Nonlinear Techniques for Predicting 305-Day Lactation Production of Holsteins and Jerseys

Abstract

A technique of nonlinear model to predict the 305 day milk and fat yields of Canadian Holstein and Jersy cattle is described. The parameters of this model were estimated from Canadian Record of Performance test-day records collected from 1966-1970. By multiplicative factors and regression coefficients derived from the same data, 3 methods of extending records in progress to 305 days were compared. The method of nonlinear model was at least as accurate as either the multiplicative or regression methods, required less computer storage for parameter estimates than for multiplicative factors, and could be implemented easily into a milk recording program.