University Library
  • Login
A gateway to Melbourne's research publications
Minerva Access is the University's Institutional Repository. It aims to collect, preserve, and showcase the intellectual output of staff and students of the University of Melbourne for a global audience.
View Item 
  • Minerva Access
  • Veterinary and Agricultural Sciences
  • Melbourne Veterinary School
  • Veterinary Clinical Sciences
  • Veterinary Clinical Sciences - Research Publications
  • View Item
  • Minerva Access
  • Veterinary and Agricultural Sciences
  • Melbourne Veterinary School
  • Veterinary Clinical Sciences
  • Veterinary Clinical Sciences - Research Publications
  • View Item
JavaScript is disabled for your browser. Some features of this site may not work without it.

    Strategic test-day recording regimes to estimate lactation yield in tropical dairy animals

    Thumbnail
    Download
    Published version (517.4Kb)

    Citations
    Scopus
    Web of Science
    Altmetric
    1
    1
    Author
    McGill, DM; Thomson, PC; Mulder, HA; Lievaart, JJ
    Date
    2014-12-02
    Source Title
    Genetics Selection Evolution
    Publisher
    BIOMED CENTRAL LTD
    University of Melbourne Author/s
    McGill, David
    Affiliation
    Veterinary Clinical Sciences
    Metadata
    Show full item record
    Document Type
    Journal Article
    Citations
    McGill, D. M., Thomson, P. C., Mulder, H. A. & Lievaart, J. J. (2014). Strategic test-day recording regimes to estimate lactation yield in tropical dairy animals. GENETICS SELECTION EVOLUTION, 46 (1), https://doi.org/10.1186/s12711-014-0078-0.
    Access Status
    Open Access
    URI
    http://hdl.handle.net/11343/258121
    DOI
    10.1186/s12711-014-0078-0
    Abstract
    BACKGROUND: In developing dairy sectors, genetic improvement programs have limited resources and recording of herds is minimal. This study evaluated different methods to estimate lactation yield and sampling schedules with fewer test-day records per lactation to determine recording regimes that (1) estimate lactation yield with a minimal impact on the accuracy of selection and (2) optimise the available resources. METHODS: Using Sahiwal cattle as a tropical dairy breed example, weekly milk records from 464 cows were used in a simulation study to generate different shaped lactation curves. The daily milk yields from these simulated lactation curves were subset to equally spaced (weekly, monthly and quarterly) and unequally spaced (with four, five or six records per lactation) test-day intervals. Lactation yield estimates were calculated from these subsets using two methods: the test-interval method and Wood's (Nature 216:164-165, 1967) lactation curve model. Using the resulting lactation yields, breeding values were predicted and comparisons were made between the sampling regimes and estimation methods. RESULTS: The results show that, based on the mean square error of prediction, use of Wood's lactation curve model to estimate total yield was more accurate than use of the test-interval method. However, the differences in the ranking of animals were small, i.e. a 1 to 5% difference in accuracy. Comparisons between the different test-day sampling regimes showed that, with the same number of records per lactation (for example, quarterly and four test-days), strategically timed test-days can result in more accurate estimates of lactation yield than test-days at equal intervals. CONCLUSIONS: An important outcome of these results is that combining Wood's model for lactation yield estimation and as few as four, five or six strategically placed test-day records can produce estimates of lactation yield that are comparable with estimates based on monthly test-day records using the test-interval method. Furthermore, calculations show that although using fewer test-days results in a decrease in the accuracy of selection, it does provide an opportunity to progeny-test more sires. Thus, using strategically timed test-days and Wood's model to estimate lactation yield, can lead to a more efficient use of the allocated resources.

    Export Reference in RIS Format     

    Endnote

    • Click on "Export Reference in RIS Format" and choose "open with... Endnote".

    Refworks

    • Click on "Export Reference in RIS Format". Login to Refworks, go to References => Import References


    Collections
    • Minerva Elements Records [53102]
    • Veterinary Clinical Sciences - Research Publications [118]
    Minerva AccessDepositing Your Work (for University of Melbourne Staff and Students)NewsFAQs

    BrowseCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects
    My AccountLoginRegister
    StatisticsMost Popular ItemsStatistics by CountryMost Popular Authors