bluuebunny/crossref_metadata_2025 huggingface dataset:
Progress and Problems in the Study of the Pulsating White Dwarf Stars
Authors: Winget D. E.
Published: June 2019

We currently know of at least three distinct classes of degenerate pulsating variable stars; they occur with a practically uniform spacing in the log of the effective temperature and span nearly the full sweep of the white dwarf cooling sequence in the H-R diagram. The hottest of these variable stars are the pulsating PG 1159-035 stars. Extremely hot, compact, stars, they appear to be contracting and cooling on their way to becoming white dwarf stars. These proto-white dwarfs have photometric properties similar to the pulsating white dwarf stars, and are reviewed separately in these proceedings by A. N. Cox. The two remaining classes of compact pulsating variables are found in relatively narrow instability strips occupying distinct portions of the white dwarf cooling sequence after the constant radius, purely cooling, phase has been reached. These two classes of variable stars are the topic of this review. In this work I will use the concise notation introduced by Sion et al. (1983) to indicate the two classes of variables: the ZZ Ceti’s, and the pulsating DB white dwarfs, become simply the DAV, and the DBV stars, respectively.
Dependence of Linear Sizes and Spectral Indices of Extended Radio Galaxies on Redshift and Radio Luminosity
Authors: Kapahi Vijay K.
Published: June 2019

Apart from the well known evolution in the space density of powerful radio sources, the maximum linear sizes and the spectral indices of extended radio sources could also evolve with epoch and it is important to investigate their epoch-dependence in order to understand the cosmological evolution of radio sources. Evidence for size evolution (in the sense that sources were smaller at earlier epochs) has been presented both from the angular size – redshift relation (θ – z) for quasars and from the angular size – flux density relation (θ – S) for all radio sources. Doubts have sometimes been expressed, however, mainly because it has been difficult to investigate the epoch dependence independent of a possible dependence on radio luminosity. Reasonably reliable estimates of the distances of radio sources have generally been limited to a relatively small range in flux density (S), so that high redshift sources are also of high luminosity. An inverse correlation between linear size (l) and radio luminosity (P) is therefore hard to distinguish from a genuine evolution with epoch. A similar situation appears to hold for the spectral indices (α) of extended radio sources, which have generally been assumed to get steeper at higher radio luminosities (eg. Laing and Peacock 1980) but a dependence on epoch cannot at present be ruled out (Katgert-Merkelijn et al. 1980).
A Study of Three RS CVn-Type Eclipsing Binaries
Authors: Sarma M.B.K.
Published: June 2019

I would like to present the results of the studies of three RS CVn-type eclipsing binaries that are conducted by our group at the Osmania University.
The Initial Mass Function in Young Star Clusters
Authors: Zinnecker Hans
Published: June 2019

This review discusses both the earlier and the most recent work on the IMF in young star clusters. It is argued that the study of the stellar content of young star clusters offers the best chance of developing a theory of star formation and of the IMF.
Summary
Authors: Freeman Ken
Published: June 2019

I would like to pick out a few items that I found particularly interesting. The choice probably reflects my ignorance, because many of these topics are no doubt more known to most of you. I am fairly sure that some of them are basic and important. We will start with the first session.
Hipparcos – Activities of the Data Reduction Consortia
Authors: Lindegren L. , Kovalevsky J.
Published: June 2019

The complete reduction of data from the ESA astrometry satellite Hipparcos, from some 1012 bits of photon counts and ancillary data to a catalogue of astrometric parameters and magnitudes for the 100 000 programme stars, will be independently undertaken by two scientific consortia, NDAC and FAST. This approach is motivated by the size and complexity of the reductions and to ensure the validity of the results. The end product will be a single, agreed-upon catalogue. This paper describes briefly the principles of reduction and the organisation and status within each consortium.
Hipparcos – The Tycho Input Catalogue
Authors: Russell J.L. , Egret D.
Published: June 2019

The Tycho Input Catalogue will be used as a finding list to identify the stellar data within the stream of raw data received from the Hipparcos star mappers. It is based on an a priori list of stars, namely the Guide Star Catalogue being created for the Hubble Space Telescope at the Space Telescope Science Institute. The Guide Star Catalogue will contain positions and magnitudes for objects in the sky complete to at least 14 mag, and will contain about 20 million stars. The data for the sky complete to approximately 12.5 mag, extracted from the Guide Star Catalogue, along with some additional data from the SIMBAD data base of about 500 000 stars at the Strasbourg Stellar Data Centre, will form the Tycho Input Catalogue of approximately 2 million objects. As of the 1985 IAU General Assembly nearly 50 per cent of the plates for the Guide Star Catalogue had been measured, and 10 per cent of them were completely processed and catalogued.
New Radio Telescopes
Authors: Kellermann K. I.
Published: June 2019

Nearly all of the exciting discoveries in radio astronomy have come from new instruments or techniques which have provided new frequencies, high sensitivity, higher spatial or time resolution, or improved image quality. Since the last General Assembly a number of major new radio telescopes have been completed while construction of others have only just begun. At the same time telescopes of the more distant future are still in the conceptual stage. This paper summarizes a full-day meeting of Commission 40 on recently completed radio telescopes, new radio telescopes now under construction, and radio telescopes of the future.
New Developments in Documentation and Data Services for Astronomers
Authors: Wilkins G. A.
Published: June 2019

