bluuebunny/crossref_metadata_2025 huggingface dataset:
Water displacement of soils and the soil solution
Authors: Burd John S. , Martin J. C.
Published: March 2009

1. The use of a positive air pressure on closely packed soils decreases the time of recovery and increases the yield of solution obtained by water displacement.

2. Equipment and technique for the recovery of displaced solutions is described.

3. Data from three sandy loams and two silty clay loams are reported.

4. Successive displaced solutions of equal electrical conductivity were obtained from each soil. The concentration thus measured was in each case the same as that of the liquid obtained without the use of displacing water.

5. Concentrations of individual ions in successive portions of displaced solution are uniform in soils at optimum and this also appears to be true at half optimum.

6. There is an inverse proportion between total moisture content of soil and concentration of displaced solution as indicated by measurements of specific resistance.

7. When the solution displaced by water from a given mass of soil was used as displacing agent on another portion of the same soil, the newly displaced solution had the same concentration of electrolytes as the displacing solution. The opinion is expressed that this result indicates that the displaced solution has the same concentration as the solution with which it came in contact in the soil.

8. Typical differences in behaviour of the various solutes in displaced solutions are discussed.

9. The significance and limitations of water extractions of soils are discussed in the light of the results from displaced solutions.
The maximum water-retaining capacity of colloidal soils; the interpretation of this and of certain other soil moisture constants
Authors: Hardy F.
Published: March 2009

Themaximum water-retaining capacity of a soil may be defined as the quantity of water, measured as a percentage of the mass of oven-dry material, that the soil can retain after it has been thoroughly wetted and then allowed to drain freely. It is generally estimated in the laboratory by Hilgard's method (1893). The air-dried sifted soil is packed by jarring into a small perforated cylindrical brass box which is then placed in a vessel containing water, so that the bottom layer of the soil is in contact with the liquid surface. After standing an hour, the cylinder is removed, surplus water wiped away, and the whole weighed. The cylinder and contents are then dried to constant mass in an air-oven at 110° C. The weighings are corrected for the mass of the cylinder and that of the filter paper employed to cover the sieve. From the results, the maximum water-retaining capacity may directly be calculated.
On the vibration method of obtaining a suspension of the bacteria in a soil sample, developed by C. L. Whittles
Authors: Thornton H. G.
Published: March 2009

As has long been realised by soil bacteriologists, the present plating technique used in estimating bacterial numbers in soil suffers from the lack of a really efficient means of disintegrating the soil, so as to produce an even suspension of the organisms in the diluting fluid. As a consequence of this, although we are able, by careful standardisation of the shaking and dilution, to compare the bacterial numbers in two or more samples of the same soil type, the figures obtained are only relative, and do not give an estimate of the total bacterial numbers of the soil.
Field experiments
Authors: Berry Reginald Arthur , O'Brien Daniel Grant
Published: March 2009

Single plot trials owing to the magnitude of the experimental errors, are practically useless as a test for comparing the yields of grain of one variety of oat with that of another. At best the results are only applicable to the particular experiment in question. For the old Scotch varieties of oat the probable error on trials of this kind amounts to about 18 per cent, of the yield of grain and to about 20 per cent, for the new varieties. Adopting single plot trials an 18 per cent, error means that when determining the superiority in the yield of grain of one variety over that of another and when the difference is not likely to be more than about 5 per cent, it would be necessary to have 214 centres with no duplication of plots at any centre in order to endeavour to obtain a conclusive result from a single year's trials. When the difference is likely to be about 10 per cent, it would be necessary to have 53 centres.

Data are supplied showing that the experimental error for different crops also for the grain and straw of the same crop is not the same. It is greatest for the grain and lowest for the hay crop.
On the use of Taka-Diastase in estimating starch
Authors: Horton Edwakd
Published: March 2009

In an attempt to estimate starch in the grain of wheat grown under varying manurial conditions the writer has obtained results which it seems desirable to put on record for the information of others who may be using or propose fco use the Taka-diastase method.

Before devoting attention to wheat, experiments were made with pure potato starch under the conditions advocated by Davis and Daish. At first, owing to the use of insufficient enzyme, the results were low but immediately 0·1 gm. was taken the results were satisfactory (Table I).
Studies on soil organic matter: Part II. The extraction of organic matter from soil by neutral reagents
Authors: Bremner J. M. , Lees H.
Published: March 2009

A study of extracting reagents has been made to find mild but reasonably efficient methods of extracting organic matter from soil. Sodium pyrophosphate proved to be the most satisfactory of the neutral reagents tested, and the optimum conditions for extraction of organic matter from soil by this reagent have been defined.
The composition and nutritive value of bracken
Authors: Moon F. E. , Pal A. K.
Published: March 2009

Samples of bracken were taken at regular intervals between June and October from a hill grazing where losses of cattle from ‘bracken poisoning’ had occurred in previous years. These were separated into leaf and stem for analysis. Dry, mature bracken cut in October was examined for digestibility and nutritive value, and in the following season the digestibility of fresh, green bracken was determined for both cattle and sheep.

