collected after over‐night fasting, or after the sheep were introduced to a sward to which they were not accustomed, though the concentration of ash in the extrusa was significantly lower when the sheep were hungry than when they were not. The OM digestibility of the diet selected was approximately two units lower on the first two days after introduction to a new sward than the mean value of samples collected over the next 12 days.
A COMPARISON OF THE EFFECT OF ITALIAN RYEGRASS AND TALL FESCUE MIXTURES ON THE FOLLOWING CROPS OF KALE AND BARLEY
Authors: Charles A. H.
Published: April 2006

The effects of preeropping with Italian ryegrass and tall fescue mixtures on marrow‐stem kale (1st test crop) and barley (2nd test crop) were measured.

Application of N to the grass/clover swards reduced the yield of DM, P, K, Na, Mg, crude protein and also the percentage crude protein in the kale test‐crop.

Following the tall fescue swards, the yield of DM, P, Na, Ca, Mg and E, crude protein and percentage crude protein in the kale were lower than after the Italian ryegrass swards. These effects were particularly evident in the kale stem.

Interactions occurred which involved the method used to establish the herbage mixtures, the application of N to the swards and of fertilizers to the kale. These effects were complex, but the method of sward establishment could clearly affect the following kale crop grown several years later.

The influence of grass swards on the second test‐crop (spring barley) was much smaller than on kale. Precropping with Italian ryegrass or using a cover crop during grassland establishment reduced 1000‐grain weight of barley. The crude protein percentage in barley grain was reduced by the compound fertilizer applied to the previous kale crop, particularly when no cover crop had been used during establishment of the herbage mixtures. The converse of these effects was recorded in the crude‐protein percentage of the straw of the barley test‐crop.
THE FEEDING VALUE OF SILAGES MADE FROM WHOLE‐CROP BARLEY
Authors: WILKINS R. J. , OSBOURN D. F. , TAYLER J. C.
Published: April 2006

Whole crops of barley were conserved and fed to sheep and cattle. In the first experiment the barley was cut at the mealy‐ripe stage of growth and conserved by ensilage or by drying artificially. Cattle and sheep lost weight when the resulting silages were fed ad lib.; wilting the crop before ensiling did not improve the performance. Sheep fed artificially‐dried whole‐crop barley increased in liveweight; and the intake of this was significantly higher than that of the silages.

In the second experiment, barley was cut and ensiled at the watery‐ripe, mealy‐ripe and late mealy‐ripe stages of growth. Intakes and levels of performance by sheep fed these silages did not differ with the growth stage at which the crop was harvested, but supplementation of the silages with lucerne pellets resulted in large improvements in performance.
COMPARATIVE STUDIES OF PERENNIAL RYEGRASS, TIMOTHY AND MEADOW FESCUE
Authors: Alder F. E.
Published: April 2006

The growth of calves grazing pure swards of perennial ryegrass, timothy and meadow fescue at low grazing pressure was measured. Organic‐matter intake was estimated on three occasions during the grazing season. In 1963 rest periods of 7 days in April and May and of 21 days in June‐Octoher were used hetween 7‐day grazing periods. In 1964 the effect of long (35–55 days) and short (15–25 days) rest periods hetween 3.5‐day grazing periods were compared. There were no measurable differences in intake hetween the calves on the three grass species in 1963. In 1964 faecal production was higher with timothy than with the other species and with small differences in digestihility, the intake on this species was higher. The faecal production and intake were higher, hut not significantly so, with the long‐rest management in the second year. The liveweight gains of the calves grazing the three species were similar in 1963; in 1964 gains with meadow fescue were lower than with the other species from 13 April to 22 June but this was the only significant difference. The results obtained on slaughtering the calves at the end of each summer are presented.
THE USE OF LIVEWEIGHT‐GAIN TRIALS FOR PASTURE EVALUATION IN THE TROPICS
Authors: Stobbs T. H.
Published: April 2006

