bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ruminal ammonia formation in relation to the protein requirement of sheep: III. Ruminal ammonia formation with various diets
Authors: Annison E. F. , Chalmers Margaret I. , Marshall S. B. M. , Synge R. L. M. 
Published: March 2009

1. Ruminal ammonia concentrations were measured in sheep receiving basal diets of hay and meals with various supplementary sources of protein. Ammonia production from groundnut meal was great and from maize products slight. Herring meal behaved in an intermediate way.2. The extent of ammonia production from a given amount of protein-rich material was decreased when the amount of starch or cereal meal fed at the same time was increased.
On the composition of boar semen
Authors: Glover T. , Mann T. 
Published: March 2009

1. Twenty ejaculates were collected from the same boar at weekly intervals; the composition of semen was studied by microscopic and chemical methods. The total volume of ejaculates varied from 240 to 500 ml., and sperm concentration from 50,000 to 177,000 cells/μl. Chemical analysis revealed 2·4–12·6 mg./100ml. fructose, 5·9–23·1 mg./100 ml. ergothioneine, and 32–156 mg./100 ml. citric acid.2. The sequence with which the different parts of boar semen follow one another at ejaculation was studied by the method of fractionate collection. The earliest to be emitted was the ‘pre-sperm fraction’ from which sperm and seminal vesicle secretion were absent. The next was the ‘sperm-rich fraction’ which showed not only a high sperm content but contained also substantial quantities of substances derived from the seminal vesicles, i.e. fructose, ergothioneine and citric acid. The ‘post-sperm fraction’ consisted mainly of accessory gland secretions.3. The analysis of semen fractions collected at very brief intervals has shown that whereas the secretion of the seminal vesicles accompanies the spermatozoa at ejaculation, it attains its maximum immediately after the bulk of the sperm has been ejaculated.
The effect of high air temperature on reproduction in the ewe
Authors: Yeates N. T. M. 
Published: March 2009

Six Romney Marsh ewes exposed daily in a hot-room to temperatures averaging 105° F. dry bulb and 87° F. wet bulb for 2 months prior to the start of the breeding season all experienced oestrus and, as a group, at the same time of year as non-heated controls.However, when maintained under daily hot-room treatment throughout the pregnancy period only one ewe lambed, suggesting an adverse effect of high temperature on gestation.In a further experiment to confirm this, eight control ewes all lambed, average birth weight of lambs being 9 lb. 5 oz. Of six experimental ewes exposed to temperatures of 107° F. (dry bulb) and 92° F. (wet bulb) for 7 hr. daily during the last third of pregnancy, one failed to lamb and the lambs averaged 7 lb. 15 oz. A further six experimental ewes exposed to similar room conditions for the last two-thirds of pregnancy produced still smaller lambs, averaging 6 lb. 11 oz. at birth, and three ewes failed to lamb.The yield of lamb per ewe was 9 lb. 5 oz. for controls, 7 lb. 13 oz. and 4 lb. 1 oz. for ewes exposed to heat during the final third and two-thirds of pregnancy respectively and, in the previous year's experiment, 1 lb. 2 oz. for those exposed throughout the pre-mating, mating and post-mating period.It is concluded that although high temperature is apparently without effect on the incidence of oestrus in sheep, it is inimical to satisfactory gestation.
The occurrence of hybrid semi-lethals and the cytology ofTriticum machaandTriticum vavilovi
Authors: Sachs Leo 
Published: March 2009

1. A semi-lethal gene combination has been found in hexaploid species hybrids involving some strains ofTriticum macha, but not in comparable hybrids involving other strains ofT. macha. The production of these semi-lethal hybrids can be explained by the interaction of two genes designated as maand mb.2. The gene mais carried in some strains ofT. macha. The gene mbis carried in the third chromosome set of all other hexaploid species ofTriticum, inAegilops squarrosaand inAeg. cylindrica.3. The semi-lethal gene combination has been found between species which would otherwise produce fertile hybrids and between species which would otherwise produce sterile hybrids. The semilethal gene combination occurs between species which do not overlap geographically.4. The distribution of the genes maand mbshows that the gene maoriginated inT. machaand that the gene mboriginated inAeg. squarrosaand was introduced from there, during the course of evolution, into the hexaploid species ofTriticum(probably excludingT. macha) and intoAeg. cylindrica.5. Meiosis in semi-lethal plants was comparable to meiosis in normal plants. But the semi-lethal plants showed a reduction in fertility, probably as a result of their poor vegetative growth.6. The chromosomes ofT. machaandT. vavilovihave been no more structurally differentiated than the chromosomes of the other hexaploid species ofTriticum.7. The present study has confirmed that the third chromosome set of the genusTriticumhas been phylogenetically derived fromAeg. squarrosa.
The effect of pregnancy and lactation in the ewe on the digestibility of the ration with a note on the partition of nitrogen in the foetus at full term
Authors: Head M. J. 
Published: March 2009

