bluuebunny/crossref_metadata_2025 huggingface dataset:
Does Physics Answer Metaphysical Questions?
Authors: Ladyman James
Published: June 2019

According to logical positivism, so the story goes, metaphysical questions are meaningless, since they do not admit of empirical confirmation or refutation. However, the logical positivists did not in fact reject as meaningless all questions about for example, the structure of space and time. Rather, key figures such as Reichenbach and Schlick believed that scientific theories often presupposed a conceptual framework that was not itself empirically testable, but which was required for the theory as a whole to be empirically testable. For example, the theory of Special Relativity relies upon the simultaneity convention introduced by Einstein that assumes that the one-way speed of light is the same in all directions of space. Hence, the logical positivists accepted an a priori component to physical theories. However, they denied that this a priori component is necessarily true. Whereas for Kant, metaphysics is the a priori science of the necessary structure of rational thought about reality (rather than about things in themselves), the logical positivists were forced by the history of science to accept that the a priori structure of theories could change. Hence, they defended a notion of what Michael Friedman (1999) calls the ‘relativised’ or the ‘constitutive’ a priori. Carnap and Reichenbach held that such an a priori framework was conventional, whereas Schlick seems to have been more of a realist and held that the overall relative simplicity of different theories could count as evidence for their truth, notwithstanding the fact that some parts of them are not directly testable. All this is part of the story of how the verification principle came to be abandoned, and how logical positivism transmuted into logical empiricism.
The Moral Use of Technology
Authors: Garvey James
Published: June 2019

There is a well-worn example—well worn in some circles, anyway—of what you might think of as racist bridges. Robert Moses, the celebrated New York architect, designed unusually low bridges over the roads from Long Island to Jones Beach. The bridges were designed in this way so as to prevent the poor and predominantly black locals from travelling to the beach by bus—the affluent, white car owners can slip under them with ease. The bridges prevent certain members of the community from enjoying the beach as surely as a phalanx of clansmen. Perhaps the strongest moral drawn from the story is the claim that the bridges are political. The objects themselves are imbued with dubious values.
Beyond determinism. A case for complex explanations and human scale in framing archaeological causal explanations
Authors: Ion Alexandra
Published: June 2019

In a recent intervention, Romanian philosopher and essayist Andrei Pleşu (2018) writes on the topic of destiny,

We are not caught blindly in a network of ‘fatal’ causes and effects, rather we are integrated in an ‘epic’ structure, on a pathway which includes an ‘intrigue’, a host of significant events, sometimes stimulating, while at other times destabilising, in a ‘story’ whose makeup can only be revealed at the end of the ‘spectacle’.

Archaeology is a discipline in the privileged position of engaging with things when they have seen their end lives and conclusions, at the end of the ‘spectacle’. The downside is that sometimes too much time has passed, and traces have got lost, while at other times we forget that any story had a development, alongside moments when things could have turned out quite differently. Thus, upon trying to interpret change in the past, we sometimes end up with what Arponen and colleagues tackle in their article, namely deterministic explanations. Their article raises some points directly related to the implications of a particular kind of data set – palaeo-environmental studies – for framing historical explanations. This range of studies has become more important in recent years, as part of a wider resurgence of scientific technologies applied to interpreting the past. This trend has been accompanied by important implications, revealing the problem of integrating data sets of different kinds, from natural sciences to social sciences towards explaining historical processes. As the authors highlight, most often the explanation proceeds by identifying patterns in different data sets, climate record and archaeology, which are then correlated, and if they match they are interpreted in a causal key. But is life that simple?
Animal welfare and public perceptions as potential constraints to genetic change in animal production
Authors: Lawrence Alistair B. , Pryce Jennie E. , Stott Alistair
Published: June 2019

Selective breeding has been an important component in the increased output and efficiency of animal production since the 1950's. At the same time there has been increasing moral concern over the welfare of modern farmed animals with much of the focus on the environment and management of farm animals and relatively little consideration of the impact of genetic change on welfare. This is now changing, partly because of some well-publicised examples where selection has led to ‘undesirable’ side effects, and because of the perceived welfare risk of emerging biotechnologies. This paper will address whether and how moral concerns over animal welfare should place limitations on genetic change in animal production.
The future for the livestock industry after foot and mouth
Authors: Palmer M.
Published: June 2019

The agricultural industry, particularly the livestock section, has been beset by difficulties in recent years, with the wettest year since 1776, the lowest commodity prices since the 1930's in many sectors, and by the widespread outbreak of ‘foot and mouth’ disease (F&M). This epidemic renewed fears for the future in an industry that was just beginning to see a glimmer of hope for better times ahead after many years of depression, with the OECD forecasting in early 2001 that world agricultural markets were poised for a ‘significant recovery‘.

