bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies of natural herbage of the sub-tropics I. The digestibility of herbage grazed by cattle
Authors: Topps J. H. 
Published: March 2009

1. In two continuous digestibility trials carried out in 1960 and 1961, groups of three wether sheep were fed on oven-dried herbage which had been selectively collected from natural pastures during December 1959 to March 1960 and December 1960 to March 1961. The organic matter digestibility and the digestible crude protein content of the herbage and the nitrogen concentration in faeces were measured over periods of 5 days. The fresh faeces of dairy cattle grazing the natural pastures were regularly sampled and analysed. Regressions of organic matter digestibility and digestible crude protein content on faecal nitrogen were evaluated. From these equations and the composition of the dairy cattle faeces the digestibility of the herbage grazed was calculated.2. The herbage consumed by the cattle had a significantly higher organic matter digestibility and digestible crude protein content than the collected material. This difference, which increased as the season progressed, indicates that dairy cattle became increasingly selective in their grazing as the pasture deteriorated in quality.3. There was a marked yearly difference in digestibility-faecal nitrogen relationships and in the quality of the consumed forage. The grass eaten in 1959-60 had a higher digestibility and lower digestible crude protein content than in the following year. These differences may be part attributable to a seasonal difference in rainfall.4. The organic matter digestibility of the grazed herbage ranged from 52·71 to 65·03% and the digestible crude protein content from 3·08 to 7·43% For milk production, the herbage consumed is low in digestible protein in relation to the total amount of digestible nutrients.
Chick rearing: VI. The bacterial syndrome encountered in epidemic bacillary white diarrhoea of chicks (pullorumdisease)
Authors: Mann T. Barton 
Published: March 2009

The bacterial syndrome encountered in epidemic bacillary white diarrhoea of chicks (pullorumdisease) is initially one of invasion by faecal type organisms, this is followed by invasion by anaerogenicB. pullorum.Evidence is presented to show that ostensibly pure cultures of anaerogenicB. pullorum, consist of two organisms, a true aerogenicB. pullorumin symbiosis with an anaerobe, morphologically of thewelchiitype.Evidence is presented to show that variation in fermentation reactions of ostensibly pure cultures of anaerogenicB. pullorumdepend upon the degree of symbiosis exerted between the anaerobe and the aerobe and this degree of symbiosis is greatly affected by methods of cultivation on solid media.It is proposed that the ovarian blight peculiar to adult hens which are carriers of bacillary white diarrhoea infection is caused by putrefaction of ovarian materialin vivoby the activities of a morphologicallywelchiitype organism.It is proposed thatB. pullorumexists in one form only, namely, the aerogehic form, and that this organism is a potential pathogen only.
Effect of leaf-roll disease in potatoes on the composition of the tuber and “mother tuber.”
Authors: McLean W. 
Published: March 2009

1. Tubers obtained from secondary leaf-roll plants have a lower dry matter content than tubers from healthy plants. The percentage of nitrogen in the dry matter is appreciably higher in the former than in the latter. The difference in dry matter content is sufficiently large in many varieties to characterise leaf-roll tubers. Seventeen varieties were examined.2. The rate at which the nutrient materials are removed by the young plants from leaf-roll mother tubers is much slower than in the case of plants from healthy mother tubers. This may be a cause of the stunting characteristic of leaf-roll plants.3. When there is any doubt as to the diagnosis of secondary leaf-roll by the usual symptoms, a determination of the dry matter in the mother tuber two to three months after planting, would serve as a further diagnostic character.
The maintenance requirement of the adult sheep
Authors: Wood T. B. , Capstick J. W. 
Published: March 2009

