ALBERT

Description: 1. Under artificial conditions of plant growth, the relative development of carotene is very poor. The absence of sunlight appears to be the main cause.2. Under field conditions, the maturity of a plant plays an active part in determining the carotene content, which gradually decreases with age. This phenomenon is less discernible among the legumes. The nitrogen content generally runs parallel to the carotene.3. The species of the plant seems to be a determining factor in the capacity of the plant for carotene formation.4. A study of the distribution of the carotene in different parts of the same plant shows that the leaves of grasses contain 3·1–11·0 times more carotene than the stems. The earheads and stems have almost equal amounts. With the growth of berseem and lucerne, the ratio of carotene in leaf to carotene in stem shows a tendency to increase, suggesting that the deterioration in the stem is comparatively more rapid than in the leaves when the plant becomes older.

Description: 1. Teart soils contain molybdenum in amounts varying from about 0·002 to 0·010% in the surface horizon and are neutral or alkaline in reaction and often calcareous. The contents of molybdenum increase down the soil profile. Teart soils are developed from Lower Liassic materials, but all soils formed from the Lower Lias are not teart. Those which are acid in reaction in the surface horizons are not teart even if their molybdenum content is high. Others which contain little molybdenum are also not teart; such soils cover a large area in Glamorgan.2. Molybdenum appears to be concentrated in the (uppermost) argillaceous component of the Lower Lias. The limestone contains little molybdenum. The soils of Somerset are largely derived from the upper, argillaceous component while those of Glamorgan are largely derived from the lower, limestone component. This may explain why the soils of Somerset contain much more molybdenum than those of Glamorgan.3. Somerset soils formed from Keuper, Middle Lias, Upper Lias and Cretaceous material generally contain little molybdenum and are not teart.4. How a knowledge of the relation between soil and teartness can be turned to practical advantage is briefly discussed.

Description: Conscious selection is the prime means of keeping the useful qualities of domestic animals at the level they have attained, and of improving them. Valuable economic qualities mostly show the polygenic type of inheritance and therefore continued selection can improve them by sorting out those genes in a herd or breed which are.most desirable for the breeder At the presenttime there is probably not one breed in existence with quantitative characters brought to the homozygous condition. It is the great genetic variation present in breeds which enables selection to be effective in bringing out desirable economic characters.

Description: The amounts of nitrogen and β-carotene have been determined in oat and barley plants at different stages of growth and with and without a late top dressing of nitrogenous fertilizer. The nitrogen decreases steadily until the kernels begin to fill; it is markedly increased throughout by the extra dressing. The β-carotene, which accounts for about 80% of the ‘crude’ carotene in the oven-dried material, continues to fall until it reaches very low values when the crop is ripe. There is a very close correlation between total nitrogen and carotene in the plant.

Description: An account has been given of recent work on the chemical nature of war-time swill and on the best methods of using this product so as to ensure the maximum replacement of concentrates, consistent with economical live-weight gains, in the rations of bacon pigs.Three different types of swill have been submitted to investigation: (1) a meat-rich military camp swill, characteristic of the material available during the first 18 months of the war; (2) processed urban swill, commonly known as concentrated swill; and (3) dried, balanced swill. In addition, the results of an investigation into the variation in composition of household and restaurant swill are also given.The different types of swill have been examined from the standpoints of (1) main ingredients, (2) chemical composition, both organic and mineral, (3) digestibility, when fed to bacon pigs, and (4) nutritive value in comparison with mixtures of common pig foods. The keeping qualities of processed urban swill and dried, balanced swill have also been investigated, and attention has been devoted to the problem of the seasonal variations of urban swill in respect of main ingredients, chemical composition and feeding value.

Description: The examination of 108 first year seeds hays showed the average crude protein content to be 9·0 ― and the average crude fibre content 25·7 ―. The crude protein content varied from 5·0 to 13·5 ― and was directly associated with the clover content.Figures obtained on hays cut in the second and third years of the ley suggest that the protein content falls, and the crude fibre content rises, with increasing age of ley.The composition and digestibility of twenty first year hays were determined and the average figures quoted for hays of high, medium and low clover content. The starch equivalent values of these hays were high and moderately constant, varying from 33·3 to 41·2, average 36·8. The protein equivalent values varied from 1·8 to 8·4 ―, average 5·1 ―.The composition and digestibility of four samples of second year seeds hay, two samples of third year hay, one sample of second cut hay in its first year and one sample of lucerne and cocksfoot hay were also determined.

Description: The mean change in the pH of 134 undiluted ejaculates of clinically normal bulls was –0·302 ± 0·027 after 1 hr. storage at 37°C. The greater the pH. change, the lower was the initial pH and the higher was the initial motility and the number of spermatozoa per c.mm. The greater the decrease in pH the poorer was the motility after incubation. The motility was better maintained in semen diluted with egg-phosphate medium, compared with undiluted semen, which agreed with the smaller pH change in this medium. There was no evidence of a relationship between the pH change and the motility after incubation and the period of time for which a high motility was maintained during storage. It is suggested that the determination of the initial pH and the pH change after 1 hr. incubation may provide a useful and accurate evaluation of the semen of the bull.

Description: An experiment designed to show the effects of a complete fertilizer and of water applied extra to the rainfall on the yield of carrots grown on a gravel soil in good heart, has demonstrated that the fertilizer mixture was entirely without effect. The interaction water level × fertilizer was not significant, so that the increases in yield of carrot roots (increases which were 61·46 and 127·5 ― above the mean of the plots for rainfall only in the case of the total crop, and 61·73 and 111·5 ― for ware carrots, for 3 and 6 in. of water extra to the rainfall, respectively) were due entirely to the additional water. The response in yield of the roots of the total crop and of ware to the second application of extra water showed no falling off compared with the response to the first extra application. There was evidence to prove that additional water caused heavier infestation of the roots by aphis.

Description: 1. Cut potato tissue possesses strong inherent powers of healing which are impaired by treatment with salts of copper, cobalt, nickel and iron. Treatment is followed by mould growth, particularly by Penicillium spp., this being most profuse with copper salts and least with those of iron.2. Association between mould growth and treatment with salts of copper, cobalt, nickel and iron suggests a periodic relationship.3. Development of Penicillium on potato tissues following treatment with salts of copper is greater than may be explained solely on the basis of saprophytic growth following phytocidal action and. the prevention of suberization.4. Under moist conditions, treatment of nonliving substrata such as straw, leather and skin with copper sulphate tends to prevent mould growth whilst considerable growth develops on these materials when untreated.

Description: An investigation has been made into the effect of time of application of nitrogen as sodium nitrate to the turnip. Experiments were arranged on a statistical basis, and were carried out in sand culture. The life of the turnip up to harvest was arbitrarily divided into three equal light periods, and the fourteen possible combinations of high and low nitrogen applied in these periods constituted the treatments. The absolute amount of growth was largely determined by the level of nitrogen, but the relative proportion of growth was independent of this level. Tops developed earlier than roots, and the effect of difference in nitrogen level was more marked with the roots than the tops. For a high yield of roots it seems desirable to apply nitrogen, early, but for a high yield of tops it would be preferable to apply the nitrogen as post-seedling dressings. The chief effect of level of nitrogen on moisture content was confined to the period in which the harvest took place. A comparison of top/ root ratios also showed that high nitrogen in the early stages of growth stimulated root development.We thank Mr J. F. N. Leonard for his help during this experiment.

Description: In the past twenty years there has been no noticeable decrease in the number of Helminthosporium infected oat and barley seed samples examined at the Official Seed Testing Station, Cambridge, and in the course of advisory practice. No reduction in the intensity of the seedling diseases caused by Helminthosporium has been noted during the first ten years under review. Formalin and copper carbonate were ineffective as seed disinfectants in reducing seedling mortality, and copper sulphate, although partially effective, had serious phytocidal effects and consequently cannot be recommended. Since the advent of the organo-mercury seed disinfectants a steady improvement in the control of these diseases has been noted, and field tests of such dressings have shown them to be eminently satisfactory. Barley straw infected with H. gramineum has been shown to be a source of secondary infection of barley seedlings.

Description: Two samples of ammoniated sugar-beet pulp and one untreated sample have been examined. One sample was ammoniated at room temperature and an increase of 1·94 % in nitrogen content obtained. The other sample ammoniated at 10 atm. and 80° C. showed an increase of 3·47 % in nitrogen content. The total nitrogen contents were 3·30 and 4·83 % respectively.

Description: 1. The data summarized in this paper relate to the live weight at killing, the carcass weight, the skin weight and the loss in dressing of 813 males and 289 females of various breeds and varieties of rabbit.2. The age at killing varied with the moulting process. The extent to which variation in age contributes to the variation in weight and accounts partly for some of the differences observed is not dealt with.3. Significant differences were noted between the live weights of the various breed groups, in both sexes.