Following what with hindsight can be thought of as a ‘golden period’ in the early 1990's, things began to go really wrong in the livestock sector after the BSE crisis in 1996. The problems were exacerbated by many other ‘external economic’ pressures in the late 1990's - in particular the high value of the pound and its effect on trade and market prices, the economic problems in other parts of the world (particularly in South East Asia and the former Eastern bloc), and an oversupplied European food market (particularly for meat and dairy products). By the late 1990's these ‘macro’ pressures were affecting all livestock sectors and if things were not bad enough, the spectre of ‘disease’ was about to make matters worse, beginning with the outbreak of classical swine fever in the pig industry in 2000.

The downward pressure on market prices and the monetary losses have also brought into focus the structural changes that are sorely needed throughout the livestock production, and meat processing/marketing supply chains in Britain. It has been apparent (ignoring the international situation) since the late 1980's, following the more rapid changes that have occurred in the final domestic consumer market, that these have been needed and they are now essential if the industry is to remain competitive in the 21st century.
The future of livestock production: planning for the unknown
Authors: Webster A.J.F.
Published: June 2019

Forecasting the future is fun but futile since most forecasts are wrong. The only constructive strategy is to plan for the unknown. Therefore this talk will contain (almost) no predictions. It will simply consider how we may best cope with the shock of the new; the information explosion, the accelerating pace of change and its bewildering changes of direction. To do this we need to hold fast to a small number of big, lasting truths. I can survive on four, two of which are humanistic, two simply biological. These are:

Biological systems evolve through modification by natural selection. The word ‘modification’ does not imply new creation but redesign from a relatively small range of standard parts and processes to meet changing needs.

The application of reason is an effective and honest approach to the process of discovery and understanding. Almost all issues can benefit from application of the scientific method (reason challenged by experiment). However, almost all issues also contain elements that transcend science but these too are amenable to reason.

Humans are sentient animals. In common with other sentient animals, we are powerfully motivated by how we feel (as distinct from what we think) and most powerfully motivated by the need to feel good. This need may be physical or spiritual. The physical need to enjoy comfort, the satisfaction of a good meal, or sex, ensures our genetic survival. The emotional need for security, or spiritual satisfaction ensures the stability of our communities, since in a stable community, discretion and goodness have survival value.

All life forms have value. Moral philosophy argues that a life form such as a tree has an intrinsic value independent of its extrinsic value to us (e.g. for its beauty, utility or as a carbon sink). While I accept the concept of intrinsic value, I suggest that it is more useful to redefine the concept of extrinsic value in a less anthropocentric way (e.g. a tree has extrinsic value to a squirrel).
Demand and supply changes in the dairy sector in Kathmandu city: impact on smallholders
Authors: Tulachan P. M.
Published: June 2019

Livestock rearing in Nepal is an integral component of the farming system. It contributes about 15% to the gross domestic product (GDP) and 25% to the agriculture GDP. Milk production is therefore an important activity of the livestock sector. The majority of rural households raise one or two dairy animals for milk production. At the farm level, more than 50% of the cash income generated from livestock comes from milk and milk products.
Reference Frames and the Extragalactic Distance Scale
Authors: Feast M.W.
Published: June 2019

It is suggested that proper motions will continue to play a key role in fixing the extragalactic distance scale and that uncertainties in the present reference frame are of significance for distance scale problems.
Structure and Evolution of Giant Molecular Clouds
Authors: Stark Antony A.
Published: June 2019

The mechanism of spiral structure in galaxies is a puzzle that is only partly understood. Galaxies do not revolve like solid bodies, so the spiral patterns cannot be entirely material in nature. Yet the observable tracers of spiral structure are unquestionably material: young stars, dust and gas. These objects must be organized by a collective, wave phenomenon, the spiral density wave in the disk star population. The density wave is a small (≈ 10%) local increase in the density of stars. The interstellar medium responds to the increased gravitational force by forming Giant Molecular Clouds (GMCs), concentrations of 105M⊙ or more of interstellar matter in a region about 50 pc across. In a sense the GMCs are the spiral arms: in other galaxies, dust, gas and young star populations trace spiral structure; in the solar vicinity, these populations are seen to be associated with GMCs. This paper briefly reviews observational data supporting the hypothesis that spiral structure results from the agglomerative build-up of GMCs from smaller clouds, that this growth occurs preferentially in spiral arms, and that GMCs subsequently self-destruct because of the formation of massive stars.
The Possibilities of Synthetic Photometry
Authors: Gustafsson Bengt
Published: June 2019

The use of calculated colour indices, based on model stellar atmospheres, is discussed. It is concluded that such synthetic photometry has a variety of interesting applications, well worth further exploration and systematic utilization.
Halley’s Comet (Part II): Space Studies
Authors: Moroz Vassili I.
Published: June 2019

An international armada of spacecraft encountered Comet Halley in March 1986. The present article gives a brief overview of this unique event during which a cometary nucleus was seen as a spatially resolved object for the first time. It is a very dark body, the shape is irregular and the structure is inhomogeneous; only the sunward side is active. Many parent molecules were identified in the coma, including complicated hydrocarbons. There was also organic matter in the comet dust particles. Extensive studies were made of the complicated plasma environment of the comet.
The Rise and Fall of Quasars
Authors: Schmidt Maarten
Published: June 2019