1. Pregnancy and lactation had no effect on the digestibility of the dry matter and nitrogen-containing constituents of the ration of Cheviot ewes fed at a constant level.2. The water consumption of the pregnant ewe was almost doubled during gestation.3. The digestibility coefficients of dry matter and nitrogen in both pregnant and barren ewes fell considerably from November until the beginning of the following April.4. The average nitrogen content of a normal fullterm Cheviot foetus was approximately 99 g.
Ovulation and the passage of the ova through the fallopian tubes in the pig
Authors: Pomeroy R. W. 
Published: March 2009

1. The rate of passage of ova down the Fallopian tubes in the pig has been checked on eighteen living sows by laparotomy and in fifteen sows and gilts at autopsy.2. Both sets of observations suggest that the ova enter the uterus between 24 and 48 hr. after ovulation instead of 72 hr. as suggested by earlier workers.3. It is suggested that the rapid passage of ova through the Fallopian tubes of the pig may be facilitated by the progesterone from the large number of corpora lutea in the ovaries of the pig.
Comparative studies of meat IV. Rates of fattening in relation to the deposition of fat and protein in the fatty and muscular tissues of meat carcasses
Authors: Callow E. H. 
Published: March 2009

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.
Investigations in the Triticinae I. Colchicine techniques for chromosome doubling in interspecific and intergeneric hybridization
Authors: Bell G. D. H. 
Published: March 2009

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.
Studies in selective weed control II. The control of annual weeds in spring cereals
Authors: Blackman G. E. , Roberts H. A. 
Published: March 2009

As part of a general programme for the development of new techniques of selective weed control, numerous experiments have been carried out during 1943–7 on the eradication of annual weeds from spring-sown oats and barley. These multifactorial experiments consisted essentially of simultaneous comparisons of the relative merits of sulphuric acid, copper salts, dinitro-o-cresol and the two growth-regulating substances 2:4-dichloro-phenoxyacetic acid and 2-methyl-4-chloro-phenoxyacetic acid. All the compounds were applied as aqueous solutions or suspensions at a spray rate of 100 gal./acre.Within groups of compounds, cupric chloride is more toxic than cupric nitrate, and this in turn is more toxic than cupric sulphate to such weeds as Raphanus raphanistrwn. Similarly, dinitro-o-cresol or its ammonium salt is more effective than the sodium salt for the control of R. raphanistrum and Galeopsis tetrahit. There is some evidence that sodium methyl-chloro-phenoxyacetate is slightly superior to sodium dichloro-phenoxyacetate for the control of Galeopsis tetrahit and Sinapis arvensis.Between groups of compounds, as long as the weeds are in the young seedling stage there is little to choose between sulphuric acid, cupric chloride, ammonium dinitro-o-cresylate and the growth-regulating substances for the control of Sinapis arvensis, Raphanus raphanistrum, Thlaspi arvense and Polygonum convolvulus when the concentration ranges for the four groups are respectively 9–18, 1–4, 0·4–0·8 and 0·1–0·4%. Within these limits of concentration P. persicaria is best controlled with sulphuric acid and Atriplex patula by dinitro-o-cresol.In general, there is a decrease in the toxic effects with increasing age. There are however complex interrelationships between weed species, compound and stage of development. Whereas for cupric chloride its effectiveness against Sinapis arvensis is little changed between the cotyledon and flowering stage there is with flowering a marked falling off in the efficiency of sodium methyl-chloro-phenoxyacetate. In the intermediate phase of development the growth-regulating substances are most toxic to Raphanus raphanistrum.The results for crop yield demonstrate that sulphuric acid and cupric chloride are less selective than dinitro-o-cresol or the substituted phenoxyacetic acids, since for equivalent degrees of weed control smaller increases in grain production have often been recorded. These injurious effects are maximal at the higher concentrations and when spraying is delayed until after tillering is completed. There is a similar age trend for dinitro-o-cresol and the two growth-regulating substances, and in the case of the latter some indication of a concentration effect, i.e. the compounds are most selective at concentrations of 0·2% or less.For the twenty experiments in which the yields were recorded the most appropriate herbicidal treatments have resulted in gains in yield over the controls ranging from 0·4 to 82·2% with a mean of 23·8.
The nitrogen status of soils Part II. The effect of levels of application on the nitrification of some nitrogenous fertilizers
Authors: Owen O. , Winsor G. W. 
Published: March 2009