Description: Digestibility tests with poultry, and one with rabbits, on brans produced under war-time conditions led to the following conclusions:1. Changes in war-time milling practice, brought about by the implementation of Government policy directed towards maximum production of flour for human use, at first led to the production of a fine bran, somewhat better in food value than prewar bran, and a coarse bran, of poorer quality than pre-war bran. Later, owing to dilution of the grist with barley, the quality of the fine bran deteriorated and became worse than that of prewar bran.2. The changes noted were largely caused by the extremely efficient removal of the starch by the millers, and reflect the ability shown by the milling industry in diverting to human food supplies the maximum possible edible food material present in the wheat berry.3. The superior efficiency of the rabbit's digestive system for dealing with fibrous foods, as compared with the fowl's, is emphasized by the differences in the amounts of digestible nutrients extracted from a given sample of coarse bran by these two classes of animals. 1 kg. of coarse bran yielded 2522 kg. cal. of metabolizable energy in the rabbit as compared with 1637 kg. cal. in the fowl.

Description: An attempt has been made in the present communication to assess the value for pigs of urban swill collected during the winter months, when the main ingredients are potato peelings, cabbage leaves and other vegetable residues, and also during the summer months, at which period of the year the quality of the swill is at its lowest level, the product containing substantial proportions of pea pods, cabbage leaves and cabbage stalks. The form known as concentrated swill was used in the digestion trials, since regular and adequate supplies of this could be guaranteed, and, being already cooked, it did not require any heat treatment before feeding.Chemical analysis showed that the winter swill, on account of the presence of the potato peelings, was distinctly richer in N-free extractives than the summer product. The latter, however, was richer i n protein and lime, and, as a result of the replacement of potato peelings by pea pods as the main ingredient, displayed a much more fibrous character than the winter swill.

Description: An account has been given of an experiment in cross-breeding carried out at the Northern Breeding Station of the National Poultry Institute at Rease-heath, Cheshire.The breeds used for crossing were the Rhode Island Red and the White Leghorn. Much care was taken to ensure that the birds were of good quality and were from outbred stocks.Fertility was at a high level of about 90 ―. It was significantly lower for White Leghorn × Rhode Island Red matings (88·3 ―) than for the pure White Leghorn matings (93·7 ―).Cross-mating had little effect on hatchability of fertile eggs. The fertile eggs from Rhode Island Red dams hatched better than those from White Leghorn dams. A suggestion is made that this may be associated with a difference of porosity in the eggs of the two breeds.

Description: Results are reported of sixteen replicated experiments on spring-sown barley and oats in south-east England to compare fertilizer sown in the drills with fertilizer broadcast. In thirteen of the experiments, fertilizer in the drills gave significantly greater yields of grain and straw than fertilizer broadcast, in two of the experiments the differences between the two were not significant; in only one experiment was the grain yield significantly greater where the fertilizer was broadcast.Fertilizers were twice as effective when sown in the drills as when broadcast. On an average, broadcast fertilizer increased the yields of grain and straw by 4·0 and 6·3 cwt. per acre respectively. Drilling the fertilizer with the seed gave over double these increases, viz. 8·0 cwt. grain and 14·6 cwt. straw per acre.Drilling the fertilizer with the seed tended to delay brairding. The crop on the fertilizer-drilled plots soon caught up and overtook that on the fertilizer-broadcast plots. Drilling the fertilizer with the seed increased tillering and decreased weed-growth.Not more than about 3 cwt. of a soluble fertilizer per acre should be sown in the drills or the stand of plant may be poor. For the same amounts of soluble plant food, the higher the analysis of the fertilizer the less is the delay in brairding.The possibility of obviating the delay in brairding by sowing the fertilizer near, but not in contact with, the seed is briefly considered.

Description: 1. An experiment has been conducted with dairy cows to find the effect on milk production of feeding rations with a high dry-matter content—typical war-time rations.2. It was found that where a ration high in dry matter is fed, the cow tends to refuse food, and a statistically significant fall in milk production results. The correlation between the refusal of food, calculated in terms of starch equivalent, and the fall in milk production was 0·959.3. The factors causing this inability of the cow to consume sufficient food to meet her total nutrient requirements have been considered. It has been concluded that dry-matter consumption is not an adequate method of expressing the amount of food a cow will consume, and that the major factor influencing food consumption is the palatability of the individual foods making up the ration.My thanks are due to Dr S. J. Rowland for chemical analysis of the individual foods used in the experiments.

Description: 1. A method of assessing the biological values of proteins by the slaughter method, using day-old chicks as experimental material, is outlined.2. Whale-meat meal, when added to a cereal basal ration, is shown to possess a high biological value for chicks.3. The method of preparation of animal proteins is shown to affect their nutritive value, whale meat dried at a low temperature giving better results than that dried at a high temperature.4. The nature and amount of a protein added to a cereal ration materially affects the efficiency of utilization of the gross energy of the ration. Arising therefrom, support is given to the system of expressing the nutritive value of feeding stuffs, and the nutritive requirements of animals, in terms of digestible protein and digestible nutrients or metabolizable energy.5. Outbreaks of feather picking in the whale-meat meal groups occurred, whereas none occurred in the basal group. A possible explanation for these outbreaks is given in the text.6. The presence of gizzard erosion was noted in all individuals in the whale-meat meal groups, whereas none occurred in the basal group.

Description: 1. With insemination of approximately 2 billion sperms, pregnancy resulted from inseminations up to 6 days prior to ovulation, but not when inseminations were made earlier, or on the day after ovulation.2. Ovulation was induced in one mare by injecting pregnancy urine extract when a large follicle was present in one ovary, although the mare remained anoestrous, as judged by vaginal and cervical secretions. This mare became pregnant from an insemination 2 days prior to the induced ovulation.

Description: It has been shown in these breeding investigations that it is possible to combine the winter hardiness of low-yielding varieties possessing characters unsuited for cultivation in this country, with many of the desirable features of the best two-row spring varieties at present grown for malting purposes. Although, with the production of the new hybrid variety Pioneer, a definite advance has been made in the production of a two-row winter barley for malting, there is no reason to suppose that further improvements cannot be made, and work is proceeding with this object in view. But in addition to the special problem of malting barley, the results so far obtained indicate that there is considerable scope in this hybridization of winter and spring varieties for the production of forms suitable for growing as feeding barleys. The hybridization of varieties differing so widely in their morphological and physiological characters, and also in their ecological adaptation, gives a wide basis for the selection of a great range of forms. On the other hand, distant hybridization of this type is liable to result in the production of a very high proportion of worthless material, involving the loss of the highest expression of the very specialized characters necessary in a barley possessing the attributes of a high-yielding malting variety with satisfactory field characters.

Description: A series of digestibility trials on fowls with a number of potato products led to the following conclusions:1. Raw potatoes, though readily consumed by fowls when mixed with other foods, are not readily utilized, the potato starch largely escaping digestion.2. Boiled potatoes are readily utilized by the fowl, the preliminary cooking altering the structure of the starch grain in such a way as to render the starch readily digestible.3. The energy derived from 1 lb. of cooked potatoes is, in the fowl, equivalent to the energy derived from no less than 5 lb. of raw potatoes.4. The food value of dried potato products is shown to be dependent upon the nature of the heat treatment to which the potatoes are subjected in the preliminary treatment of drying.5. Dried potato slices of the type produced in sugar-beet factory driers have a value approximating that of well-boiled potatoes, both values being compared on a dry-matter basis.

Description: 1. An accurate method of estimating the density of spermatozoa in a suspension by the haemocytometer is described.2. A rapid method of estimating the density of a semen sample by the use of Brown's opacity tubes is given. There is a simple linear relation between opacity and density, the latter expressed in terms of millions of spermatozoa per ml. being approximately five times the opacity standard.3. The rapid method is sufficiently accurate for use in insemination centres.

Description: 1. An investigation has been carried out on the food value of beef from steers and heifers. A very varied group was used, selected as being representative of the beef animals slaughtered in England in war time. The animals were from five breeds; ages varied from 1 to over 4 years, live weights from 6½ to 14 cwt. and dressing-out percentages from 50 to 62.2. The chemical composition of the beef varied widely. The fat from the edible meat, expressed as a percentage of the live weight, varied from 4·6 to 21·6 %, the protein from 6·1 to 7·4%, and the water from 22·8 to 27·4%. The ratio of fat to protein in the edible meat varied from 0·7: 1 to 3·4: 1.

Description: To study the total-life performance of all the 156 sows, they were divided into groups consisting of sows having produced 73 to 77, 78 to 82, 83 to 87, … pigs throughout their breeding life often litters. The frequency distribution, of total number of offspring born, thus obtained is shown in Fig. 2.