It is a great honor for me to speak to you tonight on the subject of quasars. In the past twenty-five years, an enormous amount has been learned about these objects and the field has become very technical. I recognize that there are many people in the audience who are not professional astronomers and I hope not to disappoint them. At the same time my colleagues may recognize a few things that I touch upon. They will also hopefully forgive me for leaving out many attributions: many hundreds of astronomers have contributed to the field.
Space Astronomy – The Next Thirty Years
Authors: Longair M.S.
Published: June 2019

I have a strong feeling that I am not the right person to give this lecture. Many of you will have noticed that recently the National Academy of Sciences has published a report entitled “Space Science in the 21st Century – Imperatives for the Decades 1995 – 2015”. This assessment was requested by NASA and was headed by the Space Science Board of the National Academy of Sciences. This is a very large and ambitious report and is essential reading for those who wish to have a broad vision of what might become possible in the coming decades. As a result, this brief review will make no attempt to be complete but will simply raise some points which may contribute to the discussion of future directions of space astronomy. I would emphasise that these are personal views.
Some Factors Affecting the Accuracy of Stellar Photometry with CCDs (And some ways of dealing with them)
Authors: Stetson Peter B.
Published: June 2019

There are many factors which make it difficult to relate instrumental CCD photometry to a fundamental standard system with an accuracy much better than about 1%. Here I will address only three of them: (1) infrared leaks in the filters; (2) the finite opening and closing times of mechanical shutters; and (3) changes in the air mass for long integrations. I will be approaching these subjects from the point of view of a visiting astronomer at someone else’s observatory, who gets three or four nights of observing time a year, and has only the afternoons preceding those nights to perform whatever tests can be carried out while the equipment sits on the telescope.
High Precision Crowded Field Photometry
Authors: Linde Peter
Published: June 2019

Methods have been developed for high precision photometry in crowded stellar fields. The procedure includes the following steps:

• Determination of a two-dimensional point spread function

• Definition of groups of stars with mutually overlapping images

• Determination of local background for each star group

• Simultaneous fitting of point spread functions, one for each star in the group

The Lund approach emphasizes interactivity. Many fundamental procedures are facilitated by the use of an optimised image display. Extensive modelling has been done to study the influence of various error sources.
ROSAT Deep Surveys
Authors: Hasinger Günther
Published: June 2019

A series of 20 deep pointed observations with the ROSAT PSPC is discussed. 530 X-ray sources with 0.5-2 keV fluxes down to 3·10-15erg cm-2 s-1 have been discovered in 5.9 deg2. The N(>S) relation of the sources selected in the 0.5-2 keV band shows a density in excess of 200 deg-2 at the faintest fluxes and a flattening below 2·10-14erg cm-2 s-1. The average spectrum of those sources is a power law with energy index 1.2 ±0.1. The absorption column densities are consistent with the galactic HI columns. More than 50% of the 1-2 keV background has been resolved into discrete sources in the deepest field. The total background spectrum shows an emission line feature around 0.65 keV, most probably due to OVII-OVIII from a 2·106K plasma. Above ~ 1 keV the background is dominated by a power law spectrum with a normalization of 13.4 ± 0.2 keV cm-2 s-1 sr-1 keV-1 and a slope 1.2 ± 0.1, i.e. considerably steeper than the extrapolation from higher energies.
The Cosmic Microwave Background Spectrum: Theoretical Framework
Authors: Zotti G. De , Burigana C.
Published: June 2019

Preliminary analyses of COBE/FIRAS data have already produced a spectacularly accurate determination of the microwave background spectrum for 1 cm ≤ λ ≤ 500 μm. The absence of detectable deviations from a blackbody spectrum sets strong constraints on physical conditions of the intergalactic plasma and, in particular, has ruled out the possibihty of a truly diffuse thermal bremsstrahlung origin of the X-ray background. General arguments suggest that comptonization distortions due to heating of the intergalactic medium associated with the formation of cosmic structures, with hot protogalactic winds, or with the ionizing flux from AGNs, are likely to be very small (comptonization parametery ≲, 10-4). A larger signal is expected from the integrated re-radiation from dust in external galaxies; to what extent this may conceal possible comptonization distortions depends on the maximum redshift at which galaxies contain substantial amounts of dust and on the temperature distribution of dust grains. In any case, a precise determination of either theyparameter or the background from distant galaxies requires a careful subtraction of the emission from the Milky Way.