The problems of designing, conducting and interpreting the results of grazing trials to evaluate tropical pasture mixtures are discussed in relation to an experiment wbich measured the effect of three fixed stocking rates upon two grass/legume pastures. A uniformity trial prior to grazing indicated considerable soil variability, which necessitated ground replication. Sequential grazing of three pasture replicates at a fixed stocking rate and a fixed interval of grazing resulted in sites of low fertility being heavily penalized. Such a form of replication was of value for measuring the effect of treatments upon sward composition, and, to a lesser extent, variation in animal production, within the experiment area. Differences in animal production between pasture species were small when compared with the effect of various stocking rates, emphasizing the need for an objective assessment of stocking rate when evaluating pasture species. Fixed‐stocking‐rate designs have more general application in the tropics because they are easier to conduct, and the results are repeatable and can be extrapolated to farm practice.
SOME EFFECTS OF MECHANICAL TREATMENTS AND SURFACE SOWING ON ROUGH HILL GRAZINGS
Authors: Warboys I. B.
Published: April 2006

An experiment involving two adjacent, but contrasting, sites was conducted to examine the effect of using the rotary cultivator and the forage harvester as instruments in the improvement of indigenous hill swards at 1600 ft alt. by surfaee sowing. On a dry sward dominated by Nardus/ Festuca, both an autumn and a spring rotary cultivation were necessary to give the highest number of established seedlings. This also resulted in the greatest improvement in hotanieal composition. On a wetter Molinia‐dominant sward, two separate rotary cultivations did not increase seedling establishment, compared with a single rotary cultivation. On the dry site, an autumn and a spring topping with a forage harvester established fewer seedlings, but on the wetter site the difference as compared with rotary‐cultivation treatments was not significant. On this wetter site, topping by forage harvester gave an improved botanical composition by effecting a reduction in Festuca species to give a sward dominated by Agrostis and timothy.
GRAZING BEHAVIOUR AND WEIGHT CHANGES IN CALVES TURNED OUT TO PASTURE
Authors: Wilkinson J. M. , Cumberland P. H.
Published: April 2006

Two studies are described in which the behaviour of 24 seven‐month‐old Friesian steer calves was observed. The first study (G1) was undertaken at the time of turnout to pasture, and the second (G2) 5 days later. The calves appeared to adapt rapidly to the change in environment, though in study G1 grazing was frequently interrupted. In study G2 the calves showed normal behaviour patterns and spent a total of 4.25 hours grazing.

There was a positive correlation between age and weight at turnout and time spent grazing in study G1. However, this relationship was not apparent in G2, and there was no relationship between time spent grazing in G1 and G2.

Mean weight loss upon turnout was 7.44% of live weight, in spite of the feeding of hay and barley at grass. There was no relationship between weight at turnout and subsequent weight loss.

The results confirmed other experimental findings which suggest that weight loss at turnout is largely a reflection of changes in the weight of alimentary tract contents, rather than an inability to adapt to the change in environment.

The calves were grazed at two intensities (‘low’ and ‘standard’) during the grazing season. Growth rate in winter and weight at turnout were negatively correlated with growth rate in the first month of the grazing season. This relationship was more apparent in the ‘low’ intensity group which received a liberal daily herbage allowance at this stage of the season. Partial correlation analysis, in which pre‐grazing growth rate was held constant, indicated that weight and age had little independent influence on growth rate at grass, though there was a positive relationship between weight for age at turnout and gain during the grazing season.

The importance of a target weight at turnout is discussed in relation to the 18‐month beef production system. It is concluded that younger, lighter, cattle at turnout may not be at a disadvantage when adequate amounts of herbage are on offer early in the grazing season.
REGROWTH OF S24 RYEGRASS AND ITS RELATION TO YIELD MEASUREMENT OF GRAZED SWARDS
Authors: Wilson D. B. , Robson M. J.
Published: April 2006

