bluuebunny/crossref_metadata_2025 huggingface dataset:
Digestibility and chemical composition of fractions of lucerne during spring and summer
Authors: Christian K. R. , Jones D. B. , Freer M.
Published: March 2009

Bulk harvests of primary growth were made at intervals during the spring and summer of 2 consecutive years from an ungrazed area of lucerne (Medicago sativa) and the digestibility by sheep was measured. At the same times, shoots of known length representative of the sward were collected, divided into 7·5 cm lengths, and separated into leaf and stem for the determination of ash, nitrogen, cellulose, and in vitro organic matter digestibility.

Digestibility and leaf: stem ratio of the bulk harvests decreased and dry matter increased as the season advanced. Leaf composition changed little, but stem increased in lignin and decreased in ash and in vitro digestibility. In vitro digestibility and leaf: stem ratio were highly correlated with sheep digestibility.

Chemical composition of shoots of known heights was similar to that of the bulk harvests. Leaf weights/shoot tended to increase linearly with height of shoot, whereas stem increased nearly as the square of the height. Dry matter of leaf and stem were inversely related to leaf:stem ratio. Stem digestibility decreased with leaf:stem ratio and with increase in shoot height.

Chemical components of shoot fractions were associated with each other and were largely dependent on the distance from the top of the shoot at which they had been taken, irrespective of shoot height or time of year. Bottom stems had lower ash, nitrogen and digestibility but higher cellulose, dry weight and dry matter than top stems, whose composition approached that of leaves. Leaf fractions showed little consistent trend with position on the shoot.

Some of the difficulties in studying changes in plant composition under field conditions are discussed.
A note on resolving soil cation exchange capacity into ‘mineral’ and ‘organic’ fractions
Authors: Addiscott T. M.
Published: March 2009

Two methods have been used previously to resolve the ‘mineral’ and ‘organic’ fractions of the cation exchange capacities of soils. Williams (1932) and Hallsworth & Wilkinson (1958) used multiple regression analysis to relate cation exchange capacity (CEC) in several soils to percentage organic matter (OM) and percentage clay, and thence to calculate the average values of the CECs of OM and clay. For individual soils, Davies & Davies (1965) and Clark & Nichol (1968) measured the CEC before and after oxidizing the OM with hydrogen peroxide.
Corolla Tube Length and Nectar Height of Fl Red Clover Plants (Trifolium pratense) and Their Seed Yield Following Honey-Bee Pollination
Authors: Bond D. A. , Fyfe J. L.
Published: March 2009

Crosses between nine inbred lines of diploid doublecut red clover were measured for corolla tube length and nectar height, caged with honey-bees, and observations made on the number of bee visits and seed yield. There was evidence of additive genetic variation in nectar height, corolla tube length, bee visits and seed yield. The possibilities for improvement in these characters by selection are discussed. Attention is drawn to a remarkable discriminating behaviour of honey-bees, in that they could apparently recognize plants which had only one parent in common. A cage with a strong colony of honey-bees produced more than twice as much seed as a cage with a weak colony, and plants near to hives gave significantly more seed than plants distant from hives. Plants of English origin tended to have higher and more accessible nectar, more bee visits and greater seed yield than plants of continental origin.
The availability of phosphate in sheep dung
Authors: Gunary D.
Published: March 2009

The amount of labile phosphate released in two soils from incorporated sheep dung (of two phosphate levels) was determined in a pot experiment. The inorganic phosphate in dung was initially highly available but it diminished in value after a period of contact with soil. The organic fraction of the phosphate had only small availability. A further pot experiment where dung was applied to the surface of the two soils indicated that, although dung phosphate may be readily available, its value for grass depends on the extent of dung/root contact.
The effect of the size of soil aggregates on nutrient supply
Authors: Cornforth I. S.
Published: March 2009

Soil aggregates of different sizes, separated by sieving, and artificial aggregates stabilized by a chemical conditioner were used to study the effect of particle size on the uptake of nitrogen and phosphorus by plants growing in pots. Phosphate uptake was consistently less from the coarser than from the finer fractions of soil. The uptake of nitrate was also greater from smaller than from larger aggregates, despite its mobility in soil moisture.
Liquid manure as a grassland fertilizer:IV. The effect of liquid manure on the mineral content of grass and clover
Authors: Drysdale A. D. , Strachan N. H.
Published: March 2009

1. The potassium, sodium, calcium, magnesium and phosphorus contents of the grass and clover fractions of a perennial rye-grass and white clover sward were determined at each of five cuts taken between May and October in 1962 and 1963.
High potassium type red cells in cattle
Authors: Ellory J. C. , Tucker Elizabeth M.
Published: March 2009

The distribution of red cell potassium concentrations in ninety–one Jersey cows was examined, and shown to be consistent with two populations, a high (HK) and low (LK) type. In tracer potassium uptake experiments the HK type cells were shown to have a higher active K+uptake, and lower passive K+leak than LK type cells. Tests with the sheep anti–L antibody showed that the L–antigen system, which controls active potassium transport in sheep red cells does not appear to act in cattle red cells.
Results of an experiment at Woburn testing farmyard manure and N, P and K fertilizers on five arable crops and a long ley:I. Yields
Authors: Widdowson F. V. , Penny A.
Published: March 2009