The great success of COBE strengthens the need for a parallel improvement in the accuracy of spectral measurements in the Rayleigh-Jeans region, where imprints of physical processes occurring at very early epochs (such as, e.g., the dissipation of small scale density inhomogeneities) may show up.
The X-Ray Background
Authors: Soltan Andrzej
Published: June 2019

Various models of the X-ray background are discussed. It is postulated that the only explanation consistent with all the existing data is discrete sources. Present observational material suggests that known classes of active galactic nuclei also dominate the source counts below the lowest detectable flux levels.
Structure Constraints from Large Angle CMB Anisotropies
Authors: Bond J. Richard
Published: June 2019

Constraints on models of cosmic structure formation that can be drawn from current limits on large angle microwave background anisotropies are now competitive with those from recent small and intermediate angle experiments and are relatively insensitive to the reheating history of the Universe. Here I give limits on Gaussian scale invariant adiabatic fluctuations and describe the role that the large angle results play in constraining models with enhanced large distance galaxy clustering power inferred from correlation function measurements is described.
Planetary Rings as a Model in Cosmogony
Authors: Brahic André
Published: June 2019

Since the beginning of the XVIIth century, rings of dispersed matter play an important role in theories accounting for the origin of the solar system and proto-planetary nebulae. Planetary rings afford a good opportunity of studying some of the accretion mechanisms which operate during the early evolution of a proto-planetary nebula. Three new planetary rings have been recently discovered. Space and ground-based observations have completely renewed our image of ring systems. Simultaneously, a wealth of theoretical and numerical models have flourished. Collisions between ring’s particles and gravitational perturbations of nearby satellites should explain most of the ring’s structures. However, important questions are still unanswered. We do not understand why the rings are so dissimilar. We do not know the ring’s origin and their stability over billions of years. Most of the ring’s complex structures, the existence of arcs, and color and optical depth variations are not explained. Confinement mechanisms, which are so important in cosmogony, seem to be at work in planetary rings today.
HIPPARCOS Data Distribution to the Community
Authors: Perryman M.A.C.
Published: June 2019

The Hipparcos satellite generates a considerable quantity of ‘raw’ data: approximately 1Gbit per day, or some lOOOGbits over its anticipated lifetime. The Hipparcos mission follows usual practices of having elements of the observing programme selected after an invitation for proposals to the general astronomical community, as well as a strong scientific interest in the data exploitation from amongst the individuals working within the scientific consortia related to the observing programme definition and the data analysis. However, an unusual feature of this mission is the fact that the elemental observations cannot be ‘separated out’ and distributed to the proposers or the consortia ‘principal investigators’. Instead, the data analysis teams will work towards the construction of a single, agreed-upon, catalogue containing the final astrometric and photometric star parameters.
Rotation of the Solar System Bodies
Authors: Kolaczek B.
Published: June 2019

Solar System bodies are different. They have different sizes, from large planets to small asteroids, and shapes. They have different structure, from solid body to solid body with fluid atmosphere or core, to gaseous bodies, but all of them rotate. The Solar System is a big laboratory for studying rotation of solid and fluid bodies.

Different observational methods are applied to determine the rotation of the Solar system bodies. They depend on the position of the observer and on the structure of the bodies. The most accurate methods, laser ranging to the Moon and artificial satellites and Very Long Base radio Interferometry have been applied to the determination of the rotation of the Earth and the Moon. Their accuracy is better than 0.001”, which on the surface of the Earth corresponds to about 3 cm. Radiotracking of artifical satellites have been used for Earth, Moon, Venus, Mars. In the case of Jupiter, Saturn, Uranus, Neptune and Pluto-Charon magnetic and photometric observations have been used respectively. Their accuracy is of the order of one tenth of a degree.
Atomic and Molecular Data for Observations of the Interstellar Medium With the Hubble Space Telescope
Authors: Morton Donald C.
Published: June 2019

The Goddard High Resolution Spectrograph (GHRS) on the HST, with resolving powers up to 94000 or 3.2 km s−1, is giving us a new look at interstellar absorption lines in the range 1090 to 3350 Å (Savage et al 1991, Cardelli et al 1991, Smith et al 1991). The high signal-to-noise ratios possible with the digicon detectors provide precise line profiles suitable for studying individual velocity components. Morton (1991) has summarized the relevant laboratory data on wavelengths and f-values for the atomic absorptions from the ground term likely to be detected by the HST, and Hsu and Hayden Smith (1977) have provided a useful list of candidate molecular electronic transitions.
The Evolution of AGB Stars
Authors: Wood P.R. , Vassiliadis E.
Published: June 2019

Computations of AGB stellar evolution which include the effects of mass loss are still relatively rare. However, in order to relate numbers of Mira variables, OH/IR stars and carbon stars to associated stellar populations, it is necessary to understand evolutionary timescales on the AGB.

The dominant factors controlling very late AGB evolution are shell flashes and mass loss, and some quantitative estimate of the latter is needed for stellar evolution calculations. The favoured mechanism for the production of the large mass loss rates observed in late AGB stars such as OH/IR stars and dust-enshrouded carbon stars, which have mass loss rates up to a few times 10−5 M⊙ yr−1 (see van der Veen and Rugers 1989 for a compilation), is a dual process involving the lévitation of matter above the photosphere by large-amplitude radial pulsation followed by the formation of grains on which radiation pressure acts to drive the circumstellar material away from the star (Castor 1981; Holzer and MacGregor 1985; Hearn 1990). The studies by Wood (1979) and Bowen (1988) show that, by themselves, neither pulsation nor radiation pressure acting on grains can produce the very large mass loss rates from AGB stars.
Heating of Solar and Stellar Chromospheres and Coronae by MHD Waves
Authors: Musielak Z. E.
Published: June 2019

Ground-based and satellite observations have shown that all late-type dwarfs possess hot outer envelopes, and that the chromospheric and coronal emissions observed from these envelopes vary significantly for a given, fixed spectral type. In addition, there is growing evidence for nonhomogeneous and locally strong magnetic fields in the atmospheres of these stars. It is obvious that any heating theory must account for these two observational constraints as well as for the mean level of heating.

