An Algebraic Model from Mitscherlich Function to Describe Lactation Curves of Dairy Animals

The Mitscherlich function [Yt = a (1 – b e^-ct)] is generally used as growth model. A lactation curve model Yt = a (1 – b e^-ct) – dt + εt was derived from this function by subtracting the linear function (Y = dt) without intercept. The curve attains the peak position after time t_m = [ln (abc/d)]/c since parturition. This model was compared with four parameter models by fitting them on average weekly milk production of crossbred cattle and graded Murrah buffaloes. The proposed model was found to be the best for describing the lactation curves and also performed better than Mitscherlich x Exponential model.