1. In 1960 a 'reference plot' experiment was begun on Stackyard field at Woburn, where arable crops had grown for many years. The soil contained very little N or HCl-soluble K and little HC1-soluble P; it was acid, but was limed before and during the experiment to a pH at or near 7.0. Very small plots (0-00145 acre) were used.
The seasonal growth of pasture grasses
Authors: Anslow R. C. , Green J. O.
Published: March 2009

1. Twenty-one varieties of pasture grasses, including ten bred varieties, were grown on fertile soil for 3 years. Figures are presented of the rate of production of herbage cut every 3or4 weeks. Plots were cut in staggered sequence to permit growth intervals to overlap and to allow frequent assessments of the rate of production.
The reclamation of land covered with pulverized fuel ash. The influence of soil depth on crop performance
Authors: Hodgson D. R. , Holliday R. , Cope F.
Published: March 2009

1. A review of land restoration problems in relation to the soil depth required for successful crops showed that factual information on this orthodox method of restoration was inadequate.

2. A field trial sited on pulverized fuel ash is described in which the relationship between crop yield and soil depth at a range of fertilizer levels was determined; kale, oats, rape, barley and potatoes were the test crops.

3. The crops were divided into two groups, sensitive (kale and barley) and tolerant (oats, rape, potatoes) to ash toxicity, on the basis of their response to soil depth at the high fertilizer level. Quadratic expressions relating yield to soil depth, over the range 3–36 in. at each fertilizer level were fitted to the data for each crop group.

4. Yield isoquants, derived from the fertilizer response curves at each soil depth, enabled soil depth-fertilizer level combinations to be ascertained for producing a given level of crop yield. Fertilizer could be substituted for soil more effectively for tolerant than sensitive crops.

5. A 12 in. cover of soil together with 1½ times the normal farm fertilizer dressing for the crop was the minimum for acceptable yields. Fertilizer use may have to be increased to twice normal dressings to maintain yields if soil depths are reduced to below 12 in.

6. Crop yields were not increased by a soil covering greater than 24 in. deep.
A study of food intake and production in grazing ewes II. The interrelationships between food intake and productive output
Authors: Owen J. B. , Ingleton Jean W.
Published: March 2009

1. Observations were made during the autumn and spring of 1959–60, 1960–61, and 1961–62 on pregnant and lactating Clun ewes of mixed ages grazing under natural conditions. The pattern of food intake during pregnancy and lactation, the output achieved in the form of weight of lambs produced at parturition, milk yield, and bodyweight change of the ewes themselves was investigated. The interrelationships between these factors, as influenced by the feeding of supplementary concentrate, either for 7 weeks before or 7 weeks after lambing, or during both periods, was elucidated.

2. Daily dry-matter intake was found to be of the order of 1·5–2·0 kg. for this type of ewe, but there was considerable individual variation (coefficient of variation about 20%). Intake did not increase concurrently with the demands of the foetus during the later stages of pregnancy, and even became depressed as parturition approached. Immediately after lambing there was a spectacular increase in intake, which, after rising to a peak, was maintained at a high level during the lactation. Ewes receiving supplementary concentrates showed an increase in food intake over those unsupplemented, but this increase was less than the amount of dry matter fed in the supplement, even on rather bare pasture.

3. During the early stages of pregnancy there was no apparent difference in the weight gains of singleand twin-bearing ewes, but during the last 8 weeks prior to lambing twin-bearing ewes made greater weight gains. In relation to weights taken just after parturition ewes producing twins had lost most weight. Unsupplemented ewes lost more weight than those receiving supplements. Lack of supplementation prior to lambing only limited production in the case of twin-bearing ewes.
131I concentrations in blood, milk, urine and faeces of dairy cows following a single dose of radio-iodine
Authors: Lengemann F. W.
Published: March 2009

1. The concentrations of 131I in milk, urine, and faeces were compared to the total and non-proteinbound radio-iodine of blood after a single dose of radio-iodine to cows that were being maintained on diets providing about 3·5 or 12-16 mg. of stable iodine per day.

2. In general, the 131I concentrations in milk and urine tended to parallel the non-protein-bound 131I of blood. Faecal 131I levels of the low-iodine cows tended to parallel that of the whole blood, whereas it followed the non-bound radio-iodine of blood for cows on the higher stable iodine diet.

3. Compartmental analysis of the concentration curves showed a component with a T½ of from 10 to 22 hr. being common to both groups of cows. The second component of the curves constructed for the cows on the higher iodine intake had a T½ of from 41 to 58 hr. The second component for the low-iodine cows had a T½ that ranged from 83 to 169 hr. for the urine, faeces and non-bound radio-iodine of blood and 1200 and 1580 hr., respectively, for the faecal and whole-blood curves.

4. A greater proportion of bound radio-iodine was observed in the milk and blood of cows on the low-iodine diet than for the cows on the higher iodine intake. The proportion of bound 131I in blood increased with time, but the bound 131I of milk was relatively constant.
The uptake of magnesium under exhaustive cropping
Authors: Salmon B. C. , Arnold P. W.
Published: March 2009

1. A range of soils were cropped exhaustively by perennial rye-grass for up to eleven months in the glasshouse; some were also cropped with Dutch white clover.