There are at least two general classes of models that deal with the required heating. The first class assumes that outer stellar atmospheres are heated by hydrodynamic (mainly acoustic) or magnctohydrodynamic (MHD) waves, and that these waves are generated by turbulent motions in the stellar convection zones. The second class considers dissipation of currents generated by photospheric motions as the primary source of energy. Neither observation nor theory has been able to definitively determine which one of these two general classes of models dominates in the atmospheric heating. The main aim of this paper is to briefly present recent developments in the MHD wave heating theory. The key problems that will be addressed are: where and how efficiently are MHD waves generated, and how do these waves propagate and dissipate energy?
Where Are All the Single Ladies? Marital Status and Women's Organizations’ Rule-making Campaigns
Authors: English Ashley
Published: June 2019

Leading up to the 2016 election, single women were heralded as the “hot” new constituency. With unmarried women posed to comprise approximately half of the population of adult women and 23% of the electorate (Traister 2016), pundits claimed that the rising number of single women could transform American politics. Building on this recent enthusiasm about single women, this study provides one of the first systematic analyses of how contemporary women's organizations represent single women by analyzing 1,021 comments that women's organizations submitted to rule makers between 2007 and 2013. Using automated text analyses and a series of statistical analyses, it shows that despite the rising numbers of American single women, women's organizations only very rarely explicitly refer to single women during their comment writing campaigns, preferring to highlight the experiences of married mothers instead. Moreover, it shows that the political context unexpectedly has little to no effect on the degree to which women's organizations focus on single women, possibly because they so rarely mention them at all. Altogether, the results suggest that for single women to become politically powerful, they will need more than just large numbers; they may also need niche organizations that can help them organize and articulate their broader policy needs.
Estimates of genetic parameters for test day somatic cell count fitting orthogonal polynomials
Authors: Mrode R. A. , Swanson G. J. T. , Lindberg C. M.
Published: June 2019

Genetic evaluations in the United Kingdom (UK) for Somatic Cell Count (SCC) are currently based on a single trait repeatability model using the first five lactations. Only cows with completed lactations are included. However, to utilise information from cows with part lactation records and to achieve a better correction for environmental effects, a test day model (TDM) evaluation would be preferred. The objective of this study is to estimate genetic parameters needed for such a TDM evaluation by utilising a random regression (RR) approach.
The effect of genetic selection for lack of aggression towards humans on male reproductive physiology in the silver fox
Authors: Osadchuk L. V.
Published: June 2019

Most of silver foxes bred in captivity show predominantly defensive responses to human contact. Since early captive breeding humans have unconsciously carried out selection for tameness. Thus, artificial selection for the absence of aggressive and fearful responses to humans most likely played a key role in domestication process. To establish the genetic and physiological mechanisms of the early evolution of domestic animals, a model of silver fox domestication was developed at the Institute of Cytology and Genetics (Novosibirsk, Russia). A population of silver foxes has been produced in long-term selection for lack of aggression and fear towards humans (domestic behaviour). The method of selection and the behavioural changes in the course of selection have been described (Belyaev, 1979; Trut, 1995). Selected animals show no aggressiveness to humans and they are better adapted to captive conditions than their wild counterparts. The purpose of this study was to determine how behaviour selection influences testicular function in silver fox males. Plasma concentrations and testicular production of testosterone were determined in selected and control males in different parts of the reproductive cycle and prenatal life. In addition, reproductive behaviour and hormonal responses to opposite sex were estimated in the males of both behaviour groups. Sperm production and sexual activity were also compared between selected and control males.
The effect of positive and negative handling on the behaviour and stress response of Holstein Friesian heifers
Authors: Breuer K. , Hemsworth P.H. , Coleman G.J.
Published: June 2019

Extensive research into human-animal interactions, particularly in the pig industry, has led to the proposal that high fear of humans, through a stress response, can limit an animal’s growth, reproduction and welfare (Hemsworthet al., 1993). In a recent study in the Australian dairy industry, a significant negative between-farm correlation was found between the avoidance of an experimenter by cows in a standard test and milk yield of the farm, suggesting that fear of humans may also have implications for the productivity of dairy cows (Breueret al., 2000). The behaviour of stockpeople is a likely factor affecting fear of humans in dairy cows (Breueret al., 2000). It was the aim of this experiment to investigate the effects of handling on the stress physiology and behaviour of dairy heifers.
The effects of prior experience of straw and depth of straw bedding on the behaviour of growing pigs
Authors: Day J. E. L. , Burfoot A. , Docking C. M. , Whittaker X. , Spoolder H. A. M. , Edwards S. A.
Published: June 2019

