Listy Biometryczne-Biometrical Letters Vol.36(2), 1999, pp.169-178
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EVALUATION OF SELECTED MATHEMATICAL MODELS OF LACTATION CURVES Wojciech Piotr Perz and Zbigniew Sobek Department of Genetics and Animal Breeding, Agricultural University, Wołyńska 33, 60-637 Poznań, Poland |
An evaluation of 21 lactation curve models, concerning accuracy of 100-day milk yield estimation in cows based on several (4-7) test yields - a problem occurring in breeding practice - was made. Stability of the models (the lowest possible estimation error variance) was considered, instead of the most frequently used determination coefficient criterion. The results confirm the assumption adopted in this approach that simple models, although they do not exactly render the real course of lactation curve, are less vulnerable to the fluctuations appearing in the data. Thus, they give more stable prediction results, at the same time not needing intensive computations necessary to obtain parameters of complex models.
Lactation curve, milk yield, milk yield evaluation