1. Laboratory experiments in five soils to which hoof and horn materials were added at different concentrations have shown that the percentages nitrified throughout the transformation were largely independent of the level of application. The ranges of concentration used were 90–360 p.p.m., 150–350 p.p.m. and 100–300 p.p.m. nitrogen.Similar results were obtained with dried blood in two soils.2. Experiments in two soils with ammonium sulphate and in one soil with glycine, urea and guano showed a different response to level of application, the percentages nitrified at the different concentrations being widely different throughout the period of active transformation.3. An explanation of the results is given on the basis of the relative rates of formation of ammonia and of its transformation to nitrate.4. The importance of ammonia determinations in the interpretation of nitrification studies is emphasized.
Studies in oil-seed crops: II. An assessment of the interrelationships between plant development and seed production in linseed (Linum usitatissimum)
Authors: Blackman G. E. , Bunting E. S. 
Published: March 2009

Records of plant development in some twenty-five multifactorial experiments were collected with the object of analysing the effects of nutrient level, density, spatial arrangement and variety on seed production in linseed. By sampling techniques estimates were made of plant density, the extent of basal branching, the number of capsules per stem, the number of seeds per capsule and the seed weight. The expected plot yields, calculated from these data, were in good agreement with the harvested yields.In factorial trials, involving additions of nitrogen, phosphorus and potassium, only a change in the nitrogen level increased the yield of seed, and this gain was largely determined by an increase in the production of capsules and not by any alteration in either the number of seeds per capsule or the seed weight.Over a range of density of thirty to eighty plants per square foot the number of capsules produced per plant was inversely correlated with density. When the distance between drills was maintained at 6–7 in. and the density varied by changing the seed rate then—on an area basis—both capsule production and seed yield were rarely affected since the product of plant number and capsules per plant remained relatively constant. On the other hand, if the rate of seed delivery in the drill was kept the same and the distance between the drills was the variable for density then with a narrow width of drill (4 in.) the increase in plant density more than offset the fall in capsules per plant.Further experiments comparing drilling and crossdrilling did not wholly confirm the importance of spatial arrangement. There was, however, evidence that at densities over eighty plants per square foot, besides a further reduction in capsules per plant, the number of seeds per capsule was depressed. Varieties were characterized by differences in seed size, the number of seeds per capsule, capsules per plant and the ability to produce more capsules at high levels of nitrogen. The superiority of the yielding capacity of Royal could be ascribed to the high rate of capsule production. Such varietal differences in capsule production have not been reported previously, and since the number of capsules per plant is greatly influenced by varying density, the common practice of basing selection on spaced plants, may not give a true assessment of capsule formation at densities optimal for seed production.
The composition and nutritive value of hay grown in the east of Scotland and the influence of late applications of nitrogenous fertilizers
Authors: Moon F. E. 
Published: March 2009

1. Examination of the composition of hay grown in the east of Scotland during the 4-year period 1948–51 has confirmed earlier work indicating the low protein content of this material. In addition, the digestibility of the protein was found to be low, particularly in the case of the seeds-hays, most of which contained insufficient digestible protein to balance the starch equivalent in meeting the maintenance requirements of cattle.2. In nutritive value the seeds -hays were markedly inferior to samples from England and Wales examined by other workers, but very similar to mature ryegrass hay grown in Northern Ireland. The meadow hays examined were of similar starch equivalent but somewhat richer in protein, and this was associated with a higher digestibility of the protein; in consequence the ratio between digestible protein and starch equivalent was more nearly balanced for the maintenance feeding of cattle.3. Applications of sodium nitrate or ‘Nitrochalk’ about 10–20 days before mowing produced very variable responses in the unusually dry season of 1949, but in other years significant increases in protein content were almost invariably obtained. Low protein seeds-hays of the type commonly found in the Lothians were more responsive to this fertilizer treatment than timothy meadow hay, and while increases in protein content of 20–30% were commonly obtained, when relatively heavy dressings of fertilizer (3 cwt. or more per acre) were used, increases in the region of 50% were sometimes recorded. In most years treatment about 10 days before mowing was fully effective in improving the protein content of the hay. Earlier treatment may be preferable in a very dry season, but in more normal years this may increase the yield of the hay and so diminish the effect on protein percentage.
Oestrus and some related phenomena in the buffalo
Authors: Hafez E. S. E. 
Published: March 2009

