VSE knjižnice (vzajemna bibliografsko-kataložna baza podatkov COBIB.SI)
  • Modelling lactation curve in dairy sheep rose under extensive production system
    Cadavez, Vasco Augusto Pilao ...
    The objective of this study was to compare the godness-of-fit of four mathematical functions (Wilmink, 1987; Ali and Schaeffer, 1987, Guo and Swale, 1995; and a cubic regression model) for modeling ... lactation curve on dairy ewes. Data comprising 53,428 test-day records of daily milk yield (DMY) of 11,251 ewes raised under extensive production system, collected during six consecutive years (2000 to 2005) by the milking recording program of the Churra da Terra Quente (CTQ) dairy sheep breed, were used. Test-day records registered before 30 and after 150 days in milk (DIM) were discharged. All models presented similar fitting quality, with coefficient of determination between 71.0 and 71.3%, and underestimate the DMY for high production levels; this trend was more pronounced for Wilmink model. All models presented similar data fitting-quality, and Wilmink model presented higher difficulties in modelling the beginning and the enf of lactation curve, however, being a model with less parameters can present advantages in dairy ewes productions systems were small number of test controls per ewe can occuer.
    Vir: Zbornik radova = Proceedings (Str. 845-848)
    Vrsta gradiva - prispevek na konferenci
    Leto - 2008
    Jezik - angleški
    COBISS.SI-ID - 2260360

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