Model test on the relationship crude fiber consumption to the production of milk fat on dairy cattle in Kudus Regency

Abstract

This research was completed at PT. Moeria, Kudus Regency, Central Java Province, Indonesia using 35 samples (Holstein Friesian cattle, lactation period II-III and lactation month 5-9). The observational method was used in this study. Data obtained were analyzed using linear and quadratic regressions, to predict the production and quality of milk fat from crude fiber (CF) consumption that describe the diet. Analysis of variance was used to test the significance of model, then used root mean square prediction error (RMSPE), residual variance (RV) and coefficient of determination (R2) to developed equations as an indicator of the goodness of model fit. The result showed that no relationship between milk fat concentration (%) with CF consumption as predictor. There were significant relationship on between milk production (kg); milk fat production (kg) with CF consumption as predictor, on linear and quadratic model. In addition, a quadratic change in milk production (kg) (P = 0.050) and milk fat production (kg) (P = 0.044) were observed with changed CF consumption; whereas the quadratic equation has smaller RV, smaller RMSPE and bigger R2 than linear equation. It was concluded that the model fit for this research was quadratic equation.