bluuebunny/crossref_metadata_2025 huggingface dataset:
A method for the estimation of uric acid in poultry excreta
Authors: Woodman Herbert Ernest
Published: March 2009

In connection with nutritional investigations on poultry being carried out in the above Institute by the writer's colleague, Mr E. T. Halnan, it became necessary to devise a satisfactory method for the estimation of uric acid in poultry excreta. Although numerous exact methods have been elaborated for the determination of the amount of uric acid in mammalian urine, the corresponding problem in connection with the excreta of birds has received relatively little attention. This circumstance is no doubt due in large measure to the peculiar difficulty attaching to the quantitative investigation of the nitrogenous constituents of poultry excreta, arising from the fact that the urine and faeces are not excreted separately. The urine is not temporarily stored in a bladder, as with mammals, but proceeds directly from the kidneys through the ureters to the cloaca and there undergoes admixture with the faeces from the intestines.
Errors in feeding experiments with cross-bred pigs
Authors: Berry Reginald Arthur , O'Brien Daniel Grant
Published: March 2009

The probable error on one pig calculated on the average daily live weight increase was found to be for cross-bred pigs about 7 per cent.; for pure-bred pigs from the same litter and each of similar live weight about 3 per cent.; for cross-bred pigs each of similar live weight but from different parents about 4 per cent.

The error is greatest in experiments of short duration and it decreases as the period of the experiment is lengthened. The decrease is slight if the experiment is prolonged beyond seven weeks.

The errors on 18 separate pens containing four pigs to each pen (the total initial live weight of each pen being similar) varied from 2·3 per cent, to 12·08 per cent., the average being 6·21 per cent.

The percentage probable error is relatively low when the pigs are fattening rapidly and high when the pigs are fattening slowly. The average daily increase of the quicker fattening female pigs when un-speyed appears to be depressed as a result of periodic sexual disturbances.

The stage of fattening does not appear to influence the probable error. Animals in the later stages of fattening show a greater range in their rate of fattening than animals in the early stages, see Fig. 2, p. 284.

Weekly weighing of individual pigs is recommended as it gives an indication of the health of each pig. It also enables each experimenter to discriminate between differences in the rate of fattening due to individuality and differences due to ill health, etc.

The rate of fattening of pigs is very variable, periods of rapid fattening are followed by periods of depression.
A valid restriction of randomization for certain field experiments
Authors: Taylor J.
Published: March 2009

Two examples are given of field trials for which randomized blocks would seem the most suitable design, but in which special considerations of the future of the trial or the nature of the treatments make complete randomization impossible or impracticable. A type of design which takes account of these difficulties is described, together with the appropriate methods of analysis.

The author wishes to thank Mr S. C. Pearce for much valuable advice throughout this investigation.
The importance of colour vision to the grazing sheep
Authors: Tribe D. E. , Gordon J. G.
Published: March 2009

Since sheep failed to associate either a red or blue colour with the palatability of their food during the course of an experiment designed to test for colour vision, it was concluded that sheep are colour blind.
Nitrification in Egyptian Soils
Authors: Prescott James Arthur
Published: March 2009

An attempt has been made to determine the intensity of the biological processes in the soil during the most important periods of the Egyptian farm rotation. The fluctuations of the nitrate content in the surface soil have been taken as the most important index of this activity.

In all cases the moisture content of the soil limited these processes more than any other factor.

There was observed throughout the season in a cotton field a relatively large amount of nitrate, more than sufficient for the immediate needs of the cotton plant. The lack of response on the part of the Egyptian cotton crop to nitrogenous fertilisers may be accounted for in part, if not entirely, by the fact that nitrification in the soil is well ahead of the needs of the crop.

Nitrification under wheat and maize shows in general the same characteristics in Egypt as in other parts of the world; there is no accumulation of nitrate in the soil.

The winter fallow, depending for its water on the rainfall, may be a period of steady nitrification when the amount of the rainfall is sufficiently high.
The effect of late nitrogenous top-dressing on the digestibility of hay
Authors: Ferguson W. S.
Published: March 2009

Comparative digestibility trials have been carried out on hays top-dressed with nitrogenous fertilizers 8–13 days before cutting and on similar hays which were not top-dressed.

The top-dressing resulted in an increase of 2·0% crude protein and 1·2% true protein.

The digestibility of the protein was significantly higher in the top-dressed hays and no other constituents were affected.

The protein equivalents in hay dry matter were increased from 4·4 to 6·0% by the top-dressing.
Some investigations on the electrical method of soil moisture determination
Authors: Deighton Thomas
Published: March 2009

In this paper an examination is made of the processes operative and the limits of accuracy of the electrical method of determining soil moisture.

The resistance over a small plot is found to vary under similar conditions and it is concluded that these differences are most probably due to actual differences in moisture or other factors.

