ALBERT

Beschreibung: 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.

Beschreibung: 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.

Beschreibung: 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.

Beschreibung: 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.

Beschreibung: 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.

Beschreibung: 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.

Beschreibung: 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.

Beschreibung: 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.

Beschreibung: 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.

Beschreibung: 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.

Beschreibung: 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.

Beschreibung: 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.

Beschreibung: 1. Studies were made of the effects of varying ground water-levels upon the productivity and composition of Italian Ryegrass grown on a calcareous light peat in the Fenland area. Six cuts were taken throughout the season at 3 to 4-weekly intervals.2. High ground water-level (approximately 15in. below ground surface) had a very deleterious effect on the total yield of fresh grass and of dry matter. Yields were little more than half of those obtained at medium and low water-levels (24 and 38 in. below ground surface, respectively).3. High water-level apparently interfered with nitrogen metabolism in the soil, and considerably lower percentages of crude protein were found in the grass growing on the high water-level plots than at the other levels. On the other hand, the percentage of crude fibre remained fairly constant for all levels of ground water.4. High water-level also had a depressing effect on the percentage of potassium, magnesium and chlorine in the grass. It had no obvious effect upon the calcium and phosphorus levels in the plants. The silica content of the grass rose steadily as the season advanced, this being most marked on the high water-level plots.5. Physical examination of typical plants showed the effect of the various ground water-levels upon the development of the root systems, with consequent effect upon the chemical composition of the grass.6. The composition of hay and aftermath showed similar changes to those reported for the green herbage.7. The findings are discussed in relation to grassdrying policies in Fenland areas.

Beschreibung: 1. Eight Cheviot ewes, bearing twins, housed in individual pens, and given the choice of a protein concentrate, a carbohydrate concentrate, hay, minerals and water, failed to select a ration that allowed them to bear and rear strong healthy lambs.2. Three ewes maintained under these conditions developed a condition resembling pregnancy toxaemia.3. The amount of food eaten by each ewe decreased during the last few weeks of pregnancy, This is probably the reason for the disappointing performance of the ewes at lambing.4. The possible influence on the behaviour of the ewes of the constant presence of food is discussed.

Beschreibung: The digestibility of carotene in dried grass was measured by the Cr2O3 method in both cows and goats. In the goats the direct method was simultaneously used for comparison with the Cr2O3 method.The main conclusions were:1. When mixed with the concentrate portion of the ration of lactating goats, Cr2O3 was recovered in the faeces in four experiments in amounts equal to 100·0, 99·1, 99·1 and 96·0% of the amount ingested.2. The apparent digestibility of carotene in the goat was measured both directly by the use of metabolism crates and indirectly by using Cr2O3 as an indicator of equivalence of faeces and food. By the former method digestibilities of carotene in four goats were 68·7, 62·7, 61·8 and 59·6%. The corresponding digestibilities obtained from the same faeces samples by the Cr2O3 method were 67·4, 62·9, 61·8 and 58·9%.3. In six cows, on the diet similar to that of the goats, the Cr2O3 method showed that 59·3, 54·0, 54·4, 54·4, 57·1 and 55·5% of carotene was apparently digested.4. Reasons for preferring the use of added Cr2O3 to natural constituents of the food as a marker are discussed.5. The individual results from cows and goats have been statistically analysed to partition the various sources of variance, and it has been shown that fewer animals for a longer time give a more reliable result than more animals for a shorter time.

Beschreibung: 1. Trials made near Cambridge in 1949 and 1950, under ‘mild’ and ‘hard’ spring weather conditions respectively, have confirmed that the findings of Aberg & Denward in Sweden, and of Pedersen, Andersen & Hermansen in Denmark, concerning distortions in barley caused by MCPA and 2,4-D, are also valid under English conditions.2. Damage to barley caused by the application of MCPA and 2,4-D up to the 2-leaf and early 3-leaf stages may be recognized by the occurrence of many tubular leaves and bowed or trapped ears. As little as 2 lb./acre of 2,4-D, as the amine salt, applied at this stage may also cause severe stunting of theplants with distortion of the roots.3. Damage to barley by the application of MCPA and 2,4-D at the 3–4-leaf stages may be recognized by the occurrence of tweaked ears. The application of as little as 2 lb./acre of MCPA, as the sodium salt, at these stages may cause tweaking in over 50% of the ears. 2,4-D (as amine) at the same dosage causes more distortion. Although the reduction in yield due to such tweaking may be slight, the grain sample is irregular in size, with a number of naked grains, and malting quality may be reduced.