Chemical composition. Analyses of the fresh bracken fed in the digestibility trials were in line with those of the samples collected in the previous year. Crudeprotein content was high in June and July, but fell markedly in August and September, whilst the crude fibre varied in the opposite direction, increasing markedly in August. An increase in the tannin content was observed in September but this was not comparable with the increases reported by Shearer. An attempt to elucidate the significance of tannin in the in vitro digestion of bracken-leaf protein was unsuccessful. The potassium content was found to be rather lower than in good pasture grass, confirming the findings of Ferguson & Armitage. The potassium was highly soluble in water but the soluble part was not entirely in the form of chloride.
A comparative study of winter wheat varieties with especial reference to winter-killing
Authors: Newton Robert
Published: March 2009

1. A number of varieties of winter wheat, known to vary considerably in degree of winter hardiness, were compared in the hardened condition with reference to the physical constants of the cell sap, and the content of dry matter, nitrogen, sugars and starch.

2. No constant relation was found between depression of the freezing point, specific conductivity, or hydrogen-ion concentration of the cell sap and relative frost hardiness.

3. Sugars accounted for 34 to 38 per cent, of the total osmotic pressure of the sap.
On the susceptibility of clover and some other legumes to stem-disease caused by the eelworm, Tylenchus dipsaci, syn. devastatrix, Kühn
Authors: Goodey T.
Published: March 2009

It has been known for a number of years that red clover and certain other cultivated leguminous plants, besides many other non-leguminous ones, are subject to attack from the eelworm, Tylenchus dipsaci.

Kühn (1881) gave an account of the disease produced in clover and lucerne. Later on Ritzema-Bos (1892) showed that the worm attacking clover was morphologically indistinguishable from that attacking rye, oats, hyacinth, carnation and several other cultivated plants and certain weeds. In England Miss Ormerod (1886–1900) dealt with the subject in many of her annual reports and gave a good account of the symptoms produced by Tylenchus dipsaci, pointing out in 1899 the differences between these symptoms and those produced by the fungus Sclerotinia trifoliorum.
Net energy values and starch values
Authors: Armsby Henry Prentiss , Fries J. August
Published: March 2009

It is now accepted as a fundamental doctrine in animal nutrition that the prime function of food is to supply energy for the operation of the human or animal body and that all its other diverse uses are essentially tributary to this main purpose. The growing recognition of this fact in its relations to the nutrition of farm animals has given rise during the past twenty-five years to extensive investigations, especially by Zuntz and his associates, by Kellner and Köhler and by the writers, in which the attempt has been made to determine experimentally how much energy the various feeding stuffs can actually contribute toward the upkeep of the animal body.
A note on the classification of soils on the basis of mechanical analyses
Authors: Whittles C. L.
Published: March 2009

Although many schemes have been proposed for a classification of soils, not any single one seems to have found general acceptance. It is, however, generally agreed that with any method, a final subdivision based on the texture of the soil is highly desirable, even though it only be the sands, loams, and clays of common parlance. Granted then that a classification based on mechanical analyses is called for—though not necessarily as the primary division into groups—it is here proposed to examine some of the various methods so far put forward for dealing with the results of mechanical analyses. Tables of analytical results in themselves are unwieldy and make decidedly uninteresting reading. The comparison of a large number of soils is a slow and tedious process, if it is accomplished only by a study of the figures.
Observations on the mineral metabolism of pullets: VIII. The influence of gonadal hormones on retention of calcium and phosphorus
Authors: Common R. H. , Rutledge W. A. , Hale R. W.
Published: March 2009

1. Sexually immature White Wyandotte pullets have been treated with gonadal hormones with the object of simulating those changes in calcium and phosphorus metabolism which normally take place during the fortnight or so before laying begins.

2. It is shown that certain treatments of the sexually immature pullet with oestradiol dipropionate evoked hypertrophy of the oviduct and changes in blood calcium and phosphorus similar to those encountered in the normal laying pullet, but did not produce any significant increase in the rate of calcium or phosphorus retention.
Comparative studies of meat. II. The changes in the carcass during growth and fattening, and their relation to the chemical composition of the fatty and muscular tissues
Authors: Callow E. H.
Published: March 2009

1. The weights of muscular tissue, fatty tissue, bone, and tendons, etc. in the carcasses of twenty-nine cattle, fifty-five sheep and forty pigs are given. The weights of fat, dry fat-free residue, and water in the muscular and fatty tissues from the carcasses of twenty-nine cattle, twenty-nine sheep and two pigs (one wild and one domesticated) are also given. The cattle represent eight breeds, the sheep nine breeds and the pigs two breeds. Ages range from newly born to over 12 years and there are fifty females, seventy castrated males and four newly born males. The animals thus represent a very wide cross-section of the meat industry.
The dispersion of soil in water under various conditions
Authors: Puri Amar Nath , Keen Bernard A.
Published: March 2009

A study has been made of the intensity of the forces binding soil particles together, when the soil has been previously subjected to treatments simulating various field conditions, and certain laboratory processes connected with physical, chemical and biological investigations.