1. Thirty-one buffalo-cows of different ages were tested for the symptoms and duration of oestrus, and the incidence of post-partum oestrus and conception. Clinical examinations of the vagina were also carried out.2. The symptoms of heat were less intense than in cattle and there was no homosexual activity.3. Pro-oestrus occurred in 43% of the cases with an average duration of 21.20 hr. whilst metoestrus occurred in 67% of the cases with an average duration of 19.20 hr. The average duration of oestrus was 28.47 hr.4. The onset and cessation of oestrus were either abrupt or gradual. The phenomenon ‘split oestrus’ was observed intervening normal cycles. This was not characteristic of the individuals.5. The average interval to post-partum oestrus was 43.80 days. The average number of silent heats per individual was 0.86. Conception took place after an average of 1.71 services whilst the breeding efficiency was 93% in the calving buffaloes.6. Normal clinical changes in the vagina (temperature; nature and amount of secretion; picture of smear) were not reliable indicators of oestrus.7. Further problems concerning reproduction in the buffalo are suggested.
Studies on the habits of Zebu cattle I. Preliminary observations on grazing habits
Authors: Harker K. W. , Taylor J. I. , Rollinson D. H. L. 
Published: March 2009

In order to form a basis for any improvements of cattle and pasture management in East Africa it was decided to observe the grazing habits of the local cattle. A review of the literature shows that animals' habits can be influenced by temperature, but no record could be found to indicate the effect on the animals of elevation and an equable climate.A summary is given of the results obtained during 720 cow-watching hours. Comparing these results with those obtained by other workers it is clear that Bos indicus cattle on a high-level plateau under tropical conditions have distinct and unique habits. On the average, during days with 12 hr. daylight 7·7 hr. were spent in grazing, 93% of this time being during daylight; 5·2 hr. were spent in ruminating, only 23% of this being during the hours of daylight.
Lucerne investigation I. Identification and classification of lucerne ‘varieties’ and ‘strains’
Authors: Zaleski A. 
Published: March 2009

Detailed investigations on identification and classification of lucerne varieties and strains were conducted at Cambridge for four years, 1949–52, on lucerne sown in row plots and on twelve typical varieties planted out in replicated trials as single spaced plants, using 200 plants of each variety. A number of physiological and morphological characters were examined and the resulting data was analysed statistically.The characteristics used for classification are those which showed considerable variation between varieties, but at the same time these differences were maintained consistently from year to year. They proved to be unaffected by a different way of growing the plants or by small differences in soil fertility or season. The results are shown in Tables 1–17, and three basic classifications with distinguishing features of types and varieties are given. The correlations established between various characters on twelve varieties are given under the heading ‘Correlations’ at the end of the results.(a) The first classification into early, mid-season, late and extra-late types, based on the time of flowering, spring and autumn growth, gives a fair indication to the growers regarding earliness and productivity of various varieties.(b) The behaviour of certain varieties from South America, and in particular Saladina, an Argentine variety, which is vigorous and productive under native country conditions but has lost this ability under Cambridge conditions, indicates plainly that classification based on these three characters can be applied only to the country under whose conditions it was established. Therefore any variety especially obtained from a country of extremely different environmental conditions and management system should be checked in these respects even if a description is given.
Semen characteristics and fertility in the bull
Authors: Bishop M. W. H. , Campbell R. C. , Hancock J. L. , Walton A. 
Published: March 2009

1. Certain characteristics of bull semen have been examined at four artificial insemination centres in England. One hundred and twenty-one samples of semen, comprising 168 ejaculates from seventysix bulls of seven breeds, were examined. The semen from 119 tested samples was subsequently used to inseminate 4604 cows.The following semen characteristics were studied: volume of ejaculate; concentration of spermatozoa; incidence of dead spermatozoa; incidence of morphologically abnormal spermatozoa; initial fructose concentration; resistance of spermatozoa to temporature shock; methylene-blue reduction; O2uptake; fructose utilization; visual evaluation of motility; impedance change frequency; and fertilizing capacity (conception rate).A clinical examination was made of the reproductive organs of each bull.2. Variations in the concentration of living spermatozoa and in the incidence of dead spermatozoa were found to account for most of the variations in the metabolic activity of semon: they also largely explained differences in physical activity as assessed by visual estimation of motility or by impedance change frequency.3. Although the rates of methylene-blue reduction, O2uptake and fructolysis showed a close correlation with the numbers of living spermatozoa present, O2uptake and fructolysis per living cell decreased with increasing cell concentration.4. Variations in metabolic activity showed no correlation with variations in the morphological characteristics of the spermatozoa, except in the case of spermatozoa with bent tails. These forms occurred in some samples as a result of staining treatment, but their incidence was positively correlated with the O2uptake and fructolysis per living cell.5. There was evidence that highly active spermatozoa are more resistant to temperature shock than less active spermatozoa.