Beschreibung: 1. Two groups, each of six Ayrshire dairy cows, have been watched in the field for a total of twentytwo 24 hr. periods during the months May to September. No supplementary foods were fed at any time. One group grazed under a system of close-folding and the other in small rotational paddocks.2. The effect of the different systems of management was small. It was clear, however, that closefolding increased the time spent in grazing and decreased the weight of herbage eaten. The milk yields from both groups were very similar.3. A very constant pattern of behaviour over the 24 hr. period, similar for both groups, was observed. The most prolonged grazing period always occurred immediately after the cows returned from evening milking.4. The amount of grazing during the hours of darkness was small at all times of the season but tended to increase as the evenings shortened and the nights lengthened. The cessation of evening grazing was closely linked with the fall of darkness at all times of the year.5. The activities during the ‘day’ period were less regular but, nevertheless, showed a marked division into three main spells of grazing, of which one occurred immediately after morning milking, separated by two main spells of rest.6. Stage of lactation, individual milk yield and live weight appeared to have no direct relation to the amount of time spent in grazing. Cows watched in both 1949 and 1950 grazed for very similar times despite differences in their stage of lactation.7. Increasing defoliation of the paddock resulted in an increased grazing time by the rotationally grazed cows.8. Close-folded cows grazed for a shorter time on herbage of low moisture content than on herbage of high moisture content, whilst eating virtually the same weight of dry matter.9. Climatic changes to the extent met with in south-west Scotland had only a limited effect on the general pattern of grazing.10. The physiological activities of dunging, urinating and drinking showed only small day to day variations.11. The distance walked during grazing in the 24 hr. by one individual cow from each group showed only a slightly longer track for the rotationally grazed animal, the average distance being about 2000 yards.

Beschreibung: Ten experiments on sugar beet in 1949 tested a phosphate-potash fertilizer applied in different ways. There was no damage to germination or plant establishment by fertilizer placed in bands 2 in. to the side and 2 in. below the level of the seed.There were no significant differences between the yields of sugar given by placed and broadcast fertilizer. Similar yields were given by broadcast applications applied early and worked deeply into the seed-bed and by dressings on the seed-bed which were worked in shallowly. Split dressings where half the fertilizer was broadcast and half was drilled beside the seed were not markedly superior to placing or broadcasting all the fertilizer. In most of the experiments placing gave more vigorous growth than broadcasting the fertilizer during late spring and early summer; at harvest this superiority had vanished.The results of these experiments confirm those carried out in 1947 and 1948. There is no advantage from placing the full dressing of fertilizer beside the seed in districts where the crop is normally grown, except that labour is saved in applying the fertilizer.

Beschreibung: The importance of conducting studies on the behaviour of grazing animals has been stressed by several authors. Stapledon & Jones (1927) indicated the need for such work; while more recently Stapledon (1948, 1949) has made further reference to this need.Adequate reviews of the work conducted prior to 1939 are to be found elsewhere (Castle, Foot & Halley, 1950; Tribe, 1950), and only the more important aspects need be considered here. The main weakness on the part of many of these earlier studies was that they were based on few observation periods, and that few animals were observed during each period. Many workers (Cory, 1927; Hodgson, 1933; Sheppard, 1921) carried out their observations during the daytime only, on the assumption that little or no grazing occurred after dark. In spite of this and the fact that the methods of study adopted varied considerably, some correlation exists between the results reported by the different workers.

Beschreibung: 1. Chicks from commercial sources were housed intensively and fed on a series of rations containing decorticated extracted groundnut meal as the main supplementary source of protein, with and without additions of animal by-products and aureomycin. Parallel groups received rations conforming to Government regulations in their content of sources of animal protein.2. Growth and feed efficiency up to point of lay were as good in groups fed on all-vegetable rations, containing 18% of crude protein in the starting ration and 16% in the growing ration, as in groups fed on regulation rations of the same protein content.3. Performance on the all-vegetable ration up to 6 weeks of age was not as good as on the regulation ration. This inferiority could be largely or wholly corrected by adding extra groundnut meal and condensed fish solubles to the ration. Growth and feed efficiency over the whole rearing period were not improved by the addition of these supplements.4. Addition of aureomycin stimulated growth over the whole rearing period but failed to improve feed efficiency.5. Protein levels in the ration, the provision of animal protein factor(s) and aureomycin were without effect on the age at which laying began.6. Current estimates of the chick's requirement for certain amino-acids appeared to be too high when this type of ration was used.7. The addition of riboflavin to these starting rations was essential. When this was done mortality was low, leg weakness absent and feathering rate normal.

