Management considerations in beef heifer development (2002)

Because decisions about selecting and managing replacement beef heifers can affect the future productivity of an entire cowherd, programs to develop breeding heifers have focused on the physiological processes that influence puberty. The timing of puberty is critical to whether a heifer remains in the herd and whether lifetime productivity is optimized.New 6/97; Reviewed and reprinted 10/02/5M

Assessing the Value of Coordinated Sire Genetics in a Synchronized AI Program

Synchronized artificial insemination was used to inseminate cows using different types of sire genetics, including low-accuracy, calving-ease, and high-accuracy. These three calf sire groups were compared to calves born to cows bred using natural service. We found substantial production efficiency grains, carcass merit improvement, and economic value to calves born to cows following a synchronized artificial insemination program with high-accuracy semen included. The economic advantage to the high-accuracy calf sire group was computed to be in the neighborhood of $40 to$80/head, relative to the natural service calf sire group.artificial insemination, beef, cow, carcass, feed-out, genetics, pre-conditioning, sire synchronization., Agricultural Finance,

WILLINGNESS-TO-PAY FOR VALUE ADDED BRED HEIFER CHARACTERISTICS

Livestock Production/Industries,

Mass-radius relationships for exoplanets

For planets other than Earth, interpretation of the composition and structure depends largely on comparing the mass and radius with the composition expected given their distance from the parent star. The composition implies a mass-radius relation which relies heavily on equations of state calculated from electronic structure theory and measured experimentally on Earth. We lay out a method for deriving and testing equations of state, and deduce mass-radius and mass-pressure relations for key materials whose equation of state is reasonably well established, and for differentiated Fe/rock. We find that variations in the equation of state, such as may arise when extrapolating from low pressure data, can have significant effects on predicted mass- radius relations, and on planetary pressure profiles. The relations are compared with the observed masses and radii of planets and exoplanets. Kepler-10b is apparently 'Earth- like,' likely with a proportionately larger core than Earth's, nominally 2/3 of the mass of the planet. CoRoT-7b is consistent with a rocky mantle over an Fe-based core which is likely to be proportionately smaller than Earth's. GJ 1214b lies between the mass-radius curves for H2O and CH4, suggesting an 'icy' composition with a relatively large core or a relatively large proportion of H2O. CoRoT-2b is less dense than the hydrogen relation, which could be explained by an anomalously high degree of heating or by higher than assumed atmospheric opacity. HAT-P-2b is slightly denser than the mass-radius relation for hydrogen, suggesting the presence of a significant amount of matter of higher atomic number. CoRoT-3b lies close to the hydrogen relation. The pressure at the center of Kepler-10b is 1.5+1.2-1.0 TPa. The central pressure in CoRoT-7b is probably close to 0.8TPa, though may be up to 2TPa.Comment: Added more recent exoplanets. Tidied text and references. Added extra "rock" compositions. Responded to referee comment

Results of survey of stakeholders regarding knowledge of and attitudes towards feed intake, efficiency and genetic improvement concepts

Individual animal feed efficiency plays a key role in the profitability and sustainability of the US beef industry. During the growing and finishing phase of production, a 10% improvement in feed efficiency has a two-fold greater impact on profit than a 10% increase in rate of gain (Fox et al., 2001). The traits that beef producers routinely record are outputs which determine the value of product sold and not the inputs defining the cost of beef production. The inability to routinely measure feed intake and feed efficiency on large numbers of cattle has precluded the efficient application of selection despite moderate heritabilities (h2 = 0.16-0.46; Archer et al., 1999). Feed costs in calf feeding and yearling finishing systems account for approximately 66% and 77% of costs, respectively (Anderson et al., 2005).Feed costs account for approximately 65% of total beef production costs. Of the metabolizable energy required from conception to consumption of a beef animal, 72% is utilized during the cow-calf segment of production while 28% of calories are utilized in the calf growing and finishing phases of production (Ferrell and Jenkins, 1982). Of the calories consumed in the cow-calf segment, more than half are used for maintenance which presents a large selection target

Hadron formation in high energy photonuclear reactions

We present a new method to account for coherence length effects in a semi-classical transport model. This allows us to describe photo- and electroproduction at large nuclei (A>12) and high energies using a realistic coupled channel description of the final state interactions that goes beyond simple Glauber theory. We show that the purely absorptive treatment of the final state interactions can lead to wrong estimates of color transparency and formation time effects in particle production. As an example, we discuss exclusive rho^0 photoproduction on Pb at a photon energy of 7 GeV as well as K^+ production in the photon energy range 1-7 GeV.Comment: 14 pages, 6 figures, version published in Phys. Rev.

Hydrogen-Helium Mixtures at High Pressure

The properties of hydrogen-helium mixtures at high pressure are crucial to address important questions about the interior of Giant planets e.g. whether Jupiter has a rocky core and did it emerge via core accretion? Using path integral Monte Carlo simulations, we study the properties of these mixtures as a function of temperature, density and composition. The equation of state is calculated and compared to chemical models. We probe the accuracy of the ideal mixing approximation commonly used in such models. Finally, we discuss the structure of the liquid in terms of pair correlation functions.Comment: Proceedings article of the 5th Conference on Cryocrystals and Quantum Crystals in Wroclaw, Poland, submitted to J. Low. Temp. Phys. (2004

Impact of the energy-related inventions program on the national economy

The market entry, sales, and employment data presented in this paper suggest that ERIP has been able to efficiently produce positive economic impacts. It is likely that the documented successes of ERIP's inventors will be even greater as their projects mature and more current commercialization information is collected. Survey data presented elsewhere indicate that the ERIP financial support, endorsement, encouragement, and commercialization education are viewed by participants as the most important benefits of the program (Brown, Morell, Snell, Soderstrom, and Friggle, 1987). Other federal, state, and local programs might profit substantially from modelling the composition and delivery of their assistance after the Energy-Related Inventions Program

Calculation of a Deuterium Double Shock Hugoniot from Ab initio Simulations

We calculate the equation of state of dense deuterium with two ab initio simulations techniques, path integral Monte Carlo and density functional theory molecular dynamics, in the density range of 0.67 < rho < 1.60 g/cc. We derive the double shock Hugoniot and compare with the recent laser-driven double shock wave experiments by Mostovych et al. [1]. We find excellent agreement between the two types of microscopic simulations but a significant discrepancy with the laser-driven shock measurements.Comment: accept for publication in Phys. Rev. Lett., Nov. 2001, 4 pages, 4 figure

A Unified Model of Exclusive ρ0\rho^0, ϕ\phi and \jpsi Electroproduction

A two-component model is developed for diffractive electroproduction of $\rho^0$, $\phi$ and \jpsi, based on non-perturbative and perturbative two-gluon exchange. This provides a common kinematical structure for non-perturbative and perturbative effects, and allows the role of the vector-meson vertex functions to be explored independently of the production dynamics. A good global description of the vector-meson data is obtained.Comment: 30 pages, 35 figure