The technique adopted consisted in shaking soil with water under reproducible conditions, allowing the mixture to stand for 24 hours, and then determining the concentration of soil in the top 8·5 cm. of the suspension. This concentration was expressed as a percentage of the original concentration of the soil, and the value thus obtained was called the dispersion factor of the soil under the given conditions of treatment.
Studies of growth and development in the young pig Part I. The carcass composition at 56 days of age of pigs reared along different growth curves
Authors: Elsley F. W. H.
Published: March 2009

1. A comparison was made of the carcass composition at 56 days of age of early-weaned pigs grown along predetermined growth curves to 30, 40 and 50 lb. live weight and of suckled pigs grown to 50 lb. live weight at 56 days of age.

Eight blocks of four pigs were slaughtered when 56 days old and comprehensive carcass dissections undertaken.

2. There were no differences in the proportionate weight of the joints or of individual bones between the suckled and early-weaned pigs weighing 50 lb. at 56 days of age.

The difference in the proportionate weights of the joints between the three groups of early-weaned pigs reflected the change in development which took place with increasing live weight. There was, however, no clear gradient of development along the bones of the limbs with increasing weight at 56 days of age.

3. The dissected joints (hams, shoulders, neck, pelvis and loin) from the early-weaned pigs which weighed 50 lb. live weight contained 0·5% less bone, 1·5% less muscle and 1·7% more fat than the carcasses of suckled pigs reared to 50 lb. at 56 days of age.

The dissected joints of the early-weaned pigs reared to 30 lb. at 56 days of age contained 1·4% more bone, 2·7% more muscle and 5·3% less fat than the joints of the early-weaned pigs reared to 40 lb. and 2·6% more bone, 5·2% more muscle and 8·8% less fat than the joints of early-weaned pigs reared to 50 lb.
A study of wool growth: Part II. Mean fibre thickness, density of fibre population, the area of skin covered by fibre, and the mean fibre length
Authors: Galpin N.
Published: March 2009

By measurement of single fibres from tattooed squares the variation in hip region mean cross-sectional area, mean fibre length and area of skin covered by fibre substance in a small flock of Romney sheep has been studied for a few years—see Part I.

We find that under good growing conditions the area of skin covered by fibre is a constant percentage of the skin area for all sheep in all years. The number of fibres per unit area varies from sheep to sheep, and the mean cross-sectional area is inversely proportional to the number of fibres per unit area. The mean length/day is a constant for all sheep. When conditions are unfavourable the percentage of the skin area covered by fibre on a particular sheep falls below the good growing conditions percentage by an amount that is smaller the bigger the skin expansion ratio, but is greater the worse the season.
Fructose content and fructolysis in semen. Practical application in the evaluation of semen quality
Authors: Mann T.
Published: March 2009

1. A method is described whereby fructose content and fructolysis can be assayed accurately in small samples of semen. The advantages of this method lie in its simplicity, accuracy and practical convenience as a tool for the assessment of semen quality, applicable also under field conditions.

2. The content of fructose in fresh semen depends upon the secretory function of accessory glands which is influenced directly by the activity of the male sex hormone. A low level of seminal fructose may coincide with other symptoms of hormonal malfunction and poor quality of spermatozoa. A high level of seminal fructose indicates satisfactory functional ability of the accessory glands, but it does not necessarily coincide with high quality of spermatozoa as expressed in terms of density and motility.

3. The normal level of fructose in fresh semen undergoes frequent fluctuations which can be observed if semen collections are made from the same individual at different times. Considerable variations in the sperm/fructose ratio may also occur in the semen of the same individual as illustrated by the results of an ‘exhaustion test’.

4. Fructose disappears from semen incubatedin vitro. The rate of fructose disappearance forms a convenient measure of sperm fructolysis. The normal rate of fructolysis in bull semen is 1·4–2 mg. fructose per 109sperm cells in 1 hr. at 37° C. At this high level it can be maintained until almost the whole reserve of fructose has been exhausted. Azoospermic and necrospennic semen, as well as that from vasectomized animals, are unable to utilize fructose. A reduced rate of fructolysis is found in low quality semen of subfertile and infertile animals.

5. The conditions of sperm survival in semen incubated in narrow tubes as used for the fructolysis test as well as for storage of semen in the practice of artificial insemination, are almost purely anaerobic. Under such conditions the survival of spermatozoa must largely depend upon fructolysis and not upon respiration.
The effect of supermaintenance and submaintenance diets on mature Border Leicester-Cheviot ewes
Authors: Robinson P.
Published: March 2009

Ten fully grown Border Leicester-Cheviot ewes were divided into two groups of five; the heavier ones being about 150 lb. live weight, and the lighter ones about 70 lb. The former were placed on a low plane of nutrition, and the latter on a high plane. As the weights changed by successive amounts of 20 lb. animals were killed and dissected, and their organs and tissues weighed.
Nutrition of the bacon pig: XIII. The minimum level of protein intake consistent with the maximum rate of growth (Part V)
Authors: Woodman H. E. , Evans R. E.
Published: March 2009

The metabolism trials described in the present communication were undertaken with the object of testing the conclusions arrived at in farm-scale feeding trials, designed in accordance with the requirements of the modern statistical lay-out, respecting the minimum protein supply needed to support the maximum rate of growth in bacon pigs.
The subdivision of the clay fraction in mechanical analysis
Authors: Russell E. W.
Published: March 2009

An examination has been made of the possibility of extending the routine mechanical analysis of soils down to finer particles than the conventional clay. The main conclusions reached are:

(1) Sampling depths of only 2 cm., using standard mechanical analysis apparatus, appear to introduce no new sources of error.