Description: 1. Clovers and Yorkshire fog are outstanding among pasture plants in their ability to absorb molybdenum from teart soils. Many teart pastures contain a fair amount of clover, but Yorkshire fog is only a very minor component of the herbage. Other grasses as well as Yorkshire fog often contain enough molybdenum to cause scouring.2. Acidic nitrogenous fertilizers decrease teartness by suppressing clovers and by reducing molybdenum uptake by grasses.3. Acidification of the soil by regular applications of sulphur would reduce the availability of molybdenum in the soil.4. Basic materials, such as lime and slag, increase molybdenum uptake by grasses on acid soils which contain a fair amount of molybdenum. They also encourage clovers and should, therefore, be used only with the greatest discretion on such soils.5. The percentage molybdenum content of newlysown grasses is low, but it increases with age. A system of short leys consisting largely of grasses would give an increased output of material of low molybdenum content.

Description: 1. Experiments have been made to determine the effect of treating alkaline soils with manganese sulphate on the quantities of manganese which can be extracted by N-ammonium acetate.2. Two soils of known total and ‘extractable’ manganese content were treated with manganese sulphate solution in the laboratory and re-analysed after definite time intervals. In the first of these, a calcareous soil from the College Farm, the extractable manganese decreased for 14 days after treatment, after which time manganese was again liberated, presumably due to a waterlogging effect. The extractable manganese in the second soil, a slightly alkaline soil with a high organic matter content, increased appreciably after treatment and remained at this level for the duration of the experiment.3. An experiment conducted in the field on a highly calcareous soil showed that the extractable manganese content down to a depth of 12 in., had fallen to its original level only 7 days after treatment. This behaviour is in agreement with the observations of other workers that there is little residual effect from manganese sulphate treatment for subsequent crops. The desirability of performing similar experiments on other soils is suggested.4. The effect of waterlogging and steam sterilization was to increase the quantities of extractable manganese in the soils examined.The authors wish to express their grateful thanks to Mr B. S. Furneaux, M.Sc, for the descriptions of the soils investigated, and to Dr N. H. Pizer for his valuable suggestions in the preparation of this paper. They are also indebted to Mr J. Hargrave of the Agricultural Institute, Kirton, Lines, for providing the Bourne Fen soil, and to Mr J. Tinsley, B.Sc., for pH and organic matter determinations.

Description: 1. An experiment has been carried out with dairy cows to find whether feeding the same ration in different ways has any effect on milk yield or milk composition.2. No differential effect on milk yield or milk composition of the three methods of feeding which were used could be demonstrated, in spite of an extremely accurate experimental technique. It was therefore concluded that there is no advantage in increasing the number of meals into which a ration is divided, or spreading the ration over a longer period.

Description: The present account is a sequel to an earlier publication on the composition and feeding value of potato cossettes and meal. It deals with the composition, digestibility and nutritive value for pigs and ruminants of potato flakes and slices, theresults of a large-scale pig-feeding trial with potato slices and the composition and value for pigs of potato dust, a by-product of the manufacture of potato slices. Details of the processes of production of these various dried potato products are included in the text.

Description: 1. The grazing habits of Aberdeen-Angus and Hereford beef cows, on pasture without supplementary feed, were studied over continuous periods of 24 hr. during the months of July, August and September. The pastures were from 3 to 7 acres in extent and contained a good growth of Kentucky bluegrass and wild white clover, with an average moisture content of 72 %.2. During each 24 hr. period the cows spent from 7 to 8 hr. only in grazing, whatever the length of the herbage. Of this time, only some 5 hr. could be counted as actually employed in gathering herbage, as the remainder was spent in walking short distances and in selecting the area to be grazed. On the average 60 % of the grazing was performed by day, when the average distance travelled was 2 miles, and 40 % by night, when the cows travelled only about half a mile. With a dense sward of from 4 to 5 in. in height, representing about 4500 lb. green herbage to the acre, each cow was able to consume about 150 lb. of green herbage, or 32 lb. of dry matter, daily. As the amount of green herbage decreased through grazing to 2200 and 1100 lb. respectively, the daily intake was correspondingly reduced to 90 lb. (20 lb. dry matter) and 45 lb. (10 lb. dry matter). On a pasture containing about 5000 lb. green herbage of about 10 in. in height, the average daily intake was only 70 lb. (20 lb. dry matter).3. Records were made also (the average figure for the 24 hr. period being given in parentheses) of time spent in lying down (12 hr.); time spent in cudding (7 hr.); frequency of defaecation (12); amount of manure (46 lb., covering an area of 8 sq. ft.); frequency of urination (9); frequency of drinking (once only, usually in late afternoon); and frequency of suckling calf (3, each for about 15 min. at 8 hr. intervals).4. The application of the results to pasture management is discussed.

Description: A brief account is given of the work done in these laboratories on swayback and a comparison is made with a similar disease occurring in Australia. The Australian disease is due to an uncomplicated Cu deficiency of soil and herbage, but it is shown that swayback in this country is due to neither a Cu deficiency of soil nor herbage but nevertheless the affected animals suffer from a Cu deficiency and respond to Cu medication.It is shown that ewes with a low blood Cu in Derbyshire on being transferred to Cambridge rapidly attained a normal blood Cu.Analyses of grass from widely separated swayback-affected areas showed that in no case was the Cu content low.A short discussion is given of the possibility of lead being implicated in the causation of the disease, but it is concluded that lead plays only a secondary role.In the discussion it is pointed out that there is much fluorspar in the affected area of Derbyshire.

Description: Ewes. There was some variation from year to year in the times of onset and end of the breeding season; on the average it was evenly spaced on either side of the shortest day. Occasionally ewes were served and became pregnant at times well outside the normal limits of the breeding season. Lambs were allowed to suckle the ewes for as long as they would; when lambing occurred more than about 100 days from the start of the season there was no delay in onset of heat in the ewe. When lambing was later there was some delay, but the duration of the lactation anoestrum shortened to a minimum near the middle of the season and then lengthened again.In the first half of the season the period of the oestrous cycle lengthened slowly and steadily; in the second part it became more variable, there was first a slight shortening, but upon the whole it continued to increase in length. From the start of the season the frequency of twinning increased quickly to a peak in about November and then declined for the rest of the season. At the end of the season there was a high proportion of services not fertile.Lambs. Growth in the first 2 months was greatest in those born in May; in the fourth to sixth months it was greatest in the earliest born and least in the latest, the highest weight at 6 months old being reached by those earliest born.

Description: The investigations described in this paper are concerned with the influence of the various war-time changes in milling practice on the composition, digestibility and nutritive value, both for ruminants, and pigs, of the wheaten milling offals. The need for obtaining a larger output of flour for human consumption led to the raising of the rate of flour extraction from 70 to 75 % at an early stage of the war, and this was increased further to 85% with the introduction of the ‘national wheat-meal loaf’ in 1942. Two grades of wheaten offals only were marketed at this stage of the war—fine bran and coarse bran. Early in 1943 it became permissible to incorporate a proportion of rye, barley or de-husked oats in the wheat before milling. It was considered unlikely that the inclusion of rye or de-husked oats would exert any adverse influence on the nutritive value of the milling offals. When barley is used to dilute the wheat, however, the husk from this grain finds its way into the offals, and it was therefore to be anticipated that the presence of the barley husk would cause the fibre content of the offals to be raised and their nutritive value to be lowered. Authority has been given for the use of a grist that will give rise to a flour containing up to 10% of barley flour, but at the time of writing it would appear that, in actual practice, flour millers have not exceeded 10% of barley in the grist itself.

Description: 1. Results obtained from two seasons' population studies of selected spring oat varieties in Scotland indicated that extent of tillering had little or no effect on yield. These results are in sharp contrast with those obtained by workers with wheat.2. The yield of individual plants under the conditions of the experiments became adjusted to differences in population density primarily by variation in number of grains per panicle. Spikelet weight tended to be negatively correlated both with population density (external competition) and with number of grains per panicle (intrapanicle competition). These factors tended to neutralize each other.3. The decrease in size of additional grains in spikelets with more than one grain was balanced by increased weight of the basal grains as compared with the weight of a single grained spikelet. Average grain weight per spikelet therefore tends to remain constant.

Description: The influence of two years of bare fallow on the fertility of light land exhausted by continuous cropping with wheat or barley for fifty years has been very great, the immediate result being an increase in the crop of wheat by 50% and of barley by 140% over the average yield of the unmanured plots for the ten years before the fallow was taken. A repetition of the fallow after a further period of five years of continuous cropping without manure gave a very similar result.Whatever had been the treatment of the land during the fifty years before the fallowing, the yield produced as a result of the bare fallow fell off very rapidly in the succeeding years, when no further manuring was given. In fact, after the first two or, at most, three years the crop, of grain went much lower than it had been before any fallowing had taken place. This falling off in yield was almost equally felt on plots which had been treated with artificial manures during the preceding fifty years as on those which had been unmanured throughout.