The effect of the distance apart of the electrodes is investigated and a probability of a minimum resistance between two electrodes being observed under certain conditions is indicated.
A new method for the mechanical analysis of soils and other dispersions
Authors: Robinson Gilbert Wooding
Published: March 2009

(1) The expression of mechanical composition by means of continuous curves is discussed. It is suggested that a convenient representation will be obtained by showing summation percentage as a function of the logarithm of settling velocity.

(2) The effect of a gel coating on the settling velocity of a particle is examined and it is shown that a reduction in velocity takes place which is a simple function of the thickness of the gel coating.

(3) A method is outlined by which the mechanical composition of a soil or clay is derived from determinations of the concentration of a settling suspension for different values of depth/time.

(4) A shortened method for mechanical analysis is described which gives results in good agreement with results obtained by the present standard method.

(5) The effect of various modifications in conditions of working is discussed.

(6) The nature of the concentration gradients in a settling column of a suspension is examined. It is shown that below the first few centimetres the change in concentration with depth is very gradual.
The effects of copper deficiency and of chronic overdosage with copper on Border-Leicester and Merino sheep
Authors: Marston Hedley R. , Lee Hector John
Published: March 2009

The effects of copper deficiency and of copper excess on mature Merino and Border-Leicester ewes were studied experimentally over a period of 3½ years with five evenly matched groups of each breed which were all depastured together as one flock on terrain where sheep develop cobalt and copper deficiency. All were treated with the equivalent of 1 mg. Co/day. Copper was administered thrice weekly in doses which provided for individuals of the respective groups the equivalent of nil, 1, 5, 50 and 100 mg. Cu/day.

All of the individuals that received only cobalt became anaemic; they lost weight and developed marked symptoms of copper deficiency.

The supplement of 1 mg. Cu/day was sufficient to delay the onset of these symptoms, but it failed to increase significantly the concentration of copper in the blood and it was insufficient to ensure normal myelin formation in the central nervous system of lambs born of the ewes which had received this treatment for 2 years prior to mating.
Digestion trials with swine: III. The digestibility of a coarse grade of middlings
Authors: Woodman Herbert Ernest
Published: March 2009

In the foregoing communication on maize digestibility (i), reference has already been made to the early difficulties which arose as a consequence of attempting to make measurements on rations consisting wholly of maize and milk. During, the period in which a mixture of milk and flaked maize was being fed, the pigs developed constipation troubles, due, as subsequent results proved, to the almost complete digestion and assimilation of the ration by the animals. At the time, however, it was deemed expedient to alter somewhat the scheme of the experiment and to feed the maize along with a definite weight of coarse middlings. In this manner it was anticipated that the fibre of the coarse wheat offal would promote peristaltic activity in the intestinal tract and thus assist the passage of undigested food residues.

The introduction of the middlings into the experimental ration made necessary the determination of the digestibility of this feeding stuff. The results of this trial are given for convenience in this separate communication.
On the presence of supernumerary mammary glands in cows and on their functional activity
Authors: Mackenzie K. J. J. , Marshall F. H. A.
Published: March 2009

(1) Rather over 50 per cent, of the cows in this country probably possess accessory or supernumerary teats, the number of which varies from one to three.

(2) In many cases at any rate, these teats are associated with additional glands.

(3) These additional glands are frequently functional and secrete milk.

(4) Ordinarily this milk is absorbed into the circulation, the lactose being secreted in the urine.

(5) The presence of active accessory or supernumerary glands is an undesirable characteristic since it involves the formation of milk which is not utilised.
Experiments and observations on forms and strains oftrifolium repensL
Authors: Ware W. M.
Published: March 2009

Attention is drawn to the fact that there is variation, both morphological and physiological, within the aggregate of plants known as “white clover.” After a detailed study of some of the characters of the plant, it has been determined which of these are constant and which are alterable by external conditions.

The cyanogenetic behaviour has not been found correlated with any recognizable external feature of the plant, and has been found constant from year to year, and under different soil conditions. For this purpose, separate plants grown in pots and “clone” plants on various soils were used.

As a result of the study of distribution of cyanogenetic and acyanogenetic forms of white clover, it has been found that “positive” or “negative” plants give rise, under “open” conditions of pollination, to offspring approximately 75 per cent, of which are possessed of like cyanogenetic character.
Studies on soil reaction: IV. The soil reaction of continuously manured plots at Rothamsted and Woburn
Authors: Crowther Edward M.
Published: March 2009

The Rothamsted Park Grass and Woburn Barley soils are almost all acid. Ammonium sulphate has caused a considerable increase in acidity, and sodium nitrate a slight decrease. Mineral manures have but little effect, and potassium sulphate has slightly increased trie acidity of the subsoil below the more acid plots. There is some evidence that the pH value 3·8 represents a maximum acidity in the Rothamsted soil. The change in pH value as a result of liming is less than that shown in the laboratory, owing in part to the subsoil acidity.
Studies of a Scottish drift soil. III
Authors: Ogg William Gammie , Hendrick James
Published: March 2009

