National Beef Cattle Genetic Evaluation

Use of artificial insemination permits some bulls to have offspring evaluated in more than one herd. Such bulls serve as benchmarks for comparison or links between herds. For some breeds, sufficient links exist between herds that current technology may provide valid genetic comparisons between cattle from different herds, as well as within-herd comparisons. The current industry standard expression for reporting relative genetic merit of beef cattle in national evaluations is expected progeny difference (EPD). The EPD for a sire represents the expected difference in performance of a sire’s offspring when compared t o the average offspring performance of all sires evaluated. A corresponding accuracy value, reflecting the amount of information (pedigree performance, individual performance, offspring performance, etc.) on which the EPD value is based, is generally reported with each EPD value. Expected progeny difference values can be calculated not only for bulls listed in sire summaries, but also for cows, young bulls and even planned matings. EPDs for nonparents generally have low accuracy values compared to EPDs for parents. generally have low accuracy values compared t o EPDs for parents

Interpreting Experimental Results

A typical experimental format involves evaluating the response caused by application of different treatments to experimental subjects (animals, carcasses pens, pastures, etc.). The effect of a given treatment might be evaluated by comparison t o a control group or to one or more other treatment groups. However, a problem with animal research (and other types as well) is that variation not due to treatments often exists among experimental subjects

Relationship of Sire Expected Progeny Differences to Maternal Performance of First-Calf Daughters in a Commercial Herd

Maternal performance for first calf production was evaluated in retrospect for daughters whose sires had expected progeny differences (EPDs) available from 1988 beef breed association national genetic evaluation summaries. When grouped into high EPD and low EPD groups, sire EPD group averages for actual daughter milk production and weaning weights of daughters\u27 off spring consistently ranked the same as sire group average EPDs for milk and maternal weaning weight, although differences between groups were not statistically significant

Interrelationships of Heifer Milk Production and Other Biological Traits with Production Efficiency to Weaning

Interrelationships among milk production, cow-calf feed efficiency and other biological traits were evaluated on first-calf females and their calves. Production efficiency was defined as cumulative feed metabolizable energy consumed by the dam-calf pair during the year divided by calf weaning weight. Results indicated that increased levels of milk production were associated with improved production efficiency to weaning as long as calves have the genetic potential to convert the extra milk into body weight gains. However, the incremental improvement in efficiency per unit of increased milk was less for each additional unit of milk

Relationship of Relative Calving Date of Beef Heifers to Production Efficiency and Subsequent Reproductive Performance

Relative date of first calving of beef heifers was studied in relation to production efficiency and subsequent reproductive performance. Crossbred heifers were managed in drylot for 1 year, providing for measurement of feed intake through weaning of the first calf. Production traits were evaluated by calving group (CG), where CG1 included records of heifers calving (and calves born) in the first 21 days of the calving season for a particular year, CG2 included those calving from 22 through 42 days and CG3 included those calving after 42 days. Calving groups did not differ significantly for preweaning calf average daily gain, while weaning age differences resulted in heavier weaning weights for CG1 compared to CG2 and CG3. Earlier relative calving date was associated with increased cumulative feed energy intake of heifers and their calves during the 1 -year test period. In terms of production efficiency, the weaning weight advantage of earlier calving was only partly offset by increased feed energy intake of the dam-calf unit, resulting in .9 Mcal metabolizable energy (ME) less per Ib calf weaning weight for CG1 vs CG2 and 2.9 Mcal ME less per Ib calf weaning weight for CG1 vs CG3 for the 1-year period. Results suggested that within a limited calving season, earlier calving dams tended to be biologically and economically more efficient, apparently at least in part because a greater proportion of an annual production cycle consisted of a productive (lactating) mode, diluting maintenance costs as a fraction of all costs. Heifers in CG1 tended to calve earlier than CG3 heifers for the second calf. Calving interval was a biased measure under the management conditions of a limited breeding season and culling of open cows

CHANDRA Observations of X-ray Jet Structure on kpc to Mpc Scales

With its exquisite spatial resolution of better than 0.5 arcsecond, the Chandra observatory is uniquely capable of resolving and studying the spatial structure of extragalactic X-ray jets on scales of a few to a few hundred kilo-parsec. Our analyses of four recent Chandra images of quasar jets interpret the X-ray emission as inverse Compton scattering of high energy electrons on the cosmic microwave background. We infer that these jets are in bulk relativistic motion, carrying kinetic powers upwards of 10^46 ergs/s to distances of hundreds of kpc, with very high efficiency.Comment: 4 pages, 3 figures, to be published in the proceedings of the Bologna jet workshop, "The Physics of Relativistic Jets in the CHANDRA and XMM Era.

Guest Editors’ Introduction On Understanding Ethical Behavior and Decision Making

Behavioral ethics is an emerging field that takes an empirical, social scientific approach to the study of business ethics. In this special issue, we include six articles that fall within the domain of behavioral ethics and that focus on three themes—moral awareness, ethical decision making, and reactions to unethical behavior. Each of the articles sheds additional light on the specific issues addressed. However, we hope this special issue will have an impact beyond that of the new insights offered in these articles, by stimulating evenmore research in this burgeoning field

Surface Morphology and Microstructure of Al-O Alloys Grown by ECR Plasma Deposition

The growth of polycrystalline and amorphous aluminum-oxygen alloy films using electron-beam evaporation of Al in the presence of an O{sub 2} electron-cyclotron-resonance (ECR) plasma was investigated for film compositions varying from 40% Al (Al{sub 2}O{sub 3}) to near 100% Al (AlO{sub x}). Processing parameters such as deposition temperature and ion energy were varied to study their effects on surface texture and film microstructure. The Al-rich films (AlO{sub x}) contain polycrystalline fcc Al grains with finely dispersed second-phase particles of {gamma}-Al{sub 2}O{sub 3} (1-2 nm in size). The surface roughness of these films was measured by atomic force microscopy and found to increase with sample bias and deposition temperature. Stoichiometric Al{sub 2}O{sub 3} films grown at 100{degrees}C and 400{degrees}C without an applied bias were amorphous, while an applied bias of -140 V formed a nanocrystalline {gamma}-Al{sub 2}O{sub 3} film at 400{degrees}C. The surface roughness of the Al{sub 2}O{sub 3} increased with temperature while ion irradiation produced a smoother surface