UK legislation dictates that all pigs shall have access to straw or other material or object suitable to satisfy their behavioural needs (Welfare of Livestock Regulations, 1994). However, it is unknown how much straw must be provided to be behaviourally rewarding, and whether pigs’ prior experience of straw can impact upon their subsequent behavioural needs. Therefore, the aim of the current experiment was to investigate these issues by exposing pigs which did, or did not, have prior experience of straw to four levels of straw bed depth.
Octylphenol, an environmental oestrogen, affects oocyte maturation in cattle
Authors: Pocar P , Augustin R , Gandolfi F , Fischer B
Published: June 2019

4-tert-octylphenol (OP) is an alkylphenolic compound formed as metabolite of some nonionic surfactants that are widely used in industrial detergents, as plastic additives, dispersant for insecticides, etc. (Naylor et al., 1992). OP accumulates in adipose tissue. Micromolar concentrations of these compounds may constitute health hazards to animal cells. Furthermore, it has previously been shown to exert oestrogenic activity in vivo and in vitro (White et al., 1994). A growing concern about “endocrine disruptors” and their impact on oestrogen-dependent phenomena led us investigate the effects of OP on oocyte maturation. For variuos reasons bovine oocytes were chosen as the model system. We examined the effects of OP exposure on oocyte nuclear maturation in vitro and on the expression of oestrogen receptors in cumulus cells.
Effect of tropical diets on inocula used on in vitro gas production technique
Authors: Bueno I.C.S. , Filho S.L.S. Cabral , Gobbo S.P. , Carvalho M.C. , Pavan C. , Abdalla A.L.
Published: June 2019

There is much discussion about the effect of the diet of the inoculum donor animal. The ideal diet should supply microrganisms and they should be able to degrade the feed. But when we evaluate several different feeds by a gas production assay, it is very difficult to feed donor animals with a diet composed by all feeds that will be tested. The aim of this work was to investigate the effect of three different tropical diets on inoculum ability to degrade the feeds.
The performance of twin-bearing ewes and their progeny when offered red clover, lucerne and grass silages during late pregnancy
Authors: Speijers M.H.M. , Fraser M.D. , Theobald V.J. , Fychan R. , Haresign W.
Published: June 2019

Feeding conserved forage in the form of silage to pregnant ewes in winter is common practice in agricultural systems in the UK. However, silage as a sole feed in late pregnancy is unlikely to meet the nutritional requirements of ewes carrying twin lambs, and supplementary feeding is usually required. Evidence suggests forage legumes such as red clover and lucerne offer great scope for improving the supply of protein to ruminants (Frame et al., 1998), and feeding silage prepared from these crops could potentially reduce the need for protein supplements. The aim of this experiment was to compare the performance of twin-bearing ewes and their lambs when fed either ensiled red clover, lucerne or ryegrass during late pregnancy.
Effect of replacing soyabean meal with maize distillers grains on feed intake and milk yield of lactating dairy cows
Authors: Phipps R. H. , Sutton J. D. , Jones A. K. , Perrott J. G. , Witt M.
Published: June 2019

Maize distillers grains (MDG) is a high quality by-product feed containing 317 g crude protein (CP)/kg DM and 13.5 MJ metabolisable energy/kg DM, and as such is a valuable traceable feed resource. An earlier study conducted at the Centre for Dairy Research (Suttonet al.2000) with cows in late lactation using a total mixed ration (TMR) based on maize silage, compared the protein value of MDG with that of soyabean meal (SB). The study showed that MDG could be used to replace SB on a total nitrogen (TN) basis without effecting feed intake or nutrient digestion in the rumen, or flow of non-ammonia nitrogen to the duodenum. The aim of the current study was to determine the effect of replacing SB with MDG on a TN basis, on DM intake and milk production in high yielding lactating dairy cows.
Production of lactating dairy cows fed diets with lucerne or red clover silage with or without supplemental maize silage
Authors: Broderick G. A. , Walgenbach R. P.
Published: June 2019

Lucerne (Medicago sativa) is a major, high protein forage fed to dairy cattle. However, during ensiling, much of the CP in lucerne silage (LS) is broken down to nonprotein N (NPN); high levels of NPN in LS depress protein utilisation in lactating dairy cows. Red clover (Trifolium pratense) is a high quality legume forage that can be grown in Britain and Northern Europe. Polyphenol oxidase, an enzyme system in red clover, converts plant phenols into quinones that react rapidly with forage proteins in the silo and result in red clover silage (RCS) having less NPN than LS. Earlier (Broderick et al., 2000), we reported that replacing LS with RCS lowered milk yield but improved feed efficiency and apparent digestibility. Our objective was to compare the production of dairy cows fed equal amounts DM as LS or RCS, with or without maize silage (MS) and supplemental protein added to the diet.
In vivoestimation of body composition of lactating dairy cattle from urea space measurements
Authors: Agnew R. E. , McCaughey W J , McEvoy J.D. , Patterson D C , Porter M G , Steen R W J , T Yan
Published: June 2019