Description: 1. Growing young sugar-beet plants under continuous illumination before transplanting into the field induced stem elongation and anthesis in considerably greater proportions than in plants not exposed to continuous light exposure.2. The technique of growing young plants under continuous light exposure during the winter offers a means of rapid multiplication of small seed stocks, and also of isolating the various physiological types comprising the population. In particular, the technique should make it possible to select types resistant to bolting.3. Analysis of the glomerule populations obtained from the plants showing anthesis at definite dates indicates that there is a definite trend in the proportions of large, medium and small glomerules as the season progresses.

Description: 1. The question of the maintenance requirement of calcium for poultry is discussed.2. On the basis of curves relating intake of calcium to calcium in the droppings, a maintenance value for laying and non-laying birds is estimated.3. It is suggested that in the case of both laying and non-laying birds the maintenance requirement of calcium is about 0·10 g. and that the endogenous calcium value is about 0·05 g.

Description: 1. Evidence is presented in support of the view that the average daily retention of calcium from the food by the laying fowl is of the order of 50% of the intake for average daily intakes of about 1–3·5 g. calcium.2. It is suggested that the optimal calcium requirement of the laying fowl for sustained heavy production lies in the region of 4 g. calcium daily, and that of the standards proposed by Mitchell & McClure (1937) that based on a 50% utilization is more nearly in accord with the results of metabolism experiments.

Description: 1. A series of balance experiments to compare calcium carbonate, calcium sulphate and calcium gluconate as sources of calcium for laying hens is described.2. Not one of the three supplements showed all-round superiority, but calcium sulphate was the worst.3. The main results indicate that:(a) Calcium sulphate and gluconate cause scouring but carbonate does not.(b) The best retention of calcium occurs with gluconate and the worst with sulphate.(c) Calcium carbonate gives the best shells and calcium sulphate the worst.4. The experiments also throw fresh light on some more general aspects of calcium and phosphorus metabolism.5. On the basis of these general results and a review of the literature of blood calcium and phosphorus in laying hens a theory dealing with certain aspects of egg-shell formation is presented.

Description: 1. Increasing the ballast on pneumatic tyres, up to a certain weight, improves the tractor performance as judged by its speed, fuel consumption and wheel slip. Further increases beyond this point continued to decrease the wheel slip without having any marked effect on its speed or fuel consumption. No certain evidence was obtained that too heavy a ballast decreased the tractor's efficiency.2. The tyre load affects the maximum pull the tractor can exert while working reasonably efficiently, but this pull does not depend markedly on the speed of work. Wheel weights of about 12–13 cwt. seem to be the minimum required for optimum performance of the 36 or 28 in. tyres at pulls of 1800 lb. under fairly good ground conditions, and possibly a greater weight may be required by the 24 in. tyre.3. If the tractor is ploughing it is usually running tilted, and this tilt transfers sufficient weight on to the furrow wheel for it to work efficiently under most conditions. Additional ballast is, however, often necessary for the lighter land-side wheel.4. Tyre performance is much less dependent on inflation pressure than on ballast. Pressures below 10 lb./sq. in. were only of use in wet conditions when small amounts of additional ballast were not available. Pressures above 12 lb./sq. in. may allow excessive slip to take place and probably only need be used on the furrow wheel of a well-loaded tractor ploughing.

Description: Equipment. Simultaneous observation of the performance of several mole drains in heavy grassland requires recording flowmeters. Simple instruments recording instantaneous rate of flow have been designed and found satisfactory. A recording rain gauge is a necessary adjunct.Plot size and edge effects. Where the land is laid up in ridge and furrow, even though rudimentary, the ridge forms an effective barrier between furrows. One drained furrow at the edge of a plot is a sufficient, but not always necessary, guard against the neighbouring plot. Where the land is farmed on the flat, a single catch-water furrow forms adequate protection.The nature of British rainfall. Rainstorms producing drainage are almost invariably of discontinuous type, consisting of well-defined intense showers separated by periods of almost complete quiescence. Thus a storm of 8 hr. duration may consist of as many as six quite distinct showers.

Description: 1. A long-term investigation consisting of field, pot and laboratory experiments has been commenced to study the extent, rate, nature and significance of phosphate fixation in north Scottish soils with the ultimate objects of improving fertilizer practice and standardizing methods for determining readily soluble phosphate.2. Quantities of a phosphate-deficient soil derived mainly from granitic drift were treated with incremental dressings of phosphate and exposed in earthenware pots in the open. The soil had an initial pH of 5·80 and a total phosphate content of 0·250% of which 28% is soluble in constant-boiling HCl solution.3. The recovery of added phosphate by different methods from samples taken after varying periods of exposure has been studied. Data are given for extractions with calcium lactate, acetic acid, potassium bisulphate, citric acid, magnesium bicarbonate, sodium hydroxide, hydrochloric acid, and chloride and sulphate solutions, together with pot experiments and determinations by the Neubauer and aspergillus methods.4. Complete recovery is approached only in strongly acid and strongly alkaline extracts, and about 25% of the added phosphate is very firmly bound by the soil. The solubility varies greatly with the pH of the extracts and is very low at pH values in the region of 5. At lower pH values, however, the nature and concentration of the anions present are also of considerable importance. The results indicate a high capacity for fixing phosphate in difficultly soluble form.

Description: The treatment of cereal straws with dilute NaOH solutions has been developed in this country as a means of increasing the supply of digestible carbohydraten food for cattle. Watson (1941) has dealt with the principles of the treatment and has given a brief outline of the process, and it is not proposed to discuss the process or developmental work here. It is sufficient to say that the recommended standard process consists of soaking chopped cereal straw in 10 times its weight of 1·2–1·5 % NaOH solution for periods up to 22 hr., removing the soaked material from the liquor and washing free of NaOH.

Description: The results of digestion trials carried out some years ago in this Institute have led to the belief that at least 6–7 lb. of young, leafy grass is needed to replace 1 lb. of ordinary pig meal in the rations of bacon pigs. More recent farm-scale feeding trials at the Harper Adams Agricultural College have given rise to the conclusion that no more than 1¼ lb. of young grass is required for this purpose when the pigs are receiving, in addition to the grass, a basal allowance of 2½ lb. of balanced meal per head per day.

Description: 1. The sperm production of a pony stallion kept a constant high level when the collection of sperms was performed regularly three times a week. There was no adverse effect on the stallion or on the quantity and quality of the sperms. There is a negative correlation between the volume of semen and the concentration. The total number ejaculated remains relatively constant; the volume of accessory fluids is more variable.2. The motility of horse spermatozoa after dilution with eight different kinds of chemical media and stored at different temperatures was studied: Glucose-yolk-phosphate dilutor devised by Lamhert & McKenzie and glucose-yolk-tartrate dilutor devised by the author were found to be the best for the preservation of horse sperms at low temperature. There was not much difference between those diluted samples stored for 24 hr. at 10° C. and those slowly cooled to 1° C. Concentration of the semen by centrifuge is definitely beneficial for the preservation of horse sperms.3. Pregnancies were obtained by the insemination of sperms centrifuged and kept at 1° C. for 24 hr. The sperms of one stallion can be used for a great number of mares if artificial insemination is practised. The adoption of new techniques for the determination of the time of ovulation and for the induction of ovulation is suggested for successful artificial insemination of mares.

Description: Samples of bracken were taken at fortnightly intervals from June to November at two centres. These were separated into leaf and stem and analysed.Larger samples were treated for the preparation of proteins and sugars by passing the bracken through a roller-mill, precipitating the protein with acid and concentrating the juice for sugars.Chemical composition. The main points in the analyses of the whole plants were as follows, all figures quoted being on a dry-matter basis:(1) The crude and true protein contents of young bracken in early June were high, 21 and 18%, but these fell rapidly to 10% in mid-July and finally to 3% in October.(2) The lignin content was high throughout, rising from almost 20% in young bracken to 34% in the nearly dead material.(3) The cellulose content followed the lignin content.(4) In July and August the bracken contained about 10% of total sugars. A rapid fall occurred in October, and the final samples contained very little sugars.

Description: 1. A small-scale experiment in which cows have been fed at three levels for 3 weeks during mid-lactation has been carried out.2. The results show that the changes in milk yield due to changes in the level of feeding were relatively small.3. It has been suggested that where short-term food shortages occur in well-fed herds, economy should take place in the rations of the cows in mid-lactation rather than in the ration of the cows which are soon due to calve.

Description: The present paper deals with the composition and nutritive value of the following by-products of the pea-canning industry: (1) green pea pods; (2.) pea-pod meal resulting from the artificial drying of pea pods; (3) pea-pod silage as made in a tower silo; (4) molassed silage made in a sisalkraft silo from pea haulms with pods.Pea pods give rise to an excellent silage provided they are tightly trampled and a means for draining off the effluent is supplied. The silage is pale yellowish green in colour and has a pleasant, vinegary smell with little or no suggestion of the presence of butyric acid. It is much relished by sheep and cattle. It is superior in digestibility to ‘green fruity’ oat and vetch silage and contains, per 100 lb., 27·5 lb. of dry matter, including 15·9 lb. of starch equivalent and 2·3 lb. of digestible crude protein. No molasses need be added during filling, since the sugar naturally present in the pods ensures a favourable fermentation.