Beschreibung: Between 1942 and 1950, some thirty field experiments have been carried out in the southern half of England to assess the potential value, either for grain or forage production, of seventeen openpollinated flint or dent maizes together with twentynine single or double hybrids of American or Canadian origin.Early-maturing flint varieties will consistently ripen grain, but before mechanical threshing or storage, the cobs require drying. Sibthorp, a mass selection made from an unknown German variety, is the earliest and most productive flint maize so far tested, and in the experiments has yielded as much as 39 cwt. of grain per acre with an average of 24 cwt. The earliest American hybrids, i.e. those with a U.S.A. rating of 80 days from sowing to maturity, give very high yields of grain in favourable seasons. Within the group Wisconsin 240–275, a yield level equal to or exceeding 50 cwt./acre has on occasion been recorded. On the other hand, in the most unfavourable years, such hybrids just failed to produce ripe cobs.Attempts to maintain sixty-five parent inlines of the earliest hybrids have largely failed. However, many of the parent single crosses have matured, and the production on a field scale of the double-cross seed of both Wisconsin 240 and 255 has been carried out.Spacing experiments indicate that for optimum grain production a density of 6 plants/sq.yd. is required for both flint varieties and the earliest hybrids. A spatial arrangement of individual plants is to be preferred to that of groups or hills.American hybrids, in the class of ‘90 days’ to maturity, will in all but the most unfavourable seasons reach the ‘early-dent’ stage of the grain before the incidence of autumn frosts. Yields of dry matter of plants harvested in this phase have ranged from 30 to 85 cwt. of dry matter per acre. In these trials, the plant density was standardized at 4 plants/sq.yd. and higher densities may be demanded for optimal yields.The ratio of the ‘ear’ (that is, the cob, immature grain and enclosing leaf sheaths) to the total shoot weight at harvest varies greatly with the variety or hybrid. With White Horsetooth, the usual variety grown for fodder in England, no cobs are formed before the plants are killed by frost, while with the early hybrids, the ear may be half the weight of the whole shoot.The earliest variety Sibthorp from an early May sowing takes approximately 70–80 days to reach full anthesis, while ‘80-day’ American hybrids are a week later. From sowing to full maturity the period in England is from 140 to 160 days, thus compared to conditions in Minnesota the period is nearly twice as long. Because of the much slower rate of development and because of the humidity of English autumns, it is concluded that until the date of maturity can be advanced some 14 days, grain production on a field scale is not yet feasible. On the other hand, many of the American hybrids are well fitted to the production of silage. The greatest drawback to the introduction of such hybrids is the liability of the seed and seedlings to be attacked by rooks.

Beschreibung: In dealing with fertility in sheep there are a number of initial difficulties. On the one hand, there is generally a lack of any uniform definition of such terms as ‘fertility’, ‘fecundity’ and ‘prolificacy’ (cf. Marshall & Hammond, 1947; Lush, 1938; Rice, 1942; Asdell, 1946; and others); on the other hand, investigators have been confronted with a real difficulty in procuring suitable information which would conform to the requirements of any single and adequate definition of fertility. Because of this, fertility figures have been calculated in different ways* and may differ by as much as 30%. The situation is at present so confused that reference to similar work, especially when the original papers are not available, or the terms not clearly denned, is often of dubious value if not altogether misleading. In the past the data analysed were mostly based on farmers' answers to questionnaires or on flock records. The limitations of such methods are only too obvious; yet it must be clearly realized that in commercial flocks there is no possibility of any basic departure from them, even though their accuracy could in many cases be improved. In other words, only such information is collected as the circumstances allow. This, for instance, may be the number of lambs docked per ewes put to ram in one flock and number of lambs docked per ewes lambed in another.

Beschreibung: 1. A small-scale plot experiment was carried out from 1947 till 1949 to study the effect of massive dressings of nitrogen with and without phosphate and potash on the yield of a ryegrass-dominant sward. A 4 × 4 Graeco-Latin square was used.The nitrogen treatments were: (1) no nitrogenous fertilizer, (2) 260 lb., (3) 520 lb., (4) 416 lb. nitrogen per acre per annum. These applications were divided into four or five equal dressings, the first being applied in March and the others after successive cuts.In 1948 and 1949 the following mineral treatments were also applied: (A) no mineral fertilizer, (B) 180 lb. K2O per acre, (C) 120 lb. P2O5 per acre, and (D) treatments B and C combined. These treatments were applied in two parts, half in spring and half in midsummer.2. Applications of phosphate did not affect the yields of herbage but yields were severely restricted in the absence of potash.3. Where potash was applied there was no significant change in the annual yield of herbage from 1947 to 1949 for any one of the treatments. The nitrogen treatments increased the yields from 4300 lb. dry matter and 600 lb. crude protein per acre with treatment 1 to 9000 lb. dry matter and 1900 lb. crude protein with treatment 3. The yield response of dry matter to nitrogen applications was curvilinear, but that for crude protein was rectilinear.4. Increasing the application of nitrogen per cut from 52 to 104 lb. per acre raised the protein content in the dry matter of the herbage from 15·20 to 18·25%.5. The plots receiving the nitrogen treatments gave earlier production and also produced a greater proportion of the total yield in July-September than the untreated control plots.6. Where potash was present the average net efficiency of recovery of nitrogen for 3 years was 47, 39 and 37% for treatments 2, 3 and 4 respectively.7. Where potash was present the content of vigorous grasses in the sward (perennial ryegrass and timothy) was increased in relation to the quantity of nitrogen applied, from approximately 40% in treatment 1 to 75% in treatment 3. The content of vigorous grasses in the sward was reduced in the absence of potash.8. The results and their practical implications are discussed.