San Pietro and Rittenberg (1953) reported that urea appeared to meet all the requirements of a satisfactory tracer. Urea is non toxic, not foreign to the body and it shows an even and rapid distribution throughout the total body water without any physiological effect. For these reasons in addition to its easy and accurate measurement, urea is an ideal candidate tracer to estimate empty body waterin vivo. Total body water volume (urea space) can be estimated by dividing the total amount of urea infused by the increase in plasma urea concentration from prior to infusion until 12 or 30 minutes after mean infusion time. Kock and Preston (1973) reported significant relationships between urea space measurements and percentage of empty body fat and water in cattle. However, Andrewet al. (1995) using 21 Holstein cows showed that prediction of empty body water using the urea space technique only explained 31 % of the variation. The objective of this experiment was to use the urea dilution technique to estimate the body composition of lactating dairy cows and produce relationships between urea space and body fat and protein content.
Gene Regulation of Muscle, Meat and Milk
Authors: Bass J. , Davis S.
Published: June 2019

Meat and milk production from farm animals is dependent in part on fetal development and post-natal growth of specific tissues. This paper will review some of the systems controlling both muscle and mammary growth which are related to meat and milk production and some of the genes known to regulate these production traits.
Mapping genes for milk and meat quality
Authors: Haley C. S.
Published: June 2019

Genetic selection has proved itself to be the most powerful tool available for the improvement of livestock. Over the last 40 years the efficiency of livestock production has been increased radically by the success of animal breeding. Where animal breeders have been successful it has been through the application of relatively simple rules – selection based on traits that can be measured in a repeatable manner and where variation between individuals has both a genetic component and economic relevance. Until recently, this has meant that breeders have focussed on efficiency traits – for example growth rate or milk yield - and in some cases, certain easily measured aspects of quality, such as overall fatness as inferred from ultrasonically measured fat depth. As both the breeding industry and consumers have become more sophisticated, there has been an increasing focus on traits associated with reproduction, welfare and disease and quality. Such traits can be more difficult to improve by selection because heritabilities are low (i.e. only a small amount of variation between animals is genetic in origin, such as for some reproduction and disease associated traits). In addition, such traits may be difficult or expensive to measure (e.g. disease related traits, or quality related traits measured in the laboratory or by sensory panels) and have economic values that are difficult to quantify.
Relationship between rooting behaviour and foraging in growing pigs
Authors: Beattie V.E. , O’Connell N.E.
Published: June 2019

Evidence suggests that rooting behaviour in growing pigs involves elements of both foraging for food (Day et al., 1995) and exploration (Wood-Gush and Beilharz, 1983). The objective of this experiment was to investigate the relationship between rooting behaviour and foraging in growing pigs. This involved assessing the affects of food rewards and feed restriction on the performance of rooting behaviour.
Predicting genetic gain when rates of inbreeding are constrained to pre-defined values
Authors: Avendaño S. , Woolliams J.A. , Villanueva B.
Published: June 2019

Dynamic selection algorithms using quadratic indices to optimise the contributions of selection candidates for maximising rates of genetic gain (ΔG) while constraining the rate of inbreeding (ΔF) in the long-term to pre-defined values, are available (Grundy et al, 1998). Avendaño et al (2001 a,b) applied these optimal selection algorithms on the UK Meatlinc (sheep) and Aberdeen Angus (beef cattle) pedigree breeds and found substantial expected increases (of at least 17%) in the average index score at the observed ΔF. Although these algorithms constitute powerful operational tools for breeding schemes, the framework for deterministically predicting ΔG under optimal selection with restricted ΔF is not yet available. This study presents a novel approach to this problem.
An in vitro assessment of amino acid requirements for optimal xylan fermentation by mixed ruminal micro-organisms from the sheep rumen
Authors: Guliye A. Y. , Atasoglu C. , McKain N. , Wallace R. J.
Published: June 2019

Ruminal microbes play a important role in the fermentation of structural plant polysaccharides, and constitute a major source of protein for the animal. Dietary protein provides amino acids which generally stimulate microbial growth rates and yields. The aim of this experiment was to identify, using a deletion approach, which individual amino acids limit fermentation of one of the main components of plant fibre, xylan.
Effect of dietary salt (NaCl) level on the growth performance of liquid fed growing-finishing pigs.
Authors: Tsourgiannis C.A. , Demečková V. , Eddison J. , Brooks P.H.
Published: June 2019

Salt (NaCl) is an essential mineral and its rate of inclusion in diets has been implicated in the development and expression of biting behaviour. Falkowskiet al., (1998) found that withholding salt from diets reduced the feed intake and feed conversion ratio of weaned pigs and significantly decreased growth rate. Studies reported by Fraser (1987), suggested that heightened appetite for salt could make pigs particularly attracted to pen mates with injured tails. More recently Tsourgiannis,et al., (2002) reported that 1.5% salt inclusion levels can significantly reduce the incidence of tail-biting, providing that there is unrestricted access to fresh water. This study investigated the effect on growth performance of pigs fed liquid diets containing high and low dietary salt levels for growing/finishing pigs.
Effects of four contrasting grassland-based milk production systems on dairy cow fertility
Authors: Ferris C.P. , McCoy M.A. , McCaughey W.J. , Patterson D.C.
Published: June 2019