The meeting provided a forum in which those responsible for documentation and data services in astronomy could interact with users of these services in an endeavour to establish how new techniques for the distribution and retrieval of information may be used to best advantage by astronomers. The report contains summaries of each of the short papers that were presented during the four sessions and brief accounts of the ensuing discussions. The principal topics were: the preparation and publication of papers and reports; bibliographic data services; electronic-mail facilities; archiving of current observational data; the changing role of libraries; and the maintenance of the historical record of astronomical activities.
The J vs. M Relation for Binary Stars
Authors: Tohline J. E.
Published: June 2019

For a given mass M and environmental temperature T, there is a well-defined angular momentum Jmax above which physical systems cannot exist as self-gravitating entities. The quantity Jmax α M2 T−½. Observations of J and M in young binary systems should put useful constraints on the temperature of the medium from which they formed.
Iras Dust Bands and the Origin of the Zodiacal Cloud
Authors: Dermott S. F. , Nicholson P. D.
Published: June 2019

Previous discussions of the origin of the zodiacal cloud have attempted to distinguish between an asteroidal and a cometary source on the basis of collisional dynamics, that is, by calculating the rates of production and destruction of particles from the two possible sources. The uncertainties in these calculations are too large to permit a useful conclusion. The recognition that the solar system dust bands discovered by IRAS are probably produced by the gradual comminution of the asteroids in the major Hirayama asteroid families may allow us to estimate, with comparative confidence, the contribution to the zodiacal cloud of the asteroid belt as whole.
The Volatile Composition of Comets
Authors: Weaver H. A.
Published: June 2019

Comets may be our best probes of the physical and chemical conditions in the outer regions of the solar nebula during that crucial period when the planets formed. The volatile composition of cometary nuclei, in particular, can be used to decide whether comets are the product of a condensation sequence similar to that invoked to explain the compositions of the planets and asteroids, or if comets are simply agglomerations of interstellar grains which have been insignificantly modified by the events that shaped the other bodies in the solar system. Although cometary nuclei are not generally accessible to observation, observations of cometary comae can illuminate at least some of the mysteries of the nuclei provided one has a detailed knowledge of the excitation conditions in the coma and also has access to basic atomic and molecular data on the many species present in comets. This paper examines the status of our knowledge of the volatile composition of cometary nuclei and discusses how these data are obtained.
Recent Observations of the Beams in SS 433
Authors: Vermeulen R.C.
Published: June 2019

Preliminary results are presented of an intensive multifrequency observing campaign on SS 433 conducted in 1987. There were participants from all over the world; they brought all the observations together at the 1988 Dwingeloo workshop on SS 433. With a rapid sequence of VLBI maps, we have been able to follow the onset and evolution of a series of radio flares. We have also obtained a wealth of optical spectra allowing studies of the variability of the Doppler shifted lines on timescales of hours. There is little correlation between the activity in the radio regime, and that seen in the Doppler shifted lines.
Solar and Stellar Flares
Authors: Benz A.O.
Published: June 2019

This review concentrates on some selected topics concerning the release of magnetic energy and associated phenomena in flares. Emphasis is on microflares, recent studies of different phases of flares, and propagation and trapping of flare accelerated electrons. The ongoing analysis of the observations of the previous solar cycle reaches a state where quantitative models become possible. The subject of solar flares can be broken up into several, now well defined physical problems.
Review of Linked Array Instruments
Authors: Ekers R.D.
Published: June 2019

At cm wavelengths aperture synthesis radio-telescopes (arrays of linked antennas which synthesize an image of the sky with high angular resolution) are now becoming the dominant astronomical research tool. Major new facilities such as the VLA are in full operation, others such as the Australia Telescope are nearing completion and a number of telescopes designed to form images in real time have been converted to operate in the aperture synthesis mode (e.g. MOST, Bologna Cross). See Napier et al. (1983) for a review of modern synthesis telescopes. The high resolution, sensitivity and freedom from confusion have led the aperture synthesis telescopes into very diverse astronomical applications.
CCD Data Taking Modes and Flatfielding Problems
Authors: Djorgovski S. , Dickinson M.
Published: June 2019

We briefly review some problems in the flatfielding of CCD images, in the context of three data-taking modes: stare, short scan, and drift scan. The principal sources of flatfielding imperfections are: (1) mismatch in the spectra of the astronomical sources of interest and the flatfield illumination; (2) a variety of low-level additive errors; and (3) nonlinearities of the CCD response. Residual flatfielding errors are probably the limiting factor in high-precision astronomical photometry. Flatfielding accuracies of the order of 1 – 2% per pixel are commonly achieved; with some effort, accuracies of ~ 0.1% can be reached; higher accuracies require a substantial effort, or improvements in the quality of CCD chips. In general, scanning data taking modes outperform the “standard” stare mode.
Submillimeter Spectrum of the Cosmic Background Radiation
Authors: Matsumoto Toshio
Published: June 2019