It has been shown in Part II that a glacial drift soil in a comparatively unweathered condition has a considerable power of absorption for ammonia, although it has sometimes been held that it is the weathered material in soils that is responsible for the absorptive power. Glacial drift, as exemplified in the Craibstone soil, however, though its weathering is geologically recent compared with that of many English soils, has been subjected to age-long weathering since the glacial period, and in the process of soil formation a certain amount of weathering with the resultant decomposition has necessarily taken place. Craibstone soil has also been shown (Table II, Part II) to contain a fairly large percentage of organic matter and it might be contended that the absorptive power was chiefly due to either or both of these factors.
A method for estimating the number of active protozoa in the soil
Authors: Cutler D. W.
Published: March 2009

1. A method is described by which it is possible to estimate the numbers of active protozoa in a soil.

2. The total number of protozoa is first found by a dilution method. A fresh portion of the soil is then treated with 2 per cent. HCl (sp. gr. 1·15) overnight. By this means all active forms are killed. A second count by the dilution method gives the number of cystic protozoa in the soil. From these results the number of active forms can be ascertained.
The value of covariance in analysing field experimental data
Authors: Garner F. H. , Grantham J. , Sanders H. G.
Published: March 2009

It is suggested that the covariance method of statistical analysis is of considerable value in correcting for uncontrolled inequalities arising early in an experiment, and in analysing the effects of developmental factors on yield. As an example its application to the results of an experiment with beans is described.

It is with great pleasure that the writers acknowledge their indebtedness to Dr J. Wishart for his helpful criticism throughout the work.
Further experiments on the effect of removing the soluble humus from a soil on its productiveness
Authors: Crowther Edward M.
Published: March 2009

The removal of soluble humus by alkaline extraction from both a garden and a field soil reduced the productiveness over a series of crops in pot experiments. The field soil showed an initial but temporary increase in productiveness.
Studies in soil cultivation. II. A test of soil uniformity by means of dynamometer and plough
Authors: Haines William B. , Keen Bernard A.
Published: March 2009

Measurements are recorded of soil resistance to ploughing, taken with a view to testing the uniformity of a soil over a single field. The results have been examined for significance and indicate large variations over short distances. The differences have been represented by means of isodyne contours (i.e. lines of equal drawbar pull), drawn on a map.

The importance is emphasised of assuming and allowing for such variations before drawing conclusions from the drawbar pull recorded by different implements.

Preliminary work is described showing that the variations are correlated with clay content and also with the growth of a crop in its early stages.
The Carbon-Nitrogen Ratio of Soil Organic Matter
Authors: McLean W.
Published: March 2009

1. The average carbon-nitrogen ratio for fifty British soils from widely distributed areas approximates to the figure 10: 1 given by other investigators. The range of variation is from 6·5 to 13·5: 1. Sixteen foreign samples gave C/N ratios varying from 2·0 to 23·0: 1.

2. Soils from limited areas, whether high or low in organic carbon, give approximately constant ratios, but these ratios vary from place to place according to soil, climate, etc. It is suggested that the C/N ratios may be specific.

3. The C/N ratios of arable soils do not differ appreciably from those of grassland soils. The percentages of carbon and nitrogen are somewhat higher in the grassland samples than in the arable samples.
“Single Value” Soil Properties. A Study of the Significance of Certain Soil Constants. IV. A Further Note on the Technique of the “Box” Experiment (With One Text-figure.)
Authors: Keen B. A.
Published: March 2009

One of the previous papers by Coutts(1) in this series has directed attention to the value of the data obtained from what is now generally referred to as the perforated box experiment devised by the present writer and Raczkowski(3). In a further paper Coutts(2) has described an improved and simplified technique, which gives results that are either identical with the old method (pore space) or else related to them by simple linear expressions (water retention; volume expansion or “swelling”). As Coutts’ procedure is now being followed at Rothamsted, and is likely to be taken up by other workers, it appears desirable to record some hitherto unpublished data bearing on the technique of the method, obtained at Rothamsted some years ago by Prof. Ohga (S.M. Educational Institute, Mukden, Manchuria) and dealing with the effect on the results of the degree of packing to which the soil is subjected. The original method, followed by Coutts in its essential details, is to add the soil in small quantities, tapping the box on the bench after each addition, until the box is nearly full, at which stage the filling is completed in the manner described in the original communication.
Studies on calcium cyanamide. IV. The use of calcium cyanamide and other forms of nitrogen on grassland
Authors: Richardson H. L.
Published: March 2009

1. Ammonia added as sulphate of ammonia disappeared rapidly from a pasture grassland soil, while very little nitrate accumulated. In winter or early spring three-fourths of the added nitrogen had gone in less than 4 weeks. After the first fortnight there was little difference in the soil inorganic nitrogen from calcium cyanamide and from sulphate of ammonia. A moderate dressing of dicyanodiamide slightly reduced but did not inhibit nitrification; it did not appreciably retard the disappearance of inorganic nitrogen from the soil in winter.