(2) If a constant temperature room is available, sampling times of 7 days seem to be allowable.

(3) Using special pipettes and settling vessels, sampling depths of only 2½ mm. seem to be allowable.
The nutrition of the bacon pig; IX. The lehmann method of pig feeding, with particular reference to the balance of the basal meal and the use of cooked potatoes and molassed beet pulp as the supplemental foods
Authors: Woodman H. E. , Evans R. E.
Published: March 2009

The main findings of the present trials may be. summarized as follows:

(1) When ‘mineralized’, cooked potatoes are fed as the bulky supplemental food in the Lehmann system of pig-feeding, and the basal meal allowance is restricted to 3 lb. per head per day, bacon pigs are able to make as good progress, in respect both of rate of live-weight increase and economy of food conversion, and at every stage from 60 to 200 lb. live weight, as they would if kept on a diet composed wholly of balanced meal. In the present trials, pigs of about 200 lb. live weight were able to consume 15–17 lb. of cooked potatoes per day in addition to the daily allowance of 3 lb. of meal. It required, on an average, about 1030 lb. of cooked potatoes and 311 lb. of balanced meal per pig to fatten the animals from 60 to 200 lb. live weight. The cooked potatoes, when assessed on the air-dry standard of 13 % moisture, were able to replace the balanced meal on a lb. for lb. basis without detriment to the progress of the pigs, and the average saving of meal thus made possible amounted to about 225 lb. per pig, or 38·2 % of the total meal consumed per pig on the control, all-meal diet.

(2) Cooked potatoes should be introduced into the ration gradually and the allowance should be scaled according to live weight in the manner adopted in the present trials. When the amount to be fed is large, it is best to feed ‘mineralized’, cooked potatoes only during the morning and to place the basal meal in the trough towards the end of the afternoon.
The epidemiology of parasitic gastritis in sheep. Observations on the relative importance of the various factors concerned in the development of the disease
Authors: Taylor E. L.
Published: March 2009

The most obvious lines of investigation for the discovery of some method of controlling parasitic gastritis in lambs are those which endeavour to find a means either of killing the parasitic worms in the stomach and intestine, or of destroying the free-living larval stages which are present in the soil. Both of these lines have been diligently followed by research workers in different countries throughout the world, numerous drugs have been tried for the cure of affected sheep and many substances tried for ridding the land of infective larvae; but apart from treatment with copper sulphate or carbon tetrachloride, to which only Haemonchus contortus responds, none has given promise of success.
The effect of sodium nitrate on the growth and nitrogen content of a lucerne and grass mixture
Authors: Thornton H. G. , Nicol Hugh
Published: March 2009

IX. Summary and Abstract

1. Inoculated lucerne was grown alone and in association with Italian rye grass, in pots of sand watered with food solution and given three different doses of sodium nitrate.

2. The dose of nitrate did not affect the dry weight or nitrogen content of lucerne when grown alone, save that the highest dose checked the root growth somewhat.

3. When lucerne and Italian rye grass were grown in association, the growth of the grass varied directly with the dose of nitrate applied, and the growth of the lucerne varied inversely to it. Checking of the lucerne growth was probably due to root competition with the grass.
Studies on the sex-ratio and related phenomena. (7) The foetal sex-ratio in the pig
Authors: Parkes A. S.
Published: March 2009

1. Of 583 pig foetuses of all ages, 331 were found to be males and 252 females, giving a male percentage of 56·8, which is much higher than the approximate equality between the sexes that seems to exist at birth. This result confirms Jewell, who found a male percentage of 55 among 1000 cow foetuses.

2. These 583 pig foetuses when classified by weight (0–100 gm., 101–300 gm., 301+gm.) gave the following percentages of males for the respective groups, 59·1, 57·0, 53·2. In other words, the percentage of males decreases as gestation proceeds, a result which can only be brought about by a differential mortality of males and females. It would appear that the percentage at conception must be very near 60 per cent. or 150 males per 100 females.

3. The sex-ratios of foetuses from the left and right cornua show no significant difference, 55·0 for the right and 54·7 for the left.

4. The males were found to average about 7 per cent. heavier than the females.

5. There seems to be an inverse correlation between the number of foetuses in a horn and their average weight. Foetuses from the left cornu have a slightly greater weight than those from the right, and this may be connected with the slightly inferior fertility of this horn.