Recent observations of the spectrum of the 3K cosmic background radiation (CBR) indicate that the CBR spectrum is consistent with a blackbody spectrum of T = 2.74 ±0.02K (Smoot et al. 1987). These measurements, however, were carried out in the Rayleigh-Jeans part of the spectrum, while theories predict spectral distortion in the Wien part. Therefore, we tried to observe the submillimeter spectrum of the CBR with a liq.He cooled radiometer onboard a sounding rocket. The experiment was a collaboration between Nagoya University and University of California, Berkeley.
The Extreme Ultraviolet Explorer Mission
Authors: Bowyer Stuart , Jelinsky Patrick , Christian Carol , Hawkins Isabel
Published: June 2019

The Extreme Ultraviolet Explorer mission is described. For the first six months, an all-sky survey will be carried out covering 90 to 750 Å, or essentially the entire extreme ultraviolet (EUV) bandpass. This EUV survey will be made in four bands, or colors: λλ 90-150 Å, 170-250 Å, 400-600 Å, and 550-750 Å. A portion of the sky which is free from the normally intense 304 Å geocoronal helium background will be surveyed at greater sensitivity; the wavelength coverage of this band is from 90 to 400 Å. Following the sky survey portion of the mission, spectroscopy of individual sources will be carried out. Three spectrometers employing novel variable line-space gratings will provide spectra with ~1 Å resolution over the band from 70 to 760 Å. This spectroscopy will be carried out by guest observers chosen by NASA in a manner roughly analogous to the International Ultraviolet Explorer (IUE) guest observer program.
The Hipparcos Astrometry Satellite – Two Years After Launch
Authors: Perryman M.A.C.
Published: June 2019

Launched in August 1989 into a geostationary transfer orbit, the Hipparcos astrometry satellite failed to reach its intended geostationary orbit through the failure of its apogee boost motor. Present indications are that the possible operational lifetime should nevertheless extend beyond the end of 1992, with extremely high-quality scientific data being returned for some 65 per cent of the time. For an assumed 3-year operational lifetime, the original mission goals (positions, parallaxes, and annual proper motions with an accuracy of about 2 milli-arcsec) should be achievable (the pre-launch expectations of the planned 2.5-year mission would be achievable with a 3.5-year mission in the revised orbit). This paper describes the in-orbit performance of the satellite most relevant to the scientific goals.
Calibration and Characteristics of the HIPPARCOS Payload
Authors: Schrijver Hans
Published: June 2019

The Hipparcos geometrical calibrations directly linked with the astrometrical precision are shortly described, and their accuracies given. An example for the basic angle shows the very high stability of the instrument.
Chromospheres and Winds of Cool Stars
Authors: Carpenter Kenneth G.
Published: June 2019

I present data acquired during the early operations era of the HST with the Goddard High Resolution Spectrograph (GHRS) on three late-type giant and supergiant stars: α Tau (K5 III non-coronal), λ Dra (K5 III hybrid), and α Ori (M2 lab). Figure 1 shows fits to echelle (R=100,000) line profiles of three ions seen in the spectrum of α Tau. The Co II line can be fit with a single gaussian, the self-reversed Fe II line with a combination of an emission and absorption gaussian, but the unreversed C II lines require two emission gaussians of substantially different FWHM and maxima. The complex shape of the C II profiles suggests that the turbulent velocity distribution in the chromosphere is anisotropic (e.g. Gray 1988) or that the lines are formed in two regions characterized by significantly different Teff and Vturb, as in the hybrid star models of Harper (1991).
The Lack of Fundamental Atomic and Molecular Data: A Crisis in Space Astronomy?
Authors: Bruhweiler Frederick C.
Published: June 2019

A crisis is now confronting space astronomy. Many current and future investigations at UV and Extreme-UV wavelengths with space observatories such as the International Ultraviolet Explorer (IUE), Hubble Space Telescope (HST), Extreme UV Explorer, and Lyman are limited by the current availability of good fundamental atomic data such as accurate energy levels, wavelengths, and oscillator strengths.

Until very recently, spectroscopic studies using the IUE of hot O-subdwarfs have revealed the vast majority of the photospheric features could not be identified. Our recent detection of species such as Fe V, VI, and VII in very hot white dwarfs was unexpected and has definite implications for observations to be obtained by the EUVE and Lyman. Coadded spectra of these degenerate objects show many other unidentified features. Accurate atomic data for these highly ionized species will be a prerequisite to doing any quantitative analysis of these species and understanding the flux distributions in the EUV, where the strongest lines of these highly-ionized species are located.
New Models for the Spectral Evolution of Galaxies
Authors: Bruzual A. Gustavo
Published: June 2019

Bruzual & Chariot (1991, BC91 hereafter) have supplemented the purely photometric isochrone synthesis models of Chariot & Bruzual (1991) with an updated library of stellar spectra and evolutionary tracks in order to compute the spectral evolution of stellar populations. BC91 used the evolutionary tracks of Maeder & Meynet (1989), with the main-sequence lifetimes for stars in the mass range 1.3 M⊙ ≤ m ≤ 2.5 M⊙, revised as prescribed by Maeder & Meynet (1991). BC91 included an accurate description of the late evolution of low and intermediate-mass stars as hot nuclei of planetary nebulae and through the white dwarf cooling sequence. While stars in these stages contribute negligibly to the optical/near-IR light, the self-consistent model of BC91 for an initial burst of star formation can account for the UV excess observed in quiescent early-type galaxies. Models that do not include post-AGB stars require additional star formation to account for this UV excess.
Astrometry and Orbits of Asteroids and Comets
Authors: Marsden Brian G.
Published: June 2019