High genetic merit dairy cows were managed on four contrasting grassland based systems of milk production over a three-year period (Ferris et al., 2000). Each of the four systems were designed to incorporate a range of different approaches to increasing nutrient intakes. Key performance data from this study are presented in Table 1. The aim of this paper is to examine the effects of the four milk production systems on dairy cow fertility.
Use of visual image analysis for the management of pig growth in size and shape
Authors: White R. P. , Parsons D. J. , Schofield C. P. , Green D. M. , Whittemore C. T.
Published: June 2019

The purpose of an integrated management system is to optimise both pig performance and environmental protection. A major impediment to this process has been the inability to measure and control the production process in real time, for specific and contemporary pig batches. Optimisation thus requires in-line measurement of pig growth performance, together with the means to change performance with adjustments to feed quantity and quality. This report deals with the use of visual image analysis (VIA) to provide the first of these; measurement of growth. VIA determines, continuously and in-line, the size and shape of the plan view of the pig as it stands at the feeder. Three seminal questions are here addressed. (i) can VIA be used to provide a reliable measure of pig weight, and (ii) how many days are required to elapse before a change in size can be reliably determined and how does the VIA system compare with daily weighing by a conventional weigh-scale, and (iii) can VIA sort pigs according to their shape?
An estimate of heritability of clinical tail biting on a commercial pig breeding farm
Authors: Breuer K. , Sutcliffe M. E. M. , Mercer J. T. , Rance K. A. , O’Connell N. E. , Sneddon I. A , Edwards S. A.
Published: June 2019

Recent research suggests that the genetic makeup of a pig may contribute to the expression of tail biting (Breueret al., 2002). To date there has been little investigation into the genetics of tail biting. A significant population of tail biters was found at a commercial pig breeding farm at which an experiment on the genetic basis of the expression of harmful social behaviour was being performed. As pedigree data for each pig on the farm were available, the opportunity was taken to investigate the heritability of tail biting by recording the perpetrators of clinical tail biting.
Timing of ultrasonic scanning for Welsh Mountain rams
Authors: Pritchard T. C , Dewi I. Ap
Published: June 2019

Performance recording schemes for sheep flocks in the UK incorporate ultrasonic scanning to measure criteria that are linked to carcass lean content as a selection objective (Simm, 1998). In Wales, under the direction of the Welsh Sheep Strategy, fat and muscle depth has been monitored routinely in hill flocks but with a range of ram ages at scanning (Anderson, 2000; Ap Dewi, unpublished). The date of scanning is often dictated by timings of routine tasks within the flocks so there is a need to explore the impact of time of scanning on the measurements obtained. The objectives of the investigation were to study how muscle and fat depths changed over a series of scanning dates.
Disease and Biosecurity
Authors: James A. D.
Published: June 2019

There are large differences between the prices of animal products in regions with comparative advantage in livestock production and regions where production costs are higher. In particular, prices for many animal products are much higher in The European Union (EU) and The United States of America (USA) than in regions with extensive grazing areas or low-priced animal feed grains, e.g. Australia, South America and Southern Africa. These price differentials provide strong financial incentives for trade in animal products between these regions. However, trade is constrained by three main factors:

1.

The perishability of many animal products, resulting in additional processing costs (e.g. freezing) which may also reduce the value of the product and higher transport costs.

2.

The fact that in many markets, high prices have been used as an element of agricultural support policy. These are partly maintained by levies on imported products.

3.

Zoosanitary restrictions to control the risk of introducing livestock and human disease agents in animal products.
Clinical presentation, epidemiological findings, diagnosis, immunity, prevention and control of postweaning multisystemic wasting syndrome (PMWS)
Authors: Segalés J. , Domingo M.
Published: June 2019

Postweaning multisystemic wasting syndrome (PMWS) was initially described in 1991 in Saskatchewan (Canada) and has now been described in all continents rearing pigs but Oceania. Porcine circovirus type 2 (PCV2) is the aetiology of this disease, which has also been called porcine circovirosis in some countries. Although the full spectrum of clinical signs and lesions observed in natural cases of PMWS is very difficult to reproduce under experimental infections using PCV2 alone, little doubt exists on the causal relationship between the virus and the wasting syndrome. Furthermore, the clinical and pathological scope of PCV2 infection has been expanded since 1991, and it has been implicated in other conditions: reproductive disorders, porcine dermatitis and nephropathy syndrome (PDNS), the so-called porcine respiratory disease complex (PRDC), proliferative and necrotising pneumonia (PNP), and congenital tremors. The role of PCV2 in these conditions has not been fully clarified and, in some of these cases, it remains as a controversial issue. The objective of this presentation is to review some practical aspects of PMWS.