Prediction of daily milk fat and protein content using alternating (AT) recording scheme
2003
Klopcic, M. | Malovrh, S. | Gorjanc, G. | Kovac, M. | Osterc, J. (University of Ljubljana, Domzale (Slovenia). Zootechnical Dept.)
A possible introduction of alternating (AT) recording scheme instead of the currently used reference A method was studied on twelve farms in Slovenia. During the usual production control, milk yields were recorded for the evening (PM) and morning (AM) milking. The correlations between AM, PM and daily measurements were calculated and the equations for the evaluation of daily content of milk fat and proteins were tested. All the observed phenotypic correlations were significant, ranging from 0.578 (PM - AM) for fat and 0.987 (DPC - PM) for protein concentration. Coefficient of determination (R2) for fat concentration ranged between 78.83 and 81.35 % for PM, and 69.26 and 73.73 % for AM for the tested models. For protein concentration, R2 ranged from 97.47 to 97.65 % for PM and 95.48 to 95.74 % for AM. The differences between models were small and insignificant. However, the complex models reduced bias in extreme values.
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