Genetic Parameter Estimations for Persistence of Milk Yield with Different Function Definition in Dairy Cattle

Authors : Serhat ARSLAN, Hamit MİRTAGHİZADEH

Pages : 225-231

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Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :A data set containing 2-year test day milk yield records was used. Random regression model solutions established with a covariance function insert ignore into journalissuearticles values(CF); approach was used. Persistence and lactation curve explanation performances of polynomial, Wilmink and Ali-Schaeffer curve definitions were compared for CF. When comparisons were made for R2 values, polynomial insert ignore into journalissuearticles values(0.9835); definition headed the list, followed by the Ali-Schaeffer curve insert ignore into journalissuearticles values(0.9534);, and Wilmink curve insert ignore into journalissuearticles values(0.6023); definitions. Among the persistence predictions in respect of lactation orders, the Ali-Schaeffer curve provided predictions with the minimum variance, followed by the Wilmink and polynomial curve approaches. All of the curve definitions were in accord with the literature.
Keywords : Test day model, covariance function, random regression