2. At least 100 lb./acre of magnesium was taken up from most soils, and some soils supplied more than 200 lb./acre. The amounts of magnesium taken up decreased with successive harvests, suggesting that the available magnesium was progressively depleted. Although the ‘exhaustion’ magnesium (Mg taken up by crops+residual exchangeable magnesium) was greater than the initial exchangeable magnesium, these two measurements were closely correlated (r = 0·99). If non-exchangeable magnesium was released during cropping, the releases were proportional to the initial exchangeable magnesium contents. However, the exchangeable magnesium measurements may have extracted only a proportion of the magnesium available naturally.

3. Any releases of magnesium were small compared with the amounts available from the outset, and the crops obtained magnesium mainly from the exchangeable form. Rye-grass and white clover gave similar results.

4. The exchangeable magnesium in some exhausted soils was increased by wetting and drying. This effect may occur in the field, where the magnesium lost in cropping could be replenished by only small releases of non-exchangeable magnesium.
Resistance toSclerotinia trifoliorumin red clover collected from North Africa
Authors: Bond D. A. , Toynbee-Clarke Gillian
Published: March 2009

Introductions of red clover indigenous to the Atlas mountains of North Africa were shown to have a high degree of resistance toSclerotinia trifoliorumwhen a natural attack occurred in field trials at Cambridge. Differences between the two classes of clover varieties: (1) North African populations, and (2) the British varieties Essex broad red and S. 123, were highly significant for the proportion of row affected, the number of affected areas and the average length of affected area. The North African material is expected to be a useful source of resistance toSclerotinia trifoliorum, in breeding programmes.

We are indebted to Mr H. H. Rogers for his guidance and for collecting the red clover plants during the 1962 North African expedition which was supported by the Agricultural Research Council. We also acknowledge valuable criticism of the manuscript and provision of a computer programme by Mr J. L. Fyfe and help with field records by Mr M. Pope and Mrs H. E. Pape.
Some aspects of competition for light in potatoes and sugar beet
Authors: Bremner P. M. , Saeed E. A. K. El , Scott R. K.
Published: March 2009

1. In experiments on potatoes and sugar beet, interplant competition for light was varied by altering the spacing distance between plants grown in containers, while competition for water and nutrients was eliminated.

2. In both experiments the relative growth rate was 10 % less in closely spaced plants because net assimilation rate was greatly decreased; leaf area ratio was increased. Increasing competition for light decreased mineral nutrient uptake.

3. It was considered that differences between the treatments in the intensity of competition for light was greater in these experiments than it normally in the field because differences in leaf area index were greater. The leaf area of widely spaced plants was smaller in these experiments than in the field; this was thought to be due to a more limited supply mineral nutrients in the former.

4. In both species, the greatest crop growth rates were observed at leaf-area indices well below the maxima attained. The likelihood that observed crop growth rates were near maximal under the prevailing environmental conditions is discussed.
Studies on the sowing dates of cotton in the Sudan Gezira: I. The influence of date of sowing on plant growth and development
Authors: Jackson J. E.
Published: March 2009

Growth analysis of cotton crops sown in the Sudan Gezira at monthly intervals between August and May revealed a marked seasonal pattern of growth. Irrespective of plant age and fruiting state growth of non-senescent plants was slowest during the cool winter months. Relative growth rates of young plants were highest in August, September and early October due to the high specific leaf areas and fairly high net assimilation rates found then. They were lowest when minimum temperatures were lowest. Net assimilation rates were also lowest in the coolest months, probably as a result of restricted growth. High temperatures in the spring reduced fruiting. It is concluded that low minimum temperatures and high evaporation rates are both associated with slow growth, and play a large part in determining the characteristic decline of growth rates of cotton sown at the usual date in August.

I wish to thank the Chief of the Research Division, Ministry of Agriculture, Sudan, for permission to publish this paper and to record my gratitude to the team of field and laboratory assistants, especially Salih Saad and Hassan Osman, who helped in the work.
Studies on the sowing date of cotton in the Sudan Gezira: II. The relationship between sowing date of cotton and the incidence of insect pests
Authors: Schultz L. Razoux , Jackson J. E. , Faulkner R. C.
Published: March 2009

In factorial experiments covering a range of sowing dates and insecticide treatments the numbers of fleabeetle, jassid and whitefly on cotton in the Sudan Gezira were shown to be strongly influenced by the date of sowing and the age of the crop.

Attack by fleabeetle was most severe on cotton seedlings from July and early August sowings. Few fleabeetle were found on either more mature plants from these sowing dates or on seedlings from later sown cotton.

Whitefly numbers were highest on late July and early August sown cotton. Peak numbers were attained attained in late September and October and then fell to very low levels in November irrespective of date of sowing.