Astronomers have been consciously making positional observations of comets since the sixteenth century, and rough information on bright comets is available from social records collected in the Far East, the Middle East and Europe over the previous two millennia. Attempts at representing the observations with orbits also date back to the sixteenth century, well before the earliest computations were made on the basis of gravitational theory. Improvement in the accuracy of cometary astrometric data was slow to develop following the invention of the telescope and, a few decades later, the micrometer, for this had to await the availability of Flamsteed’s star catalogue and the understanding brought about by Bradley’s discovery of aberration and nutation. In spite of important contributions by some of the most celebrated scientists of the eighteenth century, orbit computation remained largely a process of trial and error until the discovery of the first asteroids and the rise of Gauss and his followers. By the 1880s the availability of a dense star catalogue like the AGK1 was allowing micrometric observations of comets and asteroids often to achieve an accuracy of 2 to 3 arcsec, and the subsequent introduction of photographic astrometry brought convenience but relatively little additional improvement in accuracy. The use nowadays of charge-coupled devices clearly has the potential for a further increase in accuracy, even for diffuse objects like comets, but for the moment the accuracy tends generally to be limited by the inadequacy of the available star catalogues. Modern orbit determination routinely includes the use of sophisticated techniques to identify isolated observations of the same asteroid at different oppositions and in the case of a comet the examination of the nongravitational effects that can strongly influence the object’s motion.
AST/RO: A submillimetre-wave telescope for the South Pole
Authors: Stark Antony A
Published: June 2019

The Antarctic submillimetre Telescope and Remote Observatory (AST/RO), a 1.7 m offset Gregorian, is scheduled for installation at the South Pole in November 1993. It is a collaboration including the Smithsonian Astrophysical Observatory, AT&T Bell Laboratories, Boston University, the University of Illinois, the University of Colorado, and the University of Cologne. Observational tests (Pajot 1990; Dragovan et al 1990) and modeling (Bally 1990) of atmospheric transparency over the Pole indicate that it is the best accessible submillimetre-wave site in the world. The immediate scientific goals are heterodyne spectroscopy of galactic molecular clouds and molecular lines in the earth’s stratosphere at wavelengths near 600 μm. Two early observational programs are a large-scale survey of the CI line at 609 μm and monitoring of the 2.8 mm O3 line arising in the stratosphere. Under the newly-formed Center for Astrophysical Research in Antarctica (centred at Yerkes Observatory), AST/RO will become a general-purpose instrument for the millimetre, sub-millimetre and far-infrared.
Gender, Nation, and Situated Intersectionality: The Case of Catalan Pro-independence Feminism
Authors: Rodó-Zárate Maria
Published: June 2019

Debates on nation, self-determination, and nationalism tend to ignore the gender dimension, women's experiences, and feminist proposals on such issues. In turn, feminist discussions on the intersection of oppressions generally avoid the national identity of stateless nations as a source of oppression. In this article, I relate feminism and nationalism through an intersectional framework in the context of the Catalan pro-independence movement. Since the 1970s, Catalan feminists have been developing theories and practices that relate gender and nationality from an intersectional perspective, which may challenge hegemonic genealogies of intersectionality and general assumptions about the relation between nationalism and gender. Focusing on developments made by feminist activists from past and present times, I argue that women are key agents in national construction and that situated intersectional frameworks may provide new insights into relations among axes of inequalities beyond the Anglocentric perspective.
Galen and Medical Autobiography
Authors: Nutton V.
Published: June 2019

The twenty-two volumes of the last edition of the collected works of Galen occupy a smaller place in the affections of classical scholars than on the library shelf. The reputation of Galen as a great physician is sufficient to ensure a respectful neglect of his writings that is as undeserved as it is effective and that hampers a reassessment of his aims and abilities. Even though recent scholarship has done much to show him as a recognizable product of and participant in the Second Sophistic movement with strong claims to be regarded as a universal scholar, Wilamowitz's dismissal of him as a ‘Seichbeutel’ still remains a typical verdict. Not that the epithet was entirely unjust, for Galen's prolixity, his frequent polemics, his repetitions and recapitulations, and the inelegance of much of his prose style are all obstacles to his readers, few of whom have had the stamina and enthusiasm, to say nothing of the linguistic competence, to read all of his works preserved in Greek, Latin, Arabic and Syriac. Thus it is not surprising that the finest contemporary account of society in Rome during the reign of Marcus Aurelius, which lies buried deep in the fourteenth volume of Kuhn's edition, has only rarely been utilized in a discussion of that period. Πɛρὶ τΞῦ πρΞγινώσκɛιν, ‘On prognosis’, whose title, given by Galen himself, disguises the variety of its contents, has remained unread and its absence from the three volumes of theScripta Minora Galeniand, as yet, from theCorpus Medicorum Graecorumhas placed it beyond the ken of most historians. It is my intention in this paper to present a description of this treatise and a discussion of its position within literary genres as a contribution to the history of autobiography.
The effect of replacing grass silage with pea/wheat bi-crops in dairy cow diets on feed intake, concentrate utilization and milk production
Authors: Adesogan A.T. , Salawu M.B. , Dewhurst R.J.
Published: June 2019