The re growth of S24 ryegrass (Lolium perenne L.) plants was studied during 4 days, following defoliation to stuhble heights of 2, 4, 6, 8, 10 and 12 cm. The weight of regrowth produced by plants cut to 6‐cm stubhie heights and higher was equal to the weight increment of uncut plants above the same heights. During the 4 days the weight of the stubble segment between 0 and 2 cm decreased in plants cut to 2 or 4 cm, but was maintained or increased in plants cut to 6 cm or higher. Weights of the 2‐ to 4‐ to 6‐cm stubble segments were just maintained at the lower cutting heights, but were increased by the same amount as in uncut plants at the highest cutting height. The percentage of water‐soluble carbohydrates in all stubble segments decreased following defoliation, but the percentage of N did not change. Root weights were either maintained or increased, depending on the severity of cutting. In relation to grazing experiments, it is pointed out that where DM disappearance is taken as the difference hetween yield on a protected site and residue on a grazed site, too close cutting of the sample areas will give an overestimate of yield.
WHOLE–CROP WINTER BEANS (VICIA FABA L.) FOR CONSERVATION
Authors: Toynbee–Clarke Gillian
Published: April 2006

Two trials with eight cultivars of winter beans were harvested as whole‐crop in 1967/8 and 1968/9. The aim was to investigate the potential of heans nnder whole‐crop management, and to assess their value as a proteio‐rich supplementary feed. Average DM yields of 106 hkg/ha were obtained for the control, and from 91 to 122 hkg/ha for other coltivars. Significant differences were found between the cultivars. At the cutting dates the crude‐protein content was in the range 13 to 18%, and digestihility (D) 55 to 67%. DM varied hetween the two seasons and was within the range of 15 to 29 and 16 to 38%, respectively. The optimum time for harvesting beans for whole‐crop conservation is when all the pods contain fully developed seeds.
THE ELECTRONIC MEASUREMENT OF THE YIELD OF RAPE (Brassica napus)
Authors: Lovett J. V. , Bofinger V. J.
Published: April 2006

The application of an electronic pasture probe to the measurement of rape is described. Measurements taken over two years demonstrated that good relationships could be established between probe readings and parameters of crop yield. Crop height, spatial distribution of crop profile, crop density and percentage DM were found to he significant factors in obtaining meaningful results.
THE EFFECT OF SOWING DENSITY AND CUTTING ON COMPETITION BETWEEN TWO PASTURE SPECIES GROWING IN MODEL POPULATIONS
Authors: Scarisbrick D. H. , Ivins J. D.
Published: April 2006

Three pot experiments are described in which perennial ryegrass (S23) and Plantago lanceolata (ribgrass) were grown alone and in mixed stands at varying densities and cent at different frequencies. With frequent cutting the yield of ryegrass was reduced to a greater extent than that of rihgrass, but the mean plant weights of both species were independent of sowing density. The pattern of competition was not altered by a single cutting treatment, the balance being quickly restored by the rapid regrowth of the ryegrass.
SILAGE AND MILK PRODUCTION, A COMPARISON BETWEEN WILTED AND UNWILTED GRASS SILAGES MADE WITH AND WITHOUT FORMIC ACID
Authors: Castle M. E. , Watson J. N.
Published: April 2006

Three grass silages, all made in mid‐Jnne from the same herbage, were compared in a 12‐week winter‐feeding experiment with 12 Ayrshire cows. The silages were fed ad lib. with a supplement of moist barley and gronndnut cake. Silage A was made from unwilted berbage with no additive, silage B from identical berbage treated with 1/2 gal of formic acidJton (2.24 L/tonne) of berbage, and silage C from the herbage after wilting for 28 b. the DM contents of silages A, B and C were 20.5, 21.1 and 31.8%, respectively, and the contents of digestible organic matter in the DM were 58.9, 68.8 and 67.8%. Silage and total DM intake were bigbest on the treatment containing silage B. the mean dafly milk yields on the treatments with sflages A, B and C were 35.1, 38.0 and 34.3 Ib (15.9, 17.2 and 15.6 kg), respectively and the solids‐not‐fat (S.N.F.) contents of the milk averaged 8.53, 8.54 and 8.50%. It is concluded tbat silage B, the unwilted silage with formic‐acid additive, was superior to botb the untreated and the wilted silage as a feed for dairy cows.
ERRORS IN MEASURING NITROGEN AND DRY–MATTER CONTENT OF PLANT AND FAECES MATERIAL
Authors: Sharkey M. J.
Published: April 2006