6. The excess of males at conception is discussed in the light of the implications of the chromosome mechanism of sex determination, and reference is made to the greater mortality of the males.
A Method of Estimating the Yield of a Missing Plot in Field Experimental Work
Authors: Allan F. E. , Wishart J.
Published: March 2009

In cases of field experiments when one plot is missing, a method has been developed for furnishing an estimate of the yield of the missing plot, based on all the other values. The calculation is given for (a) a Randomised Block experiment, and (b) a Latin Square arrangement. In both cases the actual arithmetic is very simple.

The steps in the procedure are:

(1) Determine the desired value by an application of the equation (A) or (B) according as the experiment was arranged in Randomised Blocks or in a Latin Square.

(2) Proceed as usual with the analysis of variance, using the estimated figure for the missing yield, and remembering to deduct one from the number of degrees of freedom ascribable to error.
Studies on the Carbon and Nitrogen Cycles in the Soil. III. The Formation of Natural Humic Matter
Authors: Toit M. M. S. Du , Page H. J.
Published: March 2009

Experiments are described in which the decomposition of various plant materials and of purified preparations of plant constituents, during rotting under neutral aerobic conditions in the presence of soil organisms, has been studied in relation to the formation of humic matter.

The formation of humic matter was more closely related to the change in the lignin content than to the change in content of the other groups of plant constituents estimated.
The relation between rates of growth and rickets in sheep on diets deficient in vitamin D.
Authors: Duckworth John , Godden William , Thomson William
Published: March 2009

The blood picture for Ca, inorganic P and phosphatase during the development of rickets caused by uncomplicated vitamin D deficiency in sheep has been established. The earliest and most distinctive change was found to be in the serum Ca level.

Lambs were shown to have sufficient reserves of vitamin D to protect them against avitaminosis D for a period of about 6 weeks as judged by serum Ca levels. Rickets did not develop unless there was a moderate degree of growth and, in such cases, the serum Ca level was below 7 mg./100 ml.

The practical application of the results was discussed.

The authors desire to acknowledge the co-operation of Dr A. H. H. Fraser in the earlier planning of this work.
Further evidence upon the nitrogen uptake of grass grown with lucerne
Authors: Thornton H. G. , Nicol Hugh
Published: March 2009

Summary and abstract

1. Italian rye-grass grown in the presence of lucerne in sand with no added nitrogen contained, after 18 weeks’ growth, some 2¼ times as much nitrogen as did grass of the same age similarly grown but in the absence of lucerne.

2. In another experiment, where lucerne and grass were grown together in sand:

(a) Where 0·33 gm. of sodium nitrate was added per pot, the grass after only 13½ weeks’ growth contained 2½ times, and after 18 weeks’ 5½ times, as much nitrogen as was supplied as nitrate.

(b) Where 1·0 gm. of nitrate was added, the grass after 13½ weeks contained slightly more nitrogen than was added as nitrate, and after 18 weeks it contained 2¼ times as much.
The Decomposition of Urea in Soils
Authors: Gibson T.
Published: March 2009

The decomposition of urea has been investigated in 59 soil samples of extremely varied character. Urea was decomposed readily in all and very rapidly in most of the samples.

In mountain and heath soils the decomposition was generally active, especially in soil tests. Strongly acid peat samples (pH. 3·1 to 3·3) decomposed from 0·44 to 0·86 per cent, of their own dry weights of urea in 24 hours at 22° to 23° C.

In solution and soil tests samples from permanent pastures produced a more rapid decomposition than those from cultivated land. In soil tests with pasture samples quantities of urea as large as 1 per cent, of the dry weight of soil were converted to ammonia in 24 hours at 22° to 23° C. Fertile arable soils produced a relatively slow decomposition in soil tests.
Nutritive Value of Pasture. VI. The Utilization by sheep of Mineral-deficient Herbage
Authors: Woodman H. E. , Evans R. E.
Published: March 2009

A Notable contribution to our knowledge of the factors which influence the nutritive value of grass has been made by Dr J. B. Orr in a recent publication dealing with minerals in pastures and their relation to animal nutrition (l). The treatise was primarily the outcome of the deliberations of a sub-committee appointed in 1926 by the Civil Research Committee of the Cabinet to consider and report on the relationship between the mineral content of pastures and their nutritive value. From the initial enquiries instituted by this sub-committee, it was evident that malnutrition in cattle and sheep arising from deficiency of minerals in grass was widespread in the pastoral areas of the Empire, and that the subject, which was of great economic significance, warranted close and systematic investigation. A report to this effect was duly forwarded to the Civil Research Committee, on whose further recommendation grants were made by the Empire Marketing Board in aid of a comprehensive scheme of investigations into the mineral aspects of pastures within the Empire. A two-fold scheme of work was adopted, actual investigations in selected grassland areas being supplemented by a detailed search of the literature dealing with every phase of the subject.
Experiments on the use of home grown foods for milk production: II. The effect of feeding concentrated and bulky foods prior to calving on subsequent milk production
Authors: Blaxter K. L.
Published: March 2009

1. A field experiment in which six farms cooperated, supplying fifty-one experimental cows and heifers, has been conducted. The object was to find whether feeding before calving 156 lb. of concentrates or its equivalent in feeding value as bulky food increased milk production.

