Genetics of feed intake and efficiency in grazing dairy cows : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Animal Science

Feed efficiency in dairy cows is widely acknowledged as a highly desirable characteristic to improve because of its well-documented impact on production costs. Traditional measures of feed efficiency have used ratio traits, specifically energy conversion efficiency, but these have undesirable statistical properties. Alternative measures of feed efficiency are those based on the residuals from regression-type statistical models, the most common of which is residual energy intake (REI). Residual energy intake is defined as the difference between actual and predicted intake and is usually derived from least squares regression models. The general objective of this thesis was to quantify phenotypic and genetic (co)variances between the feed intake complex, performance, and fertility traits in lactating Holstein-Friesian dairy cows. A total of 8,199 feed intake records from 2,693 lactations on 1,412 grazing lactating Holstein-Friesian dairy cows from experimental farms were used. Several alternative efficiency definitions were developed, each with their own respective strengths and weaknesses. Exploitable genetic variation was demonstrated to exist for the range of alternative efficiency traits, and the magnitude of this variation was sufficiently large to justify consideration of the feed efficiency complex in future dairy breeding goals. The heritability estimates for the different efficiency traits estimated using repeatability models varied from 0.06 to 0.21. Variance components, however, differed across lactation when estimated using random regression models; for example, the heritability of REI varied from 0.04 (34 DIM) to 0.11 (280 DIM) across lactation. Phenotypic correlations among many traits including REI and energy balance (EB) differed not only by stage of lactation but also by cow parity. Moderate to strong genetic correlations existed between REI and EB across lactation (ranging from 0.45 to 0.90). Albeit associated with large standard errors, estimated genetic correlations between feed efficiency and reproductive performance were either neutral or favourable suggesting greater genetic merit for feed efficiency does not appear to be antagonistically genetically correlated with reproductive performance. Selection index calculations using the current economic weights in the Irish Economic Breeding Index, and genetic (co)variances estimated in this thesis, indicate that the inclusion of REI in the index with an economic weight of €0.078/UFL will generate animals with improved REI

The solar flare and cosmic gamma-ray burst experiment aboard the Ulysses spacecraft

The HUS-Ulysses team has prepared an instrument for the Ulysses spacecraft consisting of 2 Csi detectors and 2 Si surface barrier detectors for measuring x rays in the range 5 to 200 keV with up to 8 ms time resolution. The prime objectives of the experiment are the study of solar flares and cosmic gamma-ray bursts. The Ulysses mission will leave the ecliptic during the forthcoming solar maximum. The total time above ecliptic latitudes + or - 70 degrees is expected to be 230 days. The solar data can be used in conjunction with other experiments to measure the directivity of the emission and for correlative studies

Book Review: “IT”

Book Review of: Stephen King, “IT” (Viking, 1986

On the Torus Degeneration of the Genus Two Partition Function

We consider the partition function of a general vertex operator algebra $V$ on a genus two Riemann surface formed by sewing together two tori. We consider the non-trivial degeneration limit where one torus is pinched down to a Riemann sphere and show that the genus one partition function on the degenerate torus is recovered up to an explicit universal $V$-independent multiplicative factor raised to the power of the central charge.Comment: 18 page

A direct N-body model of core-collapse and core oscillations

We report on the results of a direct N-body simulation of a star cluster that started with N = 200 000, comprising 195 000 single stars and 5 000 primordial binaries. The code used for the simulation includes stellar evolution, binary evolution, an external tidal field and the effects of two-body relaxation. The model cluster is evolved to 12 Gyr, losing more than 80% of its stars in the process. It reaches the end of the main core-collapse phase at 10.5 Gyr and experiences core oscillations from that point onwards -- direct numerical confirmation of this phenomenon. However, we find that after a further 1 Gyr the core oscillations are halted by the ejection of a massive binary comprised of two black holes from the core, producing a core that shows no signature of the prior core-collapse. We also show that the results of previous studies with N ranging from 500 to 100 000 scale well to this new model with larger N. In particular, the timescale to core-collapse (in units of the relaxation timescale), mass segregation, velocity dispersion, and the energies of the binary population all show similar behaviour at different N.Comment: 9 pages, 8 figures, accepted for publication in MNRA

The effect of grass genotype and spring management on the nutritive value of mid-summer ryegrass swards