Description: A method is described for determining the field volume and the air space of a clod of any shape by filling its pores with a hydrocarbon oil, such as paraffin or tetralin, and determining its weight in the oil and in air before and after impregnation. The method appears to work well for clods of any moisture content.This method is shown to give values of these volumes entirely comparable with those given by the other accurate methods described in the literature. Its accuracy for clods of Rothamsted soil, weighing between 20 and 500 g., was probably at least 1 part per thousand, i.e. 0-1%.The method has been applied to the determination of the available water held by a soil and has been used to illustrate the effect of long-continued applications of farmyard manure to a soil in increasing the amount of available water it can hold.

Description: Digestibility trials with poultry were carried out with dura, carobs and hide-fleshings.1. Dura equals the feeding value of corn and exceeds that of wheat, barley and oats. The high feeding value of dura is due to the large amount of easily digestible starch, and to the very small percentage of crude fibre.2. Carobs. The main nutrient factor in carobs is represented by the totally digestible sugars contained in the N-free extract. Protein and crude fibre are not digested to any appreciable extent. The feeding value of carobs was compared with that of grain foodstuffs.3. Hide-fleshings are a by-product of the tanneries. They contain 66·25 % of protein, which is digested by poultry like meat-meal protein (89·9 %).The authors wish to thank Mrs Gnessia Rabinovicz for her untiring assistance in the execution of these experiments.

Description: 1. Cows and heifers were injected shortly before slaughter with an extract of horse pituitary or with pregnant mare serum gonadotrophin.2. These substances were administered at different times of the cycle or in pregnancy; various doses were given simultaneously with removal of the corpus luteum.3. A series of animals were given 1500 or 5000 i.u. at intervals from 5 days before to 3 days after expression of the corpus luteum; up to thirty ovulations were so obtained.4. A small number of cows have been treated and left to calve; there have been several twin and triplet births.

Description: 1. Field experiments on the use of cut ware setts with the potato varieties Arran Banner, King Edward and Majestic have shown that with proper handling no loss in plant establishment need result. When the cut setts are planted at the same distances as whole setts, there is liable to be a reduction in the yield per acre because of the lower yield per plant, but the actual rate of increase may be increased considerably by cutting because of the larger number of plants obtainable.2. No benefit has been found from the practice of dusting the cut surfaces of tubers of Majestic with slag, lime or ashes, while adverse effects resulted from the use of a fungicide and alum.3. The exposure of cut setts to drying conditions lowers their resistance to attacks by micro-organisms, and encourages the breakdown of the tuber flesh by bacteria of the carotovorum group.4. In general, the use of certain fungicides, either directly on the cut surface, or as a means of moistening sack coverings, is not to be recommended because of the adverse effects of the fungicide on the natural resistance of the live tissue of the tuber flesh.

Description: A modified method of estimating the carotene content of plant material has been described in detail. The modifications include a combined aqueous and alcoholic potash hydrolysis of the original material before extraction is carried out.A statistical analysis and a recovery test have shown this method to be relatively more efficient than methods similar to those described by other workers.

Description: A water-culture technique has been described which makes it possible to determine with precision the effects on plant growth resulting from the absence of traces of the various heavy metals.The essential nature of copper for plant growth has been confirmed, and the quantitative data presented show that the addition of traces of copper to a nutrient solution leads to increases of growth of the order of 200–1200%.The characteristic symptoms produced by growing oats, peas, wheat, Wimmera rye-grass, Phalaris, flax, tomato, subterranean clover, and lucerne in nutrient solutions devoid of copper are described. Copper becomes necessary for normal healthy growth at an early seedling stage and is required so long as active growth is proceeding. Optimum growth of oats was obtained throughout a wide range of copper concentration in the nutrient solution.Oats grown in a copper-free nutrient solution until the development of acute deficiency symptoms recovered and completed their normal life cycle on the addition of sufficient copper to the solution.The copper content of oats at various stages of growth has been determined. The proportion of copper in the dry matter of the plant was greatest in the young stages and rapidly decreased as growth proceeded.The copper content of mature oat plants showing symptoms of copper deficiency was less than 1·0 mg. per kg. whether grown in nutrient solution or obtained from copper-deficient soils. Oats which ceased growth from copper deficiency at an earlier stage of development contained a relatively greater amount of copper in their dry matter.

Description: An account is given of experimental work on the feeding of uncooked and cooked potatoes and sugar beet to laying stock. The available literature on the use of these foods for poultry is reviewed and an explanation is offered for the poor results which have generally followed the use of raw potatoes.A description is given of an experiment in which there were two control groups fed on mash, two groups on 3 oz. mash and 8 oz. potatoes daily, uncooked for one group and steamed for the other, and two groups on 3 oz. mash and 8 oz. sugar beet daily, uncooked in one case and steamed in the other.

Description: A comparison is made, under similar cultural conditions in pot experiments, of the behaviour of a number of varieties of wheat, barley, rye and oats on two soils on which oats had previously displayed pronounced symptoms of manganese deficiency.All of these cereals were found to develop disease symptoms on these soils, rapid recovery from which invariably took place after the plants had been sprayed with 1% manganese sulphate solution. Variations in deficiency symptoms in the different cereals are indicated and observations on the course of the disease throughout the season are recorded for some thirty-two varieties.

Description: 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.

Description: 1. An individual feeding experiment using forty-eight pigs and a group feeding experiment using twenty-nine pigs have been carried out with the object of testing the so-called Lehmann system of pig feeding, where the amount of meal allowed for the fattening pig is restricted to a basal ration of 2½ lb. each and farm bulky foods or food wastes fed ad lib. used as supplementary foods.2. Using a mixture of 6 parts mangold and 1 part biscuit waste as a supplementary food, live-weight gains only slightly less than with all-meal feeding have been obtained and a great saving in meal consumption effected. Under more favourable conditions as much as 1¾ lb. of meal has been saved for each 1 lb. live-weight gain.

Description: Flax crops from a number of centres in Northern Ireland and in Norfolk have been analysed for nutrient content.Flax removes from the soil about the same amounts of nutrients as an average crop of meadow hay, but more than spring barley and much less than mangolds.There is no obvious relation between percentages of any one nutrient in the crops examined and yield data, percentage fibre in crop or grade of fibre. It is suggested that local climatic conditions, physical make-up of soil and proper cultivations are of first importance in flax growing. The importance of a clean seed-bed and even depth of sowing, and of steady growth with no checks is stressed.

Description: 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.

Description: 1. Egyptian clover, sweet lupin, Lathyrus ochrus, Eragrostis tef and Vicia narbonnensis have been analysed as to their hexosan, pentosan and lignin content. The major part of the pentosan is soluble in 2 % HCl and therefore belongs to the hemicellulose fraction, whereas most of the hexosan is insoluble in 2 % HCl and forms part of the cellulose fraction.2. The digestibility of hexosan, pentosan and lignin has been determined by experiments with sheep. The digestibility of soluble pentosan and of insoluble hexosan (2 % HCl) was found to be very constant. It ranged from 64·0 to 66·2 % for pentosan and from 74·1 to 76·5 % for hexosan. ·Lignin was in all cases digested comparatively well, the digestibility coefficients being markedly variable, depending on the plant material. They ranged between 35·1 and 64·0.3. Faeces lignin yields lower methoxyl values than plant lignin. Therefore lignin appears to have been changed during passage through the animal body.4. The partition of hexosan, pentosan and lignin on crude fibre and N-free extract prepared from different plant materials is markedly variable.5. The major portion and best digestible fraction of plant lignin is soluble in alkali and is, therefore, contained in the N-free extract.

Description: 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.

Description: 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.

Description: 1. Experiments are described demonstrating a technique for raising sugar beet seedlings under glass during the winter to provide plants for seed production after transplanting into the field.2. The use of 24 hr. illumination for this purpose is discussed, and the effect of this illumination in resolving a heterogeneous population is described.3. The association between the growth habit of the seeding plant and root characters, glomerule yield, weight and size, and the time of anthesis is considered in relation to the recognition of types showing B. maritima and B. vulgaris characteristics.

Description: 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.

Description: 1. The colour pattern in the Essex breed shows continuous variation in width and in shape of the belt, in size and number of the distal white points, in pigmentation of the skin and in the occurrence of all-black colour.2. The variation in ear shape extends from long, hanging ears to small, erect (prick) ears.3. ‘Rose back’ was observed in a small percentage of pure-bred Essex pigs.4. Observed results of crossing Wessex with Essex pigs, and the similarity in variation of colour of the two breeds, indicate that the factors upon which the colour depends are the same in Essex and in Wessex, and that there is no genetical difference in colour in these two breeds.

