Comparative grazing behaviour of lactating suckler cows of contrasting genetic merit and genotype

peer-reviewedThe objective of this study was to determine if differences in grazing behaviour exist between lactating suckler cows diverse in genetic merit for the national Irish Replacement index and of two contrasting genotypes. Data from 103 cows: 41 high and 62 low genetic merit, 43 beef and 60 beef x dairy (BDX) cows were available over a single grazing season in 2015. Milk yield, grass dry matter intake (GDMI), cow live weight (BW) and body condition score (BCS) were recorded during the experimental period, with subsequent measures of production efficiency extrapolated. Grazing behaviour data were recorded twice in conjunction with aforementioned measures, using Institute of Grassland and Environmental Research headset behaviour recorders. The effect of genotype and cow genetic merit during mid- and late-lactation on grazing behaviour phenotypes, milk yield, BW, BCS and GDMI were estimated using linear mixed models. Genetic merit had no significant effect on any production parameters investigated, with the exception that low genetic merit had a greater BCS than high genetic merit cows. Beef cows were heavier, had a greater BCS but produced less milk per day than BDX. The BDX cows produced more milk per 100 kg BW and per unit intake and had greater GDMI, intake per bite and rate of GDMI per 100 kg BW than beef cows. High genetic merit cows spent longer grazing and took more bites per day but had a lower rate of GDMI than low genetic merit cows, with the same trend found when expressed per unit of BW. High genetic merit cows spent longer grazing than low genetic merit cows when expressed on a per unit intake basis. Absolute rumination measures were similar across cow genotype and genetic merit. When expressed per unit BW, BDX cows spent longer ruminating per day compared to beef. However, on a per unit intake basis, beef cows ruminated longer and had more mastications than BDX. Intake per bite and rate of intake was positively correlated with GDMI per 100 kg BW. The current study implies that despite large differences in grazing behaviour between cows diverse in genetic merit, few differences were apparent in terms of production efficiency variables extrapolated. Conversely, differences in absolute grazing and ruminating behaviour measurements did not exist between beef cows of contrasting genotype. However, efficiency parameters investigated illustrate that BDX will subsequently convert herbage intake more efficiently to milk production

Design and testing of a high power spacecraft thermal management system

The design and test results are presented of an ammonia hybrid capillary pumped loop thermal control system which could be used for heat acquisition and transport on future large space platforms and attached payloads, such as those associated with the NASA Space Station. The High Power Spacecraft Thermal Management System (HPSTM) can operate as either a passive, capillary pumped two phase thermal control system, or, when additional pressure head is required, as a mechanically pumped loop. Testing has shown that in the capillary mode, the HPSTM evaporators can acquire a total heat load of between 600 W and 24 kW, transported over 10 meters, at a maximum heat flux density of 4.3 W/sq cm. With the mechanical pump circulating the ammonia, a heat acquisition potential of 52 kW was demonstrated for 15 minutes without an evaporator failure. These results represent a significant improvement over the maximum transport capability previously displayed in other capillary systems. The HPSTM system still retains the proven capillary capabilities of heat load sharing and flow control between evaporator plates, rapid power cycling, and nonuniform heating in both the capillary and hybrid operating modes