Jassid numbers were related both to plant age and to time of year, more being found on cotton sown, in July and early August early in the season and on later sown cotton later in the season. The highest numbers were found in November and December at which time populations were higher on cotton sown in mid-August or later than on earlier sown cotton.
A comparison of the effects of white clover (Trifolium repens) and of perennial ryegrass (Lolium perenne) on fat composition and flavour of lamb
Authors: Cramer D. A. , Barton R. A. , Shorland F. B. , Czochanska Z.
Published: March 2009

1. The carcass composition, the composition and characteristics of the subcutaneous and longissimus dorsi muscle fats, the volatile fatty acids of the rumen-reticulum fluid and the degree of flavour and odour of the cooked 12th rib chops of two groups each of fifteen Southdown–Romney cross ewe and wether lambs fed respectively white clover and perennial ryegrass have been determined. The lambs had been on treatment for 5 months and were slaughtered when about 9 months of age.

2. The white clover-fed lambs had a mean live weight at slaughter of 94 lb ± 9 lb compared with 67 lb ± 7 lb for the perennial ryegrass-fed lambs. The carcasses of the white clover-fed lambs had greater (P < 0·01) amounts of fat.

3. The iodine values of the subcutaneous fats of the white clover-fed lambs were highly significantly greater than those of the ryegrass-fed lambs and this result was consistent with the greater deposition of endogenous fat.

4. The extra fatness of the white clover-fed lambs was consistent with their greater production of rumen-reticulum volatile fatty acids.

5. The maj or differences in fatty acid composition of subcutaneous and intramuscular fats between pasture treatments were the highly significant increases in shorter-chain saturated and C15 branched-chain acids of the ryegrass-fed lambs. In addition, the subcutaneous fat of the ryegrass group contained highly significantly more octadecadienoic and octadecatrienoic acids while the 1. dorsi fat of the ryegrass group was highly significantly richer in stearic and oleic acids.
The wool growth response to the annual cycle of grazing intake in Cheviot wethers
Authors: Doney J. M. , Eadie J.
Published: March 2009

Wool-growth rates were measured at monthly intervals on eight free-grazing Cheviot wethers. Nutrient intakes provided by the upland environment were measured at the same intervals during the 2½ years. Analysis of periodic regression disclosed that both intake and wool growth had similar seasonal cycles but were slightly out of phase. It was concluded that the similarity was largely due to the relationship of both characters with some independent seasonal variable. The seasonal cycle of efficiency of wool growth depends on the time relationship between its two components, but it was found that variation amongst sheep in wool production was greater in the summer months and this depended more on variation in overall efficiency than on variation in grazing intake.
Experiments on the nutrition of the dairy heifer: VI. The effect on milk production of the level of feeding during the last six months of pregnancy and the first eight weeks of lactation
Authors: Broster W. H. , Tuck Valarie J.
Published: March 2009

1. Forty-five Friesian first calf heifers were used in an experiment to study the effect on milk production of two levels of feeding in the last 6 months of pregnancy and two levels of feeding in the first 8 weeks of lactation.

2. In each of two years herbage was rationed daily at different rates to two groups of pregnant heifers from late April until they calved in the autumn. The mean daily rations were 3·5 lb herbage dry matter and 2·4 lb herbage dry matter per 100 lb live weight for the two groups. The mean daily amounts consumed were 2·1 and 1·8 lb herbage dry matter per 100 lb live weight respectively.

3. The rates of gross live-weight gain during the period April to August were 2·2 and 1·7 lb/day for the two groups respectively. Estimated as the net gain of the dam alone, the rates of live-weight increase during the experimental period were 0·89 and 0·49 lb/day respectively, amounting to a mean difference in live weight after calving of 57 lb between the groups.
Yields and tiller numbers of four perennial ryegrass varieties grown as monocultures and certain mixtures in micro plots
Authors: Thomson A. J.
Published: March 2009

Four perennial ryegrass varieties, S.24, S.321, S.23 and Vertas Hardgrazing, were grown in micro plots containing 30 plants each at a spacing of 5 cm apart. Monocultures and four of the possible six binary mixtures between the varieties were grown in a randomized block design with four replicates. The data recorded comprised dry-matter yields and tiller numbers, and the components of the mixtures were harvested separately. The data were based on both whole plots, to give total production of mixtures and monocultures, and half plots, to give the contribution of mixture components to total mixture production. Four harvests were obtained during 1968, and the data from these were analysed separately and summed to provide the annual total data.

Mixtures and monocultures did not differ significantly for annual total dry-matter yield or for dry-matter yield at the separate harvests. However, differences in drymatter
yields between monocultures and between mixtures were detected at some harvests. Within mixtures, significant differences between some of the respective components were found at certain harvests, but these were not obtained for the annual total data.

The stability of monocultures and mixtures was investigated by a regression technique
and considered in the context of the environments used. This technique revealed that there was a specific mixture effect whereby the mixture (S.24 + S.23) differed significantly from all other treatments.

Significant differences between monocultures for fertile and sterile tiller numbers were detected. Between mixtures there were differences for fertile tiller numbers, and within mixtures certain of the components differed for fertile, sterile and total tiller numbers.

The relationship between dry-matter yield and tiller numbers was investigated by regression analyses over all treatments and for monocultures and mixtures separately. Significant differences between the slopes of the regression lines and zero and between the slopes of the regression lines themselves were obtained.

