The book "A Genetic Study of Lactation Curve in a Herd of Holstein Cattle" offers a comprehensive analysis of milk production in Holstein cattle, a crucial aspect of dairy farming. Milk production is a complex trait that is of great importance for planning improvement strategies in livestock breeding. This study examines mathematical models of the lactation curve that are useful for management and breeding decisions, as well as for simulating dairy operations. Two fundamental sets of formulas are compared: traditional linear and non-linear equations. In particular, the Incomplete Gamma Function (IG) is considered as a non-linear model, alongside a new linear model referred to as the Accumulative Model (Acc). The results indicate that the Acc model is superior in terms of accuracy, making it a more user-friendly tool for practical applications.