2. The results showed that animals fed concentrates gained more weight before calving, were in better condition at calving, and produced a maximum of 7 lb. more milk per cow per day than the controls. Although those fed bulky food increased in live weight more than the controls, they did not calve in such good condition and produced only 3 lb. of milk per cow per day more than the controls.

3. Nearly half the animals fed bulky food refused appreciable amounts of this supplement, and it is probable that this refusal of food is one of the factors responsible for the differences in milk production between the two groups receiving additional food.

4. The correlation (r) between the weight of the cow and the weight of the calf was +0·507, and there was no statistically significant difference between the weight of the calves produced by cows receiving different treatments.

5. Although the fat percentage of the milk of the cows receiving supplementary food was higher than that of the cows receiving no supplement, the difference was not statistically significant.

6. Correlation analysis showed that the farmers' judgement of the condition of their cows at calving time was very closely related to the cows' subsequent performance.
An analysis of the time change in milk production in individual lactations
Authors: Gooch Marjorie
Published: March 2009

This study treats of the progress in the milk production of a cow during a single lactation, and the relation of this trend to various factors associated with the particular lactation. The analysis is based on the monthly milk production records of all cows having six or more lactations, in a single large herd of pure-bred Jerseys. The herd provided records on ninety-nine such cows having a total of 679 lactations. Since the trend in the amount of milk produced in a lactation may be described by a simple exponential curve, this equation was fitted to the first 8-months’ production records for each of the 679 lactations. From these curves, constants were obtained which measure for each lactation: the theoretical initial yield; the decline of milk yield with time, or in other words the persistency rate; and the scatter of the observed monthly yields about the smooth curve. It is these constants which were studied relative to certain general and biological factors.
Studies on calcium cyanamide V. The Utilisation of Calcium Cyanamide in Pot Culture Experiments
Authors: Richardson H. L. , Crowther E. M.
Published: March 2009

1. In pot culture experiments with barley and mustard conducted in several soils over a number of years, the yield differences between calcium cyanamide and ammonium sulphate were generally small. Calcium cyanamide gave slightly poorer results than ammonium sulphate in soils with high responses to added nitrogen but definitely better ones in soils which contained much available nitrogen and in which calcium cyanamide greatly retarded nitrification.

2. The pot culture experiments confirmed the conclusion from earlier laboratory work that in normal soils calcium cyanamide was converted through urea into ammonia within a few days. Nitrate accumulation was less complete and slower from calcium cyanamide than from ammonium sulphate. In one soil the nitrogen from calcium cyanamide remained as ammonia for several weeks, the nitrate content being below that even of unmanured soil.
Variations in the live weight of dairy cows
Authors: Bartlett Stephen
Published: March 2009

1. A measure of the errors involved in the weighing of dairy cows for experimental work is presented.

2. Methods of avoiding a considerable part of these errors are suggested.
Studies on the fats of the bacon pig with reference to carcass quality. The relation between growth rate and chemical composition of pig depot fat
Authors: Shokland F. B. , De La Mare P. B. D.
Published: March 2009

Consideration of the composition of pig depot fats from the point of view of Callow's growth-rate theory (Callow, 1935a,b), shows that the theory appears to explain the iodine values of fats both of groups of animals and of depots of an individual pig. When, however, the fatty acid compositions of the fats are considered, the theory is untenable in respect of the depots of an individual pig. Differences in unsaturation between outer back fat, inner back fat, and perinephric fat are essentially determined by differences in the ratio of oleic acid to stearic acid, differences in linoleic acid content being inconsiderable.

It can equally be shown that the growth-rate theory does not explain the results obtained by Hilditch & Pedelty (1941) for depot fats of sheep. Differences between different depots both of the pig and of the sheep seem to be characteristic of the species and cannot readily be altered by altering either the quantity or the quality of the diet.
The composition and digestibility of Northern Irish ryegrass seed and ryegrass seed cleanings
Authors: Common R. H.
Published: March 2009

1. Data are presented for the chemical and botanical compositions of ryegrass seed and various by-products of the ryegrass seed cleaning industry.

2. Digestibility data are presented for a more limited range of samples of ryegrass seed, ryegrass seed cleanings and, for comparative purposes, of certain by-products of the milling of oats.

3. Ground high quality perennial ryegrass seed has a chemical composition and digestibility comparable with that of oats.

4. Ground rough (i.e. uncleaned) perennial ryegrass seed has a chemical composition and digestibility such that its starch equivalent is 90–95 % of that of oats.