In attempting to interpret the results of two series of sheep feeding experiments, we have been confronted with the fact that the sum of the accepted figure for maintenance requirement and the allowance for the live weight increase produced does not account for the whole of the ration consumed. Sheep averaging 100 lb. live weight folded on swedes in the winter usually eat per week at least 100 lb. of swedes, 7 lb. of hay and 3½ lb. of cake and corn. Such a ration supplies per week about 11½ lb. of starch equivalent.Sheep fed in this way normally put on per week about 2 lb. of live weight increase, starting from store condition. It is true that figures for the composition of the live weight increase put on by store sheep are somewhat scanty, being practically confined to a series of analyses by Kern and Wattenberg (Journ. Landw. 1880) which give the composition of the live weight increase of store sheep as 44 per cent, water, 45 per cent. fat and 11 per cent, protein, which corresponds to 2200 calories or 2 lb. of starch equivalent per lb.The requirement for producing 2 lb. of such increase would therefore be 4 lb. of starch equivalent per week.Measurements of the maintenance requirement of sheep are likewise scanty. There are no recent measurements, but Armsby has recalculated the experiments of Henneberg, Kellner, Hagemann and Wolff, the most recent of which were made in 1893. These workers used two methods. The more scientific method of estimating by respiration experiments the storage of fat on a known ration and arriving at the maintenance requirement by deduction was used by Henneberg, Kellner and Hagemann. Recalculating and averaging their results, which differ widely, Armsby arrives at an average figure of 719 calories per day of net energy for the maintenance requirement of the 100 lb. sheep.
The rôle of aluminium in soil infertility and toxicity
Authors: Hardy F. 
Published: March 2009

1. The main results of soil investigations on the rôle of aluminium in soil infertility are reviewed, with particular regard to the physicochemical principles involved.2. Magistad's conclusion thatsoils or other nutrient media whose reaction values lie within the range pH 4·7and pH 8·5do not contain aluminium in soluble form, and are probably therefore not toxic to plants, is discussed in the light of modern knowledge of the properties of hydrous alumina and its peptisation phenomena.3. Dialysis experiments which have led to this generalisation are criticised on the grounds that they do not take into account the disturbing effect of dialysis on hydrous colloidal systems, and that dialyser membranes do not simulate plant-cell membranes.4. Aluminium may possibly penetrate plant-root cells, and, under certain conditions, may be translocated, within the plant body, in at least four different forms, namely, (a) simple ions, (b) more complex colloidal electrolytes, (c) co-ordinated complex anions, and (d) organo-compounds. These may conceivably be interconvertible.5. Aluminium appears to exert truetoxiceffect only when presented to plant roots as simple ions, or as the more soluble colloidal electrolytes. Apparently, the degree of toxicity varies for different plant species.6. The reaction conditions of nutrient media and of plant saps doubtless largely decide the form in which aluminium occurs therein. At reactions approaching the isoelectric point of hydrous alumina, toxic effects may never be exerted, although the assignation of a strict reaction-range applicable toallsoils or nutrient media, and toallplant species, is probably inadmissible.7. Non-toxic forms of aluminium may apparently accumulate under certain conditions at definite tissue regions of certain plants, and may disturb their metabolic processes, disposing the plants to certain diseases.8. Within the reaction-range at which toxic aluminous solutes cannot exist in soils or other culture media, hydrogen-ions may exert controlling influence on plant growth, and may thus be of major significance in natural plant distribution, and in the behaviour of plants growing in normal agricultural soils.
Potassium and caesium-137 distributions in Angus steer carcasses
Authors: Duggleby J. C. , Seebeck R. M. 
Published: March 2009

Seven Angus steers were reared under controlled conditions, slaughtered and their carcasses dissected. Muscles, fat, bones, connective tissues and samples of the steers' diet were measured by gamma spectrometry and the concentrations of potassium and caesium-137 determined. Significant variations in the concentration of each element were found both within and between tissues. Average potassium concentration was about four times greater in the muscle tissue than in the remainder of the carcass. Caesium/potassium ratios were similar in both Caesium/potassium ratios were similar in both bone.The main conclusions reached were as follows:(1) The variations of potassium concentrations in muscle may impose limitations on the potassium-40 technique for estimating muscle content of the living animal for scientific purposes, though not necessarily for estimating commercial value.(2) Differences between animals in caesium-137 content of muscle were fairly consistent over the different muscle groups, and bore some relationship to caesium intake. This indicates that it may be possible to utilize caesium content of a representative muscle to monitor caesium-137 fallout in remote regions of Australia, where milk is not produced.
An improved method for the determination of dissolved oxygen in water
Authors: Subrahmanyan V. 
Published: March 2009