Possible reasons for the differences recorded both between and within monocultures and mixtures are considered and related to the competitive relations existing in the trial.
Statistical research on the fate of dietary mineral elements in dry and lactating cows
Authors: Lomba F. , Paquay R. , Bienfet V. , Lousse A.
Published: March 2009

Statistical analyses were carried out on the data obtained under strictly controlled conditions in metabolism stalls with 41 different rations fed to 127 adult non-pregnant dry cows, and with 14 other different rations fed to 35 adult non-pregnant lactating cows that had calved 2–6 months earlier and whose daily milk production ranged from 11 to 20 kg.

The authors have calculated and studied the correlations between faecal and urinary sodium losses, sodium excretion in the milk, digestible sodium and sodium balance and the 75 other nutritive factors which were analysedfor each of the 55 above mentioned experimental diets.

The most important factor in the fate of sodium is the amount of dietary sodium. Sodium digestibility is neither total nor constant: faecal losses and digestible amounts are enhanced when sodium intake is increased and faecal losses are also positively correlated with dry matter and nitrogen intakes. An increase in digestible sodium benefits both urinary excretion and balance, the latter being reduced by an increase in dry matter and nitrogen intake.

Sodium balance is always negative when sodium content of the diet is lower than 0.1% in the dry cows and 0.2% in the lactating cows. In our experimental conditions, the sodium requirements for milk production do not influence sodium digestibility, but are met above all to the detriment of urinary losses.
Plant growth in controlled environments as an adjunct to field studies experimental application and results
Authors: Hughes A. P.
Published: March 2009

1. Field studies on Impatient parviflora DC. in shaded situations indicated the need for experimental investigation of the effects on growth of varying single factors of the aerial environment in otherwise constant conditions.

2. The use of cabinets which allow accurate control of the aerial environment for studies in physiology, morphogenesis, pathology and plant selection is discussed.

3. By comparison of the development and assimilatory ability of the leaves of I. parviflora, it is shown that plants may be grown in wholly artificial conditions which are substantially identical with those grown under comparable conditions out of doors.
Epidermal pigment distribution in buffaloes (Bos bubalis)
Authors: Chandra G. , Bharadwaj M. B.
Published: March 2009

A quantitative evaluation of the pigment in Murrah buffaloes of both sexes ranging in age from 1½ to 7 years revealed that dorsal areas had most pigment, while the lateral body areas and the extremities were intermediate and the ventral and axillary regions revealed the least pigment. Maximum concentration of melanin granules occurred in stratum cylindricum, which gradually declined towards stratum corneum which was fully non-pigmented in axilla, groin, inter-digital and inter-dewclaw areas.

Pigment granules blackened in silver preparations and were seen concentrated as protective ‘nuclear caps’ in the supranuclear zone of the cells of stratum germinativum. The infranuclear light-staining cytoplasm contained PAS reactive glycogen granules.
Liquid nitrogenous fertilizers
Authors: Jameson H. R.
Published: March 2009

The results show that liquid fertilizers generally gave lower yields of dry matter than conventional solid fertilizers in four experiments on grassland. In seven trials, on autumn wheat, spring wheat, sugar beet and kale, the efficiencies of the two forms of fertilizer were similar.

Liquid fertilizers containing ammonia must be injected into the soil and this needs special equipment, more complicated, particularly where anhydrous ammonia is to be used, than the distributors used for solid fertilizers. Running the injector over established grassland sometimes resulted in considerable damage to the sward. When used to top-dress winter wheat across the line of drilling some plants were killed.
Post-natal growth changes in the fibre cortex and medulla of the new zealand romney and N-type sheep
Authors: Tibbits Janet P.
Published: March 2009

The relationship between cortical area and fibre area has been examined in the N/N, N/ +, + / +, + /nr and nr/nr genotypes of the New Zealand Romney, using skin biopsies taken at birth, 1, 3 and 16 months of age. The presence of the nr gene was shown to reduce significantly the relative cortical area. Within the genotypes there was an increase in relative cortical area with increasing age and in two-tooth ewes of N/N and N/ + there was an increase in relative cortical area in winter compared to summer.

Fibre growth rates in length for primaries and for prenatal and post-natal secondaries were found for lambs between 1 and 3 months and for 16-monthold ewes. In N/N, N/+ and nr/nr primary fibre growth tended to be increased and post-natal secondary fibre growth tended to be decreased relative to + / + values.

In both cortical area and fibre growth rate the greatest genotypic effect was shown by the primary fibres.

Some estimates of cortical volume have been made by combining the information on cortical area and fibre growth rate and the relationship of these factors to follicle density and mean fibre area has been discussed. Finally, an indication has been given of how the associations of all these four factors might be usefully examined in some British breeds.
The cellulose-lignin complex in forages and its relationship to forage nutritive value
Authors: Allinson D. W. , Osbourn D. F.
Published: March 2009

The relationships between the cellulose-lignin complex, voluntary consumption and dry-matter digestibility were examined using forages of two varieties of Italian ryegrass and two legumes, lucerne and sainfoin. These forages had previously been shown to exhibit different intake-digestibility relationships. The cellulose, acid detergent lignin and acid detergent fibre contents of these forages as well as their digestibility coefficients were determined. Lignins were extracted from the fibre fractions and their ultraviolet difference spectra determined.

Changes in maturity of a forage during a single growth phase, produced changes in dry-matter digestibility which were closely associated with changes in the digestibility of the cellulose and inversely related to the lignin content of the forage. Differences in digestibility between varieties of forage were less closely associated with lignin content. As the grasses matured a lignin fraction forming a difference peak at 350 mμ became evident and this was associated with decreased cellulose digestibility.

Differences in voluntary food consumption resulting from changes in maturity of a single forage variety, in one growth phase, were also closely correlated with both dry matter and cellulose digestibility and inversely with lignin content. Differences between varieties and growth phases of the ryegrasses and between grasses and legumes were related less to the nature of the cellulose-lignin complex and more closely to the percentage of the total digesta deriving from cellulose.

Sainfoin was characterized by the formation post-ruminally of an artifact that analysed quantitatively as lignin and qualitatively resembled a non-conjugated phenolic lignin fraction. The production of this artifact apparently disturbed fibre digestibility estimates and may have affected dry-matter digestibility estimates. Degradation of lignin apparently occurred both in the rumen and in the hind gut.
A comparison of ley and arable farming systems
Authors: Lewis A. H. , Procter John , Hood A. E. M.
Published: March 2009

1. Alternate husbandry systems containing 1-, 2- and 3-year grazed leys were compared with continuous arable cropping at Jealott's Hill during the period 1945–56. Kale and wheat were used as successive test crops to measure the fertility accruing from the following crop sequences: (a) 3-year ley; (b) wheat, 2-year ley; (c) wheat, barley, 1-year ley; (d) wheat, barley, barley. A study was also made of the effect on crop yields of compost, dung and N fertilizer dressings applied to kale.

2. The yields of kale and wheat were improved considerably by 1-, 2- and 3-year leys. Increments were: 5·2 tons fresh kale per acre and 8·7 cwt. wheat grain per acre from 1-year ley, 9·0 tons kale and 13·5 cwt. wheat per acre from 2-year ley and 9·2 tons kale and 15·0 cwt. wheat per acre from 3-year ley. Two- and 3-year leys were markedly superior to 1-year ley in their effects on kale and wheat. The slight benefit apparent in wheat yields from 3-year ley compared with 2-year ley was not significant and so the 2- and 3-year leys may be considered equal in their effect on the succeeding arable crops. In the third arable crop, wheat, the 2-year ley was still effective to the extent of 3·9 cwt. grain per acre but the residual effect of the 1-year ley had largely disappeared. Yields under the all-arable system were considered to have been reduced by the poor physical and nutrient status of the soil, by increased incidence of ‘take-all’ in wheat and by more weed growth.

3. The response of kale to dung averaged only 1·1 tons per acre over all four rotations but this was largely obtained in the ley systems and little after all-arable cropping. Compost was generally ineffective on kale with some signs of detrimental effect, especially in the arable system. Wheat following kale benefited equally from dung and compost applied in the previous year; the average response to organics was 1·6 cwt. grain per acre and this was unaffected by rotation. The residual value of dung on subsequent crops amounted to an average of 2·0 cwt. grain per acre per annum but compost had no significant effect.

4. The response to an additional 0·4 cwt. fertilizer N per acre to kale was greatest after continuous arable cropping and virtually nil after 3-year ley. Wheat grain yields were improved by 1·0 cwt. per acre on average by the addition of the extra 0·4 cwt. fertilizer N per acre to kale in the previous year.

5. It was concluded that when mixed farming is practised the aim should be to have the land under grass for at least as long as it is under arable, e.g. 3 years of ley with 3 years of arable.
The effect of rising environmental temperatures (35°–95° F.) On thyroid 131I release rate of holstein, brown swiss and jersey heifers
Authors: Johnson H. D. , Ragsdale A. C.
Published: March 2009

1. There were many distinct, consistent, individual differences in the thyroid activity of several of the animals used in this study. Graphic indications of breed differences were present at several high temperatures, and statistical analyses supported differences between the Jerseys raised at each temperature and the other two corresponding breeds. The Jerseys displayed higher rates. In no instances were there thyroid 131I release rate differences between Holsteins and Brown Swiss.

2. There was a negative correlation between thyroid 131I release rate and temperature for each breed raised at each temperature. Correlations for the 50° F. animals were statistically significant below the 0·05 level of probability and for the 80° F. animals they were significant below the 0·01 level. As the environmental temperature increased from 35° to 80° F. there was a gradual decrease in thyroid 131I release rate. Above 80° F. there was a sharp decline in thyroid 131I activity.

3. Within the range of environmental temperatures from 35° to 70° F. the animals raised at 80° F. displayed thyroid release rates higher than those of the animals raised at 50° F. At 80° and 90° F. the 50° F. Jerseys exhibited higher activity. The Jersey differences approached statistical significance. At the lower temperatures graphic differences between the Brown Swiss and the Holsteins raised at the two temperatures appeared to be present, but they were not generally supported by statistical analysis.

4. At temperatures of 80° F. and above, when regulatory mechanisms could not control body temperature, both groups showed considerable rises in body temperature concomitant with decreases in thyroid 131I activity and TDN consumption. The 80° F. group showed a rise less sharp than that of the 50° F. group.
Fission products and the dairy cow 1. The fate of orally administered cerium-144
Authors: Garner R. J. , Jones H. G. , Ekman L.
Published: March 2009

1. The excretion of 144Ce in the faeces, urine and milk has been followed in two dairy cows receiving twice daily doses of 120 μc. with the feed over a 10-day experimental period. During the terminal 3 days, recoveries from the faeces amounted to 93–119% of the daily dose. From the urine and milk, respectively, 0·23 and 0·17% and 0010 and 0·016% of the total amount fed was recovered from the two animals.

2. The concentration of 144Ce in various parts of the gut was estimated after equilibrium conditions had been attained. The highest concentrations were found in the contents of the omasum and hind-gut.

3. The possible use of 144Ce as a marker in digestibility and similar trials is discussed.
The effect of urea on the utilization of ground, pelleted roughage by penned sheep: II. Utilization of organic matter, nitrogen and minerals
Authors: Coombe J. B. , Christian K. R.
Published: March 2009

Adult Merino wethers were fed for 16 weeks on diets of oat straw mixed with urea and pelleted (A); oat straw pellets, with access to a salt block (B); oat straw pellets, with access to a salt-urea block (C); Phalaris straw mixed with urea and pelleted (D); and Phalaris straw pellets (E). A commercial mineral supplement was given during the first 8 weeks, and a laboratory-prepared complete mineral supplement supplied during the second 8 weeks. During the fifth to eighth weeks (period I), and the thirteenth to sixteenth weeks (period II), digestibility and balance studies were conducted on sheep from each treatment.

Digestibilities of organic matter (O.M.) and cellulose were generally increased by the addition of urea, but only in one comparison, between diets A and B, was the difference significant. Urea did not significantly affect water intake in relation to food intake.

Urea increased nitrogen (N) intake, faecal and urinary N excretion, and N balance, these effects being more pronounced in period II. All sheep were in negative N status in period I; five of the 12 urea-fed sheep were in positive N status in period II. In diets B and C water intake and urine output were positively related to salt intake, but in no diet was there a significant relation between urinary N excretion and total output of urine.

Sulphur balances (excluding wool) were generally positive and did not improve significantly in period II despite higher sulphur intakes. However, a corresponding increase in the intake of phosphorus, from 0·5 g/day to about 2·0 g/day, brought nearly all sheep from negative to positive phosphorus balance. With the urea diets there was a significant, negative relation between urinary N excretion and phosphorus balance.

Intakes of sodium, potassium, calcium and magnesium appeared to be sufficient in both periods.

It seems likely that the improved response to urea which occurred during the experiment was due to the change in mineral supplementation rather than to adaptation to urea.
Growth and yield of three varieties of wheat, with particular reference to the influence of unproductive tillers
Authors: Bremner P. M.
Published: March 2009

An experiment was done to see if three varieties of wheat (Jufy I, Yeoman and Cappelle) of widely different tillering propensities differed in their response to early spring application of nitrogen; and, concurrently and conjointly, to assess the effects of unproductive tillers on the growth of productive shoots.

None of the varieties responded to the higher of two levels of nitrogen. The presence of a large number of unproductive tillers appeared to have only a transitory effect on the growth of productive shoots; the latter were able to grow rapidly after the death of tillers and caught up with productive shoots which had been subjected to much less inter-tiller competition.
Nutrition in relation to reproduction in sows
Authors: Hafez E. S. E.
Published: March 2009

Gilts of the ‘Palouse’ breed were divided into two groups; one group was full fed from weaning to 1501b. and the other group was fed 70% of full feeding. After six generations, one-half of the pigs in each group were shifted to the other plane of nutrition, thus forming four groups: high-high (HH), low-high (LH), low-low (LL) and high-low (HL). F10 gilts were slaughtered 38 or 100 days post-coitum to study reproductive and prenatal phenomena.

1. Ten successive generations of controlled feeding had no significant effect on: length of Fallopian tubes, weight of corpus luteum, percentage of implantation, number of viable foetuses, foetus weight, weight of placental membranes, volume of placental fluids or embryonic mortality.

2. There were significant differences between the high and low planes of nutrition in: weight of pituitary, thyroid and adrenals, weaning weight, puberty weight, puberty weight to birth weight, puberty weight to weaning weight and puberty age. The effect of six generations of controlled feeding was not maintained when the plane of nutrition was changed from high to low or low to high.

3. The frequency of silent heat and the number of services per conception was lower in the low planes than in the high planes.

4. Ova migration occurred in both directions in 41% of the gilts; one to four ova migrated. The foetal sex ratio ranged from 4:0 to 1:7 with an average of 1:1. The sexes were unevenly distributed in the horns.

5. Foetus weight at 38 or 100 days post-coitum was not affected by plane of nutrition or sequence in the uterine horn.

6. Within-litter variations were highest in the volume of allantoic fluid followed in order by variations in weight of placental membranes and then the amniotic fluid and foetus.

7. Foetal mortality was not related to sequence in the uterine horn or the number of implantations.

8. There seemed to be two peaks of early prenatal mortality, one at implantation and another at the onset of organo-genesis.
Establishment Studies. I. The effect on spring oats of undersowing with a one-year ley
Authors: Charles Allen H.
Published: March 2009

A field experiment was carried out to study the effect on spring oats of undersowing with broad red clover, Italian rye-grass and a mixture of both. Two levels of nitrogen were used, namely, no nitrogen and 3 cwt. per acre of ‘Nitro-Chalk’.

1. Oat shoot weight was reduced by undersowing, Italian rye-grass having a greater effect than red clover, particularly where nitrogen was applied.

2. In the absence of nitrogenous fertilizer undersowing did not reduce oat plant height, but where nitrogen had been given, Italian rye-grass either alone or in a mixture with the clover, reduced the height; the legume alone had no effect.

3. Undersowing generally reduced the number of oat panicles. Italian rye-grass had no effect when nitrogen was not applied, but a marked reduction was observed when nitrogen was applied. The legume had the greater influence where nitrogen was not applied.

4. Red clover increased the number of whorls, and the number of single-grained spikelets per panicle. Grass sown alone or with clover reduced the number of single-grained spikelets per head.

5. The total number of grains per panicle, 1000 grain weight, percentage husk and the percentage of saleable grain were not influenced by undersowing.

6. No lodging occurred but there was an indication that resistance to bending of the straw was affected by undersowing with Italian rye-grass.

7. Seeding herbage under the oats had a bigger influence on the yield of straw than grain. Italian rye-grass sown alone or with clover reduced the yield of straw where nitrogen had been applied. The legume alone had no effect. Grain yields showed a similar trend.

8. Yield and percentage crude protein in the straw were reduced by Italian rye-grass alone or in a mixture with clover when nitrogen was applied, but there was no effect where nitrogen was withheld. The grass had a greater effect than red clover while a mixture of both was intermediate to the legume and grass sown separately. Italian rye-grass greatly reduced the recovery of applied nitrogen by the cereal.

9. The percentage moisture in the oat sheaves was increased by undersown herbage and red clover had a bigger influence than the grass. The application of nitrogen reduced the bulk of clover under the cereal and its adverse influence on the harvesting of the oats. In the absence of undersowing, nitrogen had no effect on the percentage moisture in the sheaves.
Studies of the skeleton of the sheep. IV. The effects and interactions of dietary supplements of calcium, phosphorus, cod-liver oil and energy, as starch, on the skeleton of growing blackface wethers
Authors: Benzie D. , Boyne A. W. , Dalgarno A. C. , Duckworth J. , Hill R. , Walker D. M.
Published: March 2009

1. A factorial experiment on wether hoggs was carried out to examine the effects on bone growth and composition and on blood composition of four dietary factors. The factors were extra calcium, phosphorus, vitamin D, and energy in the form of starch, and each was fed in all possible combinations, so that there were sixteen dietary treatment groups in all. Each group consisted of three animals.

2. Serum calcium and blood inorganic phosphorus concentrations were determined monthly, and radiographs of most parts of the skeleton were taken at the beginning and end of the experiment. After about 6 months on the experimental diets the animals were killed and the ash weights and percentage of ash of different parts of the skeleton and of the whole skeleton were determined. Live-weight changes and food intakes were also measured.
The grazing preferences of cattle and sheep
Authors: Cowlishaw S. J. , Alder F. E.
Published: March 2009

Factors affecting the grazing habits of ruminants are discussed in relation to the attractiveness and nutritive value of herbages and the observed preferences of cattle and sheep at different times.

Methods of measuring stock preferences are considered and it is concluded that, while frequent eye estimates of the quantity of each species appear to provide an adequate method, continuous observations and herbage sampling are useful adjuncts to it.

The results of five experiments are given. Four were carried out in 3 years' winter grazing and one on spring, summer and autumn grazing over 2 years. In the latter experiment herbage samples were chemically analysed and a relationship with the observed preferences was calculated.

In the winter grazing trials the greener grasses tended to be selected first, i.e. timothy, white clover, rough-stalked meadow grass, perennial and Italian rye-grass. Cocksfoot, Phalaris, red fescue and meadow fescue were not generally relished. Meadow foxtail, smooth-stalked meadow grass, tall fescue and sometimes the different varieties of rye-grass and timothy varied in rank from year to year as a result of differential frost damage and fungal attacks.

In the summer grazing trials lucerne and white clover were found palatable in all the 1956 trials; in 1957 lucerne remained so, but white clover was less well liked, especially in June and July. The amount of grass growing with the clover seemed to affect attractiveness, mixtures being preferred to either species by itself. Meadow fescue and timothy were always ranked high, perennial rye-grass and cocksfoot usually next. Agrostis and red fescue were lowest. For the grasses, preference rank was positively correlated in 1957 with water-soluble dry matter, water-soluble ash, water-soluble carbohydrate and negatively correlated with lignin content.

Results are compared with those of other investigators and they show a marked degree of similarity. Variability in the data for sheep is possibly due to limitations in technique. The results for sheep and for cattle are compared; and it was generally found that cattle were fonder of meadow fescue than sheep, and less fond of cocksfoot.

Stock appear to graze those plants which will most readily supply their requirements for salts and energy (carbohydrates). Factors like dung, fungal attack, accessibility, density and toughness may interfere with this relationship.