Effect of Feed Delivery Management on Yearling Steer Performance

Gain efficiency by cattle fed high grain diets can be affected by feed delivery management (FDM). Restricted or limit feeding improves feed efficiency but can reduce ADG. This experiment was designed to evaluate if feeding near ad libitum intake while reducing the amount of variation between daily feed deliveries could provide feed efficiency advantages over unrestricted access to feed without restricting ADG. The FDM strategies for the 121-day feeding period included prescription intakes (PI) where variability between day to day feed deliveries were minimized or ad libitum intake (ALI) where feed was always available. Crossbred yearling steers (n = 76, initial BW 866 Ib ± 6.72) of mixed origin were stratified by BW and randomly assigned to one of two treatments then to one of five pens within a treatment. The 92% concentrate, 63 Mcal NE,/cwt diet, was fed to the PI group throughout the 121 –day study. Four step-up diets were fed over 12 days to adapt the ALI group to the 92% concentrate diet. Feed was delivered daily at 0730 and 1630. The bunks were slick for the PI treatment at 0700 69% of the days on feed and 40% for the ALI treatment (P\u3c .01). The PI fed steers consumed less DM (P\u3c .001) during interim periods days 1 to 29 and 58 to 85 (P\u3c.05). The PI steers were more efficient days 1 to 29 (P\u3c .03) and overall (P\u3c.10). Carcass variables associated with yield grade were not affected (P\u3e.10) by FDM and PI caused higher marbling scores (5.67 vs 5.31; P\u3c .085), while percent choice did not differ, 74 vs 79% for the PI and ALI treatments, respectively. The PI treatment lowered (P\u3c .05) feed cost $5.30/cwt gain. This experiment indicated that FDM can influence DM1 and feed efficiency without compromising ADG

Influence of Dietary MP on the Production Rates and N Usage by Steers Fed High Grain Content Diets

An experiment was conducted to determine if dietary metabolizable protein (MP) could be manipulated to reduce N content of feedlot effluent without compromising production rates in yearling steers fed high grain content diets. Three feeding programs included: LO) 11 % CP fed throughout; HI) 13% CP fed throughout; and LHL) 11 % fed from d 1 to 35, 13% CP (HI) fed d 36 to 94 and 1 1 % CP (LO) fed from d 95 to 1 17. An estradiol-trenbalone acetate implant was administered on d 35. There were 5 pens of 8 steers (BW=7561b) assigned to each treatment. The MP allowed ADG for the diets were 3.3 and 4.0 Ib for the LO and HI diets respectively. Cumulative ADG and feed efficiency were improved (Pc.05) by feeding the HI diet. Fluctuations in interim growth rates obscured the determination of specifically when this effect occurred. The faster growth rate was associated with heavier and fatter carcasses. An evaluation of serum urea-N concentrations suggested that the influence of the growth promotant on N metabolism was beginning to diminish within 56d. The HI diet caused higher (P\u3c .05) serum urea-N levels at 63, 91 and 117d on feed. Total N intake was calculated by pen and increased (P\u3c .01) from 41.4 to 47.3 to 51.2 Ib/steer for treatments LO, LHL and HI respectively. The N intake1100 BW gained increased (P\u3c .01) from 9.89 to 10.90 to 11.33 Ib for LO, LHL and HI treatments respectively. These results indicate that increasing production efficiency by elevating the MP content of diets may not cause a concomitant improvement in the efficiency of N retention on the feedlot scale

A Millimeter-wave Galactic Plane Survey with the BICEP Polarimeter

In order to study inflationary cosmology and the Milky Way Galaxy's composition and magnetic field structure, Stokes I, Q, and U maps of the Galactic plane covering the Galactic longitude range 260° < ℓ < 340° in three atmospheric transmission windows centered on 100, 150, and 220 GHz are presented. The maps sample an optical depth 1 ≾ AV ≾ 30, and are consistent with previous characterizations of the Galactic millimeter-wave frequency spectrum and the large-scale magnetic field structure permeating the interstellar medium. The polarization angles in all three bands are generally perpendicular to those measured by starlight polarimetry as expected and show changes in the structure of the Galactic magnetic field on the scale of 60°. The frequency spectrum of degree-scale Galactic emission is plotted between 23 and 220 GHz (including WMAP data) and is fit to a two-component (synchrotron and dust) model showing that the higher frequency BICEP data are necessary to tightly constrain the amplitude and spectral index of Galactic dust. Polarized emission is detected over the entire region within two degrees of the Galactic plane, indicating the large-scale magnetic field is oriented parallel to the plane of the Galaxy. A trend of decreasing polarization fraction with increasing total intensity is observed, ruling out the simplest model of a constant Galactic magnetic field orientation along the line of sight in the Galactic plane. A generally increasing trend of polarization fraction with electromagnetic frequency is found, varying from 0.5%-1.5% at frequencies below 50 GHz to 2.5%-3.5% above 90 GHz. The effort to extend the capabilities of BICEP by installing 220 GHz band hardware is described along with analysis of the new band