2. Winter applications of sulphate of ammonia produced less increase in yield or nitrogen content of repeatedly mown herbage than did spring ones. A late autumn application was almost as effective as a spring one. Calcium cyanamide in late autumn or early winter was on the whole less effective than sulphate of ammonia, but in spring the two were substantially equal. There was little evidence that calcium cyanamide was “slow acting” in comparison with sulphate of ammonia. Dicyanodiamide was practically inert so far as the effect of winter dressings on yield or nitrogen uptake was concerned.
Nitrate Fluctuations in a South Australian Soil
Authors: Prescott J. A. , Piper G. R.
Published: March 2009

The fluctuation in the nitrate content of arable soils in southern Australia is of special significance in connection with the practice of bare fallowing as a preparation for wheat growing. In the wheat areas of Western Australia, South Australia, Victoria and the southern districts of New South Wales, fallowing is the recognised cultural basis for successful wheat production, and from a purely mechanical point of view the practice in the hands of the more skilful farmers has probably reached a degree of perfection which it would be difficult to surpass.
The Development of the Soil Profile in North Wales as Illustrated by the Character of the Clay Fraction
Authors: Robinson G. W.
Published: March 2009

1. The changes in composition of the clay fraction in different horizons of some typical North Welsh profiles have been studied.

2. The changes in the molecular ratio of silica to sesquioxides (SiO2/Al2O3+ Fe2O3) throughout a soil profile afford an indication of the nature of the eluviation which has affected the mineral portion of the soil.

3. The data for North Welsh soils indicate a general tendency to enrichment of the lower layers in sesquioxides, particularly ferric oxide, at the expense of the surface layers.

4. The silica-sesquioxide ratio of the clay fraction is an important aid to series definition.

5. The soils of North Wales, particularly in the uplands, have probably been subjected to considerable erosion in the past. The profiles are therefore considered to be more or less truncated.
Studies of the nutrition of young animals. I. Energy exchanges in the growing pig.
Authors: Wood T. B
Published: March 2009

The facts and considerations set out above provide the information necessary to enable an intelligent pig-keeper to compute on a logical and scientific basis a series of rations which from the energy point of view will produce any desired rate of live weight increase within the capacity of his animals. It is however necessary to make the reservation that the data apply strictly only to pigs of the Large White breed kept under good conditions and liberally fed.

It should also be noted that the method can only be applied to animals of known age and weight.

The method is applied as follows:

1. From the age of the animals read off from the basal metabolism chart, Fig. 1, the intensity of the basal metabolism per square metre per hour.

2. From the live weight—surface chart, Fig. 2—read off the surface area in square metres corresponding to the animal's live weight.

3. Multiply the basal metabolism per square metre per hour by the area of the animal's surface in square metres. The product multiplied by 24 gives the basal metabolism of the animal per day.

4. To get the practical maintenance requirement add to the basal metabolism per day 1000 calories to allow for an average amount of muscular effort.

5. Decide the growth rate in pounds of live weight increase per day at which it is desired to aim. The growth rate curve, Fig. 4, will help in assessing this figure.

6. Read off from Fig. 3 the calorie value per lb. of live weight increase corresponding to the live weight of the animals under consideration, and multiply the figure there found by the desired live weight increase in lb. per day. This will give the productive ration in calories per day.

7. The total ration is then found by adding together the maintenance requirement estimated in 4 above and the productive ration estimated in 6 above. This gives the total ration in calories of net energy.

8. Transform calories of net energy into lb. of meal on the assumption that 1 lb. of meal supplies to the pig 1000 calories, or preferably that 1 lb. of starch equivalent supplies 1500 calories.
Observations on the effect of method of management at mating on bovine fertility
Authors: Laing J. A.
Published: March 2009

1. The fertility records of two groups of bulls, one group used for controlled service, and one group used for free service, were compared over a period of one year.

2. The fertility of the free-service group was consistently better except during the months of December, January, February and March.

3. The difference in fertility between the two groups was correlated with the varying length of the oestral periods of the cows at different seasons of the year.

4. It is suggested that the higher fertility in the free-service group was due to a closer relationship of service to the end of heat and thus to ovulation.
A New view of the effect of Temperature on Milk Production in Dairy Cows
Authors: Campbell K. W. D.
Published: March 2009

There is still much difference of opinion as to the effect of temperature on milk production from the point of view of its effect on both quantity and quality at successive milkings or on successive days.
The chemical composition and nutritive value of ryegrass-seed meal, clover-seed meal, lucerne-seed meal and sainfoin-seed meal
Authors: Woodman H. E. , Evans R. E.
Published: March 2009

The wartime expansion in the home production of grass, clover and other seeds raised the question of the value of such seeds as food for livestock, since during the later years of the war, surpluses that had been discarded on account of low germination or other causes were being sold to compound manufacturers for inclusion in cattle foods. During 1944, the writers made determinations of the digestibility and starch equivalents of the following seeds: ryegrass (a mixture of Italian and Perennial), red clover, lucerne and un-milled sainfoin. All the samples were reduced to a fine meal before being submitted to test in the digestion trials.