One of the ways by which UK farmers can maintain profitability in the current low milk price climate is to increase home-grown forage utilization in livestock diets. Previous work has shown that pea/wheat bi-crops are energy and protein rich forages that give higher intakes and nitrogen (N) retention than grass silage but only marginal improvements in milk production (Adesogan et al., 2000). This study determined whether the milk response from such bi-crops could be improved by using a short-straw pea variety instead of the conventional tall straw variety.
Major gene effect on serum insulin-like growth factor-1 concentration in pigs
Authors: Cameron N.D. , McCullough E. , Troup K. , Penman J.C. , Pong-Wong R.
Published: June 2019

Insulin-like growth factor-1 has been positively associated components of growth in pigs, such as protein deposition. Therefore, serum insulin-like growth factor-1 concentration (IGF-1) was measured in lines of pigs divergently selected for daily food intake (DFI) or for efficient lean growth rate (LGS) to determine if there was a non-zero genetic association between IGF-1 and the selection criteria. If a genetic association did exist, then IGF-1 could be used as a physiological predictor of genetic merit in a breeding programme. The presence of a major gene effect on IGF-1 was also examined in the study.
Validation and development of a behavioural test to predict the predisposition of growing pigs to perform harmful social behaviour such as tail biting
Authors: Breuer K.B. , Beattie V.E. , Dunne L.M. , Slade E.C. , Davies Z. , Mercer J.T. , Rance K.A. , Sneddon I.A , Sutcliffe M.E.M. , Edwards S.A.
Published: June 2019

Harmful social behaviour is behaviour that is directed at pen mates which, if persistent, causes injury. It includes tail, ear and flank biting. The aim of this work was to determine if pigs that are predisposed to harmful social behaviour can be identified early in life using a test. In this experiment a test that measured the chewing behaviour of pigs on an artificial tail was developed from Fraser (1987), as one of a wider battery of tests under investigation in the overall project. The validity of the test was evaluated by correlating the rope directed behaviour in the test with harmful social behaviour in the home pen.
Bioaccummulation of the endocrine disrupting compound, dioctyl phthalate, in sheep grazing pasture treated with sewage sludge or inorganic fertiliser
Authors: Rhind S.M. , Kyle C.E. , Telfer G. , Martin G. , Smith A.
Published: June 2019

Endocrine disrupting compounds (EDC) are chemically diverse and ubiquitous compounds which are released into the environment as a result of industrial, domestic and agricultural processes. They are generally readily absorbed from ingested food and water, can accumulate in animal tissue and can have adverse effects on reproductive and immune systems at very low concentrations. They are present in high concentrations in sewage sludge which is likely to be used increasingly as a fertiliser on pasture and arable land and so there is potential for bioaccumulation in animal tissues and associated, adverse biological effects. The aim of the study was to determine the concentrations of one EDC, dioctyl phthalate (DOP), in the livers of ewes and lambs maintained on control and sludge-treated pastures.
Influence of dietary fatty acids on the fatty acid composition of intestinal mucosa in the milk fed pre-ruminant calf
Authors: O’Brian R. , Muturi N. , Birnie M. , Wallace M. , Struthers J. , Scaife J. R.
Published: June 2019

Dietary fatty acids have been shown to affect the activity of the immune system in a variety of species (Calder, 1998) although the exact mechanism by which they influence the nature of the immune response is unclear. The effect of dietary fatty acids on the fatty acid composition of intestinal mucosa is important since this tissue has a rapid turn over and is a major site of antigenic exposure and immune defence. The speed with which changes in dietary fatty acid intake are reflected in the fatty acid composition of cells and tissue of the body varies. In ruminants the development of a functional rumen greatly influences the nature of the fatty acids available for absorption from the small intestine, however, in pre-ruminant animals, milk may be used as a medium to supplement the diet with specific dietary fatty acids. This work was carried out to establish the extent to which different oil supplements could change the fatty acid composition of intestinal mucosa in milk fed pre-ruminant calves.
Application of a mechanistic model of methanogenesis in the lactating dairy cow. The fate of hydrogen during fermentation and strategies to mitigate methane emissions
Authors: Mills J A N , Dijkstra J. , Bannink A. , Kebreab E. , Cammell S.B. , Crompton L.A. , France J.
Published: June 2019

Dietary intervention to reduce methane emissions from lactating dairy cattle is both environmentally and nutritionally desirable due to the importance of methane as a causative agent in global warming and as a significant loss of feed energy. This investigation involved the development of a dynamic mechanistic model of whole rumen function (Dijkstra et al. 1992), with the objective to simulate whole-animal methane emissions for a range of dietary inputs.
The Chemical composition and digestibility of wheat straw treated with urea and white rot fungi
Authors: Rouzbehan Y , Fazaeli H. , Kiani A.
Published: June 2019