Beschreibung: 1. The methods of investigation of the effect of ground water-level on crop growth, together with tho field installations in use, are discussed.2. Direct field experiments are handicapped by the difficulties of achieving close control on a sufficiently large scale, due to considerable variations of surface level and depth of peat within individual fields and to rapid fluctuations in rainfall and evaporation. Many recorded experiments are associated with climatic conditions of substantial precipitation during the growing season.3. Seasonal fluctuations of ground water-level in Fen peat soils in England, in natural and agricultural conditions, are described.4. The local soil conditions are outlined and the implications of profile variations are discussed.5. The effective control of ground water-level on a field scale requires deep and commodious ditches and frequent large underdrains to ensure the movement of water underground with sufficient freedom to give rapid compensatory adjustment for marked disturbances of ground water-level following the incidence of heavy rain or excessive evaporation.6. A working installation for a field experiment in ordinary farming conditions is described and the measure of control attained is indicated.

Beschreibung: In the carrying out of comparative determinations of the supplemental values in pig feeding of the proteins in different protein concentrates, the writers consider the following conditions to be fundamental, and must be observed if reliable results are to be obtained:(1) The comparison must be conducted over the period from weaning to about 90 lb. live weight. Measurements made in the later stages of growth can have no meaning, since supplementation of the basal mixture (cereal plus middlings or fine bran) with the protein-rich concentrates under comparison has no significant effect at tins stage on the rate of growth or nitrogen retention. Examples of the misleading results that are obtained by prolonging the period of comparison to 150 or 200 lb. live weight, instead of terminating the trial before the attainment of 90 lb. live weight, were encountered during the course of the present investigation, and are cited in the text.(2) The diets to be compared must be so designed as to contain, as nearly as possible, equal percentages of ‘total digestible nutrients’, as based on computations from digestion coefficients derived from digestion trials with pigs.(3) The daily allowances of meal must be scaled to live weight, and the diet must be sufficiently palatable to ensure clean food consumption.(4) The diets must make adequate provision for the mineral and vitamin requirements of young growing pigs.(5) The comparison in the case of growth experiments must be made by the method of individual feeding, and in accordance with the requirements of the modern statistical lay-out, so that the records of live-weight gain and food consumption may be submitted to statistical analysis.(6) The diet forming the standard for comparison should contain the minimum amount of protein needed for the maximum rate of growth compatible with the available supply of net energy. In the case of white-fish meal, which was the standard protein supplement in the present comparisons, this condition has been found in earlier work to be realized when a diet composed substantially of barley meal and middlings contains 7% of this animal-protein food.(7) In the initial tests, the experimental diet should contain, as nearly as possible, the same percentage of digestible crude protein as the standard diet, and the percentage of the protein supplement under test should be such as to provide as much digestible crude protein as is contained in the 7% of white-fish meal in the standard diet. Under such conditions of feeding, differences of protein quality in the two feeding treatments will be the factor responsible for any observed differences in the rate of live-weight increase or of nitrogen retention.Should the pigs on the experimental treatment display a poorer rate of growth, or of nitrogen retention, than those on the standard treatment, then further trials should be undertaken in which the percentage of protein supplement under test is progressively increased, whilst still maintaining equality between the experimental and standard diets in respect of ‘total digestible nutrients’, until a level is reached at which the experimental pigs show a rate of live-weight increase, or of nitrogen retention, equal to that of the pigs on the standard treatment. The final stage of the comparison, therefore, is based on the results of feeding tests in which the maximum possible rate of growth, or of nitrogen retention, is obtained, both on the standard and experimental treatments, with diets supplying, respectively, the minimum amounts of the two types of protein supply.The object of the present investigation has been to compare the supplemental values of a typical animal-protein concentrate (white-fish meal) and vegetable-protein concentrate (ex. dec. ground-nut meal). The aim has been to determine what percentage of ex. dec. ground-nut meal must be incorporated with a basal diet, composed approximately of 2 parts by weight of barley meal, 1 part of middlings (or fine bran) and a small allowance of lucerne meal and minerals, to promote the same rate of growth, or of nitrogen retention, in young pigs as is obtained with a standard diet containing roughly the same proportions of the basal foods in conjunction with 7% white-fish meal, the diets under comparison being made up so as to contain equal percentages of ‘total digestible nutrients’.On the basis of pig digestion trials, 8 parts by weight of ex. dec. ground-nut meal contains as much digestible crude protein as 7 parts of whitefish meal. The diets under comparison in the initial growth and balance trials were made up, therefore, to contain, respectively, 7% of white-fish meal and 8% of ex. dec. ground-nut meal. Their contents of crude protein, digestible crude protein and ‘total digestible nutrients’ were approximately equal. Over a range of live weight from 36 to 90 lb., the pigs receiving the white-fish meal averaged 0·92 lb. of live-weight increase per day, with a mean efficiency of food conversion of 3·08 lb. per lb. of live-weight gain. The corresponding figures for the pigs receiving the