The attitude of Edmund Burke (1729-1797) toward Christianity and the churches

The purpose of this thesis is to bring to light the attitude of Edmund Burke (1729-1797) toward Christianity and the churches. Burke's impact on eighteenth century politics, and his rank as a philosopher, have been the subjects of many specialized studies, as well as being essential to any comprehensive view of the century in which he was such a power. However, there exists no adequate treatment of his religious thought, and it is the centrality of that theme which justifies this investigation of his life and works.In the first chapter I have attempted to set forth a brief sketch of Burke's life. Some twelve or more biographies have already appeared, and it is obviously impossible to box the compass of his many-sided life in so short a space. However, I have been guided in this first chapter by the central purpose of the study, that is, I have attempted to call attention to the religious aspect of his speeches and writings within the larger framework of the chief events of his lifetime. The examination of the Wentworth Woodhouse Manuscripts at Sheffield and the Milton Manuscripts at Lamport Hall yielded some most interesting biographical data not hitherto published, and I have Incorporated some of that material in this introductory chapter.The second chapter will carry the reader into the heart of the thesis. Here I set down Burke's attitude toward the major religious problems toward which he turned his prolific mind, together with an appraisal of his personal religion and integrity. The original work in this chapter has a two-fold aspect. First, I have endeavoured to bring together for the first time, from all Burke's published works and correspondence, the essential material on these themes. Secondly, the investigation of hundreds of Burke's hitherto unpublished letters, and his private notebooks, has made possible a fresh and comprehensive assise of his religious thought.The third chapter deals with Burke's political thought. Here I am of course indebted to all those who have so carefully and adequately set forth his political philosophy. Any claim to originality in this chapter is derived from the delineation of the religious presuppositions which Burke brought to the affairs of state. That Burke held such presuppositions has long been common knowledge; I simply document the proposi¬ tion and endeavour to show how integral was his religious thought to his political philosophy.The fourth, fifth, and sixth chapters are concerned with Burke's attitude toward The Established Church, The Dissenting Churches, and The Roman Catholic Church, respectively. There was little to be said of his attitude toward the establishment that had not already been recorded; hence chapter four is the shortest in the study. In the chapter on Dissent, however, I attempt to trace Burke's transition from a position of champion to that of cool detachment and then vigorous opposition. In the study of the Roman Catholic Church there is some hitherto unpublished material which sets into sharper focus his concern and lifelong sympathy, not only for Catholic Snancipation, but for the Roman Catholic Church as such

Spectrometric study of condensed phase species of thorium and palladium-based modifiers in a complex matrix for electrothermal atomic absorption spectrometry

The chemical and morphological transformations of condensed phase species of a thorium-based modifier were studied over the temperature range 200–2500 °C, without and with the presence of aluminium and silicon as matrix components, and in some instances, arsenic as an analyte element. A similar study was also conducted with palladium as the modifier, for comparison. Results were derived using scanning electron microscopy (SEM), energy dispersive (ED) X-ray spectrometry, Raman microanalysis and attenuated total reflectance (ATR) Fourier transform-infrared (FT-IR) spectrometry. Comparable results were found using pyrolytic and non-pyrolytic graphite platforms, with processes occurring at slightly higher temperatures on the pyrolytic graphite platform. With thorium as the modifier, metal oxides were the predominant species on the platform surface at relatively low temperatures (<1500 °C), whereas metal phases became prevalent at high temperatures, when thorium and aluminium tended to behave independently from one other. Some spatial variations in the composition of the salt residues on different regions of the platform were observed (from the region closest to the slot in the tube, to the region furthest from the slot). Nonetheless, thorium metal remained on the graphite platform to higher temperatures than did aluminium metal. In the presence of arsenic, the existence of mixtures of thorium and arsenic oxides, just before the appearance temperature of gas phase arsenic atoms, was confirmed by SEM studies, ED X-ray spectra and Raman microanalysis. This suggests that any modifying effect of thorium on arsenic occurs while the modifier is in the oxide phase rather than in the metal phase. The presence of silicon added as silica, did not influence significantly the thermochemical behaviour of mixtures of thorium and aluminium. However, coexistence of silicon and arsenic oxides at the appearance temperature of the atomic absorption signal of arsenic was obtained, confirming that silicon can act as an internal modifier for arsenic. In the presence of palladium, aluminium exhibited greater interaction with the modifier; consequently, aluminium metal was retained on the platform surface to higher temperatures than thorium, which could explain how interference effects of aluminium on e.g. arsenic are avoided or reduced. Similarly, there was evidence for interaction of palladium and arsenic in the reduced state. However, when aluminium and silicon were present, the transformation of the palladium oxide to the metallic state was affected, which could diminish the modifying benefits of palladium for arsenic in the presence of aluminium