On fitting curves to lactation data

Abstract

The usual method of fitting the model y = An^b exp(−cn) to lactation data, by a multiple regression of log_ey on n and logen, can result in an ill-fitting curve. An analysis of the untransformed data provides a better fit but requires more extensive computation and a simple approximation to this procedure is given. Since the parameters of this model have no direct biological interpretation two alternative models are introduced, each having a parameter measuring the persistency of lactation.