ex. dec. ground-nut meal were 0·73 and 3·87 lb. These differences were strongly significant and pointed clearly to the poorer supplementa. value of the vegetable protein supplement. Confirmation of this finding was given by the results of nitrogen-balance trials on young pigs. At all stages, pig (1) receiving the standard diet containing 7% of white-fish meal was retaining nitrogen at a distinctly higher rate than pig (2) subsisting on the diet containing 8% of ex. dec. ground-nut meal. Over the 43 days of continuous measurement, pig (1) consumed 1719·5 g. of nitrogen, and retained 720·5 g., or 41·9% of the total nitrogen intake; whereas pig (2), which had steadily fallen behind in live weight during this period, consumed a total of 1591·9 g. of nitrogen, and retained 566·6 g., or only 35·6% of the ingested nitrogen. It was clear from the results that the protein assimilated from the diet containing ground-nut meal is not so suitably balanced in respect of amino-acids as the digestible protein in the standard diet, and is subject on this account to a higher degree of de-amination, with a correspondingly greater wastage in terms of urinary nitrogen.This conclusion was substantiated by re-calculating the results for the same range of live weight, namely, 62·92 lb., a range which falls within the limits that have been shown to be necessary for a sensitive comparison. For this live-weight gain, pig (1), receiving white-fish meal, required 22 days, over which period the total consumption of nitrogen amounted to 771·5 g., of which 327·6 g., representing 42·5% of the ingested nitrogen, was retained, and 226·9 g. (29·4% of the nitrogen intake) eliminated in the urine. The corresponding results for pig (2) receiving groundnut meal were distinctly inferior. The time needed for the same gain in live weight averaged 25·3 days; the necessary nitrogen consumption amounted to 859·3g., and of this, 301·8g.(35·1% of the intake) was voided in the urine and 309·5 g. (36·0%) was retained in the body of the animal.A succession of growth trials was next carried out in which the effect of increasing the level of ex. dec. ground-nut meal to 12, 14, 15, 16, 17 and 20%on the rate of live-weight increase between weaning and 90 lb. live weight was investigated. Although the successive increases led to progressive improvement of the results in relation to those obtained on the standard diet containing 7% of white-fish meal, was not until the 20% level of feeding was reached that the diet containing ex. dec. ground-nut meal gave as good results in respect of rate of growth and efficiency of food conversion as were obtained by the use of the standard diet.The same result was obtained in the investigation of the problem from the standpoint of nitrogen retention, the inclusion in the experimental diet of as much as 20% of ex. dec. ground-nut meal being found necessary to so rectify the ill-balance of the amino-acids in the cereal part of the diet as to make possible, between weaning and 90 lb. live weight, the maximum rate of nitrogen retention such as was obtained in the case of the pigs receiving the control diet containing 7% of white-fish meal.In view of the variation from consignment to consignment of the protein content of such proteinrich concentrates as white-fish meal and ex. dec. ground-nut meal, it is necessary to define the different diets under test in terms of their protein content rather than their content of protein supplement. Examined from this standpoint, the results of the growth trial and the balance trial, in which ex. dec. ground-nut meal formed 20% of the diet under test, showed a substantial measure of agreement. Averaging the results of these trials, it is found that the standard diet supplying 7% of white-fish meal contained 14·2% of crude protein on the air-dry basis (16·4% on the basis of dry matter), and of this, 32%, or roughly one-third, came from the white-fish meal. In the case of the diet supplying 20% of ex. dec. ground-nut meal, the crude protein content on the air-dry basis rose to 18·5% (21·2% on the basis of dry matter), and as much as 54%, or rather more than half, of the total protein was derived from the vegetable-protein supplement. The two diets contained, respectively, 11·6 and 15·6% of digestible crude protein, and of ‘total digestible nutrients’, 62·4 and 62·7% respectively (air-dry basis). On the two diets as so made up, equality in respect of rate of growth and nitrogen retention in young pigs was made possible, only, however, at the expense of a less efficient and more wasteful utilization, as evidenced by the greater degree of de-amination and a correspondingly higher loss of nitrogen in the urine, of the protein in the ration containing ex. dec. ground-nut meal.The feeding of as much as 20% of ex. dec. groundnut meal in the rations of young bacon pigs for the purpose of ensuring the maximum rate of growth compatible with the available supply of net energy may seem an extravagant usage of the protein concentrate, but this is really not so if it is kept in mind that, in accordance with the writers’ earlier findings, the protein supplement may be omitted altogether at about 90 lb. live weight without occasioning any depression of the rate of live-weight gain or the efficiency of food conversion. Thus, in the growth trial in which the diet containing 20% of ground-nut meal was compared against the standard diet, no more than 35·5 lb. of the vegetable-protein concentrate was required, on an average per pig, between the live weights of 36 and 90 lb., and following the attainment of 90 lb., the use of the ground-nut meal could, if desired, have been discontinued.Perhaps the best way of economizing in the use of ground-nut meal, however, is to feed it in conjunction with a small allowance of an animal-protein food, such as white-fish meal. In growth trial no. 4, for example, the diet containing 6% of ex. dec. groundnut meal and 2% of white-fish meal gave as good results as the diet containing 15% of ex. dec. ground-nut meal. Thus, the introduction of as little as 2% of white-fish meal into the diet enabled the percentage of ground-nut meal to be reduced from 15 to 6%, with a consequential reduction of the total digestible crude protein from 13·9 to 11·2%, without affecting the rate of live weight gain or the efficiency of food conversion.