The determination of dissolved oxygen by Thresh's method may lead to discordant results because of the loss of iodine, which is carried away by the gas passed through the apparatus during the titration.A modified method is described, which eliminates the above error and obviates the necessity for making separate determinations of the dissolved oxygen of the reagents used.Correction for the nitrites present in the water can be made by making separate determination by the Griess-Ilosway colorimetric method.
Digestibility trials with poultry: II: The digestibility of “weak” and “strong” wheats, and their value for poultry feeding. III. The digestibility of “whole” and “flaked” maize
Authors: Halnan E. T. 
Published: March 2009

(1) Digestibility trials with wheats, carried out with White Leghorn cockerels, indicate that “weak” and “strong” wheats are equally suitable as sources of supply of food nutrients for poultry.(2) In the production of wheat for poultry feeding, yield rather than strength should be the primary aim of the grower.(3) Further research work on the Katayama method of estimating the digestibility of poultry feedingstufls is indicated.(1) Digestibility trials with “whole” maize and “flaked” maize indicate that steam cooking by commercial processes considerably increases the digestibility of the food nutrients in maize. (2) The view held that the fowl is akin to the pig so far as its powers of digestibility of low fibre foods are concerned is substantiated by the results of the trials here reported.
Nutritive value of Lucerne: IV. The Leaf-Stem Ratio.
Authors: Woodman H. E. , Evans R. E. 
Published: March 2009

In this paper are brought together a number of data concerning the ratio of the amount of leaf to stem in the lucerne crop, at different stages of growth, and the separate composition of the leafy and stemmy fractions.It is shown that the proportion of leaf falls off as the crop advances in maturity, and that the rate of decrease of leafiness is greater before budding than during the period from the beginning of budding to early flower. The changes in the leaf-stem ratio largely account for the fall in protein content, the rise in fibre content and the running-off in digestibility and feeding value that take place as the crop passes through the successive stages of growth up to flowering.
Leaf Analysis as a Means of Diagnosing Nutrient Requirements of Tropical Orchard Crops
Authors: Hardy F. , McDonald J. A. , Rodriguez G. 
Published: March 2009

1. Attention is drawn to the remarkable dissimilarity between the cacao and the grapefruit tree in their nutrient requirements, indicating that grapefruit is calcicolous in physiological habit. This conclusion is mainly based on a consideration of the results of chemical analysis of representative leaf material produced by trees grown on soil of known chemical and physical characteristics, under the same climatic conditions in Trinidad.2. The nutrient relationships that obtain between the cacao and the grapefruit tree respectively and the soil in which they are growing have been gauged by means of chemical analysis of representative leaf material.3. For this purpose, leaf material was obtained from trees growing on the differently manured plots of two large-scale field experiments in Trinidad.
Seed Disinfection: I. An Outline of an Investigation on Disinfectant Dusts Containing Mercury.
Authors: Dillon Weston W. A. R. , Booer J. R. 
Published: March 2009

An outline is given of an investigation that has dealt with disinfectant dusts containing mercury, and it is shown that the majority of the inorganic mercury salts are of little value in this respect. Some organic mercury salts have been tested and the result of laboratory and field work suggests that there is a close relationship between composition and fungicidal power. In the series R-Hg-X, where R is a hydrocarbon and X an acidic radicle, the fungicidal power appears to decrease with the increase of the molecule of R. A study is made of the significance of X in the methyl series and the results as they apply to disease control are recorded on a series of graphs.The specificity of some of the compounds is noted and a brief mention is made of the treatment of seeds other than cereals.It is suggested that there is no evidence for stimulation in the sense of tonic effect but that instances of better germination, growth and crop yields are due not only to the control of seed-borne organisms but to the preservation of the food reserves in the seed from the attack of soil organisms or mould organisms adherent to the seed.
The relation between inhibitory substances and variability in time to germination of sugar beet clusters
Authors: Battle J. P. , Whittington W. J. 
Published: March 2009