Apart from its lower content of digestible ether extract, ryegrass-seed meal resembles oats in respect of chemical composition, digestibility and starch equivalent. It is a carbohydrate concentrate, containing, on the dry matter basis, 69·4% of starch equivalent, including 7·3% of digestible protein.
Chick Rearing II. The bacterial syndrome arising from a diet which is conducive to six-day disease
Authors: Mann T. Barton
Published: March 2009

In his observations on six-day disease, Taylor (1944) reported that the chicks which died on his preliminary experiments gave negative results on bacteriological examination.

Many workers hold that for routine examination of poultry, a quick, convenient and inexpensive method of detecting certain specific bacterial infection is to inoculate slopes of nutrient agar with liver or other tissue, and incubate at 37° C. It is claimed that some organisms often grow in pure culture from diseased chicks, and that this method is especially suitable in the detection of S. pullorum or S. gallinarum infections. The resultant growth can be washed off in saline solution and tested by specific agglutinating sera or by testing on certain carbohydrates.
A Comparison of Methods for Determining the Hydrogen-Ion Concentration of Soils.
Authors: Best R. J.
Published: March 2009

1. The antimony oxide electrode has been applied in a simple form to measure thepH value of soils.

2. ThepH values of representative Australian soils have been determined by means of the hydrogen, quinhydrone and antimony oxide electrodes and the results compared.

3. The limitations of the quinhydrone electrode have been investigated and their nature elucidated, special attention being paid to alkaline and manganiferous soils.
The inter-relationships of individual proteins and carbohydrates during fermentation in the rumen of the sheep. II. The fermentation of starch in the presence of proteins and other substances containing nitrogen
Authors: Lewis D.
Published: March 2009

1. The inter-relationships of starch and proteins during fermentation in the rumen are measured by estimating volatile fatty acids, ammonia, lactic acid and amino acids after administering the starch and protein supplements alone or together.

2. The presence of casein stimulates the formation of volatile fatty acids from starch. Simpler nitrogen-containing compounds are less effective than casein; other proteins are as effective as casein provided they are fermented as rapidly in the rumen.

3. Proteins can be divided roughly into three groups on the basis of the rapidity with which they give rise to ammonia in the rumen: casein, gelatin, ground nut protein > soy protein, wheat gluten > bovine albumin, zein.

4. The proportion of acetic acid falls and of propionic acid and higher acids rises as proteins that are rapidly fermented are placed in the rumen.
An index of soil texture
Authors: Hardy F.
Published: March 2009

1. A procedure is described for evaluating an “index of texture” (I.T.), based on determinations of moisture contents at the point of stickiness (P), and of sand contents (S) of soil samples.

2. The procedure is simple, and allows of a rapid laboratory examination of a great number of spot samples, so that detailed texture maps can readily be constructed.

3. Employed in conjunction with soil-reaction maps, the texture maps form a useful basis for detailed investigations of soil genesis and soil fertility.
The capillary pull of an ideal soil
Authors: Hackett Felix E. , Strettan John S.
Published: March 2009

1. The capillary pull of an ideal soil has been determined by measuring the maximum hydrostatic pressure (H) sustainable by a liquid surface formed, amongst an assemblage of uniform spheres of mean diameter 0·0374 cm. (2a). It has been found that using liquids of low surface tension like benzene to avoid contamination, the constant K in the equation Hgp = KT/2a has the weighted value 9·5.

2. Values of K for single apertures between three and four spheres in contact have been determined, using steel spheres of a diameter ⅛ in. and benzene. It is found that K does not vary rapidly for four spheres and has a value between 9 and 10 for apertures in which the ratio of breadth to length varies between 1·0 and 0·4.

3. The equivalent capillary tube is the circular or elliptic cylinder touching the spheres forming the aperture. This assumption gives values of K in fair agreement with observation.

4. The value of K is practically independent of variations of pore-space ranging from 36 per cent, to 40 per cent, such as usually occur in ordinary packing.
The retention of protein by growing pigs
Authors: Th Reimers J. H. W. , Bartel L. H.
Published: March 2009

1. Exp. I was conducted with two pigs in each group, which pigs were kept during certain times in digestion boxes, permitting the separate collection of faeces and urine.

2. The total amount of food given to the pigs was slightly below the present standards.

3. The different rations contained different amounts of protein and different amounts of non-nitrogenous constituents.

4. Exp. II was conducted with one pig in each group and served to control and supplement the data collected in the previous experiment.
Clover rot
Authors: Weston W. A. R. Dillon , Loveless A. R. , Taylor R. Eric
Published: March 2009

1. Clover sickness caused by Sclerotinia Trifoliorum is widely distributed in the American continent and western Europe; and in Britain it is often of considerable importance, especially in parts of East Anglia and Yorkshire. The severity of the disease is dependent upon the season, and in some countries very severe financial loss may result.