In Iran, wheat straw is produced in huge amount and has been used in animal feed. However, the use of straw as an animal feed is limited due to its low available energy as well as its low nitrogen content. Various chemical delignification methods to improve the digestibility of straw have extensively investigated (Sundstol and Owen, 1984). Biological methods of treating straw using fungi such as white-rot-fungi have also been reported (Zadrazil, 1984). The solid-state fermentation (SSF) of wheat straw with white-rot fungi is a complex process, which is influenced by factors such as the species of fungus, substrate, temperature and moisture (Zadrazil, 1984). Rouzbehan et al., (2000) noted that pre-treating the straw with urea and incubation with either pleurotus ostreatus or pleurotus Persian fungi has improved the digestibility of wheat straw. In this study, the effect of urea and another two species of white rot fungi on the nutritive value of wheat straw was tested.
Influence of peptides and amino acids on ammonia assimilation by cellulolytic ruminal bacteria
Authors: Wallace R. J. , Atasoglu C. , Newbold C. J.
Published: June 2019

An understanding of the nitrogen compounds required for growth of ruminal bacteria is of importance to optimising ruminal fermentation and in formulating optimal protein requirements of ruminants. Bryant (1973) concluded that cellulolytic ruminal bacteria used only NH3 as N source for growth. The main species were unable to grow on other nitrogen sources in the absence of NH3, and the incorporation of radioactive pre-formed amino acids appeared to be minimal. Disappearance of NH3-N from the growth medium was equal to N incorporation into bacterial protein. As a consequence, the assumption was made in drawing up the Cornell Net Carbohydrate and Protein System (CNCPS) that structural carbohydrate-fermenting bacteria use ammonia as their only source of nitrogen (Russell et al., 1992). More recent studies with mixed cultures suggest, however, that fibrolytic bacteria incorporate significant quantities of amino acids (Griswold et al., 1996; Carro and Miller, 1999). The present experiments were undertaken to clarify the N sources for growth of the three main species of cellulolytic ruminal bacteria in pure culture.
A new source of Magnesium and Phosphorus for dairy heifers fed a grass silage based diet
Authors: Chaudhry A S. , Taylor W. , Harland J. I. , Rowlinson P.
Published: June 2019

Magnesium (Mg) and Phosphorus (P) are essential for various metabolic functions of dairy heifers and thus any dietary imbalance may be detrimental for growing heifers. The most frequently used source of Mg is calcined magnesite (MgO), which has an availability of only 0.20 and is unpalatable to animals. Other inorganic sources of minerals are usually expensive, may be difficult to mix into a premix and can be unpalatable. This study compared the effect of feeding fixed amounts of two mineral mixes that had almost identical mineral levels but differed in sources to supply Mg and P, on palatability, growth and health status of growing heifers.
Effects of short and long term sodium supplementation on copper accumulation in sheep
Authors: Mohammed M.O. , Chiy P.C. , Phillips C. J. C.
Published: June 2019

The presence of high concentrations of sodium in the mammalian small intestine plays a major role in facilitating copper absorption (e.g. Wapnir and Stiel, 1987). An experiment was conducted that investigated the medium and long-term effects of adding sodium to the diet of sheep on the copper accumulation in body tissues.
The potential of urinary metabolites of plant compounds as indicators of botanical composition of the diet of goats
Authors: Keir B. L. , Mayes R. W. , Ørskov E. R.
Published: June 2019

Knowledge of the nutrition of free-ranging herbivores and the impact on their environment is often limited by lack of information concerning the botanical composition of their diets. For herbivores grazing heterogeneous vegetation environments, current methods for estimating the botanical composition of their diets are limited in their scope and accuracy. The purpose of this study was to establish whether urinary metabolites, occurring as a result of ingestion of different individual plant species, have the potential to be used as markers to estimate diet composition.
The effect of diet on rumen chitin content in sheep
Authors: Rezaeian M. , Beakes G. W. , Parker D. S.
Published: June 2019

Measurement ofin situfungal populations is needed in order to determine the extent of their contribution to the ruminal digestive process. Since chitin is present in the cell wall of rumen fungi (Orpin, 1977), measurement of this polymer can be used to estimate fungal biomass and their growthin vitro(Rezaeian, 1996) andin vivo(Argyle and Douglas, 1989). The objective of this experiment was to study the effect of diet composition on the chitin content of both ruminal fluid and digesta solids as an index of the fungal population in the rumen.
The effect of temperature and fermentation time on the survival of Salmonella typhimurium DT104:30 in liquid piglet feed fermented with Pediococcus pentosaceus
Authors: Beal J.D. , Campbell A. , Brooks P.H.
Published: June 2019

Contamination of pig feed with enteric pathogens such as salmonellae has implications for the dissemination of salmonellosis in pigs and subsequent spread of these organisms through the food chain to humans. Liquid feed has the potential to be a vector for enteropathogens unless it is sterilised. However, if liquid feed is fermented with lactic acid bacteria (LAB), the production of lactic acid and consequent reduction in pH have an antimicrobial effect that can eliminate potential pathogens from the feed. The objective of this study was to determine whether the temperature at which fermented liquid feed (FLF) is fermented and maintained and the length of fermentation time affect the ability of Salmonellae to survive in the feed.
Influence of protein level of supplement on diet selection by dairy cows given a choice of grass or maize silages, and on intake of forages when offered separately
Authors: Syed J.S. , Leaver J.D.
Published: June 2019