Beschreibung: In the course of two breeding seasons 137 mature to aged ewes of mixed breeds but predominantly Border Leicester × Cheviots, Dorset × Cheviots, Suffolks and Hampshires and their crosses, have been injected with PMS or PU, and at different levels of dosage, and slaughtered at intervals after service to determine the sequence of events following treatment. In addition ten ewe lambs received similar treatment and eighty-one flock Suffolk and Romney Marsh ewes, of which forty-nine were injected, have been studied. The results may be summarized as follows:1. The injection of 500–2000 i.u. PMS on the 12th day of the oestrous cycle will regularly induce multiple ovulations at the ensuing heat.2. There is a significant dose-response relationship between 500 and 2000 i.u. PMS. Mean ovulation rates observed were: 500 i.u., 4·1; 1000 i.u., 10·6; 2000 i.u., 15·8. There is, however, considerable variation, the ranges being 2–9, 4–33 and 8–29 respectively.3. The injection of 1000 i.u. PU subcutaneously on the 12th day of the cycle causes marked ovarian and cyclic abnormalities, and heat may be entirely suppressed. When injected intravenously at heat following a priming injection with PMS on the 12th day there is no evidence that it increases the rate of ovulation; in other words, the ewe can ovulate up to at least thirty ova without difficulty, provided the follicles are matured.4. PMS levels of 500 and 1000 i.u. do not cause any apparent ovarian abnormalities apart from superovulation. A very high proportion of all follicles developed rupture and form apparently normal corpora lutea. PMS at 2000 i.u. causes lutein cysts and ovulation may be inhibited.5. PMS at 500 and 1000 i.u. causes no cyclic abnormalities, although cycle length is slightly shortened. In the event of the ewe failing to conceive, the subsequent oestrus is normal, and ovulation and fertilization of the ova occur.6. Commercial PMS is probably as effective as fresh PMS provided it is correctly standardized. There seems no reason to suspect differences in multiple ovulating efficiency between different batches of fresh PMS.7. While breed differences in response possibly exist they were not observed in these experiments. Nor were differences apparently related to the relative time of injection within the breeding season.8. There is an ovarian weight-PMS level, doseresponse relationship which is almost entirely accounted for by the numbers of corpora lutea and hence of luteal tissue.9. Multiple-ovulated ova are highly fertilizable. However, when fifteen or more are shed the rate of tubal transport is considerably accelerated and the proportion fertilized appears to fall. One- and two- cell ova have been recovered from the uterus within 48 hr. of service. Nine fertilized ova have been recovered from one ewe.10. Considerable embryonic mortality occurs before attachment of the blastocysts. None the less, multiple impregnation does occur but is followed by further early death. Up to thirteen attachments have been observed in one ewe, but all but three were showing signs of regression by the 19th day.11. Post-attachment mortality takes the form of an initial retardation commencing about the 15th day, embryos apparently dying a day or so later. The peak of mortality occurs between the 17th and 19th day, by which time definite signs of resorption are apparent.12. By 21 days equilibrium has been reached, the mean numbers of survivals of those ewes pregnant being some 260%. This level is maintained without further loss until the 68th day. Several cases of four normal foetuses were noted up to the 41st day, and one uterus containing six perfectly normal foetuses was recovered at 61 days.13. The overall fertility indicated by these slaughterhouse ewes varies with the level of PMS administered. While equilibrium is achieved by animals conceiving, at about 250–260% viable foetuses, regardless of the dose injected, there is increasing proportion of returns to service with increasing dosage. For the most part this appears due to hormonal imbalance at the time of ovulation and fertilization when an excessive number (〉 15) ova are shed. This results in accelerated ovum transport through the tubes and lowered rate of fertilization. Between ovulation rates of 4 and 12, produced by 500 i.u., rate of conception is extremely high. Of twenty-five ewes receiving 500 i.u. PMS, twenty-three (92%) conceived to the first fertile service. The conception rates were reduced to 80 and 60% by 1000 and 2000 i.u. respectively.14. Although after the end of the 3rd week there is no direct evidence of further foetal mortality, the percentage of lambs born in the flock ewes injected with 500 i.u. PMS was only 192% of those lambing or 167% of all ewes mated (147% for controls). This indicates a loss late in pregnancy. This can in part accounted for by abortion; one ewe aborted, due, is believed, to her carrying more lambs than she was physically capable of retaining.15. OffifteenflockSuffolksinjectedinthe 2nd year with 500 i.u. PMS, thirteen lambed, one aborted and one did not conceive. The thirteen ewes lambing presented twenty-five lambs, including one set triplets and one of quadruplets. All the latter were viable, but two sets of twins were bom dead. One triplet was lost on fostering and one other lamb was lost, so nineteen were tailed. Of fifteen controls, all lambed, giving twenty-one lambs bom of which twenty survived. Conception to first fertile service was higher in the injected than in the control ewes. In the preceding year when 1000 i.u. was given, both conception and lambing rates were appreciably lowered as compared with untreated controls. The significance of this in respect to the level of PMS administered is stressed.16. It is concluded that the major part of the embryonic loss is due to a uterine environment which is incapable of supporting more than a limited number of embryos. It is considered possible that there are breed differences in this, and that each breed, and individual within the breed, has ‘Maximum Potential Fertility’.17. This ‘Maximum Potential Fertility’ is not attained in normal breeding practice, since the number of ova shed by the ewe tends to constitute a limiting factor. Use of a level of PMS which will induce between three and ten ovulations—in the case of this experiment, 500 i.u.—removes this limiting factor, giving the individual full opportunity to express its full potential breeding capabilities.18. There is some indication that the use of PMS in lambs may not give good results, and its use for the while should be restricted to mature ewes.19. Since 500 i.u. PMS has resulted in a higher conception rate to first service and to a greater number of lambs born, it is apparent that this technique of injecting on the 12th day of the cycle a level of PMS which will result in a moderate number of ovulations is worthy of exhaustive field trials, notwithstanding the high post-natal mortality observed in the few cases which were allowed to go to term.20. In view of the higher indicated fertility of the slaughtered ewes which were mainly Border Leicester cross and Dorset × Cheviots—normally very highly fertile ewes as compared with the flock Suffolks—it is considered possible that this technique will yield best results with more highly fertile breeds.21. To have any hope for successful increase of fertility in mammals following gonadotrophin treatment the hormone must be administered at a time and at such a concentration that it will augment, but not upset, normal hypophysial and ovarian function.