5. Ground bulked ryegrass seed cleanings has a starch equivalent of about four-fifths that of oats and is comparable in feeding value with better grades of oat feed, i.e. those containing not more than about 20 % of fibre.
The Microbiology of Farmyard Manure Decomposition in Soil I. Changes in the Microflora, and their Relation to Nitrification
Authors: Jensen H. L.
Published: March 2009

Decomposition experiments were carried out in the laboratory with different kinds of farmyard manure in various soils (sand and clay, acid and neutral). In neutral or slightly acid soil there was a very strong multiplication of bacteria and, to a smaller extent, of actinomycetes immediately after the addition of manure. This increase, which was especially marked when fresh straw was present in the manure, was sooner or later followed by a rather sudden decrease, which caused the numbers of bacteria gradually to approach those in the control soils. The actinomycetes were generally more abundant in the later stages of the process. This suggests that they may be especially active in the decomposition of the more resistant residues. The “numbers” of fungi were not affected by the addition of manure alone (except to a slight degree in strongly acid soil, where the bacteria seemed inactive), but the presence of fresh straw caused them to become active, especially in strongly acid soil, where their “numbers” remained at a very high level for a long time, this abundance of fungi consisting of both mycelium and spores.
Calcium and Hydrogen ion Concentration and the Interfacial Tension of Pyrethrum Extracts (With Four Text-figures.)
Authors: Hobson R. P.
Published: March 2009

1. The addition of a pyrethrum extract to a petroleum solvent, semirefined white spirit, considerably lowers its interfacial tension against water. The tension also depends upon the reaction of the aqueous phase, decreasing as the alkalinity increases.

2. The addition of agral W.B. to a solution of pyrethrum extract further lowers the interfacial tension more especially against acid solutions, thereby decreasing the sensitivity of the tension value to thepH of the aqueous phase.

3. The presence of calcium salts in the aqueous phase raises the interfacial tension of solutions of pyrethrum extract.

4. Alkaline salts counteract the effect of calcium salts, and the resulting tension values can be correlated with the ratio of calcium to hydroxyl ion concentration.
Seed disinfection VI. Stripe smut of rye
Authors: Taylor R. Eric , Dillon Weston W. A. R.
Published: March 2009

1. The occurrence of stripe smut of rye, Urocystis occulta (Wallr.) Rab. in Great Britain is recorded.

2. Control of seed-borne infection by disinfecting seed prior to sowing with an approved organomercury seed disinfectant has been shown.

3. Experiments have confirmed that the disease may be soil-borne.

4. With the increase of the acreage of rye grown in Great Britain it is suggested that seed should be treated with an approved organo-mercury seed disinfectant as a preventive measure.
The Influence of Systematic Plot Arrangement upon the Estimate of Error in field Experiments.
Authors: Tedin Olof
Published: March 2009

Summary and Conclusions

The effect of systematic plot distribution upon the estimate of error of a field-plot experiment of 5 × 5 plots has been studied on ninety-one blocks taken from eight different uniformity trials, representing a wide variation in plot size and plot shape, crop, climate, and soil.

The arrangements studied are: two different knight's moves, two different diagonal arrangements, and eight irregular arrangements, seven of which have been chosen at random.

The investigation has shown that the use of systematic plans introduces a bias in the estimate of the error of the experiment. The use of the knight's move arrangement causes an over-estimation of the error, whereas the use of the diagonal causes an under-estimation.
The effect of rainfall and age on the yield of some unfertilized fodder crops in Kenya
Authors: Glover J. , Birch W. R.
Published: March 2009

Five perennial fodder crops and maize were grown for 11 years or more in unfertilized soil. The effect of rainfall, annual and seasonal, and age from planting was examined in detail. Increased rainfall, whether annual or seasonal, led to increased yields of all crops, although the extent of the increase depended on the type of crop, the nature of the rainy season, whether long or short, and in particular the age of the perennial crops. All the perennials aged at similar rates and ageing led to reduced yields. The depressing effect of age is thought to be due to overcrowding and possibly a concealed loss of fertility.
Some factors affecting the evaporation of water from soil II. The discontinuity of the drying process
Authors: Fisher E. A.
Published: March 2009

Some of the factors affecting the rate of loss of water from a drying system are shortly reviewed. These factors fall into two groups: (1) the drying system itself, and (2) the environmental conditions. The second group may include (a) diffusion of water vapour through the air, (b) bulk air movements due to (i) temperature gradients between different parts of the drying vessel, (ii) temperature lowering of the drying mass itself due to evaporation, (iii) lower density of moist air, (iv) inevitable disturbances introduced by experimental conditions such as weighing or movement of apparatus, (v) the geometry of the system. It is shown that of the external factors the most important are (2 (a)), (2 (b) (i)) and (2 (b) (ii)); (2 (b) (iv)) may produce irregularities in the rate curves of airdry granular materials; (2 (b) (iii)) and (2 (b) (v)) appear to have little or no effect.
Dye adsorption by hydrous alumina in soils
Authors: Croucher H. H.
Published: March 2009

1. A historical review of the dye adsorption method for the estimation of soil colloids is presented, and the method is criticised chiefly from the point of view of the isoelectric theory.

2. A procedure for the detection of hydrous alumina in soils is described, involving the demonstration of the isoelectrio point of hydrous alumina by means of preferential dye adsorption in suspensions of variouspH values.