In a previous study of forage choice (Syed and Leaver, 2000), cows selected a high proportion of grass relative to maize silage (0.87:0.13). Milk production level of cows and protein level in supplement were not influential in the proportion of forage selected. An understanding of forage preferences by cows should lead to the production of forages with improved intake characteristics. This experiment examined how intake of grass and maize silages offered as a choice compared with intake when offered separately with low or high protein supplements.
Bushel weight of wheat and enzyme supplementation did not affect weaner pig performance
Authors: Miller H.M. , Toplis P. , Blanchard P. , Rawling R.
Published: June 2019

Wheat is often the largest single ingredient in piglet diets and therefore variation in quality may have a large effect on piglet performance. Currently there is no rapid method for the nutritive assessment of wheat. The livestock feed industry traditionally uses bushel weight as a predictor of nutritive value; however this assumption has recently been challenged by a literature review (Miller and Wilkinson, 1998) and by a weaner trial (Miller, Toplis, Arnold, Cook and Marshall, 2000). The aim of this experiment was to compare two more extreme bushel weights of Riband (64 v 78 kg/hl) than used in the previous experiment (Miller et al., 2000) when fed to weaned piglets with and without a xylanase enzyme. In order to amplify possible differences wheats were uncooked and included in the test diets at an atypically high level. We hypothesised that 78 kg/hl bushel weight would outperform 64kg/hl bushel weight (which is below the standard accepted by feed mills for feed wheat) and that enzyme supplementation would improve the performance of both wheats.
Synchronisation of oestrus using a 14 day progestagen sponge treatment in the absence of a corpus luteum does not reduce fertility in ewes
Authors: Beard A.P. , Madgwick S. , Quinn K.M. , Evans A.C.O.
Published: June 2019

Progesterone and progestagens are widely used to synchronise oestrus in sheep, however 15 to 30 % of ewes fail to maintain a pregnancy following the first service after oestrous synchronisation and the reason(s) for this failure rate is unclear. In commercial flocks, the progestagen treatment commences at a random stage of the oestrous cycle and in some ewes luteolysis may occur soon after treatment commences, leaving the ewe solely dependent on the exogenous source of progestagen which promotes the development of persistent follicles (Flynn et al., 2000). These persistent follicles may be up to 14 days of age when they ovulate whereas the age of follicles at ovulation in natural cycles is 4 to 8 days. In cattle, it is clear that ovulation of these old follicles results in a decrease in fertility. The aim of this study was to examine the effect of ovulation of aged follicles on fertility in cyclic ewes by using treatments based on a 14-day, progestagen synchronisation protocol that is known to produce persistent follicles.
Empirical studies of effects of EDC on reproductive physiology (particularly in females)
Authors: Picton H M
Published: June 2019

Over recent years increasing evidence suggests that xeno-oestrogens including alkylphenols, such as nonylphenol and octlyphenol (OP), may represent a threat to the health and reproductive function of humans, domestic animals and wildlife populations. To date most attention has focused on the effect of these endocrine disrupting compounds (EDCs) on male reproductive health. In contrast, hardly any attention has been paid to the potential adverse effects that these compounds may exert in females, where the end points are easier to measure than in males, and where oestrogen modulated diseases such as breast cancer, are of such importance to humans. This is also despite evidence from a number of species, including humans, that exposure in utero to the potent synthetic oestrogen diethylstilbestrol (DES) has profound and long-term effects on ovarian morphology, folliculogenesis, fertility, and pregnancy outcome of female offspring.
Computerised tomography for carcass analysis
Authors: Young M. J. , Simm G. , Glasbey C.A.
Published: June 2019

Computer tomography (CT) scanning is a method for non-invasive imaging of subjects developed for use in human medicine. It allows cross-sectional images, containing a wealth of information, to be obtained for a living animal (Davies et al., 1987). These can be used to provide very accurate assessment of body composition in live animals in a welfare-friendly manner. Not only is accuracy improved but also a wide range of novel traits lend themselves to assessment and objective measurements can be collected rapidly, using mathematical algorithms for image analysis (Glasbey & Robinson, 1999; Glasbey et al., 1999).
The effect of relative abundance on diet choice in fallow deer
Authors: Alm U. , Birgersson B. , O. Leimar
Published: June 2019

The fallow deer is a generalist herbivore that eats different plants containing secondary compounds in various amounts. From observations of foraging behaviour it is known that large herbivores tend to eat from a variety of locations and, over the short term, typically ingest small quantities of a variety of foods and sample novel foods rather than making an immediate decision to either eat large amounts or to reject the food (Freeland and Janzen 1974). The diet choice of large herbivores is influenced by the presence of nutrients and toxins (Provenza 1995), but another factor that could influence the diet choice is the relative abundance of different plants and plant types. In order to study these effects we have performed experiments on the effect of the relative abundance of different food types on diet choice in fallow deer.
Preliminary investigations of behavioural and physiological responses to castration in horses
Authors: Eager R. A. , Price J. , Welsh E. , Waran N. K.
Published: June 2019