The N content of pasture species (Trifolium repens L. and Lolium perenne L.) was much less affected hy drying temperatures over the range 70° to 100°C, and hy the density of packing of the pasture sample, than was the amount of hrown colour resulting from these treatments. The DM content of faeces was measured with equal accuracy at temperatures of 80° and 100°C and in samples which varied in weight over a four‐fold range. The N lost while drying faeces at 80°C was considerable, with large variations in the amount lost by different animal species fed on particular diets. The results confirm that analyses of the N content of faeces should be carried out before drying.
FERTILIZER N AND THE YIELD OF CUT GRASS SWARDS IN EASTERN ENGLAND
Authors: Brockman J. S. , Shaw P. G. , Wolton K. M.
Published: April 2006

Single spring dressings of N were compared with split applications over the first two growth periods of the year at ten sites in eastern England in the period 1964–67. None of the four spring periods was unusually dry and the single application of N in spring did not outyield a similar total N rate applied some before and some after the first cut. At nine out of ten sites split applications of N yielded considerably more in the second growth period than the single spring dressing. It is concluded that the split applications of N in the spring, already shown superior to single dressings under moist west country conditions, are correct for many seasons in the drier east of England.
THE PLANT COMPONENT AS A FACTOR IN AMMONIA VOLATILIZATION FROM PASTURE SWARDS
Authors: McGarity J. W. , Hoult E. H.
Published: April 2006

The volatilization of ammonia which followed the application of urea to a pasture sod was determined over a period of 14 days. Significant ammonia losses were measured after foliar application of urea to sods in which the soil component had been previously isolated from the plant components by sealing the sods with an impermeable membrane. Losses of ammonia by volatilization over the experimental period were less from plant surfaces than from unsealed sods in which the soil contributed to losses. It is concluded that in addition to soil ureolytic activity, the plant and litter components of pastures may provide major pathways of loss in the N economy of grasslands.
EFFECTS OF WHITE CLOVER ON THE BOTANICAL COMPOSITION OF SWARDS OF RYEGRASS, TIMOTHY AND MEADOW FESCUE AND MIXTURES OF THESE THREE
Authors: Chestnutt D. B. M.
Published: April 2006

Results are presented to show the effect of white clover (Trifolium repens) and of applied N on the hotanical composition of swards sown with perennial ryegrass (Lolium perernne), timothy (Phleum pratense), meadow fescue (Festuca pratensis) and mixtures of two and three of these species. White clover had a more favourahle effect on the growth of perennial ryegrass than on either timothy or meadow fescue both in terms of yield and in terms of tiller numbers. Tiller numbers of rough‐stalked meadow grass (Poa trivialis) were increased and tiller numbers of Agrostis species were reduced by application of N and by inclusion of clover. Possible reasons for these effects are considered.
PRODUCTIVITY OF ITALIAN AND PERENNIAL RYEGRASS MIXTURES
Authors: Hunt I. V.
Published: April 2006

Italian ryegrass cv. Leda and perennial ryegrass cv. Presto were sown alone and in five mixtures containing different proportions of viable seed and compared with hybrid ryegrass cv. Manawa and Italian ryegrass cv. S22. Yields and herbage composition were measured five times in 1962 and 1963, with particular reference to the contribution from perennial ryegrass in the first year and the effects of Italian ryegrass on second‐year production.

Italian ryegrass dominated first‐year production wbile perennial ryegrass dominated second‐year production. Manawa was the top yielder in the first year, but both Manawa and S22 bebaved as Italian ryegrasses and were badly frosted and weedy in the second year. The mixtures were generally intermediate in yield between the components and tended towards the yield of the more vigorous component. Since the more vigorous component changed from cut to cut or from season to season, the sums of harvests sbowed some advantage for certain mixtures. Certain pairs of herbage varieties can be sown togetber witb yield advantage. Furtber physiological investigations are warranted and the breeder has a part to play in a search for complementary varieties.
THE MEASUREMENT OF PRIMARY PRODUCTION AND UTILIZATION ON HEATHER MOORS
Authors: Grant SheilaA.
Published: April 2006

The 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.