• Login
    View Item 
    •   Home
    • Journals and Magazines
    • Society for Range Management Journal Archives
    • Rangeland Ecology & Management / Journal of Range Management
    • Journal of Range Management, Volume 40 (1987)
    • Journal of Range Management, Volume 40, Number 2 (March 1987)
    • View Item
    •   Home
    • Journals and Magazines
    • Society for Range Management Journal Archives
    • Rangeland Ecology & Management / Journal of Range Management
    • Journal of Range Management, Volume 40 (1987)
    • Journal of Range Management, Volume 40, Number 2 (March 1987)
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of UA Campus RepositoryCommunitiesTitleAuthorsIssue DateSubmit DateSubjectsPublisherJournalThis CollectionTitleAuthorsIssue DateSubmit DateSubjectsPublisherJournal

    My Account

    LoginRegister

    About

    AboutUA Faculty PublicationsUA DissertationsUA Master's ThesesUA Honors ThesesUA PressUA YearbooksUA CatalogsUA Libraries

    Statistics

    Most Popular ItemsStatistics by CountryMost Popular Authors

    Examination of Methods for Estimating Rate of Passage in Grazing Steers

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    8088-7969-2-PB.pdf
    Size:
    630.0Kb
    Format:
    PDF
    Download
    Author
    Cochran, R. C.
    Adams, D. C.
    Galyean, M. L.
    Wallace, J. D.
    Issue Date
    1987-03-01
    Keywords
    ytterbium
    mathematical models
    Agropyron desertorum
    estimation
    sampling
    digestion
    steers
    digesta
    kinetics
    transit time
    grazing
    Show allShow less
    
    Metadata
    Show full item record
    Citation
    Cochran, R. C., Adams, D. C., Galyean, M. L., & Wallace, J. D. (1987). Examination of methods for estimating rate of passage in grazing steers. Journal of Range Management, 40(2), 105-108.
    Publisher
    Society for Range Management
    Journal
    Journal of Range Management
    URI
    http://hdl.handle.net/10150/645330
    DOI
    10.2307/3899197
    Additional Links
    https://rangelands.org/
    Abstract
    Understanding how rate of passage estimates are influenced by procedural variations may facilitate standardization of methodology and enhance comparisons among studies. Therefore, 12 ruminal-fistulated beef steers (mean wt. = 294 kg) were used in two 6-day grazing trials to evaluate influences of sampling site, intraruminal mixing, and mathematical model on particle passage rate estimates. Steers grazed a 13-ha pasture of immature crested wheatgrass. We estimated particle passage rate from the rumen by intraruminal administration of a pulse dose of Yb-labeled forage followed by serial collection of ruminal digesta or fecal samples. Treatments were (1) rectal sampling; (2) ruminal sampling-ruminal contents mixed before subsampling digesta; (3) ruminal sampling-ruminal contents not mixed before subsampling digesta. All steers were fitted with vibracorders to monitor grazing time before and during sampling periods. Fecal Yb curves were fitted with a one compartment, time-dependent (ICMPT-TD), a two-compartment, sequential time-dependent-time-independent (2CMPT-TD), and a two-compartment, time-independent (2CMPT-TI) model. All ruminal Yb curves were fitted with a single exponential decay model. Comparisons among models were limited to rate constants associated with the slower escape process. Intraruminal mixing did not alter (P>0.10) passage rates. The 2CMPT-TD model failed to fit some fecal profiles. Particle passage rates from the 2CMPT-TI model were greater (P<0.05) than those from the ICMPT-TD model. Similarity among passage rate constants derived from fecal Yb curves and those derived by semilogarithmic regression of ruminal Yb concentration on time depended on the model used to fit fecal Yb curves. Grazing time decreased (P<0.01) during intensive sampling periods. We conclude that for steers grazing immature grass pastures, intraruminal mixing before subsampling does not significantly alter rate of passage estimates; however, site of sampling and mathematical model may be important factors to consider in choosing appropriate methodology for estimating rate of passage.
    Type
    text
    Article
    Language
    en
    ISSN
    0022-409X
    ae974a485f413a2113503eed53cd6c53
    10.2307/3899197
    Scopus Count
    Collections
    Journal of Range Management, Volume 40, Number 2 (March 1987)

    entitlement

     
    The University of Arizona Libraries | 1510 E. University Blvd. | Tucson, AZ 85721-0055
    Tel 520-621-6442 | repository@u.library.arizona.edu
    DSpace software copyright © 2002-2017  DuraSpace
    Quick Guide | Contact Us | Send Feedback
    Open Repository is a service operated by 
    Atmire NV
     

    Export search results

    The export option will allow you to export the current search results of the entered query to a file. Different formats are available for download. To export the items, click on the button corresponding with the preferred download format.

    By default, clicking on the export buttons will result in a download of the allowed maximum amount of items.

    To select a subset of the search results, click "Selective Export" button and make a selection of the items you want to export. The amount of items that can be exported at once is similarly restricted as the full export.

    After making a selection, click one of the export format buttons. The amount of items that will be exported is indicated in the bubble next to export format.