Behavioural responses to pain are highly species specific and reflect varying strategies for survival. As prey animals, horses may fail to show obvious pain responses, instead masking pain to reduce predation through selection as the weakest of a group (Anilet al.,2002). Priceet al.(2002) identified disagreement amongst vets regarding pain assessment and management in horses. This was highlighted by recent debate concerning the existence of post-castration pain and the necessity for analgesia in equines (e.g., Capner 2001; Green 2001). While optimal assessment and management of pain is an important equine welfare issue, the behaviours of horses in response to pain are poorly defined (Raekallioet al.1997) and the relevance of physiological indicators not confirmed. Palpation or human interaction tests, used in other species (e.g. Holtonet al1998), have yet to be validated in horses. This study aimed to identify and quantify potential behavioural indicators of post-castration pain in horses.
The relationship between liveweight and the intake of bulky foods in pigs
Authors: Whittemore E.C. , Emmans G.C. , Kyriazakis I. , Knap P.W. , Simmins P.H. , Jagger S.
Published: June 2019

The amount of a bulky food that an animal can eat depends on its capacity for bulk and the bulk content of the food. For pigs between 12 and 40kg the capacity for food bulk was found to be directly proportional to liveweight (Kyriazakis and Emmans, 1995). The way in which the capacity for bulky foods changes with weight above 40 kg is not clear; there is no a priori reason to assume that the scaling rule proposed for young pigs will hold in heavier pigs. The applicability of the work in young pigs for use in more mature pigs needs investigation, to develop predictive equations for the whole relevant weight range. An experiment was designed to determine how the capacity for bulk changed with weight; the objective was to develop a relationship between the capacity for food bulk and liveweight.
The effect of nutrition on nematode faecal egg output in lactating, organically managed ewes
Authors: Keatinge R. , Houdijk J.G.M. , Jackson F. , Kyriazakis I.
Published: June 2019

Nematodes are a particular challenge to animal health and productivity in organic sheep systems, where the prophyllactic use of anthelmintic is prohibited. The peri-parturient rise in faecal egg output, a consequence of relaxation of host immunity in late pregnancy and early lactation, is potentially a key factor in the epidemiology of parasitic gastro-enteritis on organic sheep farms. Coop and Kyriazakis (1999) developed a hypothesis to explain the relationship between nutrition and periparturient breakdown of immunity to parasites, and there is now an increasing body of evidence for the involvement of dietary protein (Houdijk et al 2001). The objective of this study was to test this hypothesis in organically managed ewes carrying a mixed, naturally acquired infection, grazing on grass/clover in early lactation, and to examine the potential for a nutritional approach to parasite control in commercial practice.
The use of faecal inocula for estimating the in vitro digestibility of horse feeds
Authors: Murray J. M. D. , Moore-Colyer M.J.S , Longland A. C. , Dunnett C.
Published: June 2019

There is a dearth of information available on the effects of donor animal on the fermentative capacity of equine faecal inocula for use in in vitro digestibility determinations. Furthermore, there is little knowledge of the degradation characteristic of feedstuffs incubated with equine faecal inocula. As such this study aimed to elucidate the effect of donor animal on the fermentation of feedstuffs in vitro and to assess the in vitro degradation characteristics of three commonly fed components of horse diets incubated with equine faecal inocula.
Production of polyclonal antibody for ciprofloxacin detection in Brazilian livestock
Authors: Gobbo S.P. , Longo C. , Bueno I.C.S. , Duarte K.M.R. , Meirelles C.F.
Published: June 2019

The antibiotic use to increase the animal production can result in residual concentrations in products as meat, eggs and milk, exceeding the acceptable doses for human consumption. In Brazil nowadays, 14 antibiotics are employed as feed additive, however there are about 121 drugs used in Veterinary Medicine that contain antibiotics in their formulation. Due to amplitude and frequency of the antimicrobial resistance, it can be considered an emergent and significant question for the public health and an alert for the necessity of a global control about the use of those antibiotics. The immunoassays allow the diagnosis of these antibiotics with accessible costs and presenting good results. The aim of this work was to produce polyclonal antibodies for ciprofloxacin detection using ELISA.
Creep feeding status of piglets can be identified by an automatic marking device
Authors: Lee H. F. , Morgan C. A. , Appleby M. C. , Waran N. K.
Published: June 2019

Creep food intake of suckling piglets varies considerably between individuals (Pajor et al., 1991). The creep feeding status of individual piglets can be monitored by video recording or by combining the weight of the food removed from the electronic dispensers with monitoring by video recording. However, the analysis of videotapes is time-consuming, which limits its widespread use on farm. From a practical standpoint, monitoring the food intake by piglets either before or after weaning is important to provide useful information for a management strategy. Therefore a general, quick and valid method to detect the food intake experience of piglets would be valuable and is needed. The aim of this investigation was to determine if a device that automatically spray-marked piglets at the trough could reliably identify those pigs that had foraged the food in the trough.