2. Most of the commonly grown legumes are subject to the disease, but they vary in their susceptibility. Peas affected with the disease have not been observed in the field although they succumb to artificial inoculation.
A preliminary note on the effect of sodium silicate in increasing the yield of barley
Authors: Fisher R. A.
Published: March 2009

The addition of sodium silicate has been found to increase the yield of barley to a considerable extent, this effect being most marked when no superphosphate is added.

The phosphatic content of the ash is not greatly increased in the grain, and is diminished in one case in the straw; the conclusion from this observation that the silicate does not act by releasing soil phosphates, but as a plant stimulus, overlooks the fact that the addition of silica to the ash naturally reduces the percentage of other constituents, and should be discounted.

The phosphate removed annually in the crop is greatly increased on the plots receiving silicate, even when this removal has continued for many years without replacement.

That additional phosphate is actually made available to the crop on the plots receiving silicate is shown by the increase in the proportion of phosphate in the dry weight of the crop, which appears on all the plots, and at all periods.

This increase is quantitatively sufficient to account for the increased yield in grain and straw, without postulating the aid of any stimulus to plant growth.
A study of the metabolism of two breeds of pig: (With some remarks on a third)
Authors: Deighton Thomas
Published: March 2009

The metabolism of a Berkshire and a Middle White pig has been investigated by means of the calorimeters at the School of Agriculture, Cambridge. The general routine and technique of the observations have been as heretofore.

Measurements of the fasting katabolism of each of the two pigs have been obtained in a series extending from an early age to maturity, and the phenomena in general follow the lines of those originally discovered in the Large White; but the fasting katabolism of the Middle White was below that of the Large White earlier studied.

The fall in body temperature and in metabolism during the fasts were found to be correlated, and the possible effect of skin colour in this matter is noted.

The effect of environmental temperature is investigated and reasons are given for supposing that the critical temperature of the Middle White pig is very low.

It is concluded that the existence of a maximum somewhere in the curve showing fasting katabolism per unit area at different ages is necessitated by the two physiological facts (a) that warm blooded animals have to be maintained at a temperature which varies only within very narrow limits, and (b) that the processes of growth are accompanied by waste of energy as heat.
Body mass loss and body fluid shifts during dehydration in Dorper sheep
Authors: Degen A. A. , Kam M.
Published: March 2009

Dorper sheep are raised in extreme desert areas. Body mass loss and body fluid shifts were measured in Dorper rams denied water for 4 days and offered only wheat straw. The rams lost 16·3% body mass, 22·0% total body water volume, 35·1 % extracellular fluid volume and 41·7% plasma volume. On first drinking following dehydration, Dorpers were able to consume 19·7% of their dehydrated body mass and 100·3 % of their body mass loss. It was concluded that Dorpers can survive in harsh deserts through their ability to withstand dehydration and quickly replenish body mass losses when water becomes available.
Studies in Tropical Soils. III. The Shrinkage Behaviour of Lateritic and Kaolinitic Soils
Authors: Hardy F.
Published: March 2009

V. Summary

1. This article describes the comparative results of the determination of shrinkage constants (Haines’ method) and of certain soil moisture constants for a series of clay soils representative of three important classes, namely,tropical red soilsderived from igneous rocks and from limestone,kaolinitic soilsand materials, andgrey and yellow soils, mainly derived from aqueous sedimentary rocks.

2. An attempt is made to interpret the data in terms of Wilsdon's micro-reticular hypothesis of soil colloidal structure, and to explain the physical significance of some of the constants measured, particularly sticky point moisture (S), loss on ignition (I), water uptake from aqueous vapour (H, R), and Haines’ “residual shrinkage” moisture content (d).

3. The results indicate thattropical red soils closely resemble kaolinitic materials in their shrinkage behaviour and moisture relations, but that they are intermediate between this type and grey and yellow soils, which exhibit characteristic high total shrinkage, marked residual shrinkage and high adsorptive capacity for moisture and for cations.

4. A brief review of recent literature concerning the mineralogy of clay minerals (based on X-ray analysis and optical examination) is offered in support of these findings.

5. The need of detailed mineralogical investigations of the products of weathering of rocks under humid tropical conditions is urged. Such study might reveal the causes of the characteristic and peculiar field properties of tropical red soils which appear to have been neglected by soil physical-chemists.
The prediction of monthly rainfall as exemplified by data from south-east England
Authors: Holland D. A.
Published: March 2009

A study is made of 46 years' records of rainfall for each of the months April to September. Following the determination of the distribution of monthly rainfall recommendations are made as to the best method of specifying rainfall and of predicting the rainfall to be expected on the basis of previous observations.
Sugar-beet pulp as a source of pectin
Authors: Codling A. J. , Woodman H. E.
Published: March 2009

It has been shown that dried sugar-beet pulp contains a high percentage of pectose. A number of successive digestions of 1 hour each with 0·5 per cent. ammonium oxalate at 100° C. extracts an amount of pectin equal to 34·5 per cent. of the weight of dried beet pulp, basing the determination on the weight of crude pectin precipitated when the extracts are run into 95 per cent. alcohol. A single prolonged digestion gives a yield of crude pectin equal to 32·2 per cent. of the dried beet pulp.