Description: Mechanical peeling of potatoes removes an exceedingly thin skin that is notably richer in ether extract, fibre and lime, but much poorer in N-free extractives, than the thicker parings obtained by ordinary hand peeling. The latter, in respect of their general composition, do not differ to any marked extent from whole potatoes.The results of digestion trials with pigs have shown that potato peelings, after cooking, are highly digestible when included in the rations of bacon pigs. The N-free extractives, which form about 80% of the dry matter of the hand peelings, have a digestion coefficient of 96·2%. An allowance of 5 lb. of such peelings supplies as much digestible organic matter as 4 lb. of whole potatoes, and it is concluded that 1 lb. of barley meal in the rations of bacon pigs may be replaced by 4 lb. of potatoes or by 5 lb. of potato peelings. Both the potatoes and the potato peelings should be cooked before feeding.In conclusion, the writers take this opportunity of expressing their thanks to Messrs V. Thurlbourn and C. Bendall, in whose experienced hands the care of the experimental animals was placed during the digestion trials.

Description: The scouring of cattle and sheep caused by the teart pastures of central Somerset is due to the presence of molybdenum in the herbage in amounts varying from about 20 to 100 parts per million in the dry matter.The scouring can be prevented and cured by feeding or drenching with copper sulphate. A daily dose of 2 g. copper sulphate for cows and 1 g. for young stock, is sufficient to cure and prevent the scouring on very teart land. Less copper sulphate may be enough on mildly teart land.

Description: 1. Twelve pony mares were inseminated at various intervals (18 days to within 24 hr.) before ovulation with spermatozoa which had been concentrated by centrifugation and stored for 24 hr.2. Of fourteen inseminations, only two, both within 24 hr. of ovulation, produced pregnancies.3. The survival time of the stored spermatozoa within the female tract was concluded to be somewhat less than 24 hr.4. It is suggested that successful inseminations with stored spermatozoa could be made 24 hr. after the injection of prolan.This work was carried out while holding the Miss Aleen Curt Memorial Veterinary Research Scholarship from the Royal College of Veterinary Surgeons.My thanks are due to Dr J. Hammond and Dr A. Walton for their help and encouragement and to Mr F. T. Day for the loan of the ponies and for his help and instruction in the technique of examination.

Description: 1. Literature relevant to the elucidation of the role of riboflavin in chick nutrition is briefly reviewed.2. A series of experiments on the quantitative requirement of White Wyandotte chicks for riboflavin is described.3. The riboflavin requirement of White Wyandotte chicks for optimum growth to 6 weeks of age is the same as that for optimum efficiency of food utilization over the same period (3·0 μg. riboflavin per g. food).4. The riboflavin content for the prevention of curled-toe paralysis is 3·6 μg. per g. food, and is slightly greater than the requirement for optimum growth and food utilization.5. The curve relating the riboflavin content of the diet to the riboflavin content of the chick's liver has a sigmoid form, and in general tends to lie asymptotically to values of about 26 μg. riboflavin per g. fresh liver when the intake is grossly deficient, and 39 μg. riboflavin per g. fresh liver when the intake is fully adequate.6. It is suggested that the riboflavin content of the liver may be a more satisfactory criterion of the minimum riboflavin requirement for full well-being than the amounts necessary to secure optimum growth and prevention of curled-toe paralysis.

Description: Bracken cut in June was ensiled in various ways, and some of the products were examined for chemical composition, digestibility and palatability. The main findings were:1. Overheated silage was moderately palatable to sheep and cattle, but its digestibility was low and it approximated to wheat or barley straw in feeding value.2. Silage subjected to less heat was unpalatable, and in some cases was absolutely refused by sheep. The ensiled stems were preferred to the leaves. The digestibility was low but slightly better than that of the overheated silage.3. Ensiling seriously affects the digestibility of bracken protein. In two silages none of the true protein was digestible, and in one the digestibility of this constituent was only 12·9%.It is concluded that the ensiling of bracken is unlikely to prove profitable.

Description: Records are given for 1130 oestrous cycles in zebus and 678 cycles in grades. The mean length was 23·03 days in zebus and 22·42 days in grades. The mean duration of oestrus was 4·78 hr. in zebus. 7·40 hr. in grades. Neither exposure to additional light at night nor feeding a supplementary ration had any effect on the cycle of oestrus.Seasonal variations in both the cycle and oestrus occurred in zebus, but in grades they were much less marked. An association between climatic conditions and sexual function was noted in that a season of increased temperature and sunshine was associated with increased sexual function and vice versa.

Description: 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.

Description: 1. An experiment was carried out from 3 May to 10 October 1949 to compare close-folding with rotational grazing of dairy cows. With close-folding the cows were moved daily to an area of fresh pasture which was calculated to supply the day's feed requirements; the rate of stocking ranged from 50 to 80 cows per acre. With rotational grazing the cows were stocked on pasture at the rate of 6–8 cows per acre and moved from one pasture to another at intervals of 5–14 days. Two uniform groups of Ayrshire cows were used, and each group spent a period on each system of grazing. Two pastures, a ryegrass-dominant old pasture and a cocksfoot-dominant ley, were used, and as far as possible the pasture grazed by both groups of cows was similar. Nitrogenous top dressings up to 104 Ib. nitrogen per acre in the season were applied uniformly to both the close-folding and rotational areas. No supplementary feeding was given to the cows.2. The best methods of close-folding practised gave 215 and 201 cow-days of grazing per acre with 550 gal. milk per acre from the cocksfoot ley and 582 gal. from the permanent pasture. Rotational grazing on the same two pastures gave 181 and 138 cow-days and 450 and 351 gal. milk per acre respectively.

Description: The analysis of simple change-over trials based on Latin squares is considered. It is shown that several difficulties are encountered when estimates of residual effects are required. In particular, there may be biased error variances.In certain circumstances the amount of bias in the error variance can be estimated in a proportion of the experiments based on a given design. If this bias is sufficiently large to be of importance an average correction can be calculated for use with further experiments of the same type.

Description: 1. The myoglobin contents of selected muscles in horse, pig, domestic fowl and pigeon, and in the foetuses of horse, pig, sheep and cattle, have been determined.2. The order of increasing concentration of myoglobin in the adult animal (4 years) is given by the series heart, longissimus dorsi, diaphragm and psoas, the figures for draught horse being, respectively, 0·325, 0·465, 0·610 and 0·705% and for pig, 0·203, 0·280, 0·350 and 0·435%, and the ratios of these concentrations being the same in each animal.3. In both draught horse and pig, it is shown that the concentration of the pigment rises rapidly from birth, and that, after 2 years in the horse, and 1 year in the pig, it remains fairly constant, except in the case of horse psoas and diaphragm where there is a slow, but significant, rise throughout life.4. This relationship of myoglobin with age has been shown to be significant at a probability level of 0·1%.

Description: 1. Rumen contents of sheep given three different diets contained free bacterial α-amylase. The method of obtaining a cell-free rumen filtrate containing the enzyme is described.2. Amylase potency in the rumen was highest in the sheep given a diet of flaked maize, intermediate in that given a mixed diet of hay and concentrate and lowest in that given a diet of casein.3. The effect of rumen amylase on structural maize and potato starches has been investigated.4. Absence of amylase from sheep saliva was confirmed.5. Where flaked maize is fed, one of the organisms responsible for amylase production in the rumen of the sheep is Cl. butyricum.

Description: A study of residual phosphorus in soils resulting from the use of phosphate fertilizers has been made, using a simplification of Ghani's method for the fractionation of soil phosphorus.In cultivated soils all the residual phosphorus was extractable by successive extractions with 2·5% acetic acid-1% 8-hydroxyquinoline and 0–1 N-sodium hydroxide, and practically all had remained in the inorganic form; very little, if any, change in organic phosphorus was recorded as a result of the application of superphosphate.In pasture soils (uncultivated) the application of phosphatic fertilizers brought about an increase in both inorganic and organic phosphorus and, in addition, some of the applied phosphate may have entered a form not extractable by the two extractants. The increase in organic phosphorus was not directly proportional to the amount of phosphate applied, as were the increases in the extractable inorganic fractions. It tended to approach a constant value, irrespective of amount and nature of the phosphate applied.

Description: 1. The changes in the sheep population and in the sales of fat sheep have been examined for the West Wales region for the period 1940–8. These changes consist of a gradual annual decline in sales, whilst the severity of the 1947 winter conditions brought about a rapid drop in both sales and population by nearly 33% from 1946 to 1947.2. Analyses of sales of the four categories of fat sheep—rams, ewes, sheep and lambs—throughout the twenty-five collecting centres have been completed for the 4 years, 1943–6. These showed that lambs accounted for 85% of the fat sheep sales in this region.3. It was found that the average estimated dressed carcass weight (e.d.w.) of the four categories of sheep (rams, ewes, sheep and lambs) declined gradually from the collecting centres of west Pembrokeshire to the inland centres on the eastern boundaries of the region. This cline is also found in the case of the summer suckling lamb, the autumn wether lamb and the winter-fed fat lamb.

