Transitioning Cattle from RAMP\u3csup\u3e®\u3c/sup\u3e to a Finishing Diet on Feed Intake and Ruminal pH

A metabolism trial was conducted where steers were adapted to high grain diets using a traditional approach or one of two RAMP® adaptation programs. RAMP programs adapted cattle to a finishing diet either gradually over 28 days in four steps or switched to a finishing ration without steps. Feed intake and ruminal pH were monitored continuously throughout the trial. Cattle on the 4-STEP treatment spent more time eating compared to other treatments but total feed consumption was similar among treatments. Ruminal pH was greater for cattle on RAMP adaptation programs when compared to traditional grain adaptation. Cattle fed RAMP for 10 days can be transitioned directly to a finishing diet containing 47.5% Sweet Bran®

Economics of Distillers Grains Supplementation in a Forage System with Spayed Heifers

In a two-year study, spayed heifer calves were backgrounded on cornstalks with 2 lb or 5 lb wet distillers grains with solubles supplemented daily. During the summer, heifers grazed native range and received no summer supplementation or were supplemented with modified distillers grains with solubles at 0.6% BW daily. Heifers were finished on a common regimen, and an economic scenario was applied to each phase of production and overall. Supplementing more in winter increased profit, but summer supplementation did not impact overall profitability. Numerically, heifers not supplemented during the summer were more profitable than supplemented heifers

Economics of Distillers Grains Supplementation in a Forage System with Spayed Heifers

In a two-year study, spayed heifer calves were backgrounded on cornstalks with 2 lb or 5 lb wet distillers grains with solubles supplemented daily. During the summer, heifers grazed native range and received no summer supplementation or were supplemented with modified distillers grains with solubles at 0.6% BW daily. Heifers were finished on a common regimen, and an economic scenario was applied to each phase of production and overall. Supplementing more in winter increased profit, but summer supplementation did not impact overall profitability. Numerically, heifers not supplemented during the summer were more profitable than supplemented heifers

Use of Complete-feed Diets RAMP™ and Test Starter for Receiving Cattle

Performance of newly arrived 576 lb steer calves, fed two complete feeds or a control ration was evaluated. Treatment diets were fed for 30 or 31 days and includeda control receiving diet consisting of alfalfa hay, Sweet Bran® , dry-rolled corn, and supplement or one of two complete feeds: RAMP and Test Starter which contained a high level of Sweet Bran and a minimal amount of forage. RAMP increased ADG when compared with the control diet. Cattle fed Test Starter had similar performance to the control receiving diet

Effects of Forage Type, Storage Method, and Moisture Level in Crop Residues Mixed with Modified Distillers Grains

Two growing experiments compared effects of feeding a diet consisting of cornstalks or wheat straw and modified distillers grains when ensiled or mixed fresh daily. Wheat-straw based diets also were compared at different moisture levels (50% and 70%) when ensiled and mixed daily. In Experiment 1, steers fed ensiled diets had greater DMI compared to diets mixed daily. Moisture level and crop residue type had no effect on steer performance. In Experiment 2, steers were offered the supplements and a hay mix to determine palatability and forage replacement. Moisture level had no effect, cornstalks were consumed better than wheat straw, and steers fed freshly mixed diets gained more and were more efficient than those fed ensiled mixes

Association of Inactive Myostatin in Piedmontese-Influenced Steers and Heifers on Performance and Carcass Traits at Different Endpoints

Performance and carcass traits were evaluated using Piedmontese-influenced calf-fed steers and yearling heifers genotyped for zero, one, or two copies (homozygous active, heterozygous, or homozygous inactive, respectively) of the inactive myostatin allele. Steers and heifers had similar responses across genotypes in performance and carcass traits evaluated at different endpoints. Inactive myostatin decreased DMI, final BW (live), and ADG (live). Increased dressing percentage resulted in increased carcass-adjusted ADG and improved feed conversion for cattle with inactive myostatin. Cattle with inactive myostatin are leaner with larger LM area when finished to equal carcass weight

Retrotransposons Are the Major Contributors to the Expansion of the \u3ci\u3eDrosophila ananassae\u3c/i\u3e Muller F Element

The discordance between genome size and the complexity of eukaryotes can partly be attributed to differences in repeat density. The Muller F element (∼5.2 Mb) is the smallest chromosome in Drosophila melanogaster, but it is substantially larger (\u3e18.7 Mb) in D. ananassae. To identify the major contributors to the expansion of the F element and to assess their impact, we improved the genome sequence and annotated the genes in a 1.4-Mb region of the D. ananassae F element, and a 1.7-Mb region from the D element for comparison. We find that transposons (particularly LTR and LINE retrotransposons) are major contributors to this expansion (78.6%), while Wolbachia sequences integrated into the D. ananassae genome are minor contributors (0.02%). Both D. melanogaster and D. ananassae F-element genes exhibit distinct characteristics compared to D-element genes (e.g., larger coding spans, larger introns, more coding exons, and lower codon bias), but these differences are exaggerated in D. ananassae. Compared to D. melanogaster, the codon bias observed in D. ananassae F-element genes can primarily be attributed to mutational biases instead of selection. The 5′ ends of F-element genes in both species are enriched in dimethylation of lysine 4 on histone 3 (H3K4me2), while the coding spans are enriched in H3K9me2. Despite differences in repeat density and gene characteristics, D. ananassae F-element genes show a similar range of expression levels compared to genes in euchromatic domains. This study improves our understanding of how transposons can affect genome size and how genes can function within highly repetitive domains