Digestion with acidic reagents, such as 0·5 per cent. oxalic acid, 0·6 per cent. tartaric acid, N/20 hydrochloric acid, etc., leads to a quicker extraction of pectin, owing to a speeding up of the pectose to pectin hydrolysis. The yield of pectin, however, is not thereby necessarily enhanced, since under such conditions the pectin undergoes a slow secondary hydrolysis during the extraction with the formation of reducing substances not precipitated by alcohol.

Prolonged digestion at 100· C. of dried sugar-beet pulp with water alone also leads to a satisfactory extraction of pectin.
Chick rearing: VIII. The preparation of a sensitive and diagnostic stained antigen for the rapid whole-blood test for bacillary white diarrhoea of chicks
Authors: Mann T. Barton
Published: March 2009

A method is presented for the preparation of a sensitive and diagnostic stained antigen for the detection of fowls suspected of infection by the organisms found in epidemic bacillary white diarrhoea (pullorum disease).

Evidence is presented that an antigen prepared from organisms grown in a medium which provides for the peculiar growth requirements of the anaerobic organism associated with anaerogenic pullorum, is more sensitive than antigens prepared from organisms grown on media which lack these peculiar growth factors.

A stained antigen has been prepared which is agglutinated by pullorum antisera in 15 sec. at 4°C. and in 6 sec. a t 15°C. and which is not agglutinated by normal sera in 5 min.

The author wishes to thank the Directors of Messrs J. Bibby and Sons, Ltd., for permission to publish these papers.

In particular he would thank Mr J. Pye Bibby for his keen interest in the investigations and for his loyal support throughout.

In addition he wishes to thank Miss Margaret Davies for her assistance in the bacteriological investigations, and Miss Margaret Shafto for laboratory work and the compilation of relevant data.
Decomposition of cacao leaves under natural conditions
Authors: Humphries E. C. , Rodrigues G.
Published: March 2009

1. A method is described whereby absolute changes in the organic and mineral constituents of cacao leaves during decomposition may be followed.

2. On a basis of their behaviour during decomposition, the components measured fall naturally into three groups. The first group comprises lignin, total protein, resistant protein, dilute-acid protein, concentrated-acid protein and nitrate-nitrogen; these exhibit an absolute increase during decompositión. The second group, represented by hemicelluloses, cellulose and pentosans, all show a downward trend, the decrease being most rapid at the outset. Alcohol- and ether-soluble substances constitute the third group and are characterized by a very rapid decrease during the first few weeks of decomposition.

3. A large amount of material soluble in dilute acid which is neither protein nor reducing sugar is not accounted for; this on a carbon basis constitutes over 50% of the dilute acid hydrolysable fraction. The trend of this fraction is somewhat similar to the carbohydrate fractions. It is pointed out that this fraction should not be neglected in a proximate analysis of decomposing organic matter.

4. Potassium exhibits a very rapid decrease at the onset of decomposition, and the trend is closely parallel to the alcohol- and ether-soluble substances. At times of heavy leaf fall there is consequently a marked manurial effect which may amount to the equivalent of 1 cwt. of sulphate of potash per acre.
Control of potato golden cyst-nematode, Globodera rostochiensis, by nematicides applied once or twice in two rotations
Authors: Whitehead A. G. , Nichols A. J. F.
Published: March 2009

In soil moderately infested with potato golden cyst-nematode, Globodera rostochiensis, nematicide treatments which lessened soil infestation when a susceptible potato crop was grown permitted a satisfactory second crop to be grown 3 years later without further treatment. In two experiments on heavily infested sandy loam on the same farm (Woburn Experimental Farm, Bedfordshire), aldicarb or oxamyl, incorporated in the seedbed in 1979 or 1980, greatly increased yields of Pentland Crown tubers and reduced the number of eggs left in the soil after harvest, but had little effect on a second crop of Pentland Crown potatoes grown 4 years later. Application of aldicarb or oxamyl to the seedbed before this second crop of potatoes increased yields and lessened nematode increase. The injection of 1,3-dichloropropene mixture (Telone II) into the soil in autumn at 224 kg/ha in one of these experiments did not enhance the nematode population control achieved by aldicarb or oxamyl alone.
The design and interpretation of experiments to study animal production from grazed pasture
Authors: Owen J. B. , Ridgman W. J.
Published: March 2009

Experiments designed to assess differences between treatments in pasture productivity as measured by the production of animals are complicated by the stocking rates chosen. The paper attempts toderive a simple model relating production per animal and production per unit area to stocking rate for meat animals, based on biological considerations.

A method is proposed which would allow meaningful grazing experiments to be carried out employing only one stocking rate, thus considerably reducing the expense of this type of experimentation.

