Authors: MEHMET NURULLAH ORMAN, OKAN ERTUĞRUL
Abstract: The purpose of this study was to determine the best lactation curve. Data were collected from the dairy cattle breeding unit at Ceylanpinar State Farm. Three different lactation curve models (Wood, Schaeffer, Glasbey) were applied to all data. The values of the determination coefficients of three lactation curve models were estimated at 70.62-79.47%. Some negative estimated values were obtained during the estimation of parameters. These results were restricted by the hypothesis and were tested. All restrictions were accepted. Total actual and mature equivalent (ME, 2x3057) milk yields were estimated. Differences between the actual values of lactation milk yield, and the estimated values of the Wood and Glasbey models were found to be non-significant. There were significant differences between the Schaeffer values and the other estimated values (p<0.001). In the case of ME 2x305, milk yield, no significant differences were observed between the estimated values of the models and the actual values. It was concluded that the best model for the lactation curve was the Wood model.
Keywords: Cow, Holstein, Lactation Curve, Least Squares.
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