On the absence of molecular absorption in high redshift millimetre-band searches

We have undertaken a search for millimetre-wave band absorption (through the CO and HCO+ rotational transitions) in the host galaxies of reddened radio sources (z = 0.405-1.802). Despite the colour selection (optical-near infrared colours of V - K > 5 in all but one source), no absorption was found in any of the eight quasars for which the background continuum flux was detected. On the basis of the previous (mostly intervening) H2 and OH detections, the limits reached here and in some previous surveys should be deep enough to detect molecular absorption according to their V - K colours. However, our survey makes the assumption that the reddening is associated with dust close to the emission redshift of the quasar and that the narrow millimetre component of this emission is intercepted by the compact molecular cores. By using the known millimetre absorbers to define the colour depth and comparing this with the ultra-violet luminosities of the sources, we find that, even if these assumptions are valid, only twelve of the forty objects (mainly from this work) are potentially detectable. This is assuming an excitation temperature of 10 K at z=0, with the number decreasing with increasing temperatures (to zero detectable at 100 K).Comment: 11 pages accepted by MNRA

Site-Specific Bioconjugation of a Murine Dihydrofolate Reductase Enzyme by Copper(I)-Catalyzed Azide-Alkyne Cycloaddition with Retained Activity

Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) is an efficient reaction linking an azido and an alkynyl group in the presence of copper catalyst. Incorporation of a non-natural amino acid (NAA) containing either an azido or an alkynyl group into a protein allows site-specific bioconjugation in mild conditions via CuAAC. Despite its great potential, bioconjugation of an enzyme has been hampered by several issues including low yield, poor solubility of a ligand, and protein structural/functional perturbation by CuAAC components. In the present study, we incorporated an alkyne-bearing NAA into an enzyme, murine dihydrofolate reductase (mDHFR), in high cell density cultivation of Escherichia coli, and performed CuAAC conjugation with fluorescent azide dyes to evaluate enzyme compatibility of various CuAAC conditions comprising combination of commercially available Cu(I)-chelating ligands and reductants. The condensed culture improves the protein yield 19-fold based on the same amount of non-natural amino acid, and the enzyme incubation under the optimized reaction condition did not lead to any activity loss but allowed a fast and high-yield bioconjugation. Using the established conditions, a biotin-azide spacer was efficiently conjugated to mDHFR with retained activity leading to the site-specific immobilization of the biotin-conjugated mDHFR on a streptavidin-coated plate. These results demonstrate that the combination of reactive non-natural amino acid incorporation and the optimized CuAAC can be used to bioconjugate enzymes with retained enzymatic activityope

Tetrahymena Metallothioneins Fall into Two Discrete Subfamilies

BACKGROUND: Metallothioneins are ubiquitous small, cysteine-rich, multifunctional proteins which can bind heavy metals. METHODOLOGY/PRINCIPAL FINDINGS: We report the results of phylogenetic and gene expression analyses that include two new Tetrahymena thermophila metallothionein genes (MTT3 and MTT5). Sequence alignments of all known Tetrahymena metallothioneins have allowed us to rationalize the structure of these proteins. We now formally subdivide the known metallothioneins from the ciliate genus Tetrahymena into two well defined subfamilies, 7a and 7b, based on phylogenetic analysis, on the pattern of clustering of Cys residues, and on the pattern of inducibility by the heavy metals Cd and Cu. Sequence alignment also reveals a remarkably regular, conserved and hierarchical modular structure of all five subfamily 7a MTs, which include MTT3 and MTT5. The former has three modules, while the latter has only two. Induction levels of the three T. thermophila genes were determined using quantitative real time RT-PCR. Various stressors (including heavy metals) brought about dramatically different fold-inductions for each gene; MTT5 showed the highest fold-induction. Conserved DNA motifs with potential regulatory significance were identified, in an unbiased way, upstream of the start codons of subfamily 7a MTs. EST evidence for alternative splicing in the 3′ UTR of the MTT5 mRNA with potential regulatory activity is reported. CONCLUSION/SIGNIFICANCE: The small number and remarkably regular structure of Tetrahymena MTs, coupled with the experimental tractability of this model organism for studies of in vivo function, make it an attractive system for the experimental dissection of the roles, structure/function relationships, regulation of gene expression, and adaptive evolution of these proteins, as well as for the development of biotechnological applications for the environmental monitoring of toxic substances