End of project reportThe objective of this project was to investigate the environmental, morphological and management factors that control reproductive initiation and development in Lolium perenne L. (perennial ryegrass) and their influence on mid-season sward quality. These factors were assessed on eight perennial ryegrass cultivars through spaced plant and plot studies. The first part of this project determined the effects of meteorological conditions and latitude on reproductive initiation and ear emergence of cultivars over two consecutive years. It was concluded that the critical day length requirement for reproductive initiation varies between perennial ryegrass cultivars and is independent of latitude and the normal range of conditions. Using this information a strong correlation (r2 = 0.94) was found between the critical day length for ear initiation and the ten year standardised ear emergence dates of the cultivars. This correlation was sufficiently robust to predict the critical initiation date for any perennial ryegrass cultivar on a UK recommended list or on the EU common catalogue by using their heading dates from the UK Plant Breeders Rights trials at Crossnacreevy. Large variation was observed for secondary initiation and re-heading between cultivars of similar and varying maturity, which is a major factor reducing mid-season sward quality. The propensity for initiation of re-heading was strongly influenced by the severity of defoliation (intense to very lax), but there was also evidence to suggest that critical day length post-solstice, may determine the latest date when further reproductive initiation could occur. Differences in plant growth modes were clearly evident as the sward structure, plant morphology and nutritive compositions differed significantly between cultivars during the mid-season. Defoliation management also significantly affected mid-season sward structure, morphology and nutritive composition. While the effect of defoliation height on the sward physical and chemical compositions was inconclusive, an intensive (30 mm) defoliation resulted in plants returning to a vegetative growth mode earlier compared to a lax (60 mm) defoliation treatment. It was observed that defoliation at a critical growth stage can significantly affect subsequent sward structures. Delaying initial spring defoliation resulted in a greater leaf proportion and swards of greater herbage quality in the plot study. This study, therefore, established the need for more detailed evaluation of cultivars by national testing authorities to allow farmers to select cultivars for grazing use that will optimise animal intake and performance

The 9/11 Commission: Working Together to Keep America Safe

Streaming video requires RealPlayer to view.The University Archives has determined that this item is of continuing value to OSU's history.Michael Hurley, a career CIA officer, has twenty-one years in that organization. He served on the 9/11 Commission's staff as a senior counsel and director of the counterterrorism policy investigation. In the course of the investigation into the September 11 attacks on the United States, the team he headed interviewed more than 150 officials and reviewed hundreds of thousands of pages of sensitive documents. His team took the lead in organizing the March 2003 public hearings of highest-level officials of the Clinton and Bush administrations, and the early April public hearing of Dr. Condoleezza Rice, President Bush's national security advisor. His team drafted substantial portions of the policy chapters of the Commission's final report.Ohio State University. Mershon Center for International Security StudiesEvent webpage, streaming vide

Culture and community : researching HIV and gay and lesbian lives in Australia, 1990-2005

University of Technology Sydney. Faculty of Education.2 vols.Vol. 1 includes "A guide to gay and lesbian writing in Australia" / Michael Hurley.NO FULL TEXT AVAILABLE. This thesis contains 3rd party copyright material. The hardcopy may be available for consultation at the UTS Library.This thesis presents an essay and thirteen items published between 1990 and 2005 in support of my candidature for a Doctorate in Philosophy by Publication. The items presented range across several forms: books (1), book chapters (5), refereed journal essays (3), and research reports and report chapters (4). The items analyse various articulations of culture and community in relation to contemporary gay and, to a lesser extent, lesbian life in Australia. They are organised into three sites. The work in Site One establishes gay and lesbian writing in Australia as a scholarly field. In Site Two, the work investigates Australian responses to HIV, how the epidemic affects gay cultures and relations between ‘community’ responses to HIV and those cultures. Site Three begins a systematic consideration of the relations between media, representation and commodification and how these effect change in the social narration of gay and lesbian lives. The accompanying essay provides an overview of the presented work that argues for its contemporary relevance and original contribution to knowledge. The essay explores the ways culture and community are articulated on each of the sites. It argues that community is both a specific socio-cultural form and a mode of governmentality. It investigates these articulations in relation to everyday life and explores the resultant tensions and ambiguities, their connections and disconnections