The model is applied to some recent data obtained by Hodgson (1966) and Appleton (1967, personal communication).
On the effect of sunshine on wheat yield at Rothamsted
Authors: Tippett L. H. C.
Published: March 2009

The method used in this paper to reduce sunshine data is that developed by Fisher(1). It consists, briefly, in fitting to the distribution for each year, a curve

where T0, T1T2, etc., are orthogonal polynomial functions of zero, first, second, etc., order in time. The constants s0, s1, s2, … etc., are found by least squares, and are correlated with similar rainfall constants (r0, r1, r2 etc.) and with the crop.

The regression of the wheat yield on rainfall has already been found (1), so a method has been devised, whereby those results can be used in order to find the partial regression of wheat yield on the sunshine sequence, eliminating all rainfall effect.
The proteins of green forage plants: I. The proteins of some leguminous plants
Authors: Davies W. L.
Published: March 2009

Attention has been drawn to our ignorance concerning the nature of the proteins of green forage plants and the gap in the science of nutrition which arises thereby in trying to apply to forage plants results obtained from proteins of concentrated foods.

Methods of extraction of proteins from green tissue are outlined and applied to the study of the proteins of some common representative leguminous plants.

The proteins so isolated have been analysed and characterised. Proteins thus prepared were found to resemble each other closely with respect to distribution of nitrogen into three groups.

Representative samples of proteins were found to differ appreciably in their content of the different diamino acids as determined by the van Slyke method, showing variation to occur in the composition of protoplasmic proteins within a natural order, which confirms the observations of other workers on seed proteins within a natural order.

The occurrence of large amounts of mineral matter in the extracts from lucerne, vetch and sainfoin, but not in those of the two clovers, together with the difficulty of obtaining pure samples of proteins from the clovers, points to the slightly less nutritive properties of the latter owing to the lesser availabilities in them of both the protein and ash.

The nitrogen distribution in the protein-free extracts shows the amide nitrogen to be constant but ammonia nitrogen to be variable.
The reaction, exchangeable calcium, and “lime requirement” of certain Scottish soils
Authors: Ogg W. G. , Dow W. T.
Published: March 2009

1. Of a large number of cultivated soils examined, chiefly from the south-east of Scotland, the majority had a pH between 5 and 6·5, a “lime requirement” of 0·05 to 0·25 per cent. CaCO3 and an exchangeable calcium content of 0·1 per cent, to 0·45 per cent. CaO.

2. A general agreement was observed between these three sets of figures although numerous exceptions occurred.

3. The reaction of a district of six square miles was studied in detail and of a single farm in still greater detail.

4. Long unploughed soils were found to have a low pH, a low content of exchangeable calcium and a high “lime requirement.”

5. Woodland, hill and heath soils were characterised in their surface layers by an extremely low pH (below 5 as a rule), a low content of exchangeable calcium (usually less than 0·1 per cent. CaO) and a high “lime requirement.”
The influence of the stage of lactation and the breed of the cow on the yield and quality of the milk
Authors: Drakeley T. J. , White Margaret K.
Published: March 2009

The principal factors influencing the yield and quality of milk are (1) stage of the lactation period, (2) breed of the cow, (3) interval between milkings, (4) age of the cow, (5) individuality of the cow, (6) efficiency of the milker, (7) temperature and weather conditions, (8) health of the cow, (9) feeding.
The joint influence of the period of lactation and the age of the cow on the yield and quality of the milk
Authors: Drakeley T. J. , White Margaret K.
Published: March 2009

The respective effect of the period of lactation and the age of the cow on the yield and quality of the milk have previously been studied separately (see J. Agric. Sci. 17, PtI, p. 118, “The Influence of the Stage of Lactation and the Breed of the Cow on the Yield and Quality of the Milk,” and 17, Pt III, p. 420, “The Influence of the Age of the Cow on the Yield and Quality of the Milk”), and an analysis of the data has now been made with regard to the joint influence of these factors.
The composition and nutritive value of sugar beet pulp
Authors: Woodman H. E. , Calton W. E.
Published: March 2009

The object of the investigation which has been described in the present communication has been to secure information concerning the feeding value of sugar beet pulp as produced at the present time in this country. Data have been obtained respecting:

(1) The composition and digestibility of wet sugar beet pulp.

(2) The composition of dried sugar beet pulp and the digestibility of this feeding stuff when fed to ruminants (a) in the dry condition, and (b) after preliminary soaking in water.

(3) The composition of molasses-sugar beet pulp.

Data have been given showing the amounts of sugar beet by-products which are becoming available for use on the farm.

The commercial processes of drying wet sugar beet pulp, and the method of manufacture of molasses-sugar beet pulp, have been described.

It has been shown that crude fibre (20.3 per cent.) and N-free extractives (65.7 per cent.) constitute together more than four-fifths of the dry matter of sugar beet pulp, the latter being deficient in respect of protein, ash and oil. The carbohydrate of sugar beet pulp is invested with, special interest, being mainly in the form of pectose. A short account of the chemistry of the pectic substances has been given.