Description: Continuous records of the temperature of potatoes stored in clamps were made in 1942–3 (one clamp) and in 1943–4 (three clamps). In the first year, the temperatures at various positions in the clamp coverings were also recorded.The temperature at the middle of the potato heap showed a drift with time similar to that of mean air temperature. Deviations of mean air temperature from smooth trend, lasting for about a week, had no effect on the temperature of the potatoes; longerperiod deviations were reflected in the temperature of the potatoes after a lag of about a week. The difference in weekly mean temperature between potatoes and external air averaged about 1–5° C. in 1943–4. In 1942–3 it was greater, increasing to over 20° C. in April, because bacterial rotting of the potatoes following blight infection increased the rate of heat production and caused the clamp to collapse at the end of April.

Description: The genitalia of a control series of nineteen animals, slaughtered for other reasons than reproductive failure, were studied. Of these six were in various stages of pregnancy, one was in a ‘proliferative phase’, being slaughtered probably just before the first oestrus after calving, and twelve represented different phases of the oestrous cycle, more than half exemplifying the last 4 days before heat. Stages were judged from the appearance of the ovaries, and checked in five instances by repeated rectal examinations, and observation of behaviour during life. Of the nineteen uteri eight yielded bacteria on culture, sometimes in moderately high density; from two of them, pure cultures were recovered respectively of Pseudomonas and Neisseria catarrhalis; and in another, probably Proteus was found. No previous records of these three genera at such a site have been found. Only aerobic blood agar plate cultures, and those for tuberculosis organisms were made. Dissection results unequivocally supported the view of Tagliavini in opposition to that taken by Hammond, that the sanguineous elements in post-oestral discharge originated from endometrial extravasation. The cow slaughtered 4 days after heat indicated that congestion disappears from the caruncles before leaving the areas between them. Microscopically, no mast cells, as observed by the Italian workers, could be seen; it appeared that a ‘proliferative phase’ occurs in every cycle during the three pre-oestral days, when gland tissue proliferates from its nadir of development, surface epithelium grows in height, and vascularization progresses. The rate and interrelations of these changes seemed variable. Arterioles appeared to be withdrawn from the superficial mucosa during the secretory phase. Tagliavini's claim to have observed sloughing of epithelium about the 17th day, strictly equivalent to the process of menstruation in the Primates, must on the evidence be regarded with considerable reserve.

Description: A review of published work emphasizes the existence of a fundamental relationship between the quantity of milk and butterfat per cent. This general relationship may be stated thus: as the quantity of milk increases, the quantity of fat increases also, but at a slower rate. Therefore, the fat per cent, or concentration, falls as the volume of milk increases.

Description: 1. Sixteen colchicine treatments, involving five main methods of application and six concentrations, have been used on Triticum interspecific crosses, Triticum—Aegilops intergeneric crosses and Agropyron—Triticum intergeneric crosses.2. The efficacy of the major treatments in terms of plant survival, plant fertility and ear fertility has been compared, and the most successful method of application has been found to be absorption through the cut leaves—i.e. capping cut-back tillers with a small glass phial containing colchicine.3. Fertility induced by colchicine is not complete. In plants producing grain, every ear is not necessarily fertile, nor are all spikelets in fertile ears usually fertile.4. Evidence has been obtained of differential cross response to colchicine action, and also of cross-group response to particular treatments.

Description: Since 1943 numerous multifactorial field experiments have been concerned with the development of methods for selective weed control in a variety of crops. Between 1943 and 1947 simultaneous comparisons have been made as to the relative effectiveness of sulphuric acid, cupric chloride, dinitro-o-cresol and the two growth-regulating substances—2-methy1-4-chloro -phenoxyacetic acid and 2:4-dichloro-phenoxyacetic acid—when applied as sprays (100 gal./acre) for the destruction of annual weeds in winter wheat.There is a highly specific relationship between the weed species and the potential toxicity of any one compound. For the eradication of Ranunculus arvẹnsis and Scandix pecten-veneris, the two growth-regulating substances, as the sodium salts, are greatly superior, but for other species, such as Galium aparine, they.are wholly ineffective or only partially effective, e.g. Matricaria chamomilla. For Papaver rhoeas and Fumaria officinalis in the young seedling stage, sodium methyl-chloro-phenoxyacetate and ammonium dinitro-o-cresylate are equally toxic, while the indications are that Matricaria chamomilla and Centaurea cyanus are best killed with sulphuric acid or ammonium dinitro-o-cresylate. All these species are resistant or partially resistant to cupric chloride.As a result of weed eradication, increases in grain yield ranging from 6 to 113% have been recorded, and over the twelve experiments the average increase for the most appropriate treatment was 23%.At the concentrations employed for sulphuric acid (max. 18.4%) ammonium dinitro-o-cresylate (max. 1.1%) and cupric chloride (max. 4.0%) direct injury to the wheat, resulting in a loss in yield, has not been found when spraying is carried out in the active tillering stage. When spraying is unduly delayed, the yield depressions may be very considerable, more particularly with cupric chloride and sulphuric acid.With the growth regulating substances, the results of two experiments indicated that the greatest selectivity is obtained when the concentration does not exceed 0.2-0.3% (2–3 lb./acre), but in the remaining trials no injury was observed up to a maximum concentration of 0.5%. In none of the trials was the formation of abnormal ears noted.When mixtures of sodium methyl-chloro-phenoxy-acetate and dinitro-o-cresol are employed,. no significant interaction on crop yield has been found.

Description: With the installation of more factories for the decortication of cotton-seeds in Pakistan, the utilization of cotton-seed hulls as a feed is likely to assume great importance. During 1949–50, the writers made determinations of the chemical composition and the feeding value of Pakistan cottonseed hulls by conducting a digestibility trial on dry Sahiwal cows. They are found to contain 39.89–56.47% total digestible nutrients (mean value = 48.68%) and 0.0–0.38% digestible protein. It was observed during the trials that the cows could eat about 20 lb. of hulls per head per day without difficulty. The cows also ate hulls in preference to wheat straw.Being low in calcium and phosphorus, cotton-seed hulls should not be used as a sole roughage for long periods, unless supplemented with calcium or phosphorus in mineral form, or preferably with silage, legume hay or green fodder of good quality.Pakistan cotton-seed hulls appear to be equal, if not better, than wheat straw as a cattle feed. From the economic point of view, hulls should be used as a cattle feed only if they are purchasable at about the same price as wheat straw.

Description: 1. In the previous paper of this series (Callow, 1949) a special method of graphical analysis was developed in order to calculate the effect of different rates of fattening on the percentages of fatty tissue, muscular tissue and bone, etc., in a carcass. This method has been used in the present paper to calculate the effect of different rates of fattening on the deposition of chemical fat and protein in the fatty and muscular tissues of a carcass during fattening.2. The method of analysis depends (a) on the choice of an arch-type carcass on mathematical and biological grounds, and (b) the use of partition percentages for defining the proportions of fat, protein and water laid down in the fatty and muscular tissues during an increase in carcass weight due to fattening.

Description: 1. Evidence, both direct and indirect, has been adduced to prove that the air is sufficient both qualitatively and quantitatively to supply all the nutritional requirements of plants, independently of the soil or soil bacteria.2. The fertility of an undisturbed soil lies chiefly in the surface inch or two and is due to adsorption of plant nutrients from the air by organic and inorganic colloids, such nutrients being carried down to the roots of the growing crop by rain.

Description: 1. There was no evidence that the higher body temperature of the chick, compared with other animals, conferred any advantage on it in the digestion of high melting-point fats, as exemplified by mutton fat.2. The digestibility of linseed oil ranged from 95·0 to 99·9%. The highest digestibility observed for mutton fat was 88·1%.3. The capacity to digest considerable quantities of linseed oil was rapidly developed in the chick. Adaptation to digest mutton fat was much slower.

Description: 1. The relation between the soluble-nitrogen content of grass silage and the pepsin digestibility has been investigated, and formulae have been derived for calculating the protein digestibility in the silage dry matter from the determined solublenitrogen content.2. Comparisons have been made between the calculated results for protein digestibility, the results using the formulae of Watson and Dijkstra and the digestibility as determined on sheep.3. The peculiarities of molassed silage in the above connexion have been noted.

Description: Designs are given for factorial experiments with three, four or five factors at two levels each, using thirty-two plots in a 4 × 8 lay-out on the ground. The effects of both rows and columns can be eliminated from the estimate of error. Provided that three-factor interactions can be ignored, information can be retained on all two-factor interactions.