3. Satisfactory results were obtained with a mixture of acidic Biebrich Scarlet and basic Iodine Green. The former is adsorbed by hydrous alumina only on the acid side of its isoelectric point, and the latter only on the alkaline side.

4. The characteristics of an ideal dye for use in studies such as those described are tabulated.

5. The applicability of the mixture of dye-stuffs finally selected is demonstrated for a series of soils of varying basic ratio, and including examples of lateritic soils and clays.
The effect of the growth-promoting, appetite-stimulating or “physin” factor on the live-weight increase of swine
Authors: Dunlop George
Published: March 2009

Attention has been drawn to the remarkable growth rates obtained in certain litters of pigs under farm conditions.

It has been pointed out that no explanation has been put forward to account for their occurrence.

The literature relating to the new dietary factor, physin (Mapson), essential for optimum growth and reproduction in experimental rats, trout and dogs, has been reviewed.

Experiments are reported in which rations, adequate as far as our present knowledge of essential dietary constituents goes, were fed to young growing swine. In each of three experiments, animals which received in addition 4 oz. of raw minced liver per day showed a 40 per cent. increase in growth rate compared with the controls.

When food intake was controlled according to the new method of individual feeding, the liver animals showed the same gains in weight as the animals receiving the basal diet alone.
Changes occurring in the organic matter during the decomposition of compost heaps
Authors: Ashworth M. R. F.
Published: March 2009

1. The decomposition of the organic matter of four medium to large-scale composts has been studied by analysis of samples taken at intervals.

2. The bulk materials of the composts were grass-cuttings, oat-straw,Sphagnumpeat and anEriophorumandSphagnumpeat. All were made up to the same nutrient-content and relative water content.

3. The analytical method used was a modification of the scheme of proximate analysis used by Waksman and by Shewan. It was supplemented by ammonia and nitrate determinations, using Olsen's method.

4.Observations.

A.All composts.

(i) An increase in ammonia, water-soluble nitrogen and water-soluble organic matter took place during the first month.

(ii) Only low nitrate concentrations were developed.

(iii) Very closely parallel changes in H2SO4-soluble nitrogen and residual nitrogen were recorded.

(iv) Other nitrogen changes can be described as slight and on the whole as mutually compensating fluctuations.
Observations on ergot in cereal crops
Authors: Weston W. A. R. Dillon , Taylor R. Eric
Published: March 2009

Several cases of ergot in barley encountered in 1941 have been investigated, and records have been examined of the occurrence of ergot in cereal crops in this country during the past 24 years. These indicate that ergot is found more frequently on rye than on wheat, barley or oat, this, in descending order, being their relative susceptibility. A more detailed examination of records of the occurrence on rye in the seasons 1939–42 indicates that the disease is more prevalent in northern districts than elsewhere; of 500 acres of rye surveyed in Suffolk and Norfolk in 1942 only three crops comprising 80 acres showed a trace of ergot. It is rare on both wheat and barley and little is known as to the susceptibility of their varieties, although on several occasions it has been noted on Rivet wheat, and has been recorded on Rivet and Triticum vulgare crosses. In this country there is no record of it having been found on oat, apart from the one specimen found in a field of mixed corn in Cambridgeshire.
Digestibility trials with poultry. IX. The digestibility and metabolizable energy of sunflower seeds
Authors: Halnan E. T.
Published: March 2009

1. Field tests indicate that sunflower seeds are suitable as a wartime substitute for cereal grains for fowls, and that eggs produced on rations containing these seeds are excellent in both flavour and quality.

2. Digestibility trials indicate that sunflower seeds are a good source of protein and energy.

3. On an energy basis, metabolizable energy determinations indicate that sunflower seeds yield more energy than cereal grains on a weight-for-weight basis, with the exception of yellow maize.

4. Under commercial conditions of management, sunflower seeds appear to be quite palatable to poultry, but not under conditions of individual cage feeding.
The teart pastures of Somerset. IV. The effect of continuous administration of copper sulphate to dairy cows
Authors: Ferguson W. S.
Published: March 2009

Six dairy cows were given daily 2 g. copper sulphate for 10–18 weeks, and the effect on health and copper content of the blood noted. The cows remained in perfect health during this time. The blood copper contents rose to 73% above the initial level in 10 weeks and to 133% after 18 weeks. The highest blood copper recorded was 0·264mg./100ml., which is similar to values recorded for normal oxen.
The Obligate Anaerobic Microflora of Farmyard Manure
Authors: Glathe Hans , Cunningham Andrew
Published: March 2009

1. In a preliminary investigation of the obligate anaerobic microflora of samples of ordinary farmyard manure and of Edelmist strains ofBac. sporogenes, Bac. bifermentans, Bac. tertius, Bac. tetanomorphusandBac. saccharobutyricuswere isolated and characterised.

2. Anaerobic decomposition of cellulose was observed in media inoculated from both of the samples of Edelmist examined.

3. For the cultivation and enumeration of the anaerobic bacilli in samples of farmyard manure the superiority of liquid over solid media was demonstrated. Of the liquid enrichment media tested egg meat and liver-liver broth proved to be the best.