Beschreibung: In view of the present interest in the development of commercial poultry flocks by crossing inbred lines, at least two questions of importance arise. One is, how well does a successful cross between two inbred lines repeat itself with successive generations of the particular parental lines involved? The other, bound up with the manifest degenerative change that seems to be the fate of most inbred lines, is related to the possibility of determining minimal and/or optimal degrees of inbreeding necessary to produce commercially satisfactory offspring.As a preliminary to a major investigation of these problems it would perhaps be useful to record briefly observations on small groups of pullets derived from such a cross, which has been repeated at intervals over 11 years within the Centre's flock of Brown Leghorn fowls, and to compare them with the parental lines.

Beschreibung: 1. If a crop varies in respect to a character which shows simple Mendelian inheritance then it is possible to estimate the proportion of cross-fertilization within the crop from the data obtained by (i) drawing plants from the crop and scoring them in respect of the character, then (ii) growing their separate progenies and scoring them.2. Maximum likelihood expressions are given for the estimation of p and f { = (1 — α)/(l + α)} from the genotypic classification of the parents and from the phenotypic classification of the progenies; where p is the gametic frequency of the dominant allel and α is the proportion of fertilizations in which the pollen is equally likely to come from any plant in the population.3. When the above expressions are applied to a case in winter beans, in which the parent plants were selected for high yield it is found that the different estimates of p agree, but those of f do not.

Beschreibung: During the period 1942–50 some thirty-seven multifactorial field experiments have been carried out to determine the conditions under which weeds in fibre flax can be selectively controlled by herbicides. In order to assess the direct effects of treatment on flax, some experiments have been undertaken in weed-free crops, while others have been sited in weed-infested crops so that the increases in productivity following on weed suppression could be evaluated.In almost all experiments, the total crop weight, the yield of de-seeded straw and the amount of scutched fibre per plot were determined, while in a proportion seed yield was also measured. Where weeds were present, counts were made to establish the degree of control.The preliminary experiments demonstrated that sulphuric acid, ammonium sulphamate and ammonium thiocyanate were far too toxic to flax. An examination of a range of cupric salts suggested that the most promising compound was cupric chloride, while of the formulations of dinitro-o-cresol investigated only the sodium salt appeared to be sufficiently selective. It was also found that in terms of fibre production sodium 2-methyl-4-chlorophenoxyacetate was less toxic than sodium 2:4-dichlorophenoxyacetate. In consequence, the bulk of the investigations have related to determining the optimal conditions for the use of cupric chloride, sodium dinitro-o-cresylate and sodium methylchlorophenoxyacetate.For all three compounds it has been observed that flax is least liable to injury at a height range of 2–6 in. There are limitations to the amounts which can be safely employed, namely, 20 lb. of cupric chloride or 6 lb. of sodium dinitro-o-cresylate applied in 100 gal. of spray solution per acre. With sodium methyl-chlorophenoxyacetate the corresponding limit is 1 lb./acre, and the evidence suggests that the crop may be injured if the volume of application is reduced below 25 gal./acre.Within these limitations of concentration volume and stage of development of the crop, the suppression of annual weeds has led to significant increases in the yield of straw, seed and scutched fibre. Larger gains resulted from the use of sodium methyl-chlorophenoxyacetate and sodium dinitro-ocresylate. This superiority over cupric chloride is in part attributed to the wider range of weed species which are killed by the two sodium salts and in part due to the greater liability of crop damage if the limits on amount and time of application are not strictly observed.The results have also clearly established that for fibre flax the weight of total crop, the yield of straw, the amount of seed or plant height cannot be taken as reliable criteria for the evaluation of herbicides, for while all these may be little affected by treatment yet there may still be large reductions in the amount of recoverable fibre. A preliminary anatomical examination of the internal changes in the stems of flax has shown that when treatment with dichlorophenoxyacetic acid is delayed, a marked but localized curvature of the stem results and in this zone fibre formation is abnormal: thus breakages either during pulling or processing may occur at this point of weakness.