Description: The influence of growing plants on nitrification in the soil was studied by means of small lysimeters of which four were planted to a perennial grass, four to an annual millet crop and four were left fallow.Nitrification was entirely repressed under the grass from the second season after its establishment onwards, and did not take place even when the grass was dormant in winter. This was due to a direct influence of the living root, since in the fallow soil which was treated similarly, nitrification took place freely throughout the winter. Under the annual crop a repression of nitrification could be detected only towards maturity of the crop and the soil solution was completely depleted of nitrates at this period. Nitrification was resumed, however, immediately after the crop was ripe and had died off and continued through the winter.During the period that nitrification was depressed replaceable ammonia made its appearance in the soil in more than normal quantities. This fact is hold to indicate that the plant exerts its influence on the mineralization of nitrogen in the soil by paralysing the autotrophic dehydrogenase system of the nitrifying organisms without interfering with the process of ammonification and not, as has been claimed, by excreting such quantities of carbonaceous matter that nitrates are reassimilated by micro-organisms.By virtue of the constancy of the carbon-nitrogen ratio in soils this influence of plants on the mineralization of nitrogen has a very important bearing on the conservation of soil humus and consequently on any system of alternate husbandry. Some of its implications were discussed with particular reference to local fertilizer practice and field experience.

Description: For three consecutive years American hybrid maize was grown, under replicated experimental conditions, in the south of England. Each season, the influence of the spacing of the plants and the use of nitrogenous fertilizer on the yield and composition of the crop and of its separate portions of leaf, stem and cob was investigated.The growth of the maize, and especially its yield of dry matter, were influenced by the weather conditions during the season. The weight of fresh crop varied, with season and treatment, from 126 to 278 (averaging 209), and of dry matter from 20 to 70 (averaging 50) cwt./acre.Thinning below the established plant populations of up to 30,000 plants per acre regularly reduced these yields. Top-dressing with sulphate of ammonia increased them in 1947 and 1949, but decreased them in 1948.The yield of crude protein varied from 2.2 to 5.0, and of soluble carbohydrates from 12 to 46 cwt./acre. The top-dressing increased the protein content of all portions of the plant.The cob contributed, on a weight basis, 46% of the fresh crop, 49% of its dry matter, 54% of its crude protein and 54% of its soluble carbohydrates. Details are given of the chemical composition of the whole plant, and of its separate leaf, cob and stem, for each season and treatment.A later paper will deal with the making of silage from the maize crops and with the yield, composition and nutritive value of the silage.

Description: Mating Wessex Saddleback with Gloucester Old Spot pigs shows clearly that the former are of the three genotypes expected if the belt pattern is primarily determined by a single dominant gene (Be). Breeding tests and measurements of belt width agree in showing that homozygotes tend to have medium to wide belts, heterozygotes tend to have medium, narrow or broken belts, while pigs homozygous for the recessive are black. Crosses of Wessex with black-spotted pigs produce black piglings with or without wide symmetrical belts depending on the genotype of the Wessex parents.Selection of breeding pigs with narrow belts maintains a high incidence of recessive blacks. Solid blacks which are nevertheless genetically belted may occur, but if so their numbers are likely to be very small.Evidence is given which suggests that pigmentation in the skin and hair of Wessex × Large White pigs is much reduced if the Large White parents have blue eyes.

Description: 1. A statistical study of factors affecting variation in persistency of lactation has been made using 5000 lactation records from twelve leading herds of Ayrshire cattle in south-west Scotland for the period 1930–9.2. It is suggested that a satisfactory numerical expression for the shape of the lactation curve could be obtained from the formula, Persistency = where A is the milk yield during the first 180 days and B is the initial milk yield, namely, the milk yield during the first ten weeks of lactation.3. The interrelationships of persistency, initial milk yield and 180-day milk yield showed that these three characteristics are positively correlated with one another on a between cows within herd basis. This meant that it should be possible to combine high initial milk yield with high persistency to obtain increased total production.4. The effect of month of calving on persistency of lactation varied significantly between herds. On the average, the highest persistency was attained by cows calving in the winter, and the lowest by summer calvers.5. The variation of persistency with age showed that it is necessary to correct for the high persistency of first calvers when comparing cows with different lactations.6. The average repeatability of persistency was 0.242 in the present material, while heritability was of the order of 0.10–0.15.7. It has been concluded that improved feeding and management would bring about the greatest returns in the direction of improved persistency.

Description: 1. Differences in cattle population (4 June returns) and in average body size of fat cattle (data from the collecting centres) have been illustrated for the three counties (Cardiganshire, Carmarthenshire and Pembrokeshire) constituting this region. They indicate the superiority of Pembrokeshire.2. The six westerly collecting areas of Pembrokeshire produce the heaviest cattle of better grading. It has a higher proportion of steers to heifers than the rest of the region.3. The statistical analysis of the data has made it possible to partition the region into four main groups of centres, which show significant differences in the size of the fat cattle.4. The superiority of group 1 has been demonstrated in relation to (a) the seasonally of deliveries, (b) the percentage grading and (c) in the average live weights.5. These differences are examined in greater detail by comparisons of the deliveries to the Pembroke and to the Llandilo centres. These show that Pembroke is superior in average live weights, percentage grading and in the proportion of steers to heifers.6. The ungraded cattle are also examined, and the results indicate the same trends within the region as for the graded cattle.7. The possible explanation of the variations or the ecology of beef production has been discussed in the light of Ashton's (1930) suggestions that variations in body size between cattle of different breeds is mainly due to the calcium and phosphorus content of the soil.8. The conclusion is drawn that differences of climate dominate the whole picture, because of the effect of rainfall on leaching and soil erosion, as well as on the quality of the harvested fodders, the effect of temperature on the length of the growing season and of the beneficial influence of sunshine on the quality of both grass and hay.

Description: A study has been made of the bias in error which occurs when Latin-square change-over trials conducted on dairy cattle are analysed by the usual method for Latin-square experiments, with modification for carry-over effects. Bias is present for adjusted direct effects and for permanent effects (direct plus carry-over), but does not exist for unadjusted direct effects.Analyses of fifteen sets of experimental data showed that the bias is of no importance in 3 × 3 designs but might be serious for some practical situations in the 4 × 4 designs. A tentative factor to correct for bias was given for the latter case.

Description: 1. The structure of the cattle population (4 June returns), as well as of cattle sales to the Ministry of Food, have been illustrated.2. The trends in cattle production show the definite changes from that of the traditional storestock rearing to that of milk selling.3. A considerable part (38·2%) of the total graded animals slaughtered for beef are the ‘wastage’ animals from the breeding and dairying herds.4. Reference has also been made to the high proportion of ungraded cows (36·7% of the total cows) purchased by the Ministry. The ungraded cattle, however, are only 17% of the total sales. On the other hand, the ungraded ‘wastage’ cattle contribute 90% of the total ungraded cattle.5. More heifers than steers were sold for slaughter, and it has been shown that the average live weight of the graded steers is nearly 224 lb. heavier than that of the heifers.

Description: Between 1941 and 1946 some twenty-five field experiments were carried out at various centres in England to assess the factors which determine the yield level and seed composition of linseed (oil flax). The experiments were of multifactorial design, and the main variables studied were varietal differences, levels of mineral nutrient supply and plant population. Additions of nitrogen (35 lb./acre) over all experiments raised the yield of seed by 10%, whereas additional phosphorus (50 lb. P2O5/acre) or potassium (80 lb. K2O/acre) had small and inconsistent effects. A significant interaction between nitrogen and variety was recorded in one trial, but in twelve out of fourteen experiments the varieties reacted uniformly to a combined application of nitrogen, phosphorus and potassium, while in the remaining two experiments the interactions were contradictory.

Description: 1. The experiment previously described (series 4, Holmes, 1949) on the effect of massive applications of nitrogenous fertilizers on the productivity of a ryegrass dominant pasture was continued for 3 years (1946, 1947, 1948). The manurial treatments ranged from none to the application of 312 lb. nitrogen per acre and this was applied with and without 135 lb. P2O5 and 168 lb. K2O per acre. Farmyard manure was applied to one block in 1948.2. With the heaviest nitrogen treatment plus phosphate and potash the average yield for 3 years was 8000 lb. dry matter and 1640 lb. crude protein (similar to the yield in 1946) compared with a control yield of 4720 lb. dry matter and 590 lb. crude protein. The yields declined from year to year when phosphate and potash were not applied, the decline being greatest with the heaviest application of nitrogen.3. The seasonal distribution of the yield of herbage was very considerably modified by the time when fertilizers were applied.4. The botanical composition of the swards was related to the yield, 70% of the grasses in the highest yielding sward being perennial ryegrass and cocksfoot while the lowest yielding sward contained only 35% of these grasses.5. The manurial treatments had no effect on the pH, loss on ignition or the content of readily soluble P2O5 in the soil, but in the first year there was some evidence of a general reduction of readily soluble K2O to a low level.