Comparative Evaluation of Different Lactation Curve Models in Prediction of Monthly Test-Day Milk Yields in Murrah Buffaloes

Present investigation was undertaken to compare the different lactation curve models for describing the shape of the lactation curve in Murrah buffaloes. Data for the present study included 9071 monthly test-day milk yield (MTDMY) from 965 Murrah buffaloes calved during 1977 to 2012 at the National Dairy Research Institute, Karnal. A total of 10 monthly test-day milk yield records were taken at an interval of 30 days. The data were used to estimate lactation curve parameters for four lactation curve models viz. Gamma type function (GF), Exponential function (EF), Mixed log function (MLF) and Polynomial regression function (MLF). The mean monthly test day milk yields (MTDMY) increased from 5.91±0.13 kg on TD₁ to a peak yield of 7.41±0.12 kg on TD₃. The estimates of coefficient of determination (R²) and root mean square error (RMSE) for GF, EF, MLF, and PRF were 96.42%, 98.65%, 98.48%, 99.86% and 0.077, 0.049, 0.052, 0.015, respectively. PRF fitted best to the test day data followed by EF on the basis of higher R² and lower RMSE estimates, whereas GF fitted least.