Beschreibung: An attempt was made to determine what becomes of the nitrogen added to a poor soil in moderate quantities of organic manures or of ammonium sulphate. Losses by drainage, in two successive barley crops, and by fixation in an unavailable form in the soil were determined, and it was found that with every material used (including tare residues containing 3½% nitrogen, mustard plant residues containing 1½–2¼ nitrogen and pure ammonium sulphate) and with intensive cropping and leaching, not more than 40–51% of the added nitrogen could be accounted for at the end of the experimental period. The balance, it is suggested, must have disappeared from the system, possibly as gaseous nitrogen.Incidentally to the above, it would appear that after the first crop of barley the presence of the manurial additions of tare residues, and especially of ammonium sulphate, tends to hinder the formation of leachable nitrogen in the soil.

Beschreibung: An attempt has been made to evaluate the role of seven ‘ultra-simple’ seeds mixtures in the production of pasture during the grazing season. The individual value of each mixture is assessed and its period of production described.Pasture output was measured in dry matter and protein yields along with live-weight gains obtained with fattening cattle.

Beschreibung: 1. On the basis of 5000 records from twelve leading herds of Ayrshire cattle in south-west Scotland for the period 1930–9, a statistical study has been made of some of the causes of variations which occur in butterfat percentage.2. Butterfat percentage was found to be affected only very slightly by month of calving, age and length of calving intervals.3. Selection for milk yield would not affect butterfat percentage adversely to any appreciable extent.4. The average repeatability of butterfat percentage was 0·691 in the present material, and heritability was of the order of 0·50–0·60.5. Mass selection would be an effective tool in bringing about improvement in butterfat percentage.

Beschreibung: The cost of conducting digestibility trials with cows is high, due to the need for either elaborate equipment for separating faeces and urine or a considerable number of assistants to remain constantly behind the cows catching the excreta as they are voided. Manual collection of excreta was used extensively by earlier workers, and, in a recent report of the most suitable arrangements for experiments using this method, Eheart, Holdaway & Pratt (1945) found that one attendant was necessary for every cow on test with a trained chemist also present in the shed at all times.

Beschreibung: 1. A statistical study of the causes of variation in milk yields has been made on the basis of 5000 lactation records from twelve leading herds of Ayrshire cattle in south-west Scotland for the period 1930–9.2. The unit of measurement of milk production employed was the yield during the first 180 days of the lactation period. This eliminated the effect of variations in length of current calving interval on milk yield.3. The effect of month of calving on milk yield varied significantly between herds, and it was shown that correction factors for month of calving should be calculated on a within-herd basis. The average difference in 180-day yield between the summer and winter calvers of all herds was about 10% in favour of winter calvers.4. The milk yield of a cow was found to be influenced both by the number of her previous lactations and also by her age at calving. The types of corrections for age employed by previous investigators were discussed, and it was shown that percentage corrections are the most satisfactory.5. There was a positive correlation between milk yield and length of preceding calving interval. From an economic point of view, the optimum length of calving interval was about 400 days for the first lactation, and 1 year for subsequent ones. Corrections for preceding calving interval, like those for age, were most satisfactory when they were proportionate and not additive.6. No significant differences were found among the first three records of a cow in their ability to indicate her actual production capacity. The probable performance of a cow in any lactation was predicted as accurately from the lactation immediately preceding it as from the average of a number of previous lactations.7. The average repeatability of milk yield was 0.46, and heritability was of the order of 0.25–0.30.8. The probable effect on herd improvement of selecting breeding females was found to be very small, extremely little genetic progress being attained by this method in the twelve herds.

Beschreibung: 1. A method of extraction and isolation of the alkaloid of blue lupine was adopted for small samples of the various plant parts: seeds, leaves and pods.2. From the evidence presented, it is shown that the seeds of blue lupine contain a higher percentage of crude alkaloid, than do the pods and leaves. On the basis of the extractions and isolation, seeds contained as much as 2·25%, leaves were found to contain 0·69%, and pods contained 1·46%.3. The alkaloid isolated was identified as D-lupanine by its characteristic physical and chemical properties. The anhydrous monohydrochloride salt was prepared in pure form and from it were obtained samples of the pure free base, d-lupanine.4. Toxicity determinations, involving the injection of water solutions of the crude free base, hydrochloride salt and the pure free base, administered intraperitoneally in guinea-pigs, rats and mice were carried out. Mice were found to be most susceptible, rats less susceptible, and guineapigs least susceptible to the effect of the various solutions injected. The minimal lethal dose (m.l.d.) is given for all three species of animals, and in addition the 50% lethal doses l.d. 50 are given for mice. The purest samples were the most toxic.5. The symptoms shown by guinea-pigs, rats and mice poisoned by the alkaloid are similar. Gross pathology of the animals killed indicated death by asphyxiation.