Roscoe Pound Round-Table Discussion

Conference of Chief Justices and Conference of State Court Administrators Annual Meeting July 29-August 2, 2006 Indianapolis, Indiana

Nonlinear Semi-Analytic Methods for Trajectory Estimation

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76298/1/AIAA-29106-621.pd

Coupled-channels analysis of the 16^{{\bf 16}}O+208^{{\bf 208}}Pb fusion barrier distribution

Analyses using simplified coupled-channels models have been unable to describe the shape of the previously measured fusion barrier distribution for the doubly magic $^{16}$O+$^{208}$Pb system. This problem was investigated by re-measuring the fission excitation function for $^{16}$O+$^{208}$Pb with improved accuracy and performing more exact coupled-channels calculations, avoiding the constant-coupling and first-order coupling approximations often used in simplified analyses. Couplings to the single- and 2-phonon states of $^{208}$Pb, correctly taking into account the excitation energy and the phonon character of these states, particle transfers, and the effects of varying the diffuseness of the nuclear potential, were all explored. However, in contrast to other recent analyses of precise fusion data, no satisfactory simultaneous description of the shape of the experimental barrier distribution and the fusion cross-sections for $^{16}$O+$^{208}$Pb was obtained.Comment: RevTex, 29 pages, 7 postscript figures, to appear in PR

Fusion versus Breakup: Observation of Large Fusion Suppression for ^9Be + ^{208}Pb

Complete fusion excitation functions for $^{9}$Be + $^{208}$Pb have been measured to high precision at near barrier energies. The experimental fusion barrier distribution extracted from these data allows reliable prediction of the expected complete fusion cross-sections. However, the measured cross-sections are only 68% of those predicted. The large cross-sections observed for incomplete fusion products support the interpretation that this suppression of fusion is caused by $^{9}$Be breaking up into charged fragments before reaching the fusion barrier. Implications for the fusion of radioactive nuclei are discussed.Comment: RevTex, 11 pages, 2 postscript figures, to appear in PR

Relations between fusion cross sections and average angular momenta

We study the relations between moments of fusion cross sections and averages of angular momentum. The role of the centrifugal barrier and the target deformation in determining the effective barrier radius are clarified. A simple method for extracting average angular momentum from fusion cross sections is demonstrated using numerical examples as well as actual data.Comment: 16 REVTeX pages plus 8 included Postscript figures (uses the epsf macro); submitted to Phys. Rev. C; also available at http://nucth.physics.wisc.edu/preprint

Coordinate control of axon defasciculation and myelination by laminin-2 and -8

Schwann cells form basal laminae (BLs) containing laminin-2 (Ln-2; heterotrimer α2β1γ1) and Ln-8 (α4β1γ1). Loss of Ln-2 in humans and mice carrying α2-chain mutations prevents developing Schwann cells from fully defasciculating axons, resulting in partial amyelination. The principal pathogenic mechanism is thought to derive from structural defects in Schwann cell BLs, which Ln-2 scaffolds. However, we found loss of Ln-8 caused partial amyelination in mice without affecting BL structure or Ln-2 levels. Combined Ln-2/Ln-8 deficiency caused nearly complete amyelination, revealing Ln-2 and -8 together have a dominant role in defasciculation, and that Ln-8 promotes myelination without BLs. Transgenic Ln-10 (α5β1γ1) expression also promoted myelination without BL formation. Rather than BL structure, we found Ln-2 and -8 were specifically required for the increased perinatal Schwann cell proliferation that attends myelination. Purified Ln-2 and -8 directly enhanced in vitro Schwann cell proliferation in collaboration with autocrine factors, suggesting Lns control the onset of myelination by modulating responses to mitogens in vivo