SummaryEvidence was obtained for the presence of germination inhibitors in the aqueous extract from sugar-beet clusters. A positive correlation was shown between the germination of cress seeds moistened with aqueous extracts from clusters of twenty sugarbeet plants and the germination characteristics of other clusters from the same plants. Inhibition was thus greater in extracts from clusters with poor rather than good germination, and also in extracts from immature clusters or those which had received overhead irrigation. The inhibitory effect was found to be located in the perianth and pericarp tissue rather than in the true seed.
Protein, lysine and feed intake level effects on pig growth
Authors: Blair R. , Dent J. B. , English P. R. , Raeburn J. R. 
Published: March 2009

SummaryA total of 512 pigs were given from 50 lb live weight one of 16 diets (four lysine levels at each of 12, 14, 16 and 18% protein), at one of four levels of intake. They were killed at 100, 150, 200 or 250 lb live weight and the carcasses jointed in a standard manner and right sides dissected into lean meat, fat, skin and bone.Mean percentage proportion of shoulder, middle and ham joints in the dressed sides at the four weights was 36·3, 36·4 and 27·3; 35·4, 37·9 and 26·7; 34·5, 39·6 and 25·9; and 33·8, 40·7 and 25·5, respectively. Mean percentage lean meat at the four live weights was 61·5, 59·9, 56·7 and 54·2 and the mean percentage fat was 20·7, 24·4, 29·4 and 32·8.Carcass quality was influenced significantly by dietary treatment and sex. Increasing the level of protein in the diet up to 16, 16, 14–16 and 14%, respectively, for the four live weight groups gave a significant increase in carcass leanness. Increasing the level of lysine in the diet did not have a very marked effect on carcass composition, while increasing feed intake to the highest level produced fatter carcasses at all weights. Carcasses of males were fatter and with a lower proportion of ham than those of females. Interactions involving dietary treatments and sex were described.Chemical composition of the m. longissimus dorsi was not altered markedly by dietary treatment or sex but dry matter and intramuscular fat content rose with increasing weight. Protein content of the dry matter remained fairly constant at all weights, while colour and shear value rose with increasing weight but were not significantly influenced by dietary treatment or sex.The pH values of the m. multifidus dorsi just after slaughter or on the day following were not markedly affected by dietary treatment, sex or weight.
A comparison of field inoculation methods with Cercosporella herpotrichoides (Fron) on spring barley
Authors: Jones D. Gareth , Davies J. M. L. 
Published: March 2009

SUMMARYA comparison was made of six different methods of inoculation with Cercosporella herpotrichoidesFron on field plots of the spring barley variety Impala. All inoculation treatments produced significant differences in terms of disease incidence and grain yield compared with the uninoculated controls. Significant differences were found between treatments in terms of disease incidence, disease severity, mean yield/head and 1000 grain weights. The time of inoculation was also found to be significant. The earlier inoculation caused a reduction in yield of approximately 66 % compared with 50 % at the later inoculation. The application of these methods is discussed.
Fertilizer nitrogen and growth regulators for field beans (Vicia faba L.):II. The effects of large dressings of fertilizer nitrogen, single and split applications, and growth regulators
Authors: McEwen J. 
Published: March 2009

SUMMARYThe largest mean responses to nitrogen ranged from 2·1 cwt grain/acre in 1966 (2 cwt N/acre) to 3·6 cwt grain in 1968 (1–5 cwt N/acre). Responses to the largest dressings were increased by dividing them, the increases ranged from 0·2 cwt grain in 1968 to 4·0 cwt grain in 1966.In 1968 1·5 cwt N applied in late May increased grain yield by 5·5 cwt, more than the response to any other amount applied either to the seed bed or as a divided dressing. Removing the growing point of the plant at the 4-leaf stage promoted tillering but lessened yield by 5·4 cwt grain. Removing the growing point of the plant after flowering increased yield by 2·1 cwt grain in 1966 and lessened it by 1·7 cwt grain in 1967.CCC (2-chloroethyltrimethylammonium chloride) had no visible effect on growth and lessened yield by 1·9 cwt.B9 (N-dimethylaminosuccinamic acid) greatly affected growth and shortened stems by as much as 30%, depending on how much and when it was applied.B9 had inconsistent effects on yield. Without fertilizer nitrogen, it increased yield by 2·5 and 2·6 cwt grain in 1966 and 1968 but decreased it by 2·1 cwt in 1967.The main effects of B9 on the components of yield were to increase the number of stems and pods/acre and lessen 1000 grain weight. Plants given B9 in 1968 produced half a million more grains/acre than untreated plants. 1·5 cwt N had similar effects to B9 on the components of yield in 1968. Stems and pods/acre were increased, but there was also a small increase in 1000 grain weight. Plants given 1·5 cwt N produced half a million more grains/acre than plants not given N. A further1·5 cwt N lessened number of stems/acre but this was more than compensated for by an increased number of pods/stem, leading to a further increase of 160000 grains/acre. The effects of season were large and exceeded the effects of any of the treatments.
A critical study of the failure of a long-term calcium and phosphorus balance experiment with laying hens
Authors: Jenkins N. K. , Tyler C. 
Published: March 2009

A long-term calcium and phosphorus balance experiment with laying hens is described.The cumulative balances of calcium and phosphorus over a whole year were seen to be physiologically impossible.Results from other workers using short term balancescouldbe equally impossible and a similar situation has recently been noted in balance experiments with ruminants.The techniques employed in the experiment were, therefore, investigated in detail.Only systematic errors could be responsible and it was found that the most likely source of such errors was (a) the spilling of food on to the floor or into the water bowl, and (b) failure to collect all the droppings.These errors only become apparent in long-term experiments and are more pronounced when diets containing high levels of calcium and/or phosphorus are fed.
Reduction of nodule numbers and growth, produced by the addition of sodium nitrate to lucerne in sand culture
Authors: Thornton H. G. , Nicol Hugh 
Published: March 2009

A sand-culture experiment with inoculated lucerne was made to test the effect of increasing doses of sodium nitrate upon the yield and nitrogen content of tops and roots, and upon the number and development of nodules. The pots were divided into six series receiving from 0 to 10 gm. of sodium nitrate per pot containing 12 kg. of sand.There was no correlation between yield or nitrogen content of the lucerne, and the dose of nitrate.The number of nodules, though unaffected by 1 gm. of sodium nitrate, was progressively decreased by the stronger doses.The length of nodules was reduced about 30 per cent, by 1 gm. of sodium nitrate, and decreased progressively with stronger doses.Nodules were found to show a definite relationship between their overall length and the volume of contained bacterial tissue. Using this relation, the mean volumes of bacterial tissue per nodule and per pot for each series were calculated. The reduction effected by nitrate was far greater when measured in this way, owing to the small contribution of bacterial tissue derived from nodules less than 1·5 mm. in length.
The relative importance of plot variation and of field and laboratory sampling errors in small plot pasture productivity experiments
Authors: Bartlett M. S. , Greenhill A. W. 
Published: March 2009

An investigation of the relative importance in small plot pasture productivity experiments, of plot variations and of field and laboratory errors in sampling and subsampling for percentage dry matter and percentage nitrogen figures, revealed little advantage from duplicate sampling or subsampling in reducing the experimental error, which was due mainly to plot variation.The effect of sampling errors was of even less importance in the estimation of the actual yields of dry matter or of nitrogen.
Studies on Azotobacter in Malayan soils
Authors: Altson R. A. 
Published: March 2009

These observations have shown that the strains of Azotobacter occurring in certain Malayan soils are unable to initiate growth on standard media, except after a lag phase of considerable duration. Evidence has been obtained which suggests that this inability is not necessarily an indication of a scarcity of the organisms in the soil used as an inoculum, but may be due to factors associated with the composition of the culture medium.In particular the strains of Azotobacter developing from these soils are checked by the presence of calcium carbonate in the medium. They will grow well in a medium in which calcium chloride replaces calcium carbonate, but equally well where the medium contains but traces of calcium.These strains can tolerate a wide range of hydrogen-ion concentration extending on the acid side to pH. 3·6. Their existence invalidates the use for these soils of all such microbiological tests of lime